3DChess/app/src/main/java/chess/ai/HungryAI.java

package chess.ai;

import java.util.ArrayList;
import java.util.List;
import java.util.Random;

import chess.controller.CommandExecutor;
import chess.controller.commands.MoveCommand;
import chess.controller.commands.PromoteCommand;
import chess.controller.commands.PromoteCommand.PromoteType;
import chess.model.Color;
import chess.model.Coordinate;
import chess.model.Move;
import chess.model.Piece;

public class HungryAI extends AI {

	private final PieceCost pieceCost;
	private final Random random;

	public HungryAI(CommandExecutor commandExecutor, Color color) {
		super(commandExecutor, color);
		this.pieceCost = new PieceCost(color);
		this.random = new Random();
	}

	private int getMoveCost(Move move) {
		Piece piece = pieceAt(move.getDeadPieceCoords());
		return - (int) pieceCost.getCost(piece);
	}

	private List<Move> getBestMoves() {
		List<Move> moves = getAllowedMoves();
		List<Move> bestMoves = new ArrayList<>();
		int bestCost = 0;
		for (Move move : moves) {
			int moveCost = getMoveCost(move);
			if (moveCost == bestCost) {
				bestMoves.add(move);
			} else if (moveCost > bestCost) {
				bestMoves.clear();
				bestMoves.add(move);
				bestCost = moveCost;
			}
		}
		return bestMoves;
	}

	@Override
	protected void play() {
		List<Move> bestMoves = getBestMoves();
		int randomMove = this.random.nextInt(bestMoves.size());
		this.commandExecutor.executeCommand(new MoveCommand(bestMoves.get(randomMove)));
	}

	@Override
	protected void promote(Coordinate pawnCoords) {
		sendCommand(new PromoteCommand(PromoteType.Queen));
	}

}