fix tests

Reviewed-on: #37

.github/workflows/build.yml

@@ -19,7 +19,7 @@ jobs:
         uses: gradle/actions/setup-gradle@v4
      
       - name: Build with Gradle
-        run: ./gradlew build
+        run: ./gradlew assemble
 
       - name: Test
         run: ./gradlew test

app/build.gradle

@@ -18,19 +18,18 @@ repositories {
 
 dependencies {
     // Use JUnit Jupiter for testing.
-    testImplementation 'org.junit.jupiter:junit-jupiter:5.9.1'
-
-    // This dependency is used by the application.
-    implementation 'com.google.guava:guava:31.1-jre'
-
-    // uml
-    implementation 'com.github.javaparser:javaparser-symbol-solver-core:3.26.2'
+    testImplementation 'org.junit.jupiter:junit-jupiter-api:5.8.1'
+    testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.8.1'
 
     implementation 'org.json:json:20250107'
 
-    implementation 'com.fasterxml.jackson.core:jackson-databind:2.18.2'
-
     implementation "io.github.spair:imgui-java-app:1.88.0"
+
+    implementation "org.lwjgl:lwjgl-stb:3.3.4"
+
+    implementation "org.lwjgl:lwjgl-stb::natives-linux"
+    implementation "org.lwjgl:lwjgl-stb::natives-windows"
+    implementation "org.lwjgl:lwjgl-stb::natives-macos"
 }
 
 application {
@@ -38,8 +37,19 @@ application {
     mainClass = 'gui.Main'
 }
 
-tasks.named('test') {
-    // Use JUnit Platform for unit tests.
+// Add libraries into the final jar
+jar {
+    archiveBaseName = rootProject.getName()
+    duplicatesStrategy = DuplicatesStrategy.EXCLUDE
+    manifest {
+        attributes "Main-Class": application.mainClass
+    }
+    from {
+        configurations.compileClasspath.collect { it.isDirectory() ? it : zipTree(it) }
+    } 
+}
+
+test {
     useJUnitPlatform()
 }
 

app/src/main/java/common/ConsumerSignal.java

@@ -0,0 +1,27 @@
+package common;
+
+import java.util.HashSet;
+import java.util.Set;
+import java.util.function.Consumer;
+
+public class ConsumerSignal<T> {
+	private final Set<Consumer<T>> listeners;
+
+	public ConsumerSignal() {
+		this.listeners = new HashSet<>();
+	}
+
+	public void connect(Consumer<T> listener) {
+		this.listeners.add(listener);
+	}
+
+	public void clear() {
+		this.listeners.clear();
+	}
+
+	public void emit(T arg) {
+		for (Consumer<T> listener : this.listeners) {
+			listener.accept(arg);
+		}
+	}
+}

app/src/main/java/game/Game.java

@@ -1,6 +1,10 @@
 package game;
 
+import java.time.Instant;
+import java.util.ArrayList;
+import java.util.Collections;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 
 import sudoku.structure.MultiDoku;
@@ -8,15 +12,19 @@ import sudoku.structure.MultiDoku;
 public class Game {
 
 	public static enum GameState {
-		GameNotStarted, GameGoing, GameEnd
+		GameNotStarted, GameGoing
 	}
 
 	private final Map<Integer, Player> players;
+	private final List<Player> leaderboard;
 	private GameState gameState;
 	private MultiDoku doku;
+	private Instant startTime = null;
+	private long gameDuration;
 
 	public Game() {
 		this.players = new HashMap<>();
+		this.leaderboard = new ArrayList<>();
 		this.gameState = GameState.GameNotStarted;
 	}
 
@@ -26,19 +34,33 @@ public class Game {
 
 	public void addPlayer(Player player) {
 		players.put(player.getId(), player);
+		leaderboard.add(player);
+	}
+
+	public void setPlayerRemainingCells(Player player, int newScore) {
+		player.setRemainingCells(newScore);
+		Collections.sort(this.leaderboard,
+				(player1, player2) -> Integer.compare(player1.getRemainingCells(), player2.getRemainingCells()));
 	}
 
 	public void removePlayer(int id) {
-		players.remove(id);
+		this.leaderboard.remove(getPlayerById(id));
+		this.players.remove(id);
 	}
 
 	public Map<Integer, Player> getPlayers() {
 		return players;
 	}
 
-	public void startGame(MultiDoku doku) {
+	public void startGame(MultiDoku doku, Instant startTime, long gameDuration) {
 		this.doku = doku;
 		this.gameState = GameState.GameGoing;
+		this.startTime = startTime;
+		this.gameDuration = gameDuration;
+	}
+
+	public void stopGame() {
+		this.gameState = GameState.GameNotStarted;
 	}
 
 	public GameState getGameState() {
@@ -49,4 +71,16 @@ public class Game {
 		return doku;
 	}
 
+	public List<Player> getLeaderboard() {
+		return leaderboard;
+	}
+
+	public Instant getStartTime() {
+		return startTime;
+	}
+
+	public long getGameDuration() {
+		return gameDuration;
+	}
+
 }

app/src/main/java/game/Player.java

@@ -8,10 +8,20 @@ public class Player implements Serializable {
 
 	private final String pseudo;
 	private final int id;
+	private int score;
 
 	public Player(int id, String pseudo) {
 		this.pseudo = pseudo;
 		this.id = id;
+		this.score = 0;
+	}
+
+	public int getRemainingCells() {
+		return score;
+	}
+
+	void setRemainingCells(int score) {
+		this.score = score;
 	}
 
 	public String getPseudo() {

app/src/main/java/gui/AssetManager.java

@@ -0,0 +1,32 @@
+package gui;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+public class AssetManager {
+
+	public static byte[] getResource(String name) {
+		// we first search it in files
+		File f = new File(name);
+		if (f.exists()){
+			FileInputStream fis;
+			try {
+				fis = new FileInputStream(f);
+				return fis.readAllBytes();
+			} catch (IOException e) {
+				e.printStackTrace();
+			}
+		}
+		// then in the jar
+		InputStream is = ClassLoader.getSystemResourceAsStream(name);
+		try {
+			return is.readAllBytes();
+		} catch (IOException e) {
+			e.printStackTrace();
+		}
+		return null;
+	}
+
+}

app/src/main/java/gui/Fonts.java

@@ -1,24 +0,0 @@
-package gui;
-
-import imgui.ImFont;
-import imgui.ImGui;
-
-public class Fonts {
-
-	public static ImFont ARIAL;
-	public static ImFont ARIAL_BOLD;
-	public static ImFont CHERI;
-	public static ImFont COMIC;
-	public static ImFont INFECTED;
-
-	private static final String baseDir = "";
-
-	public static void createFonts() {
-		COMIC = ImGui.getIO().getFonts().addFontFromFileTTF(baseDir + "comic.ttf", 50.0f);
-        ARIAL_BOLD = ImGui.getIO().getFonts().addFontFromFileTTF(baseDir + "arial_bold.ttf", 50.0f);
-        ARIAL = ImGui.getIO().getFonts().addFontFromFileTTF(baseDir + "arial.ttf", 50.0f);
-        CHERI = ImGui.getIO().getFonts().addFontFromFileTTF(baseDir + "cheri.ttf", 50.0f);
-		INFECTED = ImGui.getIO().getFonts().addFontFromFileTTF(baseDir + "INFECTED.ttf", 50.0f);
-	}
-
-}

app/src/main/java/gui/Main.java

@@ -1,8 +1,9 @@
 package gui;
 
+import gui.constants.Fonts;
+import gui.constants.Images;
 import gui.menu.MainMenu;
 import gui.menu.StateMachine;
-import imgui.ImGui;
 import imgui.app.Application;
 import imgui.app.Configuration;
 
@@ -27,6 +28,12 @@ public class Main extends Application {
         stateMachine.pushState(new MainMenu(stateMachine));
     }
     
+    @Override
+    protected void preRun() {
+        super.preRun();
+        Images.reloadImages();
+    }
+
     @Override
     public void process() {
         stateMachine.render();

app/src/main/java/gui/RenderableMultidoku.java

@@ -27,10 +27,6 @@ public class RenderableMultidoku {
 		this.doku = doku;
 	}
 
-	public boolean isResolved() {
-		return this.doku.isSolved();
-	}
-
 	public int getWidth() {
 		return width;
 	}
@@ -51,22 +47,6 @@ public class RenderableMultidoku {
 		return cells.get(index);
 	}
 
-	public boolean setCellValue(Cell cell, int value) {
-		for (Sudoku s : doku.getSubGrids()) {
-			int cellIndex = s.getCells().indexOf(cell);
-			// la cellule existe
-			if (cellIndex != -1) {
-				int cellX = cellIndex % s.getSize();
-				int cellY = cellIndex / s.getSize();
-				if (!s.canBePlaced(cellX, cellY, value)) {
-					return false;
-				}
-			}
-		}
-		cell.setSymbolIndex(value);
-		return true;
-	}
-
 	private static record PositionConstraint(Sudoku sudoku1, Sudoku sudoku2, Coordinate offset) {
 	}
 

app/src/main/java/gui/SudokuSelector.java

@@ -1,147 +0,0 @@
-package gui;
-
-import java.util.ArrayList;
-import java.util.List;
-
-import common.Signal;
-import imgui.ImGui;
-import imgui.extension.imguifiledialog.ImGuiFileDialog;
-import imgui.extension.imguifiledialog.flag.ImGuiFileDialogFlags;
-import imgui.type.ImBoolean;
-import imgui.type.ImInt;
-import sudoku.constraint.Constraint;
-import sudoku.structure.Difficulty;
-import sudoku.structure.MultiDoku;
-import sudoku.structure.SudokuFactory;
-
-public class SudokuSelector {
-
-	public final Signal onSelect = new Signal();
-	private MultiDoku doku;
-
-	private final boolean canGenEmptyGrid;
-
-	private final ImInt sudokuType = new ImInt(0);
-
-	private final ImInt difficulty = new ImInt(Difficulty.Medium.ordinal());
-	private final List<ImBoolean> contraints = new ArrayList<>();
-
-	private static final String[] sudokuTypes = { "Carré", "Rectangle", "Multidoku" };
-	private static final int SQUARE = 0, RECTANGLE = 1, MULTIDOKU = 2;
-
-	private final ImInt sudokuSize = new ImInt(3);
-
-	private final ImInt sudokuWidth = new ImInt(3);
-	private final ImInt sudokuHeight = new ImInt(3);
-
-	public SudokuSelector(boolean canGenEmptyGrid) {
-		this.canGenEmptyGrid = canGenEmptyGrid;
-		initConstraints();
-	}
-
-	private List<Constraint> getConstraints() {
-		List<Constraint> constraints = new ArrayList<>();
-		for (int i = 0; i < this.contraints.size(); i++) {
-			if (this.contraints.get(i).get())
-				constraints.add(Constraint.values()[i]);
-		}
-		return constraints;
-	}
-
-	private void initConstraints() {
-		for (Constraint cons : Constraint.values()) {
-			contraints.add(new ImBoolean(SudokuFactory.DEFAULT_CONSTRAINTS.contains(cons)));
-		}
-	}
-
-	private void selectSudoku(MultiDoku doku, boolean empty) {
-		this.doku = doku;
-		if (!empty) {
-			try {
-				SudokuFactory.fillDoku(doku, Difficulty.values()[difficulty.get()]);
-			} catch (Exception e) {
-				e.printStackTrace();
-			}
-		}
-		this.onSelect.emit();
-	}
-
-	public void renderFileDialog() {
-		if (ImGuiFileDialog.display("browse-sudoku", ImGuiFileDialogFlags.None)) {
-			if (ImGuiFileDialog.isOk()) {
-				var selection = ImGuiFileDialog.getSelection();
-				for (var entry : selection.entrySet()) {
-					try {
-						String filePath = entry.getValue();
-						this.doku = SudokuFactory.fromfile(filePath);
-						if (this.doku != null)
-							this.onSelect.emit();
-					} catch (Exception e) {
-						e.printStackTrace();
-					}
-				}
-			}
-			ImGuiFileDialog.close();
-		}
-	}
-
-	public void render() {
-		ImGui.combo("Type de Sudoku", sudokuType, sudokuTypes);
-		ImGui.combo("Difficulté", difficulty, Difficulty.getDifficultyNames());
-		if (ImGui.treeNode("Constraintes")) {
-			for (Constraint cons : Constraint.values()) {
-				ImGui.checkbox(cons.getDisplayName(), contraints.get(cons.ordinal()));
-			}
-			ImGui.treePop();
-		}
-		switch (sudokuType.get()) {
-			case SQUARE:
-				ImGui.inputInt("Taille", sudokuSize);
-				if (ImGui.button("Résoudre un sudoku")) {
-					selectSudoku(SudokuFactory.createBasicEmptySquareDoku(sudokuSize.get(), getConstraints()), false);
-				}
-				if (canGenEmptyGrid && ImGui.button("Générer une grille vide")) {
-					selectSudoku(SudokuFactory.createBasicEmptySquareDoku(sudokuSize.get(), getConstraints()), true);
-				}
-				break;
-
-			case RECTANGLE:
-				ImGui.inputInt("Largeur", sudokuHeight);
-				ImGui.inputInt("Longueur", sudokuWidth);
-				if (ImGui.button("Résoudre un sudoku")) {
-					selectSudoku(
-							SudokuFactory.createBasicEmptyRectangleDoku(sudokuWidth.get(), sudokuHeight.get(),
-									getConstraints()),
-							false);
-				}
-				if (canGenEmptyGrid && ImGui.button("Générer une grille vide")) {
-					selectSudoku(
-							SudokuFactory.createBasicEmptyRectangleDoku(sudokuWidth.get(), sudokuHeight.get(),
-									getConstraints()),
-							true);
-				}
-				break;
-
-			case MULTIDOKU:
-				ImGui.inputInt("Taille", sudokuSize);
-				if (ImGui.button("Résoudre un sudoku")) {
-					selectSudoku(SudokuFactory.createBasicXShapedMultidoku(sudokuSize.get(), getConstraints()), false);
-				}
-				if (canGenEmptyGrid && ImGui.button("Générer une grille vide")) {
-					selectSudoku(SudokuFactory.createBasicXShapedMultidoku(sudokuSize.get(), getConstraints()), true);
-				}
-
-			default:
-				break;
-		}
-		if (ImGui.button("À partir d'un fichier")) {
-			ImGuiFileDialog.openDialog("browse-sudoku", "Choisissez un fichier", ".json", ".");
-		}
-		renderFileDialog();
-	}
-
-	public MultiDoku getDoku() {
-		return doku;
-	}
-
-}

app/src/main/java/gui/constants/Fonts.java

@@ -0,0 +1,35 @@
+package gui.constants;
+
+import gui.AssetManager;
+import imgui.ImFont;
+import imgui.ImFontConfig;
+import imgui.ImFontGlyphRangesBuilder;
+import imgui.ImGui;
+
+public class Fonts {
+
+	public static ImFont ARIAL;
+	public static ImFont ARIAL_BOLD;
+	public static ImFont CHERI;
+	public static ImFont COMIC;
+	public static ImFont INFECTED;
+	public static ImFont EMOJIS;
+
+	private static final String baseDir = "";
+
+	public static void createFonts() {
+		ImFontGlyphRangesBuilder builder = new ImFontGlyphRangesBuilder();
+		builder.addRanges(ImGui.getIO().getFonts().getGlyphRangesDefault());
+		builder.addRanges(ImGui.getIO().getFonts().getGlyphRangesCyrillic());
+		
+		ImFontConfig cfg = new ImFontConfig();
+		cfg.setGlyphRanges(builder.buildRanges());
+
+		COMIC = ImGui.getIO().getFonts().addFontFromMemoryTTF(AssetManager.getResource("comic.ttf"), 50.0f);
+		ARIAL_BOLD = ImGui.getIO().getFonts().addFontFromMemoryTTF(AssetManager.getResource("arial_bold.ttf"), 50.0f);
+		ARIAL = ImGui.getIO().getFonts().addFontFromMemoryTTF(AssetManager.getResource("arial.ttf"), 50.0f, cfg);
+		CHERI = ImGui.getIO().getFonts().addFontFromMemoryTTF(AssetManager.getResource("cheri.ttf"), 50.0f);
+		INFECTED = ImGui.getIO().getFonts().addFontFromMemoryTTF(AssetManager.getResource("INFECTED.ttf"), 50.0f);
+	}
+
+}

app/src/main/java/gui/constants/Images.java

@@ -0,0 +1,44 @@
+package gui.constants;
+
+import java.nio.ByteBuffer;
+
+import org.lwjgl.opengl.GL11;
+import org.lwjgl.stb.STBImage;
+
+import gui.AssetManager;
+
+public class Images {
+
+	public static int BACKGROUND;
+
+	private static int loadTexture(byte[] imageData) {
+		int[] width = new int[1];
+		int[] height = new int[1];
+		int[] channelCount = new int[1];
+
+		ByteBuffer img = ByteBuffer.allocateDirect(imageData.length);
+		img.put(imageData);
+		img.flip();
+		ByteBuffer pixels = STBImage.stbi_load_from_memory(img, width, height, channelCount, 4);
+
+		int textureID = GL11.glGenTextures();
+		GL11.glBindTexture(GL11.GL_TEXTURE_2D, textureID);
+		GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MIN_FILTER, GL11.GL_LINEAR);
+		GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MAG_FILTER, GL11.GL_LINEAR);
+		GL11.glPixelStorei(GL11.GL_UNPACK_ALIGNMENT, 1); // Not on WebGL/ES
+		GL11.glPixelStorei(GL11.GL_UNPACK_SKIP_PIXELS, 0); // Not on WebGL/ES
+		GL11.glPixelStorei(GL11.GL_UNPACK_SKIP_ROWS, 0); // Not on WebGL/ES
+		GL11.glPixelStorei(GL11.GL_UNPACK_ROW_LENGTH, 0); // Not on WebGL/ES
+		GL11.glTexImage2D(GL11.GL_TEXTURE_2D, 0, GL11.GL_RGBA, width[0], height[0], 0,
+				GL11.GL_RGBA,
+				GL11.GL_UNSIGNED_BYTE, pixels);
+		GL11.glBindTexture(GL11.GL_TEXTURE_2D, 0);
+
+		return textureID;
+	}
+
+	public static void reloadImages() {
+		BACKGROUND = loadTexture(AssetManager.getResource(Options.BackgroundPath));
+	}
+
+}

app/src/main/java/gui/constants/Options.java

@@ -0,0 +1,9 @@
+package gui.constants;
+
+public class Options {
+
+	public static Symbols Symboles = Symbols.Numbers;
+	public static float BackgroundSpeed = 1.0f;
+	public static String BackgroundPath = "background.png";
+
+}

app/src/main/java/gui/constants/SudokuType.java

@@ -0,0 +1,63 @@
+package gui.constants;
+
+import java.util.List;
+
+import sudoku.constraint.IConstraint;
+import sudoku.structure.MultiDoku;
+import sudoku.structure.SudokuFactory;;
+
+public enum SudokuType {
+
+	Square("Carré", 1,
+			(constraints, params) -> SudokuFactory.createBasicEmptySquareDoku(params[0], constraints)),
+	Rectangle("Rectangle", 2,
+			(constraints, params) -> SudokuFactory.createBasicEmptyRectangleDoku(params[0], params[1], constraints)),
+	RandomBloc("Blocs aléatoires", 1,
+			(constraints, params) -> SudokuFactory.createBasicEmptyRandomBlockDoku(params[0], constraints)),
+	MultiDokuSquare("Multidoku carré (X)", 1,
+			(constraints, params) -> SudokuFactory.createBasicXShapedMultidoku(params[0], constraints)),
+	MultidokuRectangle("Multidoku rectangle (X)", 2,
+			(constraints, params) -> SudokuFactory.createBasicXShapedMultidoku(params[0], params[1], constraints));
+
+	String displayName;
+	SudokuMaker maker;
+	int paramCount;
+
+	private SudokuType(String displayName, int paramCount, SudokuMaker maker) {
+		this.displayName = displayName;
+		this.maker = maker;
+		this.paramCount = paramCount;
+	}
+
+	public String getDisplayName() {
+		return this.displayName;
+	}
+
+	public MultiDoku createDoku(List<IConstraint> constraints, int... params) {
+		return maker.makeSudoku(constraints, params);
+	}
+
+	public int getMakerParamCount() {
+		return this.paramCount;
+	}
+
+	@FunctionalInterface
+	private static interface SudokuMaker {
+		MultiDoku makeSudoku(List<IConstraint> constraints, int... params);
+	}
+
+	private static final String[] dokuNames;
+
+	static {
+		SudokuType[] types = SudokuType.values();
+		dokuNames = new String[types.length];
+		for (int i = 0; i < types.length; i++) {
+			dokuNames[i] = types[i].getDisplayName();
+		}
+	}
+
+	public static String[] getTypeNames() {
+		return dokuNames;
+	}
+
+}

app/src/main/java/gui/constants/Symbols.java

@@ -0,0 +1,83 @@
+package gui.constants;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public enum Symbols {
+
+	Numbers("Nombres", getNumbers()),
+	Letters("Lettres", getLetters()),
+	Russian("Cyrilique", getRussian()),
+	Emojis("Emojis (Console uniquement)", getEmojis());
+
+	String displayName;
+	List<String> symbols;
+
+	private Symbols(String displayName, List<String> symbols) {
+		this.symbols = symbols;
+		this.displayName = displayName;
+	}
+
+	public String getDisplayName() {
+		return displayName;
+	}
+
+	public List<String> getSymbols() {
+		return symbols;
+	}
+
+	private static List<String> getNumbers() {
+		List<String> sym = new ArrayList<>();
+		for (int i = 1; i <= 100; i++) {
+			sym.add(Integer.toString(i));
+		}
+		return sym;
+	}
+
+	private static List<String> getLetters() {
+		List<String> sym = new ArrayList<>();
+		for (int i = 0; i < 100; i++) {
+			int currentOffset = i;
+			String letter = "";
+			while (currentOffset >= 26) {
+				letter += Character.toString((char) ('A' + currentOffset % 26));
+				currentOffset /= 26;
+				currentOffset--;
+			}
+			letter += Character.toString((char) ('A' + currentOffset % 26));
+			sym.add(new StringBuilder(letter).reverse().toString());
+		}
+		return sym;
+	}
+
+	private static List<String> getRussian() {
+		List<String> sym = new ArrayList<>();
+		for (int i = 0; i < 100; i++) {
+			sym.add(new String(Character.toChars(0X0400 + i)));
+		}
+		return sym;
+	}
+
+	private static List<String> getEmojis() {
+		List<String> sym = new ArrayList<>();
+		for (int i = 0; i < 100; i++) {
+			sym.add(new String(Character.toChars(0X1F600 + i)));
+		}
+		return sym;
+	}
+
+	private static final String[] symbolNames;
+
+	static {
+		Symbols[] symbols = Symbols.values();
+		symbolNames = new String[symbols.length];
+		for (int i = 0; i < symbols.length; i++) {
+			symbolNames[i] = symbols[i].getDisplayName();
+		}
+	}
+
+	public static String[] getSymbolsNames() {
+		return symbolNames;
+	}
+
+}

app/src/main/java/gui/menu/ConnexionStatusView.java

@@ -14,12 +14,12 @@ public class ConnexionStatusView extends BaseView {
 
 	private String displayText = "Connecting ...";
 
-	public ConnexionStatusView(StateMachine stateMachine, String address, short port)
+	public ConnexionStatusView(StateMachine stateMachine, String pseudo, String address, short port)
 			throws UnknownHostException, IOException {
 		super(stateMachine);
 		Thread t = new Thread(() -> {
 			try {
-				this.client = new Client(address, port);
+				this.client = new Client(pseudo, address, port);
 				bindListeners();
 			} catch (IOException e) {
 				e.printStackTrace();
@@ -29,12 +29,13 @@ public class ConnexionStatusView extends BaseView {
 		t.start();
 	}
 
-	public ConnexionStatusView(StateMachine stateMachine, short port) throws UnknownHostException, IOException {
+	public ConnexionStatusView(StateMachine stateMachine, String pseudo, short port)
+			throws UnknownHostException, IOException {
 		super(stateMachine);
 		Thread t = new Thread(() -> {
 			try {
 				this.server = new Server(port);
-				this.client = new Client("localhost", port);
+				this.client = new Client(pseudo, "localhost", port);
 				bindListeners();
 			} catch (IOException e) {
 				e.printStackTrace();

app/src/main/java/gui/menu/EndGameView.java

@@ -0,0 +1,49 @@
+package gui.menu;
+
+import game.Player;
+import gui.ColorGenerator;
+import gui.widget.SudokuRenderer;
+import imgui.ImGui;
+import imgui.ImVec4;
+import sudoku.structure.MultiDoku;
+
+public class EndGameView extends BaseView {
+
+	private final Player winner;
+	private float time = 0;
+
+	private static final ImVec4 YELLOW = new ImVec4(1, 1, 0, 1);
+
+	private final SudokuRenderer sudokuRenderer;
+
+	public EndGameView(StateMachine stateMachine, MultiDoku resolved, Player winner) {
+		super(stateMachine);
+		this.winner = winner;
+		this.sudokuRenderer = new SudokuRenderer(resolved);
+	}
+
+	private ImVec4 getPseudoColor() {
+		time += ImGui.getIO().getDeltaTime();
+		float factor = (float) Math.cos(time);
+		var color = ColorGenerator.hslToRgb(factor * factor, 0.9f, 0.4f);
+		return new ImVec4(color.r, color.g, color.b, 1.0f);
+	}
+
+	private void renderWinText() {
+		String winText = " a gagné !";
+		String text = winner.getPseudo() + winText;
+		float textWidth = ImGui.calcTextSizeX(text);
+		ImGui.setCursorPosX(ImGui.getIO().getDisplaySizeX() / 2.0f - textWidth / 2.0f);
+		ImGui.textColored(getPseudoColor(), winner.getPseudo());
+		ImGui.sameLine();
+		ImGui.textColored(YELLOW, winText);
+	}
+
+	@Override
+	public void render() {
+		renderWinText();
+		this.sudokuRenderer.render();
+		renderReturnButton();
+	}
+
+}

app/src/main/java/gui/menu/MultiMenu.java

@@ -1,6 +1,7 @@
 package gui.menu;
 
 import java.io.IOException;
+import java.util.Random;
 
 import imgui.ImGui;
 import imgui.ImVec2;
@@ -11,6 +12,7 @@ public class MultiMenu extends BaseView {
 
 	private final ImInt port = new ImInt(25565);
 	private final ImString address = new ImString("localhost");
+	private final ImString pseudo = new ImString("Joueur" + new Random().nextInt());
 
 	public MultiMenu(StateMachine stateMachine) {
 		super(stateMachine);
@@ -20,10 +22,12 @@ public class MultiMenu extends BaseView {
 	private void renderCreate() {
 		ImVec2 displaySize = ImGui.getIO().getDisplaySize();
 		ImGui.beginChild("##CreateGame", new ImVec2(displaySize.x / 2.0f, displaySize.y * 8.0f / 9.0f));
-		ImGui.inputInt("Port", port);
+		if (ImGui.inputInt("Port", port))
+			port.set(Math.clamp(port.get(), 1, 65535));
+		ImGui.inputText("Pseudo", pseudo);
 		if (ImGui.button("Créer")) {
 			try {
-				this.stateMachine.pushState(new ConnexionStatusView(stateMachine, (short) port.get()));
+				this.stateMachine.pushState(new ConnexionStatusView(stateMachine, pseudo.get(), (short) port.get()));
 			} catch (IOException e) {
 				e.printStackTrace();
 			}
@@ -35,12 +39,13 @@ public class MultiMenu extends BaseView {
 		ImVec2 displaySize = ImGui.getIO().getDisplaySize();
 		ImGui.beginChild("##JoinGame", new ImVec2(displaySize.x / 2.0f, displaySize.y * 8.0f / 9.0f));
 		ImGui.inputText("Adresse", address);
-		ImGui.inputInt("Port", port);
+		if (ImGui.inputInt("Port", port))
+			port.set(Math.clamp(port.get(), 1, 65535));
+		ImGui.inputText("Pseudo", pseudo);
 		if (ImGui.button("Rejoindre")) {
 			try {
 				this.stateMachine.pushState(new ConnexionStatusView(stateMachine, address.get(), (short) port.get()));
 			} catch (IOException e) {
-				// TODO Auto-generated catch block
 				e.printStackTrace();
 			}
 		}

app/src/main/java/gui/menu/MultiPlayerDokuView.java

@@ -1,22 +1,50 @@
 package gui.menu;
 
-import gui.SudokuRenderer;
+import game.Player;
+import gui.widget.LeaderboardRenderer;
+import gui.widget.MultiPlayerCompleteProgress;
+import gui.widget.SudokuRenderer;
+import gui.widget.TimerRenderer;
 import imgui.ImGui;
 import network.client.Client;
 import network.server.Server;
+import sudoku.solver.BacktrackingSolver;
+import sudoku.solver.Solver;
+import sudoku.structure.Cell;
+import sudoku.structure.MultiDoku;
 
-public class MultiPlayerDokuView extends BaseView{
+public class MultiPlayerDokuView extends BaseView {
 
 	private final Client client;
 	private final Server server;
 	private final SudokuRenderer sudokuRenderer;
+	private final LeaderboardRenderer leaderboardRenderer;
+	private final TimerRenderer timerRenderer;
+	private final MultiPlayerCompleteProgress completeProgress;
 
 	public MultiPlayerDokuView(StateMachine stateMachine, Client client, Server server) {
 		super(stateMachine);
 		this.client = client;
 		this.server = server;
 		this.sudokuRenderer = new SudokuRenderer(this.client.getGame().getDoku());
+		this.leaderboardRenderer = new LeaderboardRenderer(client.getGame(), client.getPlayer());
+		this.sudokuRenderer.onCellChange.connect(this::onCellChange);
 		this.client.onDisconnect.connect(this::onDisconnect);
+		this.client.onGameEnd.connect(this::onGameEnd);
+		this.timerRenderer = new TimerRenderer(this.client.getGame().getStartTime(), this.client.getGame().getGameDuration());
+		this.completeProgress = new MultiPlayerCompleteProgress(this.client.getGame());
+	}
+
+	private void onGameEnd(Player winner) {
+		MultiDoku doku = this.client.getGame().getDoku();
+		doku.clearMutableCells();
+		Solver solver = new BacktrackingSolver();
+		solver.solve(doku);
+		this.stateMachine.overrideState(new EndGameView(stateMachine, doku, winner));
+	}
+
+	private void onCellChange(Cell cell) {
+		this.client.sendCellChange(cell);
 	}
 
 	public void onDisconnect() {
@@ -27,6 +55,9 @@ public class MultiPlayerDokuView extends BaseView{
 
 	@Override
 	public void render() {
+		this.timerRenderer.render();
+		this.leaderboardRenderer.render();
+		this.completeProgress.render();
 		this.sudokuRenderer.render();
 		if (ImGui.button("Quitter")) {
 			this.client.stop();

app/src/main/java/gui/menu/MultiPlayerView.java

@@ -1,24 +1,30 @@
 package gui.menu;
 
-import java.util.Arrays;
-
 import game.Player;
+import gui.widget.SudokuSelector;
 import imgui.ImGui;
+import imgui.type.ImInt;
 import network.client.Client;
 import network.server.Server;
-import sudoku.constraint.Constraint;
 import sudoku.structure.MultiDoku;
-import sudoku.structure.SudokuFactory;
 
 public class MultiPlayerView extends BaseView {
 
 	private final Client client;
 	private final Server server;
 
+	private final SudokuSelector selector;
+
+	private ImInt gameDurationMinutes = new ImInt(10);
+
+	private MultiDoku doku = null;
+
 	public MultiPlayerView(StateMachine stateMachine, Client client, Server server) {
 		super(stateMachine);
 		this.client = client;
 		this.server = server;
+		this.selector = new SudokuSelector(false, "Sélectionner le sudoku");
+		this.selector.onSelect.connect(this::onSelected);
 		this.client.onDisconnect.connect(this::onDisconnect);
 		this.client.onGameStarted
 				.connect(() -> this.stateMachine.pushState(new MultiPlayerDokuView(stateMachine, client, server)));
@@ -34,27 +40,47 @@ public class MultiPlayerView extends BaseView {
 		this.stateMachine.popState();
 	}
 
+	private void onSelected(MultiDoku doku) {
+		this.doku = doku;
+	}
+
 	public void renderGameStatus() {
 		if (this.server == null) {
 			ImGui.text("En attente de l'administrateur du serveur ...");
 		} else {
+			renderTimer();
+			ImGui.beginDisabled(this.doku == null);
 			if (ImGui.button("Démarrer")) {
-				// temp
-				MultiDoku doku = SudokuFactory.createBasicXShapedMultidoku(3, Arrays.asList(Constraint.Diagonal));
-				this.server.startGame(doku);
+				this.server.startGame(this.doku, this.gameDurationMinutes.get() * 60);
 			}
+			ImGui.endDisabled();
+			selector.render();
 		}
 	}
 
-	@Override
-	public void render() {
+	private void renderPlayers() {
 		ImGui.text("Joueurs :");
 		{
 			for (Player player : this.client.getGame().getPlayers().values()) {
 				ImGui.bulletText(player.getPseudo());
 			}
 		}
+	}
+
+	private void renderTimer() {
+		if (ImGui.inputInt("Temps de la partie (minutes)", gameDurationMinutes))
+			gameDurationMinutes.set(Math.clamp(gameDurationMinutes.get(), 1, 90));
+	}
+
+	@Override
+	public void render() {
+		renderPlayers();
 		renderGameStatus();
 	}
 
+	@Override
+	public void cleanResources() {
+		this.selector.clean();
+	}
+
 }

app/src/main/java/gui/menu/OptionsMenu.java

@@ -1,17 +1,56 @@
 package gui.menu;
 
+import gui.constants.Images;
+import gui.constants.Options;
+import gui.constants.Symbols;
 import imgui.ImGui;
+import imgui.extension.imguifiledialog.ImGuiFileDialog;
+import imgui.extension.imguifiledialog.flag.ImGuiFileDialogFlags;
+import imgui.type.ImInt;
 
 public class OptionsMenu extends BaseView {
 
+	private ImInt currentValue = new ImInt();
+	private float backgroundSpeed[] = new float[] { Options.BackgroundSpeed };
+
 	public OptionsMenu(StateMachine stateMachine) {
 		super(stateMachine);
 	}
 
+	private void renderImageSelectDialog() {
+		if (ImGuiFileDialog.display("browse-img", ImGuiFileDialogFlags.None)) {
+			if (ImGuiFileDialog.isOk()) {
+				var selection = ImGuiFileDialog.getSelection();
+				for (var entry : selection.entrySet()) {
+					try {
+						String filePath = entry.getValue();
+						Options.BackgroundPath = filePath;
+						Images.reloadImages();
+					} catch (Exception e) {
+						e.printStackTrace();
+					}
+				}
+			}
+			ImGuiFileDialog.close();
+		}
+	}
+
+	private void renderImageSelectButton() {
+		if (ImGui.button("Changer de fond d'écran"))
+			ImGuiFileDialog.openDialog("browse-img", "Choisissez un fichier", ".png,.jpg,.jpeg", ".");
+		renderImageSelectDialog();
+	}
+
 	@Override
 	public void render() {
-		// TODO Auto-generated method stub
 		ImGui.text("Options");
+		if (ImGui.combo("Jeu de symboles", currentValue, Symbols.getSymbolsNames())) {
+			Options.Symboles = Symbols.values()[currentValue.get()];
+		}
+		if (ImGui.sliderFloat("Vitesse d'animation de l'arrière plan", backgroundSpeed, 0.0f, 10.0f)) {
+			Options.BackgroundSpeed = backgroundSpeed[0];
+		}
+		renderImageSelectButton();
 		renderReturnButton();
 	}
 

app/src/main/java/gui/menu/SoloMenu.java

@@ -1,7 +1,8 @@
 package gui.menu;
 
-import gui.SudokuSelector;
+import gui.widget.SudokuSelector;
 import imgui.ImGui;
+import sudoku.structure.MultiDoku;
 
 public class SoloMenu extends BaseView {
 
@@ -9,12 +10,12 @@ public class SoloMenu extends BaseView {
 
 	public SoloMenu(StateMachine stateMachine) {
 		super(stateMachine);
-		this.sudokuSelector = new SudokuSelector(true);
+		this.sudokuSelector = new SudokuSelector(true, "Résoudre le sudoku");
 		this.sudokuSelector.onSelect.connect(this::pushSudokuState);
 	}
 
-	private void pushSudokuState() {
-		this.stateMachine.pushState(new SudokuView(stateMachine, this.sudokuSelector.getDoku()));
+	private void pushSudokuState(MultiDoku doku) {
+		this.stateMachine.pushState(new SudokuView(stateMachine, doku));
 	}
 
 	@Override
@@ -24,4 +25,9 @@ public class SoloMenu extends BaseView {
 		renderReturnButton();
 	}
 
+	@Override
+	public void cleanResources() {
+		this.sudokuSelector.clean();
+	}
+
 }

app/src/main/java/gui/menu/StateMachine.java

@@ -2,6 +2,7 @@ package gui.menu;
 
 import java.util.Stack;
 
+import gui.widget.AnimatedBackground;
 import imgui.ImGui;
 import imgui.ImVec2;
 import imgui.flag.ImGuiKey;
@@ -10,9 +11,11 @@ import imgui.flag.ImGuiWindowFlags;
 public class StateMachine {
 
 	private final Stack<BaseView> menus;
+	private final AnimatedBackground background;
 
 	public StateMachine() {
 		this.menus = new Stack<>();
+		this.background = new AnimatedBackground();
 	}
 
 	public void clear() {
@@ -26,6 +29,11 @@ public class StateMachine {
 		menus.add(menu);
 	}
 
+	public void overrideState(BaseView menu) {
+		menus.getLast().cleanResources();
+		menus.set(menus.size() - 1, menu);
+	}
+
 	public void popState() {
 		menus.getLast().cleanResources();
 		menus.pop();
@@ -39,6 +47,7 @@ public class StateMachine {
 
 	public void render() {
 		var displaySize = ImGui.getIO().getDisplaySize();
+		this.background.render();
 		ImGui.setNextWindowPos(new ImVec2(0.0f, 0.0f));
 		ImGui.setNextWindowSize(displaySize);
 		ImGui.begin("##Main Window", null, ImGuiWindowFlags.NoDecoration | ImGuiWindowFlags.NoMove

app/src/main/java/gui/menu/SudokuView.java

@@ -1,13 +1,20 @@
 package gui.menu;
 
-import java.util.Random;
+import java.util.ArrayList;
+import java.util.List;
 import java.util.concurrent.CancellationException;
 
-import gui.SudokuRenderer;
+import gui.widget.SudokuRenderer;
 import imgui.ImGui;
 import imgui.ImGuiStyle;
 import sudoku.io.SudokuSerializer;
+import sudoku.solver.BacktrackingSolver;
+import sudoku.solver.HintHelper;
+import sudoku.solver.HumanSolver;
+import sudoku.solver.MixedSolver;
 import sudoku.solver.Solver;
+import sudoku.solver.SolverStep;
+import sudoku.solver.HintHelper.Hint;
 import sudoku.structure.MultiDoku;
 
 public class SudokuView extends BaseView {
@@ -18,6 +25,8 @@ public class SudokuView extends BaseView {
 	private String lastSavePath = null;
 
 	private boolean resolved = false;
+	// if the solver can't solve
+	private volatile boolean unresolved = false;
 
 	public SudokuView(StateMachine stateMachine, MultiDoku doku) {
 		super(stateMachine);
@@ -66,34 +75,73 @@ public class SudokuView extends BaseView {
 			stopResolve();
 	}
 
+	private void renderHintButton() {
+		if (!this.resolved && centeredButton("Indice")) {
+			Hint hint = HintHelper.getHint(this.doku, new BacktrackingSolver());
+			assert (hint != null);
+			hint.cell().setSymbolIndex(hint.newValue());
+			if (this.doku.isSolved())
+				this.sudokuRenderer.onResolve.emit();
+		}
+	}
+
+	private void renderUnsolvableText() {
+		if (this.unresolved)
+			ImGui.text("Impossible de résoudre avec l'algorithme actuel !");
+
+	}
+
+	private void startSolve(Solver solver) {
+		this.doku.clearMutableCells();
+		resolveThread = new Thread(() -> {
+			List<SolverStep> steps = new ArrayList<>();
+			try {
+				unresolved = !solver.solve(this.doku, steps);
+			} catch (CancellationException e) {
+				System.out.println("The user is bored !");
+			}
+			stopResolve();
+		});
+	}
+
+	private void renderResolvedText() {
+		if (this.resolved)
+			ImGui.text("Bravo !");
+	}
+
+	private void renderSolvePopup() {
+		if (ImGui.beginPopup("solve")) {
+			if (ImGui.button("Résoudre avec backtrace")) {
+				startSolve(new BacktrackingSolver());
+				ImGui.closeCurrentPopup();
+			}
+			if (ImGui.button("Résoudre avec déduction")) {
+				startSolve(new HumanSolver());
+				ImGui.closeCurrentPopup();
+			}
+			if (ImGui.button("Résoudre avec déduction et backtrace")) {
+				startSolve(new MixedSolver());
+				ImGui.closeCurrentPopup();
+			}
+			ImGui.endPopup();
+		}
+	}
+
 	private void renderSolveButton() {
 		if (resolveThread != null)
 			ImGui.beginDisabled();
 
-		boolean beginSolve = false;
-
-		if (!resolved && centeredButton("Résoudre")) {
-			beginSolve = true;
+		if (!this.resolved && centeredButton("Résoudre")) {
+			ImGui.openPopup("solve");
 		}
+
 		if (resolveThread != null)
 			ImGui.endDisabled();
 
-		if (beginSolve) {
-			resolveThread = new Thread(() -> {
-				try {
-					Random rand = new Random();
-					Solver.solveRandom(doku, rand);
-					Thread.sleep(200);
-				} catch (CancellationException | InterruptedException e) {
-					System.out.println("The user is bored !");
-				}
-				stopResolve();
-			});
-		}
+		renderResolvedText();
+		renderUnsolvableText();
 
-		if (resolved) {
-			ImGui.text("Bravo !");
-		}
+		renderSolvePopup();
 	}
 
 	private void renderSaveButton() {
@@ -108,9 +156,19 @@ public class SudokuView extends BaseView {
 		}
 	}
 
+	private void renderClearButton() {
+		if (centeredButton("Effacer")) {
+			this.doku.clearMutableCells();
+			this.resolved = false;
+			this.unresolved = false;
+		}
+	}
+
 	@Override
 	public void render() {
 		sudokuRenderer.render();
+		renderHintButton();
+		renderClearButton();
 		renderSolveButton();
 		renderSaveButton();
 		renderCancelButton();

app/src/main/java/gui/widget/AnimatedBackground.java

@@ -0,0 +1,32 @@
+package gui.widget;
+
+import gui.constants.Images;
+import gui.constants.Options;
+import imgui.ImGui;
+import imgui.ImVec2;
+import imgui.flag.ImGuiWindowFlags;
+
+public class AnimatedBackground {
+
+	private float backgroundOffset = 0;
+
+	private static final float defaultSpeed = 0.05f;
+
+	public AnimatedBackground() {
+
+	}
+
+	public void render() {
+		backgroundOffset += ImGui.getIO().getDeltaTime() * defaultSpeed * Options.BackgroundSpeed;
+		var displaySize = ImGui.getIO().getDisplaySize();
+		ImGui.setNextWindowPos(new ImVec2(0.0f, 0.0f));
+		ImGui.setNextWindowSize(displaySize);
+		ImGui.begin("Background", null, ImGuiWindowFlags.NoDecoration | ImGuiWindowFlags.NoMove
+				| ImGuiWindowFlags.NoSavedSettings | ImGuiWindowFlags.NoBackground
+				| ImGuiWindowFlags.NoBringToFrontOnFocus | ImGuiWindowFlags.NoInputs);
+		ImGui.image(Images.BACKGROUND, displaySize, new ImVec2(backgroundOffset, backgroundOffset),
+				new ImVec2(1.0f + backgroundOffset, 1.0f + backgroundOffset));
+		ImGui.end();
+	}
+
+}

app/src/main/java/gui/widget/LeaderboardRenderer.java

@@ -0,0 +1,73 @@
+package gui.widget;
+
+import game.Game;
+import game.Player;
+import imgui.ImGui;
+import imgui.ImVec2;
+import imgui.ImVec4;
+import imgui.flag.ImGuiCol;
+import imgui.flag.ImGuiStyleVar;
+
+public class LeaderboardRenderer {
+
+	private final Game game;
+	private final Player currentPlayer;
+
+	private final float cellHeight = 75;
+	private final ImVec2 cellSize = new ImVec2(12 * cellHeight, cellHeight);
+	private final ImVec2 rankSize = new ImVec2(cellHeight, cellHeight);
+	private final ImVec2 scoreSize = rankSize;
+	private final ImVec2 nameSize = new ImVec2(cellSize.x - cellHeight * 2.0f, cellHeight);
+	private final ImVec4 cellColorPlayer = new ImVec4(0.20f, 0.67f, 1.0f, 0.5f);
+	private final ImVec4 cellColorEnemy = new ImVec4(1.0f, 0.0f, 0.0f, 0.5f);
+	private final int maxPlayersShowed = 2;
+
+	private final int emptyCellCount;
+
+	public LeaderboardRenderer(Game game, Player player) {
+		this.game = game;
+		this.currentPlayer = player;
+		this.emptyCellCount = game.getDoku().getEmptyCells().size();
+	}
+
+	private void renderRank(int rank) {
+		ImGui.button(Integer.toString(rank), rankSize);
+	}
+
+	private void renderName(String name) {
+		ImGui.button(name, nameSize);
+	}
+
+	private void renderScore(int score) {
+		ImGui.button(Integer.toString(score), scoreSize);
+	}
+
+	private void renderCell(Player player, int rank, ImVec4 color) {
+		ImGui.pushStyleColor(ImGuiCol.Button, color);
+		ImGui.pushStyleColor(ImGuiCol.ButtonHovered, color);
+		ImGui.pushStyleColor(ImGuiCol.ButtonActive, color);
+		ImGui.beginChild(player.getPseudo() + "##" + player.getId(), cellSize);
+		renderRank(rank);
+		ImGui.sameLine();
+		renderName(player.getPseudo());
+		ImGui.sameLine();
+		renderScore(emptyCellCount - player.getRemainingCells());
+		ImGui.endChild();
+		ImGui.popStyleColor(3);
+	}
+
+	public void render() {
+		var displaySize = ImGui.getIO().getDisplaySize();
+		ImGui.setCursorPosX(displaySize.x / 2.0f - cellSize.x / 2.0f);
+		ImGui.beginChild("Leaderboard", new ImVec2(cellSize.x + 15.0f, cellHeight * maxPlayersShowed));
+		ImGui.pushStyleVar(ImGuiStyleVar.ItemSpacing, new ImVec2());
+		ImGui.pushStyleVar(ImGuiStyleVar.FrameBorderSize, 3.0f);
+		for (int i = 0; i < game.getLeaderboard().size(); i++) {
+			Player player = game.getLeaderboard().get(i);
+			renderCell(player, i + 1, player == currentPlayer ? cellColorPlayer : cellColorEnemy);
+		}
+		ImGui.popStyleVar(2);
+		ImGui.endChild();
+	}
+
+}

app/src/main/java/gui/widget/MultiPlayerCompleteProgress.java

@@ -0,0 +1,28 @@
+package gui.widget;
+
+import game.Game;
+import game.Player;
+import imgui.ImGui;
+import imgui.ImVec2;
+
+public class MultiPlayerCompleteProgress {
+
+	private final Game game;
+	private final int emptyCellCount;
+	private final ImVec2 progressSize = new ImVec2(700, 50);
+	private final SmoothProgressBar progressBar;
+
+	public MultiPlayerCompleteProgress(Game game) {
+		this.game = game;
+		this.emptyCellCount = game.getDoku().getEmptyCells().size();
+		this.progressBar = new SmoothProgressBar();
+	}
+
+	public void render() {
+		Player firstPlayer = game.getLeaderboard().getFirst();
+		ImGui.setCursorPosX(ImGui.getIO().getDisplaySizeX() / 2.0f - progressSize.x / 2.0f);
+		String progressText = firstPlayer.getPseudo() + " - " + (emptyCellCount - firstPlayer.getRemainingCells()) + "/" + emptyCellCount;
+		this.progressBar.render(progressText, progressSize, 1.0f - firstPlayer.getRemainingCells() / (float) emptyCellCount);
+	}
+
+}

app/src/main/java/gui/widget/SmoothProgressBar.java

@@ -0,0 +1,30 @@
+package gui.widget;
+
+import imgui.ImGui;
+import imgui.ImVec2;
+
+public class SmoothProgressBar {
+
+	private float lastProgress = 0;
+	private final float speed = 2.0f;
+	private final float clipConstant = 0.001f;
+
+	private void updateProgress(float newProgress) {
+		float delta = newProgress - lastProgress;
+		if (Math.abs(delta) < clipConstant)
+			lastProgress = newProgress;
+		else
+			lastProgress = lastProgress + delta * ImGui.getIO().getDeltaTime() * speed;
+	}
+
+	public void render(String label, ImVec2 size, float progress) {
+		updateProgress(progress);
+		ImGui.progressBar(lastProgress, size, label);
+	}
+
+	public void render(float progress) {
+		updateProgress(progress);
+		ImGui.progressBar(lastProgress);
+	}
+
+}

app/src/main/java/gui/widget/SudokuRenderer.java

@@ -1,4 +1,4 @@
-package gui;
+package gui.widget;
 
 import java.util.HashMap;
 import java.util.HashSet;
@@ -6,8 +6,14 @@ import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
+import common.ConsumerSignal;
 import common.Signal;
+import gui.ColorGenerator;
 import gui.ColorGenerator.Color;
+import gui.RenderableMultidoku;
+import gui.constants.Fonts;
+import gui.constants.Options;
+import gui.constants.Symbols;
 import imgui.ImGui;
 import imgui.ImVec2;
 import imgui.ImVec4;
@@ -33,6 +39,7 @@ public class SudokuRenderer {
 	private final Set<Cell> diagonals = new HashSet<>();
 
 	public final Signal onResolve = new Signal();
+	public final ConsumerSignal<Cell> onCellChange = new ConsumerSignal<>();
 
 	public SudokuRenderer(MultiDoku doku) {
 		this.doku = RenderableMultidoku.fromMultidoku(doku);
@@ -72,12 +79,14 @@ public class SudokuRenderer {
 				if (currentCell.getSymbolIndex() == i) {
 					if (ImGui.button("X", cellSize)) {
 						currentCell.setSymbolIndex(Cell.NOSYMBOL);
+						this.onCellChange.emit(currentCell);
 						ImGui.closeCurrentPopup();
 					}
 				} else {
-					if (ImGui.button(Integer.toString(i + 1), cellSize)) {
-						this.doku.setCellValue(currentCell, i);
-						if (this.doku.isResolved())
+					if (ImGui.button(Options.Symboles.getSymbols().get(i), cellSize)) {
+						currentCell.setSymbolIndex(i);
+						this.onCellChange.emit(currentCell);
+						if (this.doku.getDoku().isSolved())
 							this.onResolve.emit();
 						ImGui.closeCurrentPopup();
 					}
@@ -88,6 +97,9 @@ public class SudokuRenderer {
 	}
 
 	public void render() {
+		if (Options.Symboles == Symbols.Russian) {
+			ImGui.pushFont(Fonts.ARIAL);
+		}
 		final float sudokuViewWidth = cellSize.x * doku.getWidth();
 		final float displayWidth = ImGui.getIO().getDisplaySizeX();
 		float offsetX = displayWidth / 2.0f - sudokuViewWidth / 2.0f;
@@ -95,7 +107,7 @@ public class SudokuRenderer {
 		if (offsetX > 0) {
 			ImGui.setCursorPosX(offsetX);
 		}
-		ImGui.beginChild(1, new ImVec2(cellSize.x * doku.getWidth(), cellSize.y * doku.getHeight()));
+		ImGui.beginChild("sudokuChild", new ImVec2(cellSize.x * doku.getWidth(), cellSize.y * doku.getHeight()));
 
 		ImGui.pushStyleVar(ImGuiStyleVar.FrameBorderSize, 2.0f);
 		ImGui.pushStyleVar(ImGuiStyleVar.ItemSpacing, new ImVec2(0.0f, 0.0f));
@@ -105,6 +117,7 @@ public class SudokuRenderer {
 					ImGui.sameLine();
 				int index = y * doku.getWidth() + x;
 				Cell cell = doku.getCell(x, y);
+				ImGui.beginDisabled(cell == null);
 				if (cell == null) {
 					ImGui.pushStyleColor(ImGuiCol.Border, TRANSPARENT);
 					ImGui.pushStyleColor(ImGuiCol.Button, TRANSPARENT);
@@ -123,18 +136,22 @@ public class SudokuRenderer {
 					ImGui.pushStyleColor(ImGuiCol.Button, new ImVec4(blockColor.r, blockColor.g, blockColor.b, 1.0f));
 					String cellText = "";
 					if (symbol != -1)
-						cellText += Integer.toString(symbol + 1);
+						cellText += Options.Symboles.getSymbols().get(symbol);
 					if (ImGui.button(cellText + "##" + index, cellSize) && cell.isMutable()) {
 						ImGui.openPopup("editPopup");
 						currentCell = cell;
 					}
 				}
+				ImGui.endDisabled();
 				ImGui.popStyleColor(2);
 			}
 		}
 		ImGui.popStyleVar(2);
 		renderPopup();
 		ImGui.endChild();
+		if (Options.Symboles == Symbols.Russian) {
+			ImGui.popFont();
+		}
 	}
 
 }

app/src/main/java/gui/widget/SudokuSelector.java

@@ -0,0 +1,170 @@
+package gui.widget;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import common.ConsumerSignal;
+import gui.constants.SudokuType;
+import imgui.ImGui;
+import imgui.extension.imguifiledialog.ImGuiFileDialog;
+import imgui.extension.imguifiledialog.flag.ImGuiFileDialogFlags;
+import imgui.type.ImBoolean;
+import imgui.type.ImInt;
+import sudoku.constraint.Constraint;
+import sudoku.constraint.IConstraint;
+import sudoku.structure.Difficulty;
+import sudoku.structure.MultiDoku;
+import sudoku.structure.SudokuFactory;
+
+public class SudokuSelector {
+
+	public final ConsumerSignal<MultiDoku> onSelect = new ConsumerSignal<>();
+	private MultiDoku doku;
+
+	private final boolean canGenEmptyGrid;
+
+	private final ImInt sudokuType = new ImInt(0);
+
+	private final ImInt difficulty = new ImInt(Difficulty.Easy.ordinal());
+	private final List<ImBoolean> contraints = new ArrayList<>();
+
+	private final ImInt sudokuSize = new ImInt(3);
+
+	private final ImInt sudokuWidth = new ImInt(3);
+	private final ImInt sudokuHeight = new ImInt(3);
+
+	private final String confirmMessage;
+
+	private Thread genThread = null;
+
+	private final SmoothProgressBar genProgressBar;
+
+	public SudokuSelector(boolean canGenEmptyGrid, String confirmMessage) {
+		this.canGenEmptyGrid = canGenEmptyGrid;
+		this.confirmMessage = confirmMessage;
+		initConstraints();
+		this.genProgressBar = new SmoothProgressBar();
+	}
+
+	private List<IConstraint> getConstraints() {
+		List<IConstraint> constraints = new ArrayList<>();
+		for (int i = 0; i < this.contraints.size(); i++) {
+			if (this.contraints.get(i).get())
+				constraints.add(Constraint.values()[i].getConstraint());
+		}
+		return constraints;
+	}
+
+	private void initConstraints() {
+		for (Constraint cons : Constraint.values()) {
+			contraints.add(new ImBoolean(SudokuFactory.DEFAULT_CONSTRAINTS.contains(cons.getConstraint())));
+		}
+	}
+
+	private void stopGenThread() {
+		if (this.genThread != null) {
+			this.genThread.interrupt();
+			this.genThread = null;
+		}
+	}
+
+	private void renderGenProgress() {
+		if (ImGui.beginPopup("genProgress")) {
+			ImGui.text("Chargement de la grille ...");
+			int filled = this.doku.getFilledCells().size();
+			int total = this.doku.getCells().size();
+			this.genProgressBar.render(filled / (float) total);
+			ImGui.endPopup();
+		} else {
+			stopGenThread();
+		}
+	}
+
+	private void selectSudoku(MultiDoku doku, boolean empty) {
+		this.doku = doku;
+		ImGui.openPopup("genProgress");
+		this.genThread = new Thread(() -> {
+			try {
+				if (!empty) {
+					SudokuFactory.fillDoku(doku, Difficulty.values()[difficulty.get()]);
+				}
+				this.onSelect.emit(this.doku);
+			} catch (Exception e) {
+				e.printStackTrace();
+			}
+		});
+		this.genThread.start();
+	}
+
+	public void renderFileDialog() {
+		if (ImGuiFileDialog.display("browse-sudoku", ImGuiFileDialogFlags.None)) {
+			if (ImGuiFileDialog.isOk()) {
+				var selection = ImGuiFileDialog.getSelection();
+				for (var entry : selection.entrySet()) {
+					try {
+						String filePath = entry.getValue();
+						this.doku = SudokuFactory.fromfile(filePath);
+						if (this.doku != null)
+							this.onSelect.emit(this.doku);
+					} catch (Exception e) {
+						e.printStackTrace();
+					}
+				}
+			}
+			ImGuiFileDialog.close();
+		}
+	}
+
+	public void render() {
+		ImGui.combo("Difficulté", difficulty, Difficulty.getDifficultyNames());
+		if (ImGui.treeNode("Constraintes")) {
+			for (Constraint cons : Constraint.values()) {
+				ImGui.checkbox(cons.getDisplayName(), contraints.get(cons.ordinal()));
+			}
+			ImGui.treePop();
+		}
+		ImGui.combo("Type de Sudoku", sudokuType, SudokuType.getTypeNames());
+		SudokuType currentType = SudokuType.values()[sudokuType.get()];
+		switch (currentType.getMakerParamCount()) {
+			case 1:
+				if (ImGui.inputInt("Taille", sudokuSize))
+					sudokuSize.set(Math.clamp(sudokuSize.get(), 1, 10));
+				if (ImGui.button(confirmMessage)) {
+					selectSudoku(currentType.createDoku(getConstraints(), sudokuSize.get()), false);
+				}
+				if (canGenEmptyGrid && ImGui.button("Générer une grille vide")) {
+					selectSudoku(currentType.createDoku(getConstraints(), sudokuSize.get()), true);
+				}
+				break;
+
+			case 2:
+				if (ImGui.inputInt("Longueur", sudokuWidth))
+					sudokuWidth.set(Math.clamp(sudokuWidth.get(), 1, 10));
+				if (ImGui.inputInt("Hauteur", sudokuHeight))
+					sudokuHeight.set(Math.clamp(sudokuHeight.get(), 1, 10));
+				if (ImGui.button(confirmMessage)) {
+					selectSudoku(currentType.createDoku(getConstraints(), sudokuWidth.get(), sudokuHeight.get()),
+							false);
+				}
+				if (canGenEmptyGrid && ImGui.button("Générer une grille vide")) {
+					selectSudoku(currentType.createDoku(getConstraints(), sudokuWidth.get(), sudokuHeight.get()), true);
+				}
+				break;
+
+			default:
+				assert (false);
+				break;
+		}
+
+		if (ImGui.button("À partir d'un fichier")) {
+			ImGuiFileDialog.openDialog("browse-sudoku", "Choisissez un fichier", ".json", ".");
+		}
+		renderGenProgress();
+		renderFileDialog();
+	}
+
+	public void clean() {
+		stopGenThread();
+	}
+
+}

app/src/main/java/gui/widget/TimerRenderer.java

@@ -0,0 +1,29 @@
+package gui.widget;
+
+import java.time.Instant;
+
+import imgui.ImGui;
+
+public class TimerRenderer {
+
+	private final long endTime;
+
+	public TimerRenderer(Instant startTime, long duration) {
+		this.endTime = startTime.getEpochSecond() + duration;
+	}
+
+	private long getTimeRemaining() {
+		long currentTime = Instant.now().getEpochSecond();
+		return endTime - currentTime;
+	}
+
+	public void render() {
+		long seconds = getTimeRemaining();
+		long minutes = seconds / 60;
+		String text = String.format("%02d:%02d", minutes, seconds % 60);
+		var textSize = ImGui.calcTextSize(text);
+		ImGui.setCursorPosX(ImGui.getIO().getDisplaySizeX() / 2.0f - textSize.x / 2.0f);
+		ImGui.text(text);
+	}
+
+}

app/src/main/java/network/ConnexionThread.java

@@ -22,7 +22,7 @@ public class ConnexionThread extends Thread {
 				// System.out.println(objectInputStream.available());
 				Object o = objectInputStream.readObject();
 				if (o instanceof Packet packet) {
-					connexion.visitPacket(packet);
+					connexion.visit(packet);
 				}
 			} catch (ClassNotFoundException | IOException e) {
 				e.printStackTrace();

app/src/main/java/network/client/Client.java

@@ -4,10 +4,15 @@ import java.io.IOException;
 import java.net.UnknownHostException;
 import java.util.Random;
 
+import common.ConsumerSignal;
 import common.Signal;
 import game.Game;
 import game.Player;
+import network.protocol.packets.ChangeCellPacket;
 import network.protocol.packets.LoginPacket;
+import sudoku.structure.Cell;
+import sudoku.structure.MultiDoku;
+import sudoku.structure.Sudoku;
 
 public class Client {
 	private final ClientConnexion clientConnection;
@@ -17,15 +22,16 @@ public class Client {
 	public final Signal onDisconnect = new Signal();
 	public final Signal onClosed = new Signal();
 	public final Signal onGameStarted = new Signal();
+	public final ConsumerSignal<Player> onGameEnd = new ConsumerSignal<>();
+
+	Player player;
 
 	String disconnectReason = null;
 
-	public Client(String address, short port) throws UnknownHostException, IOException {
+	public Client(String pseudo, String address, short port) throws UnknownHostException, IOException {
 		this.clientConnection = new ClientConnexion(address, port, this);
 		this.game = new Game();
-		// temp
-		Random r = new Random();
-		login("Player" + r.nextInt());
+		login(pseudo);
 	}
 
 	public void login(String pseudo) {
@@ -54,4 +60,20 @@ public class Client {
 		stop();
 	}
 
+	public void sendCellChange(Cell cell) {
+		MultiDoku doku = getGame().getDoku();
+		for (int sudokuIndex = 0; sudokuIndex < doku.getNbSubGrids(); sudokuIndex++) {
+			Sudoku sudoku = doku.getSubGrid(sudokuIndex);
+			int cellIndex = sudoku.getCells().indexOf(cell);
+			if (cellIndex != -1) {
+				this.clientConnection.sendPacket(new ChangeCellPacket(sudokuIndex, cellIndex, cell.getSymbolIndex()));
+				return;
+			}
+		}
+	}
+
+	public Player getPlayer() {
+		return player;
+	}
+
 }

app/src/main/java/network/client/ClientConnexion.java

@@ -6,19 +6,21 @@ import java.net.UnknownHostException;
 
 import game.Player;
 import network.Connexion;
+import network.protocol.packets.ChangeCellPacket;
 import network.protocol.packets.ConnexionInfoPacket;
 import network.protocol.packets.DisconnectPacket;
+import network.protocol.packets.EndGamePacket;
 import network.protocol.packets.KeepAlivePacket;
 import network.protocol.packets.LoginPacket;
 import network.protocol.packets.PlayerJoinPacket;
 import network.protocol.packets.PlayerLeavePacket;
 import network.protocol.packets.StartGamePacket;
+import network.protocol.packets.UpdatePlayerScorePacket;
 import sudoku.io.SudokuSerializer;
 
 public class ClientConnexion extends Connexion {
 
 	private final Client client;
-	private Player player = null;
 
 	public ClientConnexion(String address, short port, Client client) throws UnknownHostException, IOException {
 		super(new Socket(address, port));
@@ -35,7 +37,7 @@ public class ClientConnexion extends Connexion {
 
 	@Override
 	public void visitPacket(ConnexionInfoPacket packet) {
-		this.player = this.client.getGame().getPlayerById(packet.getConnectionId());
+		this.client.player = this.client.getGame().getPlayerById(packet.getConnectionId());
 		client.onConnect.emit();
 	}
 
@@ -69,8 +71,28 @@ public class ClientConnexion extends Connexion {
 
 	@Override
 	public void visitPacket(StartGamePacket packet) {
-		this.client.getGame().startGame(SudokuSerializer.deserializeSudoku(packet.getSerializedSudoku()));
+		this.client.getGame().startGame(SudokuSerializer.deserializeSudoku(packet.getSerializedSudoku()),
+				packet.getInstant(), packet.getGameDuration());
 		this.client.onGameStarted.emit();
 	}
 
+	@Override
+	public void visitPacket(EndGamePacket packet) {
+		Player winner = this.client.getGame().getLeaderboard().getFirst();
+		this.client.getGame().stopGame();
+		this.client.onGameEnd.emit(winner);
+	}
+
+	@Override
+	public void visitPacket(UpdatePlayerScorePacket packet) {
+		Player player = this.client.getGame().getPlayerById(packet.getPlayerId());
+		assert (player != null);
+		this.client.getGame().setPlayerRemainingCells(player, packet.getCellsLeft());
+	}
+
+	@Override
+	public void visitPacket(ChangeCellPacket packet) {
+		throw new UnsupportedOperationException("Unimplemented method 'visitPacketChangeCell'");
+	}
+
 }

app/src/main/java/network/protocol/PacketVisitor.java

@@ -1,16 +1,19 @@
 package network.protocol;
 
+import network.protocol.packets.ChangeCellPacket;
 import network.protocol.packets.ConnexionInfoPacket;
 import network.protocol.packets.DisconnectPacket;
+import network.protocol.packets.EndGamePacket;
 import network.protocol.packets.KeepAlivePacket;
 import network.protocol.packets.LoginPacket;
 import network.protocol.packets.PlayerJoinPacket;
 import network.protocol.packets.PlayerLeavePacket;
 import network.protocol.packets.StartGamePacket;
+import network.protocol.packets.UpdatePlayerScorePacket;
 
 public interface PacketVisitor {
 
-	default void visitPacket(Packet packet) {
+	default void visit(Packet packet) {
 		packet.accept(this);
 	}
 	
@@ -21,5 +24,8 @@ public interface PacketVisitor {
 	void visitPacket(PlayerJoinPacket packet);
 	void visitPacket(PlayerLeavePacket packet);
 	void visitPacket(StartGamePacket packet);
+	void visitPacket(EndGamePacket packet);
+	void visitPacket(UpdatePlayerScorePacket packet);
+	void visitPacket(ChangeCellPacket packet);
 	
 }

app/src/main/java/network/protocol/Packets.java

@@ -2,6 +2,6 @@ package network.protocol;
 
 public enum Packets {
 
-	ConnectionInfo, KeepAlive, Disconnect, Login, PlayerJoin, PlayerLeave, StartGame
+	ConnectionInfo, KeepAlive, Disconnect, Login, PlayerJoin, PlayerLeave, StartGame, ChangeCell, EndGame, UpdatePlayerScore
 
 }

app/src/main/java/network/protocol/packets/ChangeCellPacket.java

@@ -0,0 +1,38 @@
+package network.protocol.packets;
+
+import network.protocol.Packet;
+import network.protocol.PacketVisitor;
+import network.protocol.Packets;
+
+public class ChangeCellPacket extends Packet {
+
+	static private final long serialVersionUID = Packets.ChangeCell.ordinal();
+
+	private final int sudokuIndex;
+	private final int cellIndex;
+	private final int newValue;
+
+	public ChangeCellPacket(int sudokuIndex, int cellIndex, int newValue) {
+		this.sudokuIndex = sudokuIndex;
+		this.cellIndex = cellIndex;
+		this.newValue = newValue;
+	}
+
+	public int getSudokuIndex() {
+		return sudokuIndex;
+	}
+
+	public int getCellIndex() {
+		return cellIndex;
+	}
+
+	public int getNewValue() {
+		return newValue;
+	}
+
+	@Override
+	public void accept(PacketVisitor packetVisitor) {
+		packetVisitor.visitPacket(this);
+	}
+
+}

app/src/main/java/network/protocol/packets/EndGamePacket.java

@@ -0,0 +1,18 @@
+package network.protocol.packets;
+
+import network.protocol.Packet;
+import network.protocol.PacketVisitor;
+import network.protocol.Packets;
+
+public class EndGamePacket extends Packet {
+
+	static private final long serialVersionUID = Packets.EndGame.ordinal();
+
+	public EndGamePacket() { }
+
+	@Override
+	public void accept(PacketVisitor packetVisitor) {
+		packetVisitor.visitPacket(this);
+	}
+
+}

app/src/main/java/network/protocol/packets/StartGamePacket.java

@@ -1,5 +1,7 @@
 package network.protocol.packets;
 
+import java.time.Instant;
+
 import network.protocol.Packet;
 import network.protocol.PacketVisitor;
 import network.protocol.Packets;
@@ -9,15 +11,28 @@ public class StartGamePacket extends Packet {
 	static private final long serialVersionUID = Packets.StartGame.ordinal();
 
 	private final String serializedSudoku;
+	// used to resume game
+	private final Instant instant;
+	private final long gameDuration;
 
-	public StartGamePacket(String serializedSudoku) {
+	public StartGamePacket(String serializedSudoku, Instant instant, long gameDuration) {
 		this.serializedSudoku = serializedSudoku;
+		this.instant = instant;
+		this.gameDuration = gameDuration;
 	}
 
 	public String getSerializedSudoku() {
 		return serializedSudoku;
 	}
 
+	public Instant getInstant() {
+		return instant;
+	}
+
+	public long getGameDuration() {
+		return gameDuration;
+	}
+
 	@Override
 	public void accept(PacketVisitor packetVisitor) {
 		packetVisitor.visitPacket(this);

app/src/main/java/network/protocol/packets/UpdatePlayerScorePacket.java

@@ -0,0 +1,32 @@
+package network.protocol.packets;
+
+import network.protocol.Packet;
+import network.protocol.PacketVisitor;
+import network.protocol.Packets;
+
+public class UpdatePlayerScorePacket extends Packet {
+
+	static private final long serialVersionUID = Packets.UpdatePlayerScore.ordinal();
+
+	private final int playerId;
+	private final int cellsLeft;
+
+	public UpdatePlayerScorePacket(int playerId, int cellsLeft) {
+		this.playerId = playerId;
+		this.cellsLeft = cellsLeft;
+	}
+
+	public int getPlayerId() {
+		return playerId;
+	}
+
+	public int getCellsLeft() {
+		return cellsLeft;
+	}
+
+	@Override
+	public void accept(PacketVisitor packetVisitor) {
+		packetVisitor.visitPacket(this);
+	}
+
+}

app/src/main/java/network/server/Server.java

@@ -2,12 +2,15 @@ package network.server;
 
 import java.io.IOException;
 import java.net.ServerSocket;
+import java.time.Instant;
 import java.util.ArrayList;
 import java.util.List;
 
 import game.Game;
 import game.Player;
+import game.Game.GameState;
 import network.protocol.Packet;
+import network.protocol.packets.EndGamePacket;
 import network.protocol.packets.StartGamePacket;
 import sudoku.io.SudokuSerializer;
 import sudoku.structure.MultiDoku;
@@ -37,7 +40,16 @@ public class Server {
 		}
 	}
 
-	public void update() {
+	private void checkTimer() {
+		if (getGame() == null || getGame().getGameState() != GameState.GameGoing)
+			return;
+		long now = Instant.now().getEpochSecond();
+		long end = getGame().getStartTime().getEpochSecond() + getGame().getGameDuration();
+		if (now > end)
+			stopGame();
+	}
+
+	private void checkConnexions() {
 		for (var it = connexions.iterator(); it.hasNext();) {
 			ServerConnexion connexion = it.next();
 			if (!connexion.update()) {
@@ -48,6 +60,11 @@ public class Server {
 		}
 	}
 
+	public void update() {
+		checkTimer();
+		checkConnexions();
+	}
+
 	public void stop() {
 		this.acceptThread.cancel();
 		this.logicThread.cancel();
@@ -68,9 +85,19 @@ public class Server {
 		return game;
 	}
 
-	public void startGame(MultiDoku doku) {
-		this.game.startGame(doku);
-		broadcastPacket(new StartGamePacket(SudokuSerializer.serializeSudoku(doku).toString()));
+	public void startGame(MultiDoku doku, long gameDuration) {
+		Instant now = Instant.now();
+		this.game.startGame(doku, now, gameDuration);
+		for (ServerConnexion connexion : this.connexions) {
+			connexion.setSudoku(doku.clone());
+		}
+		broadcastPacket(new StartGamePacket(SudokuSerializer.serializeSudoku(doku).toString(), now, gameDuration));
+	}
+
+	public void stopGame() {
+		// we don't need to specify the winner since it has to be the first
+		broadcastPacket(new EndGamePacket());
+		getGame().stopGame();
 	}
 
 }

app/src/main/java/network/server/ServerConnexion.java

@@ -3,17 +3,23 @@ package network.server;
 import java.io.IOException;
 import java.net.Socket;
 
+import game.Game;
 import game.Player;
 import game.Game.GameState;
 import network.Connexion;
+import network.protocol.packets.ChangeCellPacket;
 import network.protocol.packets.ConnexionInfoPacket;
 import network.protocol.packets.DisconnectPacket;
+import network.protocol.packets.EndGamePacket;
 import network.protocol.packets.KeepAlivePacket;
 import network.protocol.packets.LoginPacket;
 import network.protocol.packets.PlayerJoinPacket;
 import network.protocol.packets.PlayerLeavePacket;
 import network.protocol.packets.StartGamePacket;
+import network.protocol.packets.UpdatePlayerScorePacket;
 import sudoku.io.SudokuSerializer;
+import sudoku.structure.Cell;
+import sudoku.structure.MultiDoku;
 
 public class ServerConnexion extends Connexion {
 
@@ -21,6 +27,7 @@ public class ServerConnexion extends Connexion {
 	private final KeepAliveHandler keepAliveHandler;
 	private boolean shouldClose = false;
 	private Player player = null;
+	private MultiDoku doku;
 
 	public ServerConnexion(Socket socket, Server server) throws IOException {
 		super(socket);
@@ -29,7 +36,7 @@ public class ServerConnexion extends Connexion {
 	}
 
 	public boolean update() {
-		if (shouldClose | isClosed())
+		if (shouldClose || isClosed())
 			return false;
 		return this.keepAliveHandler.update();
 	}
@@ -44,7 +51,7 @@ public class ServerConnexion extends Connexion {
 
 	@Override
 	public synchronized void close() {
-		if(shouldClose)
+		if (shouldClose)
 			return;
 		super.close();
 		shouldClose = true;
@@ -54,13 +61,22 @@ public class ServerConnexion extends Connexion {
 	private void finishLogin() {
 		// send players that have already joined (excluding this one)
 		for (Player p : this.server.getGame().getPlayers().values()) {
-			if (p.getId() != player.getId())
+			if (p.getId() != player.getId()) {
 				sendPacket(new PlayerJoinPacket(p));
+				sendPacket(new UpdatePlayerScorePacket(p.getId(), p.getRemainingCells()));
+			}
 		}
+
 		this.server.broadcastPacket(new PlayerJoinPacket(player));
 		sendPacket(new ConnexionInfoPacket(player.getId()));
-		if (this.server.getGame().getGameState() == GameState.GameGoing) {
-			sendPacket(new StartGamePacket(SudokuSerializer.serializeSudoku(this.server.getGame().getDoku()).toString()));
+
+		Game game = this.server.getGame();
+
+		if (game.getGameState() == GameState.GameGoing) {
+			setSudoku(game.getDoku().clone());
+			sendPacket(
+					new StartGamePacket(SudokuSerializer.serializeSudoku(game.getDoku()).toString(),
+							game.getStartTime(), game.getGameDuration()));
 		}
 	}
 
@@ -102,4 +118,50 @@ public class ServerConnexion extends Connexion {
 		throw new UnsupportedOperationException("Unimplemented method 'visitPacketStartGame'");
 	}
 
+	@Override
+	public void visitPacket(EndGamePacket packet) {
+		throw new UnsupportedOperationException("Unimplemented method 'visitPacket'");
+	}
+
+	@Override
+	public void visitPacket(UpdatePlayerScorePacket packet) {
+		throw new UnsupportedOperationException("Unimplemented method 'visitPacket'");
+	}
+
+	@Override
+	public void visitPacket(ChangeCellPacket packet) {
+		Cell cell = this.doku.getSubGrid(packet.getSudokuIndex()).getCell(packet.getCellIndex());
+		if (cell.getSymbolIndex() == Cell.NOSYMBOL && packet.getNewValue() == Cell.NOSYMBOL)
+			return;
+		if (cell.getSymbolIndex() != Cell.NOSYMBOL && packet.getNewValue() != Cell.NOSYMBOL) {
+			cell.trySetValue(packet.getNewValue());
+			return;
+		}
+		if (cell.getSymbolIndex() != Cell.NOSYMBOL && packet.getNewValue() == Cell.NOSYMBOL) {
+			cell.empty();
+			this.server.getGame().setPlayerRemainingCells(player, player.getRemainingCells() + 1);
+			this.server.broadcastPacket(new UpdatePlayerScorePacket(player.getId(), player.getRemainingCells()));
+			return;
+		}
+		// on rajoute un chiffre à la grille
+		if (cell.trySetValue(packet.getNewValue())) {
+			this.server.getGame().setPlayerRemainingCells(player, player.getRemainingCells() - 1);
+			this.server.broadcastPacket(new UpdatePlayerScorePacket(player.getId(), player.getRemainingCells()));
+		}
+		checkWin();
+	}
+
+	private void checkWin() {
+		if (this.player.getRemainingCells() == 0) {
+			this.server.stopGame();
+		}
+	}
+
+	public void setSudoku(MultiDoku doku) {
+		this.doku = doku;
+		assert (player != null);
+		this.server.getGame().setPlayerRemainingCells(player, this.doku.getEmptyCells().size());
+		this.server.broadcastPacket(new UpdatePlayerScorePacket(player.getId(), player.getRemainingCells()));
+	}
+
 }

app/src/main/java/network/server/ServerLogicThread.java

@@ -19,7 +19,7 @@ public class ServerLogicThread extends Thread {
 			try {
 				Thread.sleep(50);
 			} catch (InterruptedException e) {
-				// e.printStackTrace();
+				e.printStackTrace();
 				break;
 			}
 		}

app/src/main/java/sudoku/Main.java

@@ -3,15 +3,48 @@
  */
 package sudoku;
 
+import gui.RenderableMultidoku;
+import gui.constants.Symbols;
 import sudoku.io.ConsoleInterface;
+import sudoku.io.SudokuPrinter;
+import sudoku.io.SudokuSerializer;
+import sudoku.solver.RandomSolver;
+import sudoku.structure.MultiDoku;
+import sudoku.structure.SudokuFactory;
 
 public class Main {
     public String getGreeting() {
         return "Hello World!";
     }
 
+    public static void voidTest(){
+        MultiDoku md = SudokuFactory.createBasicXShapedMultidoku(3, SudokuFactory.DEFAULT_CONSTRAINTS);
+        SudokuPrinter.printMultiDoku(RenderableMultidoku.fromMultidoku(md), Symbols.Numbers, 3, 3);
+        SudokuSerializer.saveMultiDoku(md);
+    }
+
+    public static void filledTest(){
+        MultiDoku md = SudokuFactory.createBasicXShapedMultidoku(3, SudokuFactory.DEFAULT_CONSTRAINTS);
+        new RandomSolver().solve(md);
+        SudokuPrinter.printMultiDoku(RenderableMultidoku.fromMultidoku(md), Symbols.Numbers, 3, 3);
+        SudokuSerializer.saveMultiDoku(md);
+    }
+
+    public static void overwriteTest(int n){
+        MultiDoku md = SudokuFactory.createBasicXShapedMultidoku(3, SudokuFactory.DEFAULT_CONSTRAINTS);
+        new RandomSolver().solve(md);
+        SudokuPrinter.printMultiDoku(RenderableMultidoku.fromMultidoku(md), Symbols.Numbers, 3, 3);
+        SudokuSerializer.saveMultiDoku(md, n);
+    }
+
     public static void main(String[] args) {
         ConsoleInterface console = new ConsoleInterface();
-        console.start();
+        /*
+        voidTest();
+        filledTest();
+        overwriteTest(0);
+        overwriteTest(17)
+        */
+        console.welcome();
     }
 }

app/src/main/java/sudoku/constraint/IConstraint.java

@@ -1,12 +1,12 @@
 package sudoku.constraint;
 
+import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.List;
 
 import sudoku.structure.Sudoku;
 
-public interface IConstraint {
-
+public interface IConstraint extends Serializable {
 	boolean canBePlaced(final Sudoku s, int x, int y, int newSymbolIndex);
 
 	default List<Integer> getPossibleSymbols(final Sudoku s, int x, int y) {

app/src/main/java/sudoku/io/ConsoleInterface.java

@@ -1,69 +1,118 @@
 package sudoku.io;
 
+import gui.RenderableMultidoku;
+import gui.constants.Symbols;
 import sudoku.constraint.*;
-import sudoku.solver.Solver;
-import sudoku.structure.Difficulty;
-import sudoku.structure.MultiDoku;
-import sudoku.structure.Sudoku;
-import sudoku.structure.SudokuFactory;
+import sudoku.solver.*;
+import sudoku.structure.*;
 
 import java.util.ArrayList;
 import java.util.List;
-import java.util.Random;
 import java.util.Scanner;
 
 public class ConsoleInterface {
     public Scanner reader = new Scanner(System.in);
 
-    public void start(){
-        welcome();
+    public void welcome() {
+        System.out.println("Welcome to our Sudoku Solver!");
+        System.out.println("This is the project of Melvyn Bauvent, Lilas Grenier and Simon Pribylski.");
+        System.out.println("Do you have a save sudoku you would like to continue? (y/n, default n)");
+        if (reader.next().equalsIgnoreCase("y")) {
+            useSavedDoku();
+        } else {
+            createDoku();
+        }
+    }
+
+    private void useSavedDoku() {
+        System.out.println("What save should we use? Please enter the save number.");
+        MultiDoku md = saveChoice();
+        int blockWidth = md.getSubGrid(0).getBlockWidth();
+        int blockHeight = md.getSubGrid(0).getBlocks().getFirst().getCells().size() / blockWidth;
+        List<String> listSymbols = pickSymbols(blockWidth * blockHeight);
+        System.out.println("This is the saved sudoku:");
+        showMultidoku(md, listSymbols, blockWidth, blockHeight);
+        do {
+            turn(md, listSymbols, blockWidth, blockHeight);
+        } while (!md.isSolved());
+        congrats();
+    }
+
+    public void createDoku() {
         System.out.println("First of all, you need to tell me the size of the sudoku you want to generate.");
         int width = getBlockWidth();
         int height = getBlockHeight();
         System.out.println("Your sudoku will have blocks of a " + width + " x " + height + " format.");
         int numberOfSymbols = width * height;
-        System.out.println("Would you like to pick the " + numberOfSymbols + " symbols from the sudoku? (y/n, default 'no' will use numbers)" );
-        List<String> listSymbols = new ArrayList<>();
-        if(reader.next().equalsIgnoreCase("y")){
-            pickSymbols(listSymbols, numberOfSymbols);
-        }
-        else {
-            // TODO
-            System.out.println("Simon doit finir sa partie.");
-            assert false;
-        }
-        List<Constraint> listConstraints = getListConstraints();
-
-
-        System.out.println("Now that we have the size of our sudoku, would you rather have a single grid ('one', default), " +
+        List<String> listSymbols = pickSymbols(numberOfSymbols);
+        List<IConstraint> listConstraints = getListConstraints();
+        System.out.println("Now that we have the size of our sudoku, " +
+                "would you rather have a single grid ('one', default), " +
                 "or a a multidoku composed of 5 subgrids ('multi') ?");
-        List<Sudoku> subGrids = new ArrayList<>();
         MultiDoku doku;
         if (reader.next().equalsIgnoreCase("multi")) {
+            doku = SudokuFactory.createBasicXShapedMultidoku(width, height, listConstraints);
+        } else {
             doku = SudokuFactory.createBasicEmptyRectangleDoku(width, height, listConstraints);
         }
-        else {
-            doku = SudokuFactory.createBasicXShapedMultidoku(width, height, listConstraints);
-        }
         System.out.println("Your sudoku will look like this:");
-        // TODO printMultiDoku method not yet implemented
-        SudokuPrinter.printMultiDoku(doku, width, height);
-        System.out.println("We now will fill this sudoku.");
-        System.out.println("What level of difficulty would you like? ('very easy', 'easy', 'medium' (default), 'hard', 'full' (sudoku fully completed))");
+        showMultidoku(doku, listSymbols, width, height);
+        System.out.println(
+                "You can now manually fill this sudoku ('fill'), or generate a playable one ('generate', default):");
+        if (reader.next().equalsIgnoreCase("fill")) {
+            findSolution(doku, listSymbols, width, height);
+        } else {
+            playableDoku(doku, listSymbols, width, height);
+        }
+    }
+
+    private void playableDoku(MultiDoku doku, List<String> listSymbols, int width, int height) {
+        System.out.println("We will now fill this sudoku.");
+        System.out.println("What level of difficulty would you like?" +
+                " ('very easy', 'easy', 'medium' (default), 'hard', 'full' (sudoku fully completed))");
         String difficulty = reader.next().toLowerCase();
         if (difficulty.equals("full")) {
             generateFullDoku(doku);
-        }
-        else {
+            System.out.println("Here's your sudoku !");
+            exit();
+        } else {
             generatePartialDoku(doku, difficulty);
+            System.out.println("Here's your sudoku !");
+            showMultidoku(doku, listSymbols, width, height);
+            do {
+                turn(doku, listSymbols, width, height);
+            } while (!doku.isSolved());
+            congrats();
         }
-        System.out.println("Here's your sudoku !");
-        SudokuPrinter.printMultiDoku(doku, width, height);
     }
 
-    public void welcome(){
-        System.out.println("Welcome to our Sudoku Solver!");
-        System.out.println("This is the project of Melvyn Bauvent, Lilas Grenier and Simon Priblyski.");
+    private void findSolution(MultiDoku doku, List<String> listSymbols, int width, int height){
+        do {
+            turn(doku, listSymbols, width, height);
+        } while (!doku.isSolved());
+        System.out.println("This doku can be solved like this :");
+        showMultidoku(doku, listSymbols, width, height);
+        exit();
+
+    }
+
+    private void congrats() {
+        System.out.println("Congrats! You've solved this sudoku! We hope this was fun! Let's play together again!");
+        System.exit(0);
+    }
+
+    private MultiDoku saveChoice() {
+        int nbSave;
+        MultiDoku md = null;
+        do {
+            nbSave = reader.nextInt();
+            try {
+                md = SudokuSerializer.getSavedMultiDoku(nbSave);
+            } catch (Exception e) {
+                System.out.println("There seems to be a problem with this save, please try again.");
+            }
+        } while (md == null);
+        return md;
     }
 
     public int getBlockWidth() {
@@ -94,36 +143,55 @@ public class ConsoleInterface {
         return (size > 0);
     }
 
-    private void pickSymbols(List<String> listSymbols, int numberOfSymbols) {
-        System.out.println("You have chosen to pick your own symbols.");
-        for (int i = 0; i < numberOfSymbols; i++) {
-            System.out.println("Choose for the symbol number " + i + ": ");
-            String newSymbol = reader.next();
-            while (listSymbols.contains(newSymbol)) {
-                System.out.println("This symbol has already been given. Try again:");
-                newSymbol = reader.next();
+    private List<String> pickSymbols(int numberOfSymbols) {
+        System.out.println("Would you like to pick the " + numberOfSymbols
+                + " symbols from the sudoku? (y/n, default 'no')");
+        if (reader.next().equalsIgnoreCase("y")) {
+            List<String> listSymbols = new ArrayList<>();
+            System.out.println("You have chosen to pick your own symbols.");
+            for (int i = 0; i < numberOfSymbols; i++) {
+                System.out.println("Choose for the symbol number " + i + ": ");
+                String newSymbol = reader.next();
+                while (listSymbols.contains(newSymbol)) {
+                    System.out.println("This symbol has already been given. Try again:");
+                    newSymbol = reader.next();
+                }
+                listSymbols.add(newSymbol);
             }
-            listSymbols.add(newSymbol);
+            System.out.println("You chose the symbols: " + listSymbols.toString());
+            return listSymbols;
+        } else {
+            System.out.println(
+                    "What existing sets of symbols do you want to use? Numbers ('n', default), letters ('l'), or emojis ('e', may not work on all consoles)?");
+            return switch (reader.next().toLowerCase()) {
+                case "l" -> Symbols.Letters.getSymbols();
+                case "e" -> Symbols.Emojis.getSymbols();
+                default -> Symbols.Numbers.getSymbols();
+            };
         }
-        System.out.println("You chose the symbols: " + listSymbols.toString());
     }
 
-    private List<Constraint> getListConstraints() {
-        List<Constraint> listConstraints = SudokuFactory.DEFAULT_CONSTRAINTS;
-        System.out.println("The sudoku have constraints of blocks, lines and columns. Would you like to add the diagonal constraints ? (y/n, default 'no')");
-        if(reader.next().equalsIgnoreCase("y")){
-            listConstraints.add(Constraint.Diagonal);
+    private List<IConstraint> getListConstraints() {
+        List<IConstraint> listConstraints = SudokuFactory.DEFAULT_CONSTRAINTS;
+        System.out.println(
+                "The sudoku have constraints of blocks, lines and columns. Would you like to add the diagonal constraints ? (y/n, default 'no')");
+        if (reader.next().equalsIgnoreCase("y")) {
+            listConstraints.add(Constraint.Diagonal.getConstraint());
         }
         return listConstraints;
     }
 
     private void generatePartialDoku(MultiDoku doku, String difficultyName) {
         Difficulty difficulty;
-        switch (difficultyName){
-            case "very easy": difficulty = Difficulty.VeryEasy;
-            case "easy": difficulty = Difficulty.Easy;
-            case "hard": difficulty = Difficulty.Hard;
-            default: difficulty = Difficulty.Medium;
+        switch (difficultyName) {
+            case "very easy":
+                difficulty = Difficulty.VeryEasy;
+            case "easy":
+                difficulty = Difficulty.Easy;
+            case "hard":
+                difficulty = Difficulty.Hard;
+            default:
+                difficulty = Difficulty.Medium;
         }
         try {
             SudokuFactory.fillDoku(doku, difficulty);
@@ -133,7 +201,136 @@ public class ConsoleInterface {
     }
 
     private void generateFullDoku(MultiDoku doku) {
-        Solver.solveRandom(doku, new Random());
+        new RandomSolver().solve(doku);
     }
 
+    private void showMultidoku(MultiDoku doku, List<String> listSymbols, int width, int height) {
+        showMultiDoku(RenderableMultidoku.fromMultidoku(doku), listSymbols, width, height);
+    }
+
+    private void showMultiDoku(RenderableMultidoku doku, List<String> listSymbols, int width, int height) {
+        SudokuPrinter.printMultiDokuWithIndex(doku, listSymbols, width, height);
+    }
+
+    private void saveMultiDoku(MultiDoku doku) {
+        System.out.println("Number of the file to overwrite ('-1' or unused save file number to create a new save) :");
+        int n = reader.nextInt();
+        String path = SudokuSerializer.saveMultiDoku(doku, n);
+        System.out.println("The path to your save is:" + path);
+    }
+
+    private void turn(MultiDoku doku, List<String> listSymbols, int width, int height) {
+        System.out.println(
+                "You can now put a number in a cell ('play', default), save the state of the doku ('save'), show a solution ('solution') or exit the program ('exit').");
+        switch (reader.next()) {
+            case "save":
+                saveMultiDoku(doku);
+                break;
+            case "solution":
+                solve(doku, listSymbols, width, height);
+                break;
+            case "exit":
+                exit();
+                break;
+            default:
+                play(doku, listSymbols, width, height);
+                break;
+        }
+    }
+
+    private void applyStep(SolverStep step) {
+        step.getCell().setSymbolIndex(step.getNewValue());
+    }
+
+    private boolean showStep(MultiDoku doku, List<String> listSymbols, int width, int height, SolverStep step) {
+        System.out.println("Here is the step : \n");
+        showMultidoku(doku, listSymbols, width, height);
+        applyStep(step);
+        System.out.println("\nTurns into :\n");
+        showMultidoku(doku, listSymbols, width, height);
+        System.out.println("Do you want to see the next step ? (y/n, default n)");
+        return reader.next().equals("y");
+    }
+
+    private void showSolveSteps(MultiDoku doku, List<String> listSymbols, int width, int height, List<SolverStep> steps) {
+        System.out.println("Would you like to see the steps of the solver ? (y/n, default n)");
+        doku.getStateManager().popState();
+        switch (reader.next()) {
+            case "y":
+                int stepCount = 0;
+                while(stepCount < steps.size() && showStep(doku, listSymbols, width, height, steps.get(stepCount))){stepCount++;}
+                break;
+        
+            default:
+                break;
+        }
+    }
+
+    private void solve(MultiDoku doku, List<String> listSymbols, int width, int height){
+        System.out.println("Pick a solver to use : random ('random', default), human ('human') or mixed solver ('mixed').");
+        List<SolverStep> steps = new ArrayList<>();
+        doku.getStateManager().pushState();
+        switch (reader.next()) {
+            case "human":
+                new HumanSolver().solve(doku, steps);
+                break;
+            case "mixed":
+                new MixedSolver().solve(doku, steps);
+                break;
+            default:
+                new RandomSolver().solve(doku, steps);
+                break;
+        }
+        showSolveSteps(doku, listSymbols, width, height, steps);
+    }
+
+    private void play(MultiDoku doku, List<String> listSymbols, int width, int height) {
+        int x, y;
+        RenderableMultidoku rdoku = RenderableMultidoku.fromMultidoku(doku);
+        do {
+            System.out.println("Line of the cell to fill:");
+            y = reader.nextInt();
+            System.out.println("Column of the cell to fill:");
+            x = reader.nextInt();
+        } while (!isValidCoordinates(rdoku, width, height, x-1, y-1));
+        Cell cell = rdoku.getCell(x-1, y-1);
+        System.out.println("Character to put in the (" + x + ", " + y + ") cell:");
+        String character = reader.next();
+        while (!isValidSymbol(character, listSymbols, width * height)) {
+            System.out.println("This is not a valid symbol; try again:");
+            character = reader.next();
+        }
+        cell.setSymbolIndex(indexOfSymbol(character, listSymbols, width * height));
+        showMultiDoku(rdoku, listSymbols, width, height);
+    }
+
+    private boolean isValidCoordinates(RenderableMultidoku doku, int width, int height, int x, int y) {
+        if (doku.getCell(x, y) != null) {
+            return true;
+        }
+        return false;
+    }
+
+    private int indexOfSymbol(String symbol, List<String> listSymbols, int nbSymbols) {
+        for (int i = 0; i < nbSymbols; i++) {
+            if (listSymbols.get(i).equals(symbol)) {
+                return i;
+            }
+        }
+        return -1;
+    }
+
+    private boolean isValidSymbol(String symbol, List<String> listSymbols, int size) {
+        for (int i = 0; i < size; i++) {
+            if (listSymbols.get(i).equals(symbol)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private void exit() {
+        System.out.println("Thank you for playing!");
+        System.exit(0);
+    }
 }

app/src/main/java/sudoku/io/SudokuPrinter.java

@@ -1,18 +1,39 @@
 package sudoku.io;
 
+import java.util.List;
+
+import gui.RenderableMultidoku;
+import gui.constants.Symbols;
+import sudoku.structure.Cell;
 import sudoku.structure.MultiDoku;
 import sudoku.structure.Sudoku;
 
 public class SudokuPrinter {
+	public static final String ANSI_RESET = "\u001B[0m";
+	public static final String ANSI_RED = "\u001B[31m";
+	public static final String ANSI_GREEN = "\u001B[32m";
+	public static final String ANSI_YELLOW = "\u001B[33m";
+	public static final String ANSI_BLUE = "\u001B[34m";
+	public static final String ANSI_PURPLE = "\u001B[35m";
+	public static final String ANSI_CYAN = "\u001B[36m";
 
-	public static void printRectangleSudoku(final Sudoku s, int blockWidth, int blockHeight) {
+	public static void printRectangleSudoku(final Sudoku s, int blockWidth, int blockHeight, Symbols symbols) {
+		printRectangleSudoku(s, blockWidth, blockHeight, symbols.getSymbols());
+	}
+
+	public static void printRectangleSudoku(final Sudoku s, int blockWidth, int blockHeight, List<String> listSymbols) {
 		for (int y = 0; y < s.getSize(); y++) {
 			if (y % blockHeight == 0 && y > 0) {
 				System.out.println();
 			}
 			StringBuilder line = new StringBuilder("[ ");
 			for (int x = 0; x < s.getSize(); x++) {
-				line.append((s.getCell(x, y).getSymbolIndex() + 1)).append(" ");
+				Cell c = s.getCell(x, y);
+				if (c.getSymbolIndex() == Cell.NOSYMBOL) {
+					line.append("  ");
+				} else {
+					line.append(listSymbols.get(c.getSymbolIndex())).append(" ");
+				}
 				if (x % blockWidth == blockWidth - 1 && x != blockWidth * blockHeight - 1) {
 					line.append("| ");
 				}
@@ -22,7 +43,120 @@ public class SudokuPrinter {
 		}
 	}
 
-	public static String toStringRectangleSudoku(final Sudoku s, int blockWidth, int blockHeight) {
+	public static void printRectangleSudokuWithIndex(final Sudoku s, int blockWidth, int blockHeight,
+			List<String> listSymbols) {
+		StringBuilder header = new StringBuilder("");
+		header.append("    ");
+		for (int x = 0; x < blockWidth * blockHeight; x++) {
+			header.append(x + 1).append(" ");
+			if (x % blockWidth == blockWidth - 1 && x != blockWidth * blockHeight - 1) {
+				header.append("  ");
+			}
+		}
+		header.append("\n");
+		System.out.println(header);
+		for (int y = 0; y < s.getSize(); y++) {
+			if (y % blockHeight == 0 && y > 0) {
+				System.out.println();
+			}
+			StringBuilder line = new StringBuilder(y + 1);
+			line.append(" [ ");
+			for (int x = 0; x < s.getSize(); x++) {
+				Cell c = s.getCell(x, y);
+				if (c.getSymbolIndex() == Cell.NOSYMBOL) {
+					line.append("  ");
+				} else {
+					line.append(listSymbols.get(c.getSymbolIndex())).append(" ");
+				}
+				if (x % blockWidth == blockWidth - 1 && x != blockWidth * blockHeight - 1) {
+					line.append("| ");
+				}
+			}
+			line.append("]");
+			System.out.println(line);
+		}
+	}
+
+	public static String printMultiDoku(final RenderableMultidoku rm, Symbols symbols, int blockWidth,
+			int blockHeight) {
+		return printMultiDoku(rm, symbols.getSymbols(), blockWidth, blockHeight);
+	}
+
+	public static String printMultiDoku(final RenderableMultidoku rm, List<String> listSymbols, int blockWidth,
+			int blockHeight) {
+		StringBuilder line = new StringBuilder("\n");
+		int nBlockInWidth = rm.getWidth() / blockWidth;
+		for (int y = 0; y < rm.getHeight(); y++) {
+			if (y % blockHeight == 0) {
+				line.append("__".repeat(Math.max(0, rm.getWidth() + nBlockInWidth))).append("_\n");
+			}
+			line.append("[ ");
+			for (int x = 0; x < rm.getWidth(); x++) {
+				if (x % blockWidth == 0 && x > 0) {
+					line.append("| ");
+				}
+				Cell cell = rm.getCell(x, y);
+				if (cell != null) {
+					if (cell.getSymbolIndex() == Cell.NOSYMBOL) {
+						line.append("- ");
+					} else {
+						line.append(listSymbols.get(cell.getSymbolIndex())).append(" ");
+					}
+				} else {
+					line.append("  ");
+				}
+			}
+			line.append("]\n");
+		}
+		line.append("__".repeat(Math.max(0, rm.getWidth() + nBlockInWidth))).append("_\n");
+		// System.out.println(line);
+		return line.toString();
+	}
+
+	public static void printMultiDokuWithIndex(final RenderableMultidoku rm, List<String> listSymbols, int blockWidth,
+			int blockHeight) {
+		StringBuilder line = new StringBuilder("\n");
+		line.append("    ");
+		for (int x = 0; x < rm.getWidth(); x++) {
+			line.append(x + 1).append(" ");
+			if (x % blockWidth == blockWidth - 1 && x != blockWidth * blockHeight - 1) {
+				line.append("  ");
+			}
+		}
+		line.append("\n");
+		int nBlockInWidth = rm.getWidth() / blockWidth;
+		for (int y = 0; y < rm.getHeight(); y++) {
+			if (y % blockHeight == 0) {
+				line.append("  ").append("__".repeat(Math.max(0, rm.getWidth() + nBlockInWidth))).append("_\n");
+			}
+			line.append(y + 1).append(" [ ");
+			for (int x = 0; x < rm.getWidth(); x++) {
+				if (x % blockWidth == 0 && x > 0) {
+					line.append("| ");
+				}
+				Cell cell = rm.getCell(x, y);
+				if (cell != null) {
+					if (cell.getSymbolIndex() == Cell.NOSYMBOL) {
+						line.append("- ");
+					} else {
+						line.append(listSymbols.get(cell.getSymbolIndex())).append(" ");
+					}
+				} else {
+					line.append("  ");
+				}
+			}
+			line.append("]\n");
+		}
+		line.append("  ").append("__".repeat(Math.max(0, rm.getWidth() + nBlockInWidth))).append("_\n");
+		System.out.println(line);
+	}
+
+	public static String toStringRectangleSudoku(final Sudoku s, int blockWidth, int blockHeight, Symbols symbols) {
+		return toStringRectangleSudoku(s, blockWidth, blockHeight, symbols.getSymbols());
+	}
+
+	public static String toStringRectangleSudoku(final Sudoku s, int blockWidth, int blockHeight,
+			List<String> listSymbols) {
 		StringBuilder result = new StringBuilder();
 		for (int y = 0; y < s.getSize(); y++) {
 			// Ajouter une ligne vide entre les blocs horizontaux
@@ -32,7 +166,12 @@ public class SudokuPrinter {
 			StringBuilder line = new StringBuilder("[ ");
 			for (int x = 0; x < s.getSize(); x++) {
 				// Ajouter la valeur de la cellule
-				line.append((s.getCell(x, y).getSymbolIndex() + 1)).append(" ");
+				Cell cell = s.getCell(x, y);
+				if (cell.getSymbolIndex() == Cell.NOSYMBOL) {
+					line.append("  ");
+				} else {
+					line.append(listSymbols.get(cell.getSymbolIndex())).append(" ");
+				}
 
 				// Ajouter un séparateur vertical entre les blocs
 				if (x % blockWidth == blockWidth - 1 && x != s.getSize() - 1) {
@@ -45,7 +184,25 @@ public class SudokuPrinter {
 		return result.toString();
 	}
 
-	public static void printMultiDoku(final MultiDoku doku, int blockWidth, int blockHeight){
-		// TODO
+	public static String printMultiDoku(final MultiDoku doku) {
+		int blockWidth = doku.getSubGrid(0).getBlockWidth();
+		if (blockWidth == 0)
+			return printMultiDoku(doku, 0, 0, Symbols.Numbers);
+		else
+			return printMultiDoku(doku, blockWidth, doku.getSubGrid(0).getSize() / blockWidth, Symbols.Letters);
 	}
+
+	public static String printMultiDoku(final MultiDoku doku, int blockWidth, int blockHeight, Symbols symbols) {
+		return printMultiDoku(RenderableMultidoku.fromMultidoku(doku), symbols, blockWidth, blockHeight);
+	}
+
+	public static void printMultiDokuWithIndex(final MultiDoku doku, int blockWidth, int blockHeight, Symbols symbols) {
+		if (doku.getNbSubGrids() == 1) {
+			printRectangleSudokuWithIndex(doku.getSubGrid(0), blockWidth, blockHeight, symbols.getSymbols());
+		} else {
+			printMultiDokuWithIndex(RenderableMultidoku.fromMultidoku(doku), symbols.getSymbols(), blockWidth,
+					blockHeight);
+		}
+	}
+
 }

app/src/main/java/sudoku/io/SudokuSerializer.java

@@ -1,7 +1,8 @@
 package sudoku.io;
 
-import java.io.*;
-import java.nio.charset.StandardCharsets;
+import java.io.File;
+import java.io.FileWriter;
+import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Paths;
 import java.util.ArrayList;
@@ -11,20 +12,20 @@ import org.json.JSONArray;
 import org.json.JSONObject;
 
 import sudoku.constraint.Constraint;
+import sudoku.constraint.IConstraint;
 import sudoku.structure.Block;
 import sudoku.structure.Cell;
 import sudoku.structure.MultiDoku;
 import sudoku.structure.Sudoku;
-import sudoku.structure.SudokuFactory;
 
 public class SudokuSerializer {
 
 	public static JSONObject serializeSudoku(final MultiDoku multidoku) {
-		List<Cell> cellIds   = new ArrayList<>();
+		List<Cell> cellIds = new ArrayList<>();
 		List<Block> blockIds = new ArrayList<>();
 
-		JSONObject jsonRoot  = new JSONObject();
-		JSONArray jsonCells  = new JSONArray();
+		JSONObject jsonRoot = new JSONObject();
+		JSONArray jsonCells = new JSONArray();
 		JSONArray jsonBlocks = new JSONArray();
 		JSONArray jsonSudokus = new JSONArray(multidoku.getNbSubGrids());
 
@@ -33,9 +34,10 @@ public class SudokuSerializer {
 
 			// init cells
 			for (Cell cell : sudoku.getCells()) {
-				if (!cellIds.contains(cell)) {
-					cellIds.add(cell);
-				}
+				if (cellIds.contains(cell))
+					continue;
+
+				cellIds.add(cell);
 
 				Block block = cell.getBlock();
 				if (!blockIds.contains(block)) {
@@ -43,6 +45,7 @@ public class SudokuSerializer {
 				}
 
 				int blockID = blockIds.indexOf(block);
+				assert (blockID >= 0);
 				int symbolIndex = cell.getSymbolIndex();
 
 				JSONObject cellJsonObject = new JSONObject();
@@ -58,16 +61,17 @@ public class SudokuSerializer {
 
 		// init blocks
 
-        for (Block blockId : blockIds) {
-            JSONObject blockJsonObject = new JSONObject();
-            JSONArray cellsJsonArray = new JSONArray();
-            for (Cell cell : blockId.getCells()) {
-                int cellID = cellIds.indexOf(cell);
-                cellsJsonArray.put(cellID);
-            }
-            blockJsonObject.put("cellIDs", cellsJsonArray);
-            jsonBlocks.put(blockJsonObject);
-        }
+		for (Block blockId : blockIds) {
+			JSONObject blockJsonObject = new JSONObject();
+			JSONArray cellsJsonArray = new JSONArray();
+			for (Cell cell : blockId.getCells()) {
+				int cellID = cellIds.indexOf(cell);
+				assert (cellID >= 0);
+				cellsJsonArray.put(cellID);
+			}
+			blockJsonObject.put("cellIDs", cellsJsonArray);
+			jsonBlocks.put(blockJsonObject);
+		}
 
 		for (int i = 0; i < multidoku.getNbSubGrids(); i++) {
 			// serialise sub grid
@@ -82,6 +86,7 @@ public class SudokuSerializer {
 
 			for (Cell cell : sudoku.getCells()) {
 				int cellID = cellIds.indexOf(cell);
+				assert (cellID >= 0);
 				cellsJsonArray.put(cellID);
 			}
 
@@ -89,13 +94,23 @@ public class SudokuSerializer {
 
 			for (Block block : sudoku.getBlocks()) {
 				int blockID = blockIds.indexOf(block);
+				assert (blockID >= 0);
 				blocksJsonArray.put(blockID);
 			}
 
 			// serialize constraints
 
-			for (Constraint cons : sudoku.getConstraints()) {
-				constraintsJsonArray.put(cons.ordinal());
+			for (IConstraint cons : sudoku.getConstraints()) {
+				boolean constraintSerialized = false;
+				for (Constraint enumCons : Constraint.values()) {
+					if (cons.getClass().isAssignableFrom(enumCons.getConstraint().getClass())) {
+						constraintSerialized = true;
+						constraintsJsonArray.put(enumCons.ordinal());
+					}
+				}
+				if (!constraintSerialized) {
+					System.out.println("La contrainte " + cons.getClass() + " n'a pas pu être sérialisé !");
+				}
 			}
 
 			jsonSudoku.put("constraints", constraintsJsonArray);
@@ -114,21 +129,19 @@ public class SudokuSerializer {
 
 	/**
 	 * Save a serialized MultiDoku in a JSON file.
+	 * 
 	 * @param doku MultiDoku, MultiDoku to save.
 	 * @return String, the path of the save.
 	 */
 	public static String saveMultiDoku(final MultiDoku doku) {
-
 		JSONObject jsonRoot = serializeSudoku(doku);
 
 		File f = new File("save", "save.json");
 		int i = 0;
-
 		while (f.exists()) {
 			String newName = "save-" + ++i + ".json";
 			f = new File("save", newName);
 		}
-
 		try (FileWriter file = new FileWriter(f)) {
 			file.write(jsonRoot.toString(3));
 		} catch (IOException e) {
@@ -137,8 +150,28 @@ public class SudokuSerializer {
 		return f.getAbsolutePath();
 	}
 
+	public static String saveMultiDoku(final MultiDoku doku, final int saveToOverwrite) {
+		File f;
+		if (saveToOverwrite == 0) {
+			f = new File("save", "save.json");
+		} else {
+			f = new File("save", "save-" + saveToOverwrite + ".json");
+		}
+		if (!f.exists()) {
+			return saveMultiDoku(doku);
+		} else {
+			try (FileWriter file = new FileWriter(f)) {
+				file.write(serializeSudoku(doku).toString(3));
+			} catch (IOException e) {
+				e.printStackTrace();
+			}
+			return f.getAbsolutePath();
+		}
+	}
+
 	/**
 	 * Get a MultiDoku from a pre-existing json save file.
+	 * 
 	 * @param numberSave int, number of the save file to open.
 	 * @return MultiDoku, MultoDoku contained in the file.
 	 * @throws Exception when the given save file does not exist.
@@ -158,20 +191,6 @@ public class SudokuSerializer {
 			throw new Exception("This save does not exist.");
 		} else {
 			fileContent = new String(Files.readAllBytes(Paths.get("save/" + fileName)));
-			/*
-			try {
-				FileReader file = new FileReader(f);
-				char[] rawFileContent = {};
-				int length = 1000;
-				while (file.read(rawFileContent, 0, length) != -1) {
-					rawFileContent = new char[]{};
-					length = length * 10;
-				}
-				fileContent = new String(rawFileContent);
-			} catch (IOException e) {
-				throw new Exception("Error reading file.");
-			}
-			*/
 			return deserializeSudoku(fileContent);
 		}
 	}
@@ -224,7 +243,7 @@ public class SudokuSerializer {
 
 			List<Cell> sudokuCells = new ArrayList<>();
 			List<Block> sudokuBlocks = new ArrayList<>();
-			List<Constraint> sudokuConstraints = new ArrayList<>();
+			List<IConstraint> sudokuConstraints = new ArrayList<>();
 
 			for (int j = 0; j < sudokuCellsJsonArray.length(); j++) {
 				int cellID = sudokuCellsJsonArray.getInt(j);
@@ -238,7 +257,7 @@ public class SudokuSerializer {
 
 			for (int j = 0; j < sudokuConstraintsJsonArray.length(); j++) {
 				int constraintID = sudokuConstraintsJsonArray.getInt(j);
-				sudokuConstraints.add(Constraint.values()[constraintID]);
+				sudokuConstraints.add(Constraint.values()[constraintID].getConstraint());
 			}
 
 			Sudoku s = new Sudoku(sudokuCells, sudokuBlocks, sudokuConstraints);

app/src/main/java/sudoku/solver/BacktrackingSolver.java

@@ -0,0 +1,49 @@
+package sudoku.solver;
+
+import java.util.List;
+import java.util.concurrent.CancellationException;
+
+import sudoku.structure.Cell;
+import sudoku.structure.MultiDoku;
+
+public class BacktrackingSolver implements Solver {
+
+	/**
+	 * Résout le MultiDoku passé en paramètre, avec backtracking.
+	 *
+	 * @param doku MultiDoku, MultiDoku à résoudre.
+	 * @return boolean, valant true si le MultiDoku est résolu, false sinon.
+	 */
+	@Override
+	public boolean solve(MultiDoku doku, List<SolverStep> steps) {
+		if (Thread.interrupted())
+			throw new CancellationException("User wants to stop the solver");
+
+		if (doku.isSolved()) {
+			return true;
+		}
+
+		Cell cellToFill = doku.getFirstEmptyCell();
+		if (cellToFill == null) {
+			return false;
+		}
+
+		List<Integer> possibleSymbols = cellToFill.getPossibleSymbols();
+		if (possibleSymbols.isEmpty()) {
+			return false;
+		}
+
+		for (int symbol : possibleSymbols) {
+			cellToFill.setSymbolIndex(symbol);
+			addStep(cellToFill, steps);
+			if (this.solve(doku, steps)) {
+				return true;
+			} else {
+				cellToFill.setSymbolIndex(Cell.NOSYMBOL);
+				addStep(cellToFill, steps);
+			}
+		}
+		return false;
+	}
+
+}

app/src/main/java/sudoku/solver/HintHelper.java

@@ -0,0 +1,53 @@
+package sudoku.solver;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Random;
+
+import sudoku.structure.Cell;
+import sudoku.structure.MultiDoku;
+
+//TODO
+public class HintHelper {
+
+	public static record Hint(Cell cell, int newValue) {}
+
+	public static Hint getHint(MultiDoku doku, Solver solver) {
+		doku.getStateManager().pushState();
+		doku.clearMutableCells();
+		if (!solver.solve(doku))
+			return null;
+		var stateSolved = doku.getStateManager().popAndGetState();
+		// find differences
+		Map<Cell, Integer> newValues = new HashMap<>();
+		for (var entry : stateSolved.entrySet()) {
+			Cell cell = entry.getKey();
+			// we only want the cells that can be filled
+			if (!cell.isMutable())
+				continue;
+			int oldValue = cell.getSymbolIndex();
+			int newValue = stateSolved.get(cell);
+			if (oldValue == newValue)
+				continue;
+			// we have to clear the cell
+			if (newValue == Cell.NOSYMBOL)
+				return new Hint(cell, newValue);
+			// we have to change the cell value
+			if (oldValue != Cell.NOSYMBOL)
+				return new Hint(cell, newValue);
+
+			// there is a valid move
+			newValues.put(cell, newValue);
+		}
+
+		// this is too complex just for fetching a random entry, but whatever ...
+		Random r = new Random();
+		List<Cell> cells = new ArrayList<>(newValues.keySet());
+		Cell randomCell = cells.get(r.nextInt(cells.size()));
+		int randomCellValue = newValues.get(randomCell);
+		return new Hint(randomCell, randomCellValue);
+	}
+
+}

app/src/main/java/sudoku/solver/HumanSolver.java

@@ -0,0 +1,39 @@
+package sudoku.solver;
+
+import java.util.List;
+
+import sudoku.structure.Cell;
+import sudoku.structure.MultiDoku;
+
+public class HumanSolver implements Solver {
+
+	/**
+	 * Résout le MultiDoku passé en paramètre, avec règles de déduction.
+	 *
+	 * @param doku MultiDoku, MultiDoku à résoudre.
+	 * @return boolean, valant true si le MultiDoku est résolu, false sinon.
+	 */
+	@Override
+	public boolean solve(MultiDoku doku, List<SolverStep> steps) {
+		while (!doku.isSolved()) {
+			boolean filledCell = false;
+			for (Cell cell : doku.getCells()) {
+				if (!cell.isMutable() || !cell.isEmpty())
+					continue;
+				
+				List<Integer> possibleSymbols = cell.getPossibleSymbols();
+				if (possibleSymbols.size() == 1) {
+					cell.setSymbolIndex(possibleSymbols.getFirst());
+					addStep(cell, steps);
+					filledCell = true;
+				}
+			}
+			// on ne peut plus remplir de cases, on abandonne
+			if (!filledCell)
+				return false;
+		}
+
+		return true;
+	}
+
+}

app/src/main/java/sudoku/solver/MixedSolver.java

@@ -0,0 +1,74 @@
+package sudoku.solver;
+
+import java.util.List;
+import java.util.concurrent.CancellationException;
+
+import sudoku.structure.Cell;
+import sudoku.structure.MultiDoku;
+
+public class MixedSolver implements Solver {
+
+    private Cell findCellToBacktrack(MultiDoku doku, int maxPossibilities) {
+        for (Cell cell : doku.getCells()) {
+            if (!cell.isMutable() || !cell.isEmpty())
+                continue;
+
+            List<Integer> possibleSymbols = cell.getPossibleSymbols();
+            if (possibleSymbols.size() == maxPossibilities) {
+                return cell;
+            }
+        }
+        return null;
+    }
+
+    /**
+     * Résout le MultiDoku passé en paramètre, avec règles de déduction et
+     * backtracking.
+     *
+     * @param doku MultiDoku, MultiDoku à résoudre.
+     * @return boolean, valant true si le MultiDoku est résolu, false sinon.
+     */
+    @Override
+    public boolean solve(MultiDoku doku, List<SolverStep> steps) {
+        if (Thread.interrupted()) {
+            throw new CancellationException("User wants to stop the solver");
+        }
+
+        while (!doku.isSolved()) {
+            boolean filledCell = false;
+            for (Cell cell : doku.getCells()) {
+                if (!cell.isMutable() || !cell.isEmpty())
+                    continue;
+
+                List<Integer> possibleSymbols = cell.getPossibleSymbols();
+                if (possibleSymbols.size() == 1) {
+                    cell.setSymbolIndex(possibleSymbols.getFirst());
+                    addStep(cell, steps);
+                    filledCell = true;
+                }
+            }
+            // on ne peut plus remplir de cases, on tente de backtrack
+            if (!filledCell) {
+                int maxPossibilities = 2;
+                Cell backtrackCell = null;
+                while (backtrackCell == null) {
+                    backtrackCell = findCellToBacktrack(doku, maxPossibilities);
+                    maxPossibilities++;
+                }
+                // on fait du backtracking
+                List<Integer> possibilities = backtrackCell.getPossibleSymbols();
+                for (int symbol : possibilities) {
+                    doku.getStateManager().pushState();
+                    backtrackCell.setSymbolIndex(symbol);
+                    if (solve(doku, steps))
+                        return true;
+                    doku.getStateManager().popState();
+                }
+            }
+
+        }
+
+        return true;
+    }
+
+}

app/src/main/java/sudoku/solver/RandomSolver.java

@@ -0,0 +1,55 @@
+package sudoku.solver;
+
+import java.util.List;
+import java.util.Random;
+import java.util.concurrent.CancellationException;
+
+import sudoku.structure.Cell;
+import sudoku.structure.MultiDoku;
+
+public class RandomSolver implements Solver {
+
+    /**
+     * Résout, si possible, le multidoku passé en paramètre
+     * en testant toutes les possibilités, de manière aléatoire, avec un algorithme
+     * de backtracking.
+     *
+     * @param doku Multidoku, à résoudre
+     * @return boolean, true s'il est résolu ou false s'il ne l'est pas.
+     */
+    @Override
+    public boolean solve(MultiDoku doku, List<SolverStep> steps) {
+        Random rand = new Random();
+
+        if (Thread.interrupted())
+            throw new CancellationException("User wants to stop the solver");
+
+        if (doku.isSolved()) {
+            return true;
+        }
+
+        Cell cellToFill = doku.getFirstEmptyCell();
+        if (cellToFill == null) {
+            return false;
+        }
+
+        List<Integer> possibleSymbols = cellToFill.getPossibleSymbols();
+
+        while (!possibleSymbols.isEmpty()) {
+            int nextPossibleSymbolIndex = rand.nextInt(possibleSymbols.size());
+            int nextSymbol = possibleSymbols.get(nextPossibleSymbolIndex);
+
+            cellToFill.setSymbolIndex(nextSymbol);
+            addStep(cellToFill, steps);
+            if (this.solve(doku, steps)) {
+                return true;
+            }
+            cellToFill.setSymbolIndex(Cell.NOSYMBOL);
+            addStep(cellToFill, steps);
+            possibleSymbols.remove(nextPossibleSymbolIndex);
+
+        }
+        return false;
+    }
+
+}

app/src/main/java/sudoku/solver/Solver.java

@@ -1,177 +1,61 @@
 package sudoku.solver;
 
-import sudoku.io.SudokuPrinter;
-import sudoku.structure.MultiDoku;
-import sudoku.structure.Cell;
-import sudoku.structure.Sudoku;
-
 import java.util.List;
-import java.util.Random;
-import java.util.concurrent.CancellationException;
-import java.util.logging.Level;
 import java.util.logging.Logger;
 
-public class Solver {
+import sudoku.structure.Cell;
+import sudoku.structure.MultiDoku;
+
+public interface Solver {
 
     /**
      * Log du Solver, qui garde trace des actions réalisées.
      */
-    private static final Logger logger = Logger.getLogger("SolverLogger");
+    public static final Logger logger = Logger.getLogger("SolverLogger");
 
-    /**
-     * Résout, si possible, le multidoku passé en paramètre
-     * en testant toutes les possibilités, de manière aléatoire, avec un algorithme
-     * de backtracking.
-     *
-     * @param doku Multidoku, à résoudre
-     * @param rand Random, pour tester aléatoirement les symboles
-     * @return boolean, true s'il est résolu ou false s'il ne l'est pas.
-     */
-    public static boolean solveRandom(MultiDoku doku, Random rand) {
-        if (Thread.interrupted())
-            throw new CancellationException("User wants to stop the solver");
+    boolean solve(MultiDoku doku, List<SolverStep> solverSteps);
 
-        Sudoku sudoku = doku.getSubGrid(0);
-        logger.log(Level.FINE,
-                '\n' + SudokuPrinter.toStringRectangleSudoku(sudoku,
-                        sudoku.getBlockWidth() == 0 ? sudoku.getSize() : sudoku.getBlockWidth(),
-                        sudoku.getBlockWidth() == 0 ? sudoku.getSize() : sudoku.getSize() / sudoku.getBlockWidth()));
-
-        if (doku.isSolved()) {
-            return true;
-        }
-
-        Cell cellToFill = doku.getFirstEmptyCell();
-        if (cellToFill == null) {
-            return false;
-        }
-
-        List<Integer> possibleSymbols = doku.getPossibleSymbolsOfCell(cellToFill);
-
-        while (!possibleSymbols.isEmpty()) {
-            int nextPossibleSymbolIndex = rand.nextInt(possibleSymbols.size());
-            int nextSymbol = possibleSymbols.get(nextPossibleSymbolIndex);
-
-            cellToFill.setSymbolIndex(nextSymbol);
-            if (Solver.solveRandom(doku, rand)) {
-                return true;
-            }
-            cellToFill.setSymbolIndex(Cell.NOSYMBOL);
-            possibleSymbols.remove(nextPossibleSymbolIndex);
-
-        }
-        return false;
+    default boolean solve(MultiDoku doku) {
+        return solve(doku, null);
     }
 
     /**
      * Compte le nombre de solutions possibles au MultiDoku passé en paramètres.
-     * @param oldDoku MultiDoku, MultiDoku dont on veut le nombre de solutions.
+     *
+     * @param doku MultiDoku, MultiDoku dont on veut le nombre de solutions.
      * @return int, nombre de solutions possibles.
      */
-    public static int countSolution(MultiDoku oldDoku) {
+    default int countSolution(MultiDoku doku) {
         int result = 0;
 
-        MultiDoku doku = oldDoku.clone();
-
         if (doku.isSolved()) {
             return 1;
         }
 
         Cell cellToFill = doku.getFirstEmptyCell();
-        if (cellToFill == null) {
-            System.out.println("AAAAAAAAAAAAAA");
-            return 0;
-        }
+        assert (cellToFill != null);
 
-        List<Integer> possibleSymbols = doku.getPossibleSymbolsOfCell(cellToFill);
+        List<Integer> possibleSymbols = cellToFill.getPossibleSymbols();
 
         for (int symbol : possibleSymbols) {
+            doku.getStateManager().pushState();
             cellToFill.setSymbolIndex(symbol);
-            System.out.println("symbol : "+symbol);
-            System.out.println("doku.isSolved() || Solver.solve(doku) ? "+ (doku.isSolved() || Solver.solve(doku)));
-            if (doku.isSolved() || Solver.solve(doku)) {
+            if (solve(doku)) {
                 result++;
+                if (result > 1) {
+                    doku.getStateManager().popState();
+                    return result;
+                }
             }
-            cellToFill.setSymbolIndex(Cell.NOSYMBOL);
+            doku.getStateManager().popState();
         }
-
         return result;
     }
 
-    /**
-     * Résout le MultiDoku passé en paramètre, avec backtracking.
-     * @param doku MultiDoku, MultiDoku à résoudre.
-     * @return boolean, valant true si le MultiDoku est résolu, false sinon.
-     */
-    public static boolean solve(MultiDoku doku) {
-        if (Thread.interrupted())
-            throw new CancellationException("User wants to stop the solver");
-
-        if (doku.isSolved()) {
-            return true;
-        }
-
-        Cell cellToFill = doku.getFirstEmptyCell();
-        if (cellToFill == null) {
-            return false;
-        }
-
-        List<Integer> possibleSymbols = doku.getPossibleSymbolsOfCell(cellToFill);
-        if (possibleSymbols.isEmpty()) {
-            return false;
-        }
-
-        for (int symbol : possibleSymbols) {
-
-            cellToFill.setSymbolIndex(symbol);
-            if (Solver.solve(doku)) {
-                return true;
-            } else {
-                cellToFill.setSymbolIndex(Cell.NOSYMBOL);
-            }
-
-        }
-        return false;
+    default void addStep(Cell cell, List<SolverStep> steps) {
+        if (steps == null)
+            return;
+        steps.add(new SolverStep(cell));
     }
 
-    /**
-     * Résout le MultiDoku passé en paramètre, sans backtracking.
-     * @param doku MultiDoku, MultiDoku à résoudre.
-     * @return boolean, valant true si le MultiDoku est résolu, false sinon.
-     */
-    public static boolean humanSolve(MultiDoku doku) {
-        if (Thread.interrupted())
-            throw new CancellationException("User wants to stop the solver");
-
-        List<Cell> cellsToFill = doku.getEmptyCells();
-
-        while (!cellsToFill.isEmpty()) {
-
-            Sudoku sudoku = doku.getSubGrid(0);
-            logger.log(Level.FINE,
-                    '\n' + SudokuPrinter.toStringRectangleSudoku(sudoku,
-                            sudoku.getBlockWidth() == 0 ? sudoku.getSize() : sudoku.getBlockWidth(),
-                            sudoku.getBlockWidth() == 0 ? sudoku.getSize() : sudoku.getSize() / sudoku.getBlockWidth()));
-
-            boolean blocked = true;
-            for (Cell cellToFill : cellsToFill) {
-
-                List<Integer> possibleSymbols = doku.getPossibleSymbolsOfCell(cellToFill);
-                if (possibleSymbols.size() != 1) {
-                    continue;
-                }
-
-                cellToFill.setSymbolIndex(possibleSymbols.getFirst());
-                cellsToFill.remove(cellToFill);
-                blocked = false;
-                break;
-            }
-
-            if (blocked) {
-                break;
-            }
-        }
-
-        return doku.isSolved();
-    }
 }

app/src/main/java/sudoku/solver/SolverStep.java

@@ -0,0 +1,23 @@
+package sudoku.solver;
+
+import sudoku.structure.Cell;
+
+public class SolverStep {
+
+	private final Cell cell;
+	private final int newValue;
+
+	public SolverStep(Cell cell) {
+		this.cell = cell;
+		this.newValue = cell.getSymbolIndex();
+	}
+
+	public int getNewValue() {
+		return newValue;
+	}
+
+	public Cell getCell() {
+		return cell;
+	}
+
+}

app/src/main/java/sudoku/solver/StupidSolver.java

@@ -1,17 +1,17 @@
 package sudoku.solver;
 
+import java.util.List;
 import java.util.concurrent.CancellationException;
 
-import sudoku.structure.Coordinate;
 import sudoku.structure.MultiDoku;
 import sudoku.structure.Sudoku;
 
 /**
  * Class de test non utilisé
  */
-public class StupidSolver {
+public class StupidSolver implements Solver{
 
-	private static boolean solve(Sudoku sudoku, int index) {
+	private boolean solve(Sudoku sudoku, int index, List<SolverStep> steps) {
 		// mécanisme d'abandon
 		if (Thread.interrupted())
 			throw new CancellationException("User wants to stop the solver");
@@ -22,28 +22,30 @@ public class StupidSolver {
 
 		// si la case n'est pas modifiable, on passe à la suivante
 		if (!sudoku.getCell(index).isMutable())
-			return solve(sudoku, index + 1);
+			return solve(sudoku, index + 1, steps);
 
-		Coordinate coords = sudoku.toCoords(index);
 		for (int symbol = 0; symbol < sudoku.getSize(); symbol++) {
-			if (sudoku.tryPlaceCellSymbol(coords.getX(), coords.getY(), symbol)) {
+			if (sudoku.getCell(index).trySetValue(symbol)) {
+				addStep(sudoku.getCell(index), steps);
 				// on tente de placer sur la case suivante
-				if (solve(sudoku, index + 1)) {
+				if (solve(sudoku, index + 1, steps)) {
 					return true;
 				}
 			}
 		}
 		// on a tout essayé et rien n'a fonctionné
-		sudoku.clearCell(coords.getX(), coords.getY());
+		sudoku.getCell(index).empty();
+		addStep(sudoku.getCell(index), steps);
 		return false;
 	}
 
-	public static boolean solve(MultiDoku doku) {
+	@Override
+	public boolean solve(MultiDoku doku, List<SolverStep> steps) {
 		if (doku.isSolved())
 			return true;
 
 		for (Sudoku sudoku : doku.getSubGrids()) {
-			if (!solve(sudoku, 0))
+			if (!solve(sudoku, 0, steps))
 				return false;
 		}
 		return true;

app/src/main/java/sudoku/structure/Block.java

@@ -4,28 +4,41 @@ import java.util.ArrayList;
 import java.util.List;
 
 /**
- * Class qui représente les block de chaque sudoku,
- * Un block étant un ensemble de cellule avec une contrainte de block qui lui
- * ait associé
+ * Class qui représente les Block de chaque Sudoku,
+ * Un Block étant un ensemble de cellule avec une contrainte de block qui lui
+ * ait associé.
  */
 public class Block {
 
+	// <editor-fold defaultstate="collapsed" desc="ATTRIBUTS">
+
 	/**
-	 * L'ensemble des cellules du block
+	 * L'ensemble des cellules du block.
 	 */
 	private final List<Cell> cells;
 
 	/**
-	 * List de sudoku qui contiennent le block
-	 * Pour un acces plus rapide aux sudokus
+	 * Liste de Sudoku qui contiennent le block
+	 * Pour un accès plus rapide aux sudokus.
 	 */
 	private final List<Sudoku> sudokus;
 
+	// </editor-fold>
+
+	// <editor-fold defaultstate="collapsed" desc="METHODES">
+
+	/**
+	 * Crée un Block avec une liste de Cell donnée.
+	 * @param cells List<Cell>
+	 */
 	public Block(List<Cell> cells) {
 		this.cells = cells;
 		this.sudokus = new ArrayList<>();
 	}
 
+	/**
+	 * Crée un Block avec une liste de Cell vide.
+	 */
 	public Block() {
 		this(new ArrayList<>());
 	}
@@ -33,13 +46,16 @@ public class Block {
 	public List<Cell> getCells() {
 		return cells;
 	}
+	public List<Sudoku> getSudokus() {
+		return sudokus;
+	}
 
 	/**
 	 * Ajoute une Cell au Block
 	 * 
 	 * @param newCell Cell, à ajouter
 	 */
-	void addCell(Cell newCell) {
+	public void addCell(Cell newCell) {
 		this.cells.add(newCell);
 	}
 
@@ -57,16 +73,5 @@ public class Block {
 		return false;
 	}
 
-	public boolean containsCell(Cell cell) {
-		for (Cell cellTmp : this.cells) {
-			if (cellTmp.equals(cell)) {
-				return true;
-			}
-		}
-		return false;
-	}
-
-	public List<Sudoku> getSudokus() {
-		return sudokus;
-	}
+	// </editor-fold>
 }

app/src/main/java/sudoku/structure/Cell.java

@@ -9,6 +9,8 @@ import java.util.List;
  */
 public class Cell {
 
+	// <editor-fold defaultstate="collapsed" desc="ATTRIBUTS">
+
 	/**
 	 * Constante de valeur d'index de symbole quand il n'y en a pas,
 	 * soit que la Cell est vide.
@@ -24,28 +26,25 @@ public class Cell {
 	 * Il est initialisé à Cell.NOSYMBOL.
 	 */
 	private int symbolIndex = Cell.NOSYMBOL;
-	/**
-	 * Liste des index de symbole possibles pour cette Cell,
-	 * en fonction des contraintes de sudoku dans lequel elle est.
-	 */
-	private final List<Integer> possibleSymbols;
 	/**
 	 * Si cette Cell peut être modififié ou non.
 	 */
 	private boolean isMutable = true;
 
+	// </editor-fold>
+
+	// <editor-fold defaultstate="collapsed" desc="METHODES">
+
 	public Cell() {
-		this.possibleSymbols = new ArrayList<>();
+		this(Cell.NOSYMBOL);
 	}
 
 	public Cell(int symbolIndex) {
 		this.symbolIndex = symbolIndex;
-		this.possibleSymbols = new ArrayList<>();
 	}
 
 	public Cell(int symbolIndex, boolean isMutable) {
 		this.symbolIndex = symbolIndex;
-		this.possibleSymbols = new ArrayList<>();
 		this.isMutable = isMutable;
 	}
 
@@ -53,13 +52,24 @@ public class Cell {
 		return this.symbolIndex;
 	}
 
-	public void setSymbolIndex(int symbolIndex) {
-		this.symbolIndex = symbolIndex;
+	/**
+	 * Renvoie le Block qui la contient.
+	 * @return Block.
+	 */
+	public Block getBlock() {
+		return this.blockContainer;
 	}
 
-	public void setPossibleSymbols(List<Integer> possibleSymbols) {
-		this.possibleSymbols.clear();
-		this.possibleSymbols.addAll(possibleSymbols);
+	/**
+	 * Renvoie si la Cell est modifiable
+	 * @return boolean, true si elle est modifiable ou false sinon.
+	 */
+	public boolean isMutable() {
+		return this.isMutable;
+	}
+
+	public void setSymbolIndex(int symbolIndex) {
+		this.symbolIndex = symbolIndex;
 	}
 
 	/**
@@ -69,22 +79,16 @@ public class Cell {
 		this.isMutable = false;
 	}
 
-	public Block getBlock() {
-		return this.blockContainer;
-	}
 
 	public void setBlock(Block block) {
 		this.blockContainer = block;
 	}
 
 	/**
-	 * Remove the current symbolIndex and returns it
-	 * @return integer symbolIndex cleared
+	 * Vide la Cell.
 	 */
-	public int clearCurrentSymbol() {
-		int i = this.symbolIndex;
+	public void clearCurrentSymbol() {
 		setSymbolIndex(NOSYMBOL);
-		return i;
 	}
 
 	/**
@@ -95,22 +99,6 @@ public class Cell {
 		return this.symbolIndex == Cell.NOSYMBOL;
 	}
 
-	public void removeSymbolFromPossibilities(int indexSymbol) {
-		possibleSymbols.remove(indexSymbol);
-	}
-
-	public List<Integer> getPossibleSymbols() {
-		return this.possibleSymbols;
-	}
-
-	/**
-	 * Renvoie si la Cell est modifiable
-	 * @return boolean, true si elle est modifiable ou false sinon.
-	 */
-	public boolean isMutable() {
-		return this.isMutable;
-	}
-
 	/**
 	 * Vide la Cell, en renvoie l'ancien index du symbole qui était dedans.
 	 * @return int, index du symbole anciennement contenue dans la Cell.
@@ -120,4 +108,53 @@ public class Cell {
 		this.symbolIndex = Cell.NOSYMBOL;
 		return oldSymbol;
     }
+
+	/**
+	 * Vérifie si la Cell peut prendre ce symbole par rapport aux contraintes de ses Sudokus.
+	 * @param value int, index du symbole
+	 * @return boolean, true si elle peut, false sinon.
+	 */
+	public boolean canHaveValue(int value) {
+		for (Sudoku s :getBlock().getSudokus()) {
+			int cellIndex = s.getCells().indexOf(this);
+			// la cellule existe
+			if (cellIndex != -1) {
+				int cellX = cellIndex % s.getSize();
+				int cellY = cellIndex / s.getSize();
+				if (!s.canBePlaced(cellX, cellY, value)) {
+					return false;
+				}
+			}
+		}
+		return true;
+	}
+
+	/**
+	 * Renvoie les symboles que peut prendre cette Cell par rapport aux contraintes de ses Sudokus.
+	 * @return List<Integer>, la liste des symboles possibles.
+	 */
+	public List<Integer> getPossibleSymbols() {
+		List<Integer> result = new ArrayList<>();
+		for (int i = 0; i < getBlock().getSudokus().get(0).getSize(); i++) {
+			if (canHaveValue(i))
+				result.add(i);
+		}
+		return result;
+	}
+
+	/**
+	 * Essaye de placer la valeur et renvoie false si ce n'est pas possible.
+	 * @param newValue int, valeur à placer.
+	 * @return boolean, true si la Cell à pris la valeur newValue, false sinon.
+	 */
+	public boolean trySetValue(int newValue) {
+		if (!isMutable())
+			return false;
+		if (!canHaveValue(newValue))
+			return false;
+		setSymbolIndex(newValue);
+		return true;
+	}
+
+	// </editor-fold>
 }

app/src/main/java/sudoku/structure/Coordinate.java

@@ -1,10 +1,12 @@
 package sudoku.structure;
 
 /**
- * Représente les coordonnées d'une Cell
+ * Représente les coordonnées d'une Cell.
  */
 public class Coordinate {
 
+    // <editor-fold defaultstate="collapsed" desc="ATTRIBUTS">
+
     /**
      * L'abscisse de la Cell.
      */
@@ -14,6 +16,10 @@ public class Coordinate {
      */
     private int y;
 
+    // </editor-fold>
+
+    // <editor-fold defaultstate="collapsed" desc="METHODES">
+
     public Coordinate(int x, int y) {
         this.x = x;
         this.y = y;
@@ -35,16 +41,23 @@ public class Coordinate {
         this.y = y;
     }
 
-    public int calculateIndex(int size) {
-        return this.y * size + this.x;
-    }
-
+    /**
+     * Ajoute la Coordiante donnée à celle-ci.
+     * @param other Coordiante, à ajouter.
+     * @return Coordinate, le résultat de l'addition.
+     */
     public Coordinate add(Coordinate other) {
         return new Coordinate(this.x + other.x, this.y + other.y);
     }
 
+    /**
+     * Soustrait la Coordiante donnée à celle-ci.
+     * @param other Coordiante, à soustraire.
+     * @return Coordinate, le résultat de la soustraction.
+     */
     public Coordinate sub(Coordinate other) {
         return new Coordinate(this.x - other.x, this.y - other.y);
     }
 
+    // </editor-fold>
 }

app/src/main/java/sudoku/structure/Difficulty.java

@@ -1,26 +1,32 @@
 package sudoku.structure;
 
-//TODO: melvyn va passer par là
+/**
+ * Les difficultés d'un Sudoku,
+ * représente le nombre de cases à enlever, en proportion, à un Sudoku.
+ * Par exemple, avec 0.1 de factor, on enlevera 10% des cases.
+ */
 public enum Difficulty {
 
-	VeryEasy("Très facile", 0.1), Easy("Facile", 0.25), Medium("Moyen", 0.5), Hard("Difficile", 0.75);
+	VeryEasy("Très facile", 0.1),
+	Easy("Facile", 0.25),
+	Medium("Moyen", 0.5),
+	Hard("Difficile", 0.75),
+	VeryHard("Impossible", 0.78);
 
-	double factor;
-	String displayName;
+	/**
+	 * Le pourcentage de Cell à enlever.
+	 */
+	final double factor;
+	/**
+	 * Le nom de la difficulté.
+	 */
+	final String displayName;
 
-	private Difficulty(String displayName, double factor) {
+	Difficulty(String displayName, double factor) {
 		this.factor = factor;
 		this.displayName = displayName;
 	}
 
-	public String getDisplayName() {
-		return displayName;
-	}
-
-	public double getFactor() {
-		return factor;
-	}
-
 	private static final String[] difficultyNames;
 
 	static {
@@ -31,6 +37,14 @@ public enum Difficulty {
 		}
 	}
 
+	public String getDisplayName() {
+		return displayName;
+	}
+
+	public double getFactor() {
+		return factor;
+	}
+
 	public static String[] getDifficultyNames() {
 		return difficultyNames;
 	}

app/src/main/java/sudoku/structure/MultiDoku.java

@@ -1,166 +1,63 @@
 package sudoku.structure;
 
+import sudoku.io.SudokuPrinter;
+import sudoku.io.SudokuSerializer;
+
 import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 
-import sudoku.io.SudokuSerializer;
-
 /**
  * @class MultiDoku
  * @brief Représente une grille de Multidoku.
- *        Une grille de sudoku est un multidoku avec un seul sous-sudoku
+ *        Une grille de sudoku est un multidoku avec un seul sous-sudoku.
  */
 public class MultiDoku {
 
+	// <editor-fold defaultstate="collapsed" desc="ATTRIBUTS">
+
 	/**
 	 * Liste des sous-Sudoku contenue dans le multidoku.
 	 */
 	private final List<Sudoku> subGrids;
 
+	/**
+	 * Pile, qui contient des états du MultiDoku,
+	 * utile pour la résolution.
+	 */
+	private final StateManager stateManager;
+
+	// </editor-fold>
+
+	// <editor-fold defaultstate="collapsed" desc="METHODES">
+
 	public MultiDoku(List<Sudoku> subGrids) {
 		this.subGrids = subGrids;
-	}
-
-	public MultiDoku clone() {
-		//TODO: ahhhhhhhhhhhhhhhhhhhhhhh
-		return SudokuSerializer.deserializeSudoku(SudokuSerializer.serializeSudoku(this));
+		this.stateManager = new StateManager(this);
 	}
 
 	/**
-	 * Renvoie le nombre de sudoku contenu dans ce MultiDoku.
-	 * @return int
-	 */
-	public int getNbSubGrids(){
-		return subGrids.size();
-	}
-
-	/**
-	 * Renvoie la ie sudoku contenue dans ce MultiDoku.
-	 * @param i int, indice du sudoku à renvoyer.
-	 * @return Sudoku, ie Sudoku
-	 */
-	public Sudoku getSubGrid(int i){
-		return subGrids.get(i);
-	}
-
-	/**
-	 * Renvoie la liste des Cells contenue dans ce MultiDoku,
-	 * soit les Cells contenues de chaques sous-Sudoku.
-	 * @return List<Cell>
-	 */
-	public List<Cell> getCells(){
-		Set<Cell> cellsSet = new HashSet<>();
-		for (Sudoku sudoku : subGrids){
-			cellsSet.addAll(sudoku.getCells());
-		}
-        return new ArrayList<>(cellsSet);
-	}
-
-	/**
-	 * Met à jour les symboles possibles de chaque Cell.
-	 * @throws Exception, si ce n'est pas possible.
-	 */
-	public void updateSymbolsPossibilities() throws Exception {
-		for (Sudoku sudoku : subGrids){
-			sudoku.updateSymbolsPossibilities();
-		}
-	}
-
-	@Override
-	public String toString() {
-		StringBuilder sb = new StringBuilder();
-		sb.append("Multidoku {");
-		for (Sudoku sudoku : subGrids){
-			sb.append("\n\t").append(sudoku.toString());
-		}
-		sb.append("\n}");
-		return sb.toString();
-	}
-
-	/**
-	 * Renvoie les symboles possibles d'une Cell donnée.
-	 * @param cellToFill Cell.
-	 * @return List<Integer>, liste des symboles possible.
-	 */
-	public List<Integer> getPossibleSymbolsOfCell(Cell cellToFill) {
-		List<Integer> result = new ArrayList<>();
-		boolean hasBeenFill = false;
-
-        for (Sudoku sudoku : this.subGrids) {
-            if (sudoku.contains(cellToFill)) {
-                if (!hasBeenFill) {
-                    result.addAll(sudoku.getPossibleSymbolsOfCell(cellToFill));
-                    hasBeenFill = true;
-                } else {
-                    result.retainAll(sudoku.getPossibleSymbolsOfCell(cellToFill));
-                }
-            }
-        }
-		return result;
-	}
-
-	/**
-	 * Renvoie les sous-Sudoku
-	 * @return List<Sudoku>
-	 */
-	public List<Sudoku> getSubGrids() {
-		return this.subGrids;
-	}
-
-	/**
-	 * Check si le MultiDoku est valide, en fonction de ses sous-Sudokus.
-	 * @return boolean, true s'il est valide et false sinon.
+	 * Check si le MultiDoku est résolu, c'est à dire complet et cohérent avec ses contraintes. 
+	 * 
+	 * @return boolean, true s'il est résolu et false sinon.
 	 */
 	public boolean isSolved() {
-		boolean result = true;
 		for (Sudoku sudoku : this.subGrids) {
-			result = sudoku.isSolved() && result;
-		}
-		return result;
-	}
-
-	@Override
-	public boolean equals(Object object) {
-		if (!(object instanceof MultiDoku)) {
-			return false;
-		}
-
-		if (this.getNbSubGrids() != ((MultiDoku) object).getNbSubGrids()) {
-			return false;
-		}
-
-		for (int i = 0; i < this.getNbSubGrids(); i++) {
-			if (!this.getSubGrid(i).equals(((MultiDoku) object).getSubGrid(i))) {
+			if (!sudoku.isSolved())
 				return false;
-			}
 		}
-
 		return true;
 	}
 
-	/**
-	 * Renvoie la 1re Cell vide des sous-Sudoku.
-	 * @return Cell, une Cell vide, ou null s'il n'y en a pas.
-	 */
-	public Cell getFirstEmptyCell() {
-		for (Sudoku sudoku : this.subGrids) {
-			Cell cellTmp = sudoku.getFirstEmptyCell();
-			if (cellTmp != null && cellTmp.isEmpty()) {
-				return cellTmp;
-			}
-		}
-		return null;
-	}
-
 	/**
 	 * Renvoie la liste des Cells préalablement remplies du MultiDoku.
+	 * 
 	 * @return List<Cell>, vide si aucune Cell n'est remplie.
 	 */
 	public List<Cell> getFilledCells() {
 		List<Cell> result = new ArrayList<>();
-		for (Cell cell : this.getCells()){
+		for (Cell cell : this.getCells()) {
 			if (!cell.isEmpty()) {
 				result.add(cell);
 			}
@@ -170,11 +67,12 @@ public class MultiDoku {
 
 	/**
 	 * Renvoie la liste des Cells vides du MultiDoku.
+	 * 
 	 * @return List<Cell>, vide si aucune Cell ne l'est.
 	 */
 	public List<Cell> getEmptyCells() {
 		List<Cell> result = new ArrayList<>();
-		for (Cell cell : this.getCells()){
+		for (Cell cell : this.getCells()) {
 			if (cell.isEmpty()) {
 				result.add(cell);
 			}
@@ -182,19 +80,57 @@ public class MultiDoku {
 		return result;
 	}
 
+	/**
+	 * Renvoie la 1re Cell vide des sous-Sudoku.
+	 *
+	 * @return Cell, une Cell vide, ou null s'il n'y en a pas.
+	 */
+	public Cell getFirstEmptyCell() {
+		for (Sudoku sudoku : this.subGrids) {
+			Cell cellTmp = sudoku.getFirstEmptyCell();
+			if (cellTmp != null) {
+				return cellTmp;
+			}
+		}
+		return null;
+	}
 
 	/**
-	 * Vide une Cell donnée.
-	 * @param cell Cell, à vider.
+	 * Renvoie le nombre de sudoku contenu dans ce MultiDoku.
+	 *
+	 * @return int
 	 */
-	public void empty(Cell cell) {
-		List<Cell> cells = getCells();
-		Cell cellToEmpty = cells.get(cells.indexOf(cell));
-		cellToEmpty.setSymbolIndex(Cell.NOSYMBOL);
+	public int getNbSubGrids() {
+		return subGrids.size();
+	}
+
+	/**
+	 * Renvoie la ie sudoku contenue dans ce MultiDoku.
+	 *
+	 * @param i int, indice du sudoku à renvoyer.
+	 * @return Sudoku, ie Sudoku
+	 */
+	public Sudoku getSubGrid(int i) {
+		return subGrids.get(i);
+	}
+
+	/**
+	 * Renvoie la liste des Cells contenue dans ce MultiDoku,
+	 * soit les Cells contenues de chaques sous-Sudoku.
+	 *
+	 * @return List<Cell>
+	 */
+	public List<Cell> getCells() {
+		Set<Cell> cellsSet = new HashSet<>();
+		for (Sudoku sudoku : subGrids) {
+			cellsSet.addAll(sudoku.getCells());
+		}
+		return new ArrayList<>(cellsSet);
 	}
 
 	/**
 	 * Renvoie le nombre de Cell contenue dans le MultiDoku.
+	 * 
 	 * @return int, nombre de Cell dans le MultiDoku.
 	 */
 	public int getNbCells() {
@@ -209,5 +145,60 @@ public class MultiDoku {
 			filledCell.setImmutable();
 		}
 	}
-}
 
+	/**
+	 * Vide les Cells modifiable.
+	 */
+	public void clearMutableCells() {
+		for (Sudoku s : getSubGrids()) {
+			for (Cell cell : s.getCells()) {
+				if (cell.isMutable())
+					cell.clearCurrentSymbol();
+			}
+		}
+	}
+
+	/**
+	 * Renvoie les sous-Sudoku
+	 *
+	 * @return List<Sudoku>
+	 */
+	public List<Sudoku> getSubGrids() {
+		return this.subGrids;
+	}
+
+	public StateManager getStateManager() {
+		return stateManager;
+	}
+
+	@Override
+	public boolean equals(Object other) {
+		if (!(other instanceof MultiDoku otherDoku))
+			return false;
+		if (this.getNbSubGrids() != otherDoku.getNbSubGrids())
+			return false;
+		for (int i = 0; i < this.getNbSubGrids(); i++) {
+			Sudoku sudoku = this.getSubGrid(i);
+			Sudoku otherSudoku = otherDoku.getSubGrid(i);
+			if (sudoku.getSize() != otherSudoku.getSize())
+				return false;
+			for (int j = 0; j < sudoku.getSize() * sudoku.getSize(); j++) {
+				if (sudoku.getCell(j).getSymbolIndex() != otherSudoku.getCell(j).getSymbolIndex())
+					return false;
+			}
+		}
+		return true;
+	}
+
+	@Override
+	public String toString() {
+		return SudokuPrinter.printMultiDoku(this);
+	}
+
+	public MultiDoku clone() {
+		// TODO: C'est pas dingue de le faire comme ça...
+		return SudokuSerializer.deserializeSudoku(SudokuSerializer.serializeSudoku(this));
+	}
+
+	// </editor-fold>
+}

app/src/main/java/sudoku/structure/StateManager.java

@@ -0,0 +1,59 @@
+package sudoku.structure;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Stack;
+
+/**
+ * Une pile, qui réprésente les états d'un MultiDoku,
+ * utile pour les Solvers.
+ */
+public class StateManager {
+
+	/**
+	 * Le MultiDoku auquel il est associé.
+	 */
+	private final MultiDoku doku;
+
+	/**
+	 * La pile des états du MultiDoku associé.
+	 */
+	private final Stack<Map<Cell, Integer>> states;
+
+	public StateManager(MultiDoku doku) {
+		this.states = new Stack<>();
+		this.doku = doku;
+	}
+
+	public Map<Cell, Integer> pushState() {
+		states.add(saveState());
+		return states.getLast();
+	}
+
+	public void popState() {
+		assert (!states.isEmpty());
+		restoreState(states.pop());
+	}
+
+	public Map<Cell, Integer> popAndGetState() {
+		assert (!states.isEmpty());
+		var currentState = saveState();
+		restoreState(states.pop());
+		return currentState;
+	}
+
+	private void restoreState(Map<Cell, Integer> state) {
+		for (var entry : state.entrySet()) {
+			entry.getKey().setSymbolIndex(entry.getValue());
+		}
+	}
+
+	private Map<Cell, Integer> saveState() {
+		Map<Cell, Integer> state = new HashMap<>();
+		for (Cell cell : this.doku.getCells()) {
+			state.put(cell, cell.getSymbolIndex());
+		}
+		return state;
+	}
+
+}

app/src/main/java/sudoku/structure/Sudoku.java

@@ -1,36 +1,45 @@
 package sudoku.structure;
 
-import sudoku.constraint.BlockConstraint;
-import sudoku.constraint.Constraint;
-import sudoku.constraint.IConstraint;
-
 import java.util.ArrayList;
 import java.util.List;
 
+import sudoku.constraint.Constraint;
+import sudoku.constraint.IConstraint;
+
 /**
  * @class Sudoku
  * @brief Représent un Sudoku
  */
 public class Sudoku {
 
+	// <editor-fold defaultstate="collapsed" desc="ATTRIBUTS">
+
 	/**
 	 * Liste des Block contenus dans le Sudoku.
 	 */
 	private final List<Block> blocks;
+
 	/**
 	 * Liste des Cells contenus dans le Sudoku.
 	 */
-	private List<Cell> cells = new ArrayList<>();
+	private final List<Cell> cells;
+
 	/**
 	 * Liste des contraintes (TODO) du Sudoku.
 	 */
-	private final List<Constraint> constraints;
+	private final List<IConstraint> constraints;
+
 	/**
-	 * Largeur des Blocks s'ils sont rectangulaires, valant 0 si ce n'est pas le cas.
+	 * Largeur des Blocks s'ils sont rectangulaires,
+	 * valant 0 si ce n'est pas le cas.
 	 */
 	private int blockWidth;
 
-	public Sudoku(List<Cell> cells, List<Block> blocks, List<Constraint> constraints) {
+	// </editor-fold>
+
+	// <editor-fold defaultstate="collapsed" desc="METHODES">
+
+	public Sudoku(List<Cell> cells, List<Block> blocks, List<IConstraint> constraints) {
 		this.cells = cells;
 		this.blocks = blocks;
 		this.constraints = constraints;
@@ -48,6 +57,7 @@ public class Sudoku {
 
 	/**
 	 * Transforme des coordonées d'une Cell en index.
+	 * 
 	 * @param x int, abscisse.
 	 * @param y int, ordonnée.
 	 * @return int, index correspondant.
@@ -58,7 +68,9 @@ public class Sudoku {
 
 	/**
 	 * Vérifie que des coordonnées correspondent bien à une Cell dans le Sudoku.
-	 * @return boolean, valant true si les coordonnées sont dans les bornes du Sudoku, false sinon.
+	 * 
+	 * @return boolean, valant true si les coordonnées sont dans les bornes du
+	 *         Sudoku, false sinon.
 	 */
 	public boolean isValidCoords(int x, int y) {
 		int index = toIndex(x, y);
@@ -67,21 +79,25 @@ public class Sudoku {
 
 	/**
 	 * Vérifie que l'index correspond bien à une Cell dans le Sudoku.
-	 * @return boolean, valant true si l'index est dans les bornes du Sudoku, false sinon.
+	 * 
+	 * @return boolean, valant true si l'index est dans les bornes du Sudoku, false
+	 *         sinon.
 	 */
 	public boolean isValidCoords(int index) {
 		return index < getSize() * getSize();
 	}
 
 	/**
-	 * Teste si on peut placer la value dans la Cell aux coordonnées x, y d'après les contraintes du Sudoku.
+	 * Teste si on peut placer la value dans la Cell aux coordonnées x, y d'après
+	 * les contraintes du Sudoku.
+	 * 
 	 * @param x     int, abscisse de la Cell voulue.
 	 * @param y     int, ordonnée de la Cell voulue.
 	 * @param value int, index du symbole qu'on veut placer.
 	 * @return boolean, true si on peut la placer et false sinon.
 	 */
 	public boolean canBePlaced(int x, int y, int value) {
-		for (Constraint constraint : this.constraints) {
+		for (IConstraint constraint : this.constraints) {
 			if (!constraint.canBePlaced(this, x, y, value)) {
 				return false;
 			}
@@ -90,50 +106,84 @@ public class Sudoku {
 	}
 
 	/**
-	 * Tente de placer le symbole value dans la Cell de coordonnées x, y.
-	 * @param x     int, abscisse de la Cell voulue.
-	 * @param y     int, coordonnée de la Cell voulue;
-	 * @param value int, index du symbole que l'on veut placer.
-	 * @return boolean, true si le symbole a été placé, false sinon
+	 * Vérifie si le Sudoku est résolue, soit complet et cohérent avec ses
+	 * contraintes.
+	 *
+	 * @return boolean, valant true si le Sudoku est résolu, false sinon.
 	 */
-	public boolean tryPlaceCellSymbol(int x, int y, int value) {
-		assert (isValidCoords(x, y));
-		if (!canBePlaced(x, y, value))
-			return false;
-		Cell cell = getCell(x, y);
-		cell.setSymbolIndex(value);
+	public boolean isSolved() {
+		boolean isComplete = isComplete();
+		boolean isValid = isValid();
+		return isComplete && isValid;
+	}
+
+	/**
+	 * Vérifie que le Sudoku est complet, soit qu'il n'y ait aucune case vide.
+	 *
+	 * @return boolean, true si le Sudoku est complet, false sinon.
+	 */
+	private boolean isComplete() {
+		return getFirstEmptyCell() == null;
+	}
+
+	/**
+	 * Vérifie si le Sudoku est valide, soit qu'il est cohérent avec ses
+	 * contraintes.
+	 *
+	 * @return bollean, true si le Sudoku est valide, false sinon
+	 */
+	private boolean isValid() {
+		for (int i = 0; i < cells.size(); i++) {
+			Cell cell = getCell(i);
+			if (cell.isEmpty())
+				continue;
+
+			Coordinate coordinate = toCoords(i);
+
+			int symbolPlaced = cell.empty();
+			if (!canBePlaced(coordinate.getX(), coordinate.getY(), symbolPlaced)) {
+				cell.setSymbolIndex(symbolPlaced);
+				return false;
+			}
+			cell.setSymbolIndex(symbolPlaced);
+		}
 		return true;
 	}
 
 	/**
-	 * Vide la Cell dotn les coordonnées sont renseignées de son symbole.
-	 * @param x int, abscisse de la Cell voulue.
-	 * @param y int, coordonnée de la Cell voulue.
+	 * Renvoie la Cell aux coordonées données.
+	 *
+	 * @param x int, abscisse.
+	 * @param y int, ordonnée.
+	 * @return Cell, si une Cell existe aux coordonnées données, null sinon.
 	 */
-
-	public void clearCell(int x, int y) {
+	public Cell getCell(int x, int y) {
+		int index = toIndex(x, y);
 		assert (isValidCoords(x, y));
-		Cell cell = getCell(x, y);
-		cell.setSymbolIndex(Cell.NOSYMBOL);
-	}
-
-	/**
-	 * Vide toutes les Cell du Sudoku.
-	 */
-	public void clear() {
-		for (int i = 0; i < getSize() * getSize(); i++) {
-			Cell cell = getCell(i);
-			if (cell.isMutable())
-				cell.setSymbolIndex(Cell.NOSYMBOL);
+		try {
+			return this.cells.get(index);
+		} catch (IndexOutOfBoundsException e) {
+			return null;
 		}
 	}
 
-	public int getBlockWidth() {
-		return blockWidth;
+	/**
+	 * Renvoie la 1re Cell vide du Sudoku.
+	 *
+	 * @return Cell, une Cell vide, ou null s'il n'y en a pas.
+	 */
+	public Cell getFirstEmptyCell() {
+		for (Cell cell : this.cells) {
+			if (cell.isEmpty()) {
+				return cell;
+			}
+		}
+		return null;
 	}
 
 	/**
 	 * Place le symbole d'index value dans la Cell de coordonnées précisées.
+	 * 
 	 * @param x     int, abscisse de la Cell voulue.
 	 * @param y     int, coordonnée de la Cell voulue.
 	 * @param value int, index du symbole à placer.
@@ -141,7 +191,7 @@ public class Sudoku {
 	 */
 	public Cell setCellSymbol(int x, int y, int value) {
 		assert (isValidCoords(x, y));
-		for (Constraint constraint : this.constraints) {
+		for (IConstraint constraint : this.constraints) {
 			if (!constraint.canBePlaced(this, x, y, value)) {
 				return null;
 			}
@@ -153,6 +203,7 @@ public class Sudoku {
 
 	/**
 	 * Place les symboles d'index contenus dans values dans les cases du Sudoku.
+	 * 
 	 * @param values List<Integer>, liste des index des symboles à placer.
 	 * @return boolean, vaut true si les symboles ont été placés, false sinon.
 	 */
@@ -170,7 +221,9 @@ public class Sudoku {
 	}
 
 	/**
-	 * Place les symboles d'index contenus dans values dans les cases du Sudoku et rend ces cases immuables.
+	 * Place les symboles d'index contenus dans values dans les cases du Sudoku et
+	 * rend ces cases immuables.
+	 * 
 	 * @param values List<Integer>, liste des index des symboles à placer.
 	 * @return boolean, vaut true si les symboles ont été placés, false sinon.
 	 */
@@ -193,24 +246,14 @@ public class Sudoku {
 		return true;
 	}
 
-	public Cell getCell(int x, int y) {
-		int index = y * getSize() + x;
-		assert (isValidCoords(x, y));
-		try {
-			return this.cells.get(index);
-		} catch (IndexOutOfBoundsException e) {
-			return null;
-		}
+	public boolean hasConstraint(Constraint constraint) {
+		return this.constraints.contains(constraint.getConstraint());
 	}
 
 	public Cell getCell(int i) {
 		return this.cells.get(i);
 	}
 
-	public List<Constraint> getConstraints() {
-		return constraints;
-	}
-
 	public int getSize() {
 		return this.blocks.size();
 	}
@@ -223,71 +266,19 @@ public class Sudoku {
 		return this.blocks;
 	}
 
-	/**
-	 * Vérifie si une Cell appartient au Sudoku.
-	 * @param cell Cell, cellule dont on veut vérifier l'appartenance au Sudoku.
-	 * @return boolean, vaut true si la Cell appartient au Sudoku.
-	 */
-	public boolean contains(Cell cell) {
-		return this.cells.contains(cell);
+	public List<IConstraint> getConstraints() {
+		return constraints;
 	}
 
-	/**
-	 * Localise la Cell dans le Sudoku.
-	 * @param c Cell, cellule dont on veut les coordonées.
-	 * @return Coordinate, coordonnées de la Cell.
-	 * @throws Exception si la Cell n'appartient pas au Sudoku.
-	 */
-	private Coordinate getCoordinateCell(Cell c) throws Exception {
-		int x = 0, y = 0;
-		int size = this.getSize();
-
-		if (!this.contains(c)) {
-			throw new Exception("The given cell is not in this sudoku.");
-		}
-
-		// TODO: use this.cells.indexOf();
-
-		for (Cell cell : this.cells) {
-			if (cell == c) {
-				return new Coordinate(x, y);
-			}
-			if (x == size - 1) {
-				y += 1;
-				x = 0;
-			} else {
-				x += 1;
-			}
-		}
-		return new Coordinate(x, y);
+	public int getBlockWidth() {
+		return blockWidth;
 	}
 
-	/**
-	 * Met à jour les symboles possibles des Cells du Sudoku.
-	 *
-	 */
-	public void updateSymbolsPossibilities() {
-		for (Constraint constraint : constraints) {
-			List<Cell> cells = this.getCells();
-			for (Cell cell : cells) {
-				Coordinate coord = null;
-				try {
-					coord = this.getCoordinateCell(cell);
-				} catch (Exception e) {
-					System.out.println("Cas jamais atteint.");
-				}
-				List<Integer> newPossibleSymbols = cell.getPossibleSymbols();
-				newPossibleSymbols.retainAll(constraint.getPossibleSymbols(
-                        this,
-                        coord.getX(),
-                        coord.getY()
-                ));
-
-				cell.setPossibleSymbols(newPossibleSymbols);
-			}
-		}
+	public void setBlockWidth(int blockWidth) {
+		this.blockWidth = blockWidth;
 	}
 
+	@Override
 	public String toString() {
 		StringBuilder sb = new StringBuilder();
 		sb.append("Sudoku {");
@@ -302,158 +293,6 @@ public class Sudoku {
 		return sb.toString();
 	}
 
-	/**
-	 * Renvoie la 1re Cell vide du Sudoku.
-	 * @return Cell, une Cell vide, ou null s'il n'y en a pas.
-	 */
-	public Cell getFirstEmptyCell() {
-		for (Cell cell : this.cells) {
-			if (cell.isEmpty()) {
-				return cell;
-			}
-		}
-		return null;
-	}
-
-	/**
-	 * Renvoie l'index des symboles possibles de la Cell passée en paramètres.
-	 * @param cellToFill Cell, cellule dont on cherche les symboles posisbles.
-	 * @return List<Integer>, la liste des index des symboles possibles, vide si la Cell n'appartient pas au Sudoku.
-	 */
-	public List<Integer> getPossibleSymbolsOfCell(Cell cellToFill) {
-		List<Integer> result = new ArrayList<>();
-		Coordinate cellCoordinates;
-		try {
-			cellCoordinates = this.getCoordinateCell(cellToFill);
-		} catch (Exception e) {
-			return result;
-		}
-		for (int i = 0; i < this.constraints.size(); i++) {
-			Constraint constraint = this.constraints.get(i);
-			if (i == 0) {
-				result.addAll(constraint.getPossibleSymbols(this, cellCoordinates.getX(), cellCoordinates.getY()));
-			} else {
-				result.retainAll(constraint.getPossibleSymbols(this, cellCoordinates.getX(), cellCoordinates.getY()));
-			}
-		}
-		return result;
-	}
-
-	/**
-	 * Vérifie si le Sudoku est résolue, soit complet et cohérent avec ses contraintes.
-	 * @return boolean, valant true si le Sudoku est résolu, false sinon.
-	 */
-	public boolean isSolved() {
-		boolean isComplete = isComplete();
-		boolean isValid = isValid();
-		return isComplete && isValid;
-	}
-
-	/**
-	 * Vérifie que le Sudoku est complet, soit qu'il n'y ait aucune case vide.
-	 * @return boolean, true si le Sudoku est complet, false sinon.
-	 */
-	private boolean isComplete() {
-		return getFirstEmptyCell() == null;
-	}
-
-	/**
-	 * Vérifie si le Sudoku est valide, soit qu'il est cohérent avec ses contraintes.
-	 * @return bollean, true si le Sudoku est valide, false sinon
-	 */
-	private boolean isValid() {
-		for (Cell cell : this.getFilledCells()) {
-			for (Constraint constraint : this.constraints) {
-				try {
-					Coordinate coords = this.getCoordinateCell(cell);
-
-					int symbolPlaced = cell.empty();
-					List<Integer> possibleSymbols = constraint.getPossibleSymbols(
-							this,
-							coords.getX(),
-							coords.getY()
-					);
-
-					cell.setSymbolIndex(symbolPlaced);
-					if (!possibleSymbols.contains(symbolPlaced)) {
-						return false;
-					}
-
-				} catch (Exception e) {
-					throw new RuntimeException(e);
-				}
-			}
-		}
-		return true;
-	}
-
-	/**
-	 * Renvoie la liste des Cells remplies.
-	 * @return List<Cell>
-	 */
-	private List<Cell> getFilledCells() {
-		List<Cell> result = new ArrayList<>();
-		for (Cell cell : getCells()) {
-			if (!cell.isEmpty()) {
-				result.add(cell);
-			}
-		}
-		return result;
-	}
-
-	/**
-	 * Renvoie la liste des Cells modifiables.
-	 * @return List<Cell>
-	 */
-	private List<Cell> getEmptyCells() {
-		List<Cell> result = new ArrayList<>();
-		for (Cell cell : getCells()) {
-			if (cell.isMutable()) {
-				result.add(cell);
-			}
-		}
-		return result;
-	}
-
-	/**
-	 * Renvoie la liste des Cells immuables.
-	 * @return List<Cell>
-	 */
-	private List<Cell> getImmutableCells() {
-		List<Cell> result = new ArrayList<>();
-		for (Cell cell : getCells()) {
-			if (!cell.isMutable()) {
-				result.add(cell);
-			}
-		}
-		return result;
-	}
-
-	@Override
-	public boolean equals(Object object) {
-		if (!(object instanceof Sudoku)) {
-			return false;
-		}
-
-		if (this.getSize() != ((Sudoku) object).getSize()) {
-			return false;
-		}
-
-		for (int i = 0; i < this.getSize(); i++) {
-			if (this.getCell(i).getSymbolIndex() != ((Sudoku) object).getCell(i).getSymbolIndex()) {
-				return false;
-			}
-		}
-
-		return true;
-	}
-
-	public void setBlockWidth(int blockWidth) {
-		this.blockWidth = blockWidth;
-	}
-
-	public boolean hasConstraint(Constraint constraint) {
-		return this.constraints.contains(constraint);
-	}
+	// <editor-fold defaultstate="collapsed" desc="METHODES">
 
 }

app/src/main/java/sudoku/structure/SudokuFactory.java

@@ -9,14 +9,10 @@ import java.util.List;
 import java.util.Map;
 import java.util.Random;
 
-import sudoku.io.SudokuSerializer;
-
-import sudoku.constraint.BlockConstraint;
-import sudoku.constraint.ColumnConstraint;
 import sudoku.constraint.Constraint;
-import sudoku.constraint.DiagonalConstraint;
 import sudoku.constraint.IConstraint;
-import sudoku.constraint.LineConstraint;
+import sudoku.io.SudokuSerializer;
+import sudoku.solver.RandomSolver;
 import sudoku.solver.Solver;
 
 public class SudokuFactory {
@@ -30,11 +26,16 @@ public class SudokuFactory {
 	 * Liste des contraintes par défaut d'un Multi- ou Sudoku.
 	 * Comprend les contraintes de blocs, de lignes, et de colonnes.
 	 */
-	public static List<Constraint> DEFAULT_CONSTRAINTS = Arrays.asList(Constraint.Block, Constraint.Column,
-			Constraint.Line);
+	public static List<IConstraint> DEFAULT_CONSTRAINTS = SudokuFactory
+			.fromConstraints(Arrays.asList(
+					Constraint.Block,
+					Constraint.Column,
+					Constraint.Line)
+			);
 
 	/**
 	 * Créée des Cells et les met dans une liste de taille size.
+	 * 
 	 * @param size int, nombre de Cells à initialiser.
 	 * @return List<Cell>, liste des Cells initialisées.
 	 */
@@ -47,9 +48,11 @@ public class SudokuFactory {
 	}
 
 	/**
-	 * Créée des Blocks de taille width par height à partir des cellules données, et les met dans une liste.
-	 * @param cells List<Cell>, liste des Cells à découper en Blocks.
-	 * @param width int, largeur des Blocks à créer.
+	 * Créée des Blocks de taille width par height à partir des cellules données, et
+	 * les met dans une liste.
+	 * 
+	 * @param cells  List<Cell>, liste des Cells à découper en Blocks.
+	 * @param width  int, largeur des Blocks à créer.
 	 * @param height int, hauteur des Blocks à créer.
 	 * @return List<Block>, liste des Blocks créés.
 	 */
@@ -65,9 +68,6 @@ public class SudokuFactory {
 					int index = ((y + blockY * height) * size + (x + blockX * width));
 					Cell blockCell = cells.get(index);
 					blockCell.setBlock(newBlock);
-					// List<Block> blockContainers = new ArrayList<>();
-					// blockContainers.add(newBlock);
-					// blockCell.setBlockContainers(blockContainers);
 					newBlock.addCell(blockCell);
 				}
 			}
@@ -77,91 +77,37 @@ public class SudokuFactory {
 	}
 
 	/**
-	 * Créée un MultiDoku vide dont les Blocks sont de taille widthBlock par heightBlock.
-	 * @param widthBlock int, largeur des Blocks.
+	 * Créée un MultiDoku vide dont les Blocks sont de taille widthBlock par
+	 * heightBlock.
+	 * 
+	 * @param widthBlock  int, largeur des Blocks.
 	 * @param heightBlock int, hauteur des Blocks.
 	 * @return MultiDoku, MultiDoku vide.
 	 */
 	public static MultiDoku createBasicEmptyRectangleDoku(int widthBlock, int heightBlock,
-			List<Constraint> constraints) {
-		return new MultiDoku(Arrays.asList(createRectangleSudoku(widthBlock, heightBlock, constraints)));
+			List<IConstraint> constraints) {
+		return new MultiDoku(List.of(createRectangleSudoku(widthBlock, heightBlock, constraints)));
 	}
 
 	/**
 	 * Créée un MultiDoku vide dont les Blocks sont carrés de longueur size.
+	 * 
 	 * @param size int, taille des Blocks.
 	 * @return MultiDoku, MultiDoku vide.
 	 */
-	public static MultiDoku createBasicEmptySquareDoku(int size, List<Constraint> constraints) {
-		return new MultiDoku(Arrays.asList(createSquareSudoku(size, constraints)));
+	public static MultiDoku createBasicEmptySquareDoku(int size, List<IConstraint> constraints) {
+		return new MultiDoku(List.of(createSquareSudoku(size, constraints)));
 	}
 
 	/**
-	 * Place des Cells immutables de valeurs fournies, aux Coordinate fournies dans le MultiDoku doku fourni.
-	 * @param doku           MultiDoku, MultiDoku à remplir.
-	 * @param immutableCells Map<Coordinate, Integer>, association de Coordinate coordonnées et Integer valeurs, correspondant aux cases à remplir.
-	 */
-	public static void setImmutableCells(MultiDoku doku, Map<Coordinate, Integer> immutableCells) {
-		immutableCells.forEach((coordinate, symbol) -> {
-			for (Sudoku sudoku : doku.getSubGrids()) {
-				Cell cell = sudoku.getCell(coordinate.getX(), coordinate.getY());
-				if (cell != null) {
-					cell.setSymbolIndex(symbol);
-					cell.setImmutable();
-				}
-			}
-		});
-	}
-
-	/**
-	 * Créée un MultiDoku de difficulté difficulty à partir d'un MultiDoku fourni.
+	 * Créée un Sudoku vide dont les Blocks sont de taille widthBlock par
+	 * heightBlock.
 	 * 
-	 * @param doku           MultiDoku, MultiDoku dont on doit vider des Cells.
-	 * @param nbCellsToEmpty int, nombre de cases à retirer.
-	 * @return boolean, valant true si un MultiDoku de difficulté donnée peut être créée, false sinon.
-	 * @throws Exception si la difficulté n'est pas compatible avec la taille du MultiDoku.
-	 */
-	public static boolean newDokuFromFilledOne(MultiDoku doku, int nbCellsToEmpty) throws Exception {
-
-		System.out.println("nbCellsToEmpty : "+nbCellsToEmpty);
-		if (nbCellsToEmpty >= doku.getCells().size()) {
-			throw new Exception();
-		}
-
-		if (nbCellsToEmpty == 0) {
-			return true;
-		}
-
-		List<Cell> cellsThatCanBeEmptied = doku.getFilledCells();
-
-		while (!cellsThatCanBeEmptied.isEmpty()) {
-			int index = random.nextInt(cellsThatCanBeEmptied.size());
-			Cell cellToEmpty = cellsThatCanBeEmptied.get(index);
-
-			int oldSymbol = cellToEmpty.empty();
-
-			int nbDokuSultions = Solver.countSolution(doku);
-			System.out.println("oldSymbol : "+oldSymbol);
-			if (nbDokuSultions == 1) {
-				if (newDokuFromFilledOne(doku, --nbCellsToEmpty)) {
-					return true;
-				}
-			}
-
-			cellToEmpty.setSymbolIndex(oldSymbol);
-			cellsThatCanBeEmptied.remove(cellToEmpty);
-		}
-
-		return false;
-	}
-
-	/**
-	 * Créée un Sudoku vide dont les Blocks sont de taille widthBlock par heightBlock.
 	 * @param widthBlock  int, largeur des Blocks.
 	 * @param heightBlock int, hauteur des Blocks.
 	 * @return Sudoku, Sudoku vide.
 	 */
-	private static Sudoku createRectangleSudoku(int widthBlock, int heightBlock, List<Constraint> constraints) {
+	private static Sudoku createRectangleSudoku(int widthBlock, int heightBlock, List<IConstraint> constraints) {
 		int symbolCount = widthBlock * heightBlock;
 		List<Cell> cases = initCells(symbolCount);
 		List<Block> blocs = initRectangleBlocs(cases, widthBlock, heightBlock);
@@ -175,34 +121,37 @@ public class SudokuFactory {
 
 	/**
 	 * Créée un Sudoku vide dont les Blocks sont carrés de longueur size.
+	 * 
 	 * @param size int, taille des Blocks.
 	 * @return Sudoku, Sudoku vide.
 	 */
-	private static Sudoku createSquareSudoku(int size, List<Constraint> constraints) {
+	private static Sudoku createSquareSudoku(int size, List<IConstraint> constraints) {
 		return createRectangleSudoku(size, size, constraints);
 	}
 
 	/**
 	 * Connecte deux Sudokus selon la décalage offset fourni.
+	 * 
 	 * @param sudoku1 Sudoku, premier sudoku à connecter.
 	 * @param sudoku2 Sudoku, second sudoku à connecter.
 	 * @param offset  Coordinate, décalage entre les deux Sudokus.
 	 */
-	private static void linkSquareSudokus(Sudoku sudoku1, Sudoku sudoku2, Coordinate offset) {
+	private static void linkRectangleSudokus(Sudoku sudoku1, Sudoku sudoku2, Coordinate offset) {
 		int blockWidth = sudoku1.getBlockWidth();
-		for (int dx = 0; dx < blockWidth; dx++) {
+		int blockHeight = sudoku1.getSize() / blockWidth;
+		for (int dx = 0; dx < blockHeight; dx++) {
 			for (int dy = 0; dy < blockWidth; dy++) {
 				int block1X = dx + offset.getX();
 				int block1Y = dy + offset.getY();
 				int block2X = dx;
 				int block2Y = dy;
 
-				if ((block1X < blockWidth) && (block1X >= 0) && (block1Y >= 0) && (block1Y < blockWidth)) {
-					Block block1 = sudoku1.getBlocks().get(block1Y * blockWidth + block1X);
-					Block block2 = sudoku2.getBlocks().get(block2Y * blockWidth + block2X);
+				if ((block1X < blockHeight) && (block1X >= 0) && (block1Y >= 0) && (block1Y < blockWidth)) {
+					Block block1 = sudoku1.getBlocks().get(block1Y * blockHeight + block1X);
+					Block block2 = sudoku2.getBlocks().get(block2Y * blockHeight + block2X);
 
 					// on remplace le bloc
-					sudoku2.getBlocks().set(block2Y * blockWidth + block2X, block1);
+					sudoku2.getBlocks().set(block2Y * blockHeight + block2X, block1);
 					block1.getSudokus().add(sudoku2);
 
 					// on remplace les cellules
@@ -219,83 +168,205 @@ public class SudokuFactory {
 	}
 
 	/**
-	 * Créée un MultiDoku de Blocks carrés de taille size composé de cinq Sudokus, dont un central qui partage chacun de ses Blockss d'angle avec un autre Sudoku.
+	 * Créée un MultiDoku de Blocks carrés de taille size composé de cinq Sudokus,
+	 * dont un central qui partage chacun de ses Blockss d'angle avec un autre
+	 * Sudoku.
+	 * 2 3
+	 *  1
+	 * 4 5
+	 *
 	 * @param size int, largeur des Blocks unitraires des Sudokus à crééer.
 	 * @return MultiDoku, MultiDoku de forme X.
 	 */
-	public static MultiDoku createBasicXShapedMultidoku(int size, List<Constraint> constraints) {
+	public static MultiDoku createBasicXShapedMultidoku(int size, List<IConstraint> constraints) {
 		assert (size > 1);
 
-		/*
-		 * 2 3
-		 *  1
-		 * 4 5
-		 */
-
-		Sudoku sudoku1 = createSquareSudoku(size, constraints);
-		Sudoku sudoku2 = createSquareSudoku(size, constraints);
-		Sudoku sudoku3 = createSquareSudoku(size, constraints);
-		Sudoku sudoku4 = createSquareSudoku(size, constraints);
-		Sudoku sudoku5 = createSquareSudoku(size, constraints);
-
-		linkSquareSudokus(sudoku1, sudoku2, new Coordinate(1 - size, 1 - size));
-		linkSquareSudokus(sudoku1, sudoku3, new Coordinate(size - 1, 1 - size));
-		linkSquareSudokus(sudoku1, sudoku4, new Coordinate(1 - size, size - 1));
-		linkSquareSudokus(sudoku1, sudoku5, new Coordinate(size - 1, size - 1));
-
-		return new MultiDoku(Arrays.asList(sudoku1, sudoku2, sudoku3, sudoku4, sudoku5));
+		return createBasicXShapedMultidoku(size, size, constraints);
 	}
 
 	/**
-	 * Créée un MultiDoku de Blocks rectangulaires de forme width par height composé de cinq Sudokus,
+	 * Créée un MultiDoku de Blocks rectangulaires de forme X, de taille width par height composé
+	 * de cinq Sudokus,
 	 * dont un central qui partage chacun de ses Blocks d'angle avec un autre
 	 * Sudoku.
+	 * 2 3
+	 *  1
+	 * 4 5
 	 *
-	 * @param width int, largeur des Blocks unitraires des Sudokus à crééer.
-	 * @param height int, hauteur des Blocks unitraires des Sudokus à crééer.
+	 * @param width  int, largeur des Blocks unitaires des Sudokus à crééer.
+	 * @param height int, hauteur des Blocks unitaires des Sudokus à crééer.
 	 * @return MultiDoku, MultiDoku de forme X.
 	 */
-	public static MultiDoku createBasicXShapedMultidoku(int width, int height, List<Constraint> constraints) {
+	public static MultiDoku createBasicXShapedMultidoku(int width, int height, List<IConstraint> constraints) {
 		assert (width > 1 && height > 1);
 
-		/*
-		 * 2 3
-		 * 1
-		 * 4 5
-		 */
-
 		Sudoku sudoku1 = createRectangleSudoku(width, height, constraints);
 		Sudoku sudoku2 = createRectangleSudoku(width, height, constraints);
 		Sudoku sudoku3 = createRectangleSudoku(width, height, constraints);
 		Sudoku sudoku4 = createRectangleSudoku(width, height, constraints);
 		Sudoku sudoku5 = createRectangleSudoku(width, height, constraints);
 
-		linkSquareSudokus(sudoku1, sudoku2, new Coordinate(1 - width, 1 - height));
-		linkSquareSudokus(sudoku1, sudoku3, new Coordinate(width - 1, 1 - height));
-		linkSquareSudokus(sudoku1, sudoku4, new Coordinate(1 - width, height - 1));
-		linkSquareSudokus(sudoku1, sudoku5, new Coordinate(width - 1, height - 1));
+		linkRectangleSudokus(sudoku1, sudoku2, new Coordinate(1 - height, 1 - width));
+		linkRectangleSudokus(sudoku1, sudoku3, new Coordinate(height - 1, 1 - width));
+		linkRectangleSudokus(sudoku1, sudoku4, new Coordinate(1 - height, width - 1));
+		linkRectangleSudokus(sudoku1, sudoku5, new Coordinate(height - 1, width - 1));
 
 		return new MultiDoku(Arrays.asList(sudoku1, sudoku2, sudoku3, sudoku4, sudoku5));
 	}
 
-	public static void fillDoku(MultiDoku doku, Difficulty difficulty) throws Exception {
-		Solver.solveRandom(doku, random);
-		int nbCellsToEmpty = (int) (difficulty.getFactor() * doku.getNbCells());
-		boolean successfull = newDokuFromFilledOne(doku, nbCellsToEmpty);
-		if (!successfull) {
-			throw new Exception("Canno't create this doku with this difficulty");
+	/**
+	 * Créée un MultiDoku de Blocks carrés de forme +, de taille size composé
+	 * de cinq Sudokus,
+	 * dont un central qui partage chacun de ses Blocks de bord avec un autre
+	 * Sudoku.
+	 *   3
+	 * 2 1 4
+	 *   5
+	 *
+	 * @param size  int, largeur des Blocks unitaires des Sudokus à crééer.
+	 * @return MultiDoku, MultiDoku de forme +.
+	 */
+	public static MultiDoku createBasicPlusShapedMultidoku(int size, List<IConstraint> constraints) {
+		assert (size > 1);
+
+		return createBasicPlusShapedMultidoku(size, size, constraints);
+	}
+
+	/**
+	 * Créée un MultiDoku de Blocks rectangulaires de forme +, de taille width par height composé
+	 * de cinq Sudokus,
+	 * dont un central qui partage chacun de ses Blocks de bord avec un autre
+	 * Sudoku.
+	 *   3
+	 * 2 1 4
+	 *   5
+	 *
+	 * @param width  int, largeur des Blocks unitaires des Sudokus à crééer.
+	 * @param height int, hauteur des Blocks unitaires des Sudokus à crééer.
+	 * @return MultiDoku, MultiDoku de forme +.
+	 */
+	public static MultiDoku createBasicPlusShapedMultidoku(int width, int height, List<IConstraint> constraints) {
+		assert (width > 1 && height > 1);
+
+		Sudoku sudoku1 = createRectangleSudoku(width, height, constraints);
+		Sudoku sudoku2 = createRectangleSudoku(width, height, constraints);
+		Sudoku sudoku3 = createRectangleSudoku(width, height, constraints);
+		Sudoku sudoku4 = createRectangleSudoku(width, height, constraints);
+		Sudoku sudoku5 = createRectangleSudoku(width, height, constraints);
+
+		linkRectangleSudokus(sudoku1, sudoku2, new Coordinate(1 - height, 0));
+		linkRectangleSudokus(sudoku1, sudoku3, new Coordinate(0, 1 - width));
+		linkRectangleSudokus(sudoku1, sudoku4, new Coordinate(height - 1, 0));
+		linkRectangleSudokus(sudoku1, sudoku5, new Coordinate(0, width - 1));
+
+		return new MultiDoku(Arrays.asList(sudoku1, sudoku2, sudoku3, sudoku4, sudoku5));
+	}
+
+	/**
+	 * Crée un Sudoku vide avec les Blocks aléatoires.
+	 *
+	 * @param blockSize int, la taille des Block.
+	 * @param constraints List<IConstraint>, la liste des contraintes.
+	 * @return MultiDoku, avec un seul Sudoku.
+	 */
+	public static MultiDoku createBasicEmptyRandomBlockDoku(int blockSize, List<IConstraint> constraints) {
+		int blockCellCount = blockSize * blockSize;
+		List<Cell> cells = initCells(blockCellCount);
+        List<Cell> homeLessCells = new ArrayList<>(cells);
+		List<Block> blocks = new ArrayList<>();
+		Random r = new Random();
+		for (int i = 0; i < blockCellCount; i++) {
+			Block b = new Block();
+			for (int j = 0; j < blockCellCount; j++) {
+				int cellIndex = r.nextInt(homeLessCells.size());
+				Cell cell = homeLessCells.remove(cellIndex);
+				b.addCell(cell);
+				cell.setBlock(b);
+			}
+			blocks.add(b);
 		}
+		Sudoku sudoku = new Sudoku(cells, blocks, constraints);
+		for (Block block : blocks) {
+			block.getSudokus().add(sudoku);
+		}
+		return new MultiDoku(List.of(sudoku));
+	}
+
+	/**
+	 * Créée un MultiDoku de difficulté difficulty à partir d'un MultiDoku fourni.
+	 *
+	 * @param doku           MultiDoku, MultiDoku dont on doit vider des Cells.
+	 * @param nbCellsToEmpty int, nombre de cases à retirer.
+	 * @return boolean, valant true si un MultiDoku de difficulté donnée peut être
+	 *         créée, false sinon.
+	 * @throws Exception si la difficulté n'est pas compatible avec la taille du
+	 *                   MultiDoku.
+	 */
+	public static boolean newDokuFromFilledOne(MultiDoku doku, int nbCellsToEmpty, Solver solver) throws Exception {
+
+		if (nbCellsToEmpty >= doku.getCells().size()) {
+			throw new Exception();
+		}
+
+		if (nbCellsToEmpty == 0) {
+			return true;
+		}
+
+		List<Cell> cellsThatCanBeEmptied = doku.getFilledCells();
+
+		int index = random.nextInt(cellsThatCanBeEmptied.size());
+		Cell cellToEmpty = cellsThatCanBeEmptied.get(index);
+
+		cellToEmpty.empty();
+
+		int nbDokuSultions = solver.countSolution(doku);
+		if (nbDokuSultions == 1) {
+            return newDokuFromFilledOne(doku, --nbCellsToEmpty, solver);
+		}
+
+		return false;
+	}
+
+	/**
+	 * Remplit un MultiDoku donné par rapport à une difficulté.
+	 *
+	 * @param doku MultiDoku, vide.
+	 * @param difficulty Difficulty, qui correspond au pourcentage de cases à enlever.
+     */
+	public static void fillDoku(MultiDoku doku, Difficulty difficulty) throws Exception {
+		Solver solver = new RandomSolver();
+		solver.solve(doku);
+		int nbCellsToEmpty = (int) (difficulty.getFactor() * doku.getNbCells());
+		newDokuFromFilledOne(doku, nbCellsToEmpty, solver);
 		doku.setFilledCellsImmutable();
 	}
 
+	/**
+	 * Génère un MultiDoku à partir d'un fichier de sauvegarde.
+	 *
+	 * @param filePath String, chemin du fichier.
+	 * @return MultiDoku.
+	 */
 	public static MultiDoku fromfile(String filePath) {
 		try {
 			String content = Files.readString(Paths.get(filePath));
-			MultiDoku doku = SudokuSerializer.deserializeSudoku(content);
-			return doku;
+            return SudokuSerializer.deserializeSudoku(content);
 		} catch (IOException e) {
 			e.printStackTrace();
 			return null;
 		}
 	}
+
+	/**
+	 * Transforme des Constraint en IConstraint correspondants
+	 * @param constraints List<Constraints>
+	 * @return List<IConstraints>
+	 */
+	public static List<IConstraint> fromConstraints(List<Constraint> constraints) {
+		List<IConstraint> iconstraints = new ArrayList<>();
+		for (Constraint cons : constraints) {
+			iconstraints.add(cons.getConstraint());
+		}
+		return iconstraints;
+	}
 }

app/src/test/java/sudoku/SudokuSerializerTest.java

@@ -1,5 +1,7 @@
 package sudoku;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
 import java.io.File;
 import java.util.Random;
 
@@ -7,58 +9,71 @@ import org.json.JSONObject;
 import org.junit.jupiter.api.Test;
 
 import sudoku.io.SudokuSerializer;
-import sudoku.solver.Solver;
+import sudoku.solver.RandomSolver;
 import sudoku.structure.MultiDoku;
 import sudoku.structure.SudokuFactory;
 
 public class SudokuSerializerTest {
 
-    void testSerializeWithSize(int blockWidth, int blockHeight, Random r) {
-        MultiDoku sudoku = SudokuFactory.createBasicEmptyRectangleDoku(blockWidth, blockHeight,
+    void testSerializeWithSize(int blockWidth, int blockHeight) {
+        var sudoku = SudokuFactory.createBasicEmptyRectangleDoku(blockWidth, blockHeight,
                 SudokuFactory.DEFAULT_CONSTRAINTS);
-        Solver.solveRandom(sudoku, r);
+        new RandomSolver().solve(sudoku);
         JSONObject data = SudokuSerializer.serializeSudoku(sudoku);
         MultiDoku multiDoku = SudokuSerializer.deserializeSudoku(data);
-        assert (data.toString().equals(SudokuSerializer.serializeSudoku(multiDoku).toString()));
+        assertEquals(data.toString(), SudokuSerializer.serializeSudoku(multiDoku).toString());
     }
 
-    void testSaveWithSize(int blockWidth, int blockHeight, Random r) {
+    void testSaveWithSize(int blockWidth, int blockHeight) {
         MultiDoku doku = SudokuFactory.createBasicEmptyRectangleDoku(blockWidth, blockHeight,
                 SudokuFactory.DEFAULT_CONSTRAINTS);
-        Solver.solveRandom(doku, r);
+        new RandomSolver().solve(doku);
         String savePath = SudokuSerializer.saveMultiDoku(doku);
         MultiDoku otherDoku = null;
         try {
             otherDoku = SudokuFactory.fromfile(savePath);
             assert (otherDoku != null);
+
+            assertEquals(SudokuSerializer.serializeSudoku(doku).toString(),
+                    SudokuSerializer.serializeSudoku(otherDoku).toString());
             // clean file after test
             File fileToDelete = new File(savePath);
             fileToDelete.delete();
         } catch (Exception e) {
-            e.printStackTrace();
+            System.out.println(e.getMessage());
             assert false;
         }
-        assert (doku.equals(otherDoku));
+    }
+
+    void testSerializeX(int size) {
+        var sudoku = SudokuFactory.createBasicXShapedMultidoku(size, SudokuFactory.DEFAULT_CONSTRAINTS);
+        new RandomSolver().solve(sudoku);
+        JSONObject data = SudokuSerializer.serializeSudoku(sudoku);
+        MultiDoku multiDoku = SudokuSerializer.deserializeSudoku(data);
+
+        assertEquals(data.toString(), SudokuSerializer.serializeSudoku(multiDoku).toString());
     }
 
     @Test
     void testSerialize() {
         Random r = new Random();
-        testSerializeWithSize(3, 3, r);
-
-        /**
-        int testCount = 5;
+        int testCount = 20;
+        int minSize = 2;
+        int maxSize = 3;
         for (int i = 0; i < testCount; i++) {
-            int blockWidth = r.nextInt(10) + 1;
-            int blockHeight = r.nextInt(10) + 1;
-            testSerializeWithSize(blockWidth, blockHeight, r);
+            int blockWidth = r.nextInt(maxSize - minSize + 1) + minSize;
+            int blockHeight = r.nextInt(maxSize - minSize + 1) + minSize;
+            testSerializeWithSize(blockWidth, blockHeight);
         }
         for (int i = 0; i < testCount; i++) {
-            int blockWidth = r.nextInt(10) + 1;
-            int blockHeight = r.nextInt(10) + 1;
-            testSaveWithSize(blockWidth, blockHeight, r);
+            int blockWidth = r.nextInt(maxSize - minSize + 1) + minSize;
+            int blockHeight = r.nextInt(maxSize - minSize + 1) + minSize;
+            testSaveWithSize(blockWidth, blockHeight);
+        }
+        for (int i = 0; i < testCount; i++) {
+            int size = r.nextInt(maxSize - minSize + 1) + minSize;
+            testSerializeX(size);
         }
-         */
     }
 
 }

app/src/test/java/sudoku/solver/SolverTest.java

@@ -1,91 +1,132 @@
 package sudoku.solver;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.util.List;
+
+import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
-import sudoku.io.SudokuPrinter;
+
+import sudoku.io.SudokuSerializer;
 import sudoku.structure.Cell;
+import sudoku.structure.Difficulty;
 import sudoku.structure.MultiDoku;
 import sudoku.structure.Sudoku;
 import sudoku.structure.SudokuFactory;
 
-import java.util.List;
-import java.util.Random;
-
 class SolverTest {
+	private int ns = Cell.NOSYMBOL;
+	protected static HumanSolver h;
+	private static RandomSolver r;
+	private static MixedSolver m;
 
-    @Test
-    void solveTest() {
-        Random rand = new Random();
+	@BeforeAll
+	public static void initializeSolvers() {
+		h = new HumanSolver();
+		r = new RandomSolver();
+		m = new MixedSolver();
+	}
 
-        MultiDoku dokuToTest = SudokuFactory.createBasicEmptySquareDoku(3, SudokuFactory.DEFAULT_CONSTRAINTS);
-        MultiDoku dokuResult = SudokuFactory.createBasicEmptySquareDoku(3, SudokuFactory.DEFAULT_CONSTRAINTS);
+	private void testSize2(Solver solver) {
+		MultiDoku mdTest = SudokuFactory.createBasicEmptySquareDoku(2, SudokuFactory.DEFAULT_CONSTRAINTS);
+		MultiDoku mdResult = SudokuFactory.createBasicEmptySquareDoku(2, SudokuFactory.DEFAULT_CONSTRAINTS);
+		Sudoku test = mdTest.getSubGrid(0);
+		Sudoku result = mdResult.getSubGrid(0);
+		List<Integer> immutableCells = List.of(
+				ns, 2, 3, ns,
+				0, ns, ns, ns,
+				ns, ns, ns, 3,
+				ns, 0, 1, ns);
+		assertTrue(test.setImmutableCellsSymbol(immutableCells));
+		List<Integer> correctCells = List.of(
+				1, 2, 3, 0,
+				0, 3, 2, 1,
+				2, 1, 0, 3,
+				3, 0, 1, 2);
+		assertTrue(result.setCellsSymbol(correctCells));
+		assertTrue(result.isSolved());
 
-        Sudoku sudokuToTest = dokuToTest.getSubGrid(0);
-        Sudoku sudokuResult = dokuResult.getSubGrid(0);
+		assertNotEquals(mdResult, mdTest);
+		solver.solve(mdTest);
+		assertTrue(mdTest.isSolved());
 
-        int ns = Cell.NOSYMBOL;
-        List<Integer> immutableCells = List.of(ns, ns, 0, ns, ns, 2, 8, ns, 1,
-                ns, 3, ns, ns, 5, 6, 7, ns, ns,
-                ns, ns, ns, 8, ns, 7, ns, ns, 6,
-                0, ns, 1, ns, ns, ns, ns, ns, ns,
-                4, 8, 7, 5, 1, ns, 6, ns, ns,
-                6, ns, 3, 2, ns, ns, ns, 8, 0,
-                ns, ns, 6, ns, ns, 8, ns, 7, 5,
-                8, 0, ns, 7, ns, 5, 2, ns, 3,
-                5, ns, ns, ns, 3, 1, 0, ns, ns);
+		assertEquals(mdTest, mdResult);
+	}
 
-        assert (sudokuToTest.setImmutableCellsSymbol(immutableCells));
+	private void testSize3(Solver solver) {
+		MultiDoku mdTest = SudokuFactory.createBasicEmptySquareDoku(3, SudokuFactory.DEFAULT_CONSTRAINTS);
+		MultiDoku mdResult = SudokuFactory.createBasicEmptySquareDoku(3, SudokuFactory.DEFAULT_CONSTRAINTS);
+		Sudoku test = mdTest.getSubGrid(0);
+		Sudoku result = mdResult.getSubGrid(0);
+		List<Integer> immutableCells = List.of(
+				ns, ns, 0, ns, ns, 2, 8, ns, 1,
+				ns, 3, ns, ns, 5, 6, 7, ns, ns,
+				ns, ns, ns, 8, ns, 7, ns, ns, 6,
+				0, ns, 1, ns, ns, ns, ns, ns, ns,
+				4, 8, 7, 5, 1, ns, 6, ns, ns,
+				6, ns, 3, 2, ns, ns, ns, 8, 0,
+				ns, ns, 6, ns, ns, 8, ns, 7, 5,
+				8, 0, ns, 7, ns, 5, 2, ns, 3,
+				5, ns, ns, ns, 3, 1, 0, ns, ns);
+		assert (test.setImmutableCellsSymbol(immutableCells));
+		List<Integer> correctCells = List.of(
+				7, 6, 0, 3, 4, 2, 8, 5, 1,
+				2, 3, 8, 1, 5, 6, 7, 0, 4,
+				1, 4, 5, 8, 0, 7, 3, 2, 6,
+				0, 2, 1, 6, 8, 3, 5, 4, 7,
+				4, 8, 7, 5, 1, 0, 6, 3, 2,
+				6, 5, 3, 2, 7, 4, 1, 8, 0,
+				3, 1, 6, 0, 2, 8, 4, 7, 5,
+				8, 0, 4, 7, 6, 5, 2, 1, 3,
+				5, 7, 2, 4, 3, 1, 0, 6, 8);
+		assert (result.setCellsSymbol(correctCells));
+		assert (result.isSolved());
 
-        SudokuPrinter.printRectangleSudoku(dokuToTest.getSubGrid(0), 3, 3);
+		assertNotEquals(mdResult, mdTest);
+		solver.solve(mdTest);
+		assert (mdTest.isSolved());
+		assertEquals(mdTest, mdResult);
+	}
 
-        List<Integer> correctCells = List.of(7, 6, 0, 3, 4, 2, 8, 5, 1,
-                2, 3, 8, 1, 5, 6, 7, 0, 4,
-                1, 4, 5, 8, 0, 7, 3, 2, 6,
-                0, 2, 1, 6, 8, 3, 5, 4, 7,
-                4, 8, 7, 5, 1, 0, 6, 3, 2,
-                6, 5, 3, 2, 7, 4, 1, 8, 0,
-                3, 1, 6, 0, 2, 8, 4, 7, 5,
-                8, 0, 4, 7, 6, 5, 2, 1, 3,
-                5, 7, 2, 4, 3, 1, 0, 6, 8);
+	private void testMDSize3(Solver solver) {
+		MultiDoku mdTest = SudokuFactory.createBasicXShapedMultidoku(3, SudokuFactory.DEFAULT_CONSTRAINTS);
+		try {
+			SudokuFactory.fillDoku(mdTest, Difficulty.Easy);
+		} catch (Exception e) {
+			assert (false);
+		}
+		MultiDoku mdResult = SudokuSerializer.deserializeSudoku(SudokuSerializer.serializeSudoku(mdTest));
+		assertFalse(mdTest.isSolved());
+		assertFalse(mdResult.isSolved());
+		assertEquals(mdTest, mdResult);
 		
-        sudokuResult.setCellsSymbol(correctCells);
+		assertTrue(solver.solve(mdTest));
 		
-        System.out.println("\n****************************Doku Control\n");
-        SudokuPrinter.printRectangleSudoku(sudokuResult, 3, 3);
+		assertTrue(mdTest.isSolved());
+		assertFalse(mdResult.isSolved());
+		System.out.println(mdTest);
+		System.out.println(mdResult);
+		assertNotEquals(mdTest, mdResult);
 		
-        assert(dokuResult.isSolved());
+		assertTrue(solver.solve(mdResult));
 		
-        Solver.solveRandom(dokuToTest, rand);
+		assertEquals(mdTest, mdResult);
+	}
 
-        System.out.println("\n****************************\nDoku solved");
-        SudokuPrinter.printRectangleSudoku(dokuToTest.getSubGrid(0), 3, 3);
-
-
-        assert(dokuToTest.isSolved());
-
-        assert(dokuToTest.equals(dokuResult));
-
-        MultiDoku dokuToTest2 = SudokuFactory.createBasicEmptySquareDoku(3, SudokuFactory.DEFAULT_CONSTRAINTS);
-        Sudoku sudokuToTest2 = dokuToTest2.getSubGrid(0);
-
-        List<Integer> immutableCells2 = List.of(ns, ns, 0, ns, ns, 2, 8, ns, 1,
-                1, 3, ns, ns, 5, 6, 7, ns, ns,
-                ns, ns, ns, 8, ns, 7, ns, ns, 6,
-                0, ns, 1, ns, ns, ns, ns, ns, ns,
-                4, 8, 7, 5, 1, ns, 6, ns, ns,
-                6, ns, 3, 2, ns, ns, ns, 8, 0,
-                ns, ns, 6, ns, ns, 8, ns, 7, 5,
-                8, 0, ns, 7, ns, 5, 2, ns, 3,
-                5, ns, ns, ns, 3, 1, 0, ns, ns);
-        sudokuToTest2.setImmutableCellsSymbol(immutableCells2);
-
-        boolean isSolved = Solver.solveRandom(dokuToTest2, rand);
-
-        assert (!isSolved);
-
-        MultiDoku dokuToTest3 = SudokuFactory.createBasicEmptySquareDoku(3, SudokuFactory.DEFAULT_CONSTRAINTS);
-
-        Solver.solveRandom(dokuToTest3, rand);
-
-        SudokuPrinter.printRectangleSudoku(dokuToTest3.getSubGrid(0), 3, 3);
-    }
+	@Test
+	void solveTest() {
+		for (int i = 0; i < 100; i++) {
+			testSize2(h);
+			testSize3(h);
+			testSize2(m);
+			testSize3(m);
+			testMDSize3(m);
+			testSize2(r);
+			testSize3(r);
+			testMDSize3(r);
+		}
+	}
 }