package sudoku.structure;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Map;

import sudoku.constraint.BlockConstraint;
import sudoku.constraint.ColumnConstraint;
import sudoku.constraint.IConstraint;
import sudoku.constraint.LineConstraint;

public class SudokuFactory {

	public static List<IConstraint> DEFAULT_CONSTRAINTS = Arrays.asList(new BlockConstraint(), new LineConstraint(), new ColumnConstraint());

	private static List<Cell> initCells(int size) {
		List<Cell> cells = new ArrayList<>(size * size);
		for (int i = 0; i < size * size; i++) {
			cells.add(new Cell());
		}
		return cells;
	}

	private static List<Block> initRectangleBlocs(List<Cell> cells, int width, int height) {
		List<Block> blocs = new ArrayList<>();
		int size = width * height;
		for (int i = 0; i < size; i++) {
			Block newBlock = new Block();
			int blockX = i % height;
			int blockY = i / height;
			for (int y = 0; y < height; y++) {
				for (int x = 0; x < width; x++) {
					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);
				}
			}
			blocs.add(newBlock);
		}
		return blocs;
	}

	public static MultiDoku createBasicEmptyRectangleSudoku(int widthBlock, int heightBlock) {
		Sudoku s = createRectangleSudoku(widthBlock, heightBlock);
		return new MultiDoku(Arrays.asList(s));
	}

	public static MultiDoku createBasicEmptySquareSudoku(int size) {
		return createBasicEmptyRectangleSudoku(size, size);
	}

	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();
				}
			}
		});
	}

	private static Sudoku createRectangleSudoku(int width, int height) {
		int symbolCount = width * height;
		List<Cell> cases = initCells(symbolCount);
		List<Block> blocs = initRectangleBlocs(cases, width, height);
		Sudoku s = new Sudoku(cases, blocs, DEFAULT_CONSTRAINTS);
		s.setBlockWidth(width);
		return s;
	}

	private static Sudoku createSquareSudoku(int size) {
		return createRectangleSudoku(size, size);
	}

	private static void linkSquareSudokus(Sudoku sudoku1, Sudoku sudoku2, Coordinate offset) {
		int blockWidth = sudoku1.getBlockWidth();
		for (int dx = 0; dx < blockWidth; 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);

					// on remplace le bloc
					sudoku2.getBlocks().set(block2Y * blockWidth + block2X, block1);

					// on remplace les cellules
					for (int i = 0; i < block1.getCells().size(); i++) {
						Cell newCell = block1.getCells().get(i);
						Cell oldCell = block2.getCells().get(i);

						int oldCellIndex = sudoku2.getCells().indexOf(oldCell);
						sudoku2.getCells().set(oldCellIndex, newCell);
					}
				}
			}
		}
	}

	public static MultiDoku createBasicSquareMultidoku(int size) {
		assert (size > 1);

		/**
		 * 2 3
		 *  1
		 * 4 5
		 */

		Sudoku sudoku1 = createSquareSudoku(size);

		Sudoku sudoku2 = createSquareSudoku(size);
		Sudoku sudoku3 = createSquareSudoku(size);
		Sudoku sudoku4 = createSquareSudoku(size);
		Sudoku sudoku5 = createSquareSudoku(size);

		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));
	}
}