package chess.controller.commands;

import chess.controller.PlayerCommand;
import chess.controller.event.GameListener;
import chess.model.ChessBoard;
import chess.model.Color;
import chess.model.Coordinate;
import chess.model.Game;
import chess.model.Piece;
import chess.model.pieces.Bishop;
import chess.model.pieces.Knight;
import chess.model.pieces.Queen;
import chess.model.pieces.Rook;
import chess.model.visitor.PawnIdentifier;

public class PromoteCommand extends PlayerCommand {

	public enum PromoteType {
		Queen,
		Rook,
		Bishop,
		Knight
	}

	private final PromoteType promoteType;
	private Coordinate pieceCoords;
	private Piece oldPawn;

	public PromoteCommand(PromoteType promoteType) {
		this.promoteType = promoteType;
		assert this.promoteType != null;
		this.pieceCoords = null;
		this.oldPawn = null;
	}

	@Override
	public CommandResult execute(Game game, GameListener outputSystem) {
		final ChessBoard board = game.getBoard();

		this.pieceCoords = board.pawnPromotePosition();

		if (this.pieceCoords == null)
			return CommandResult.NotAllowed;

		Piece pawn = board.pieceAt(this.pieceCoords);
		if (!new PawnIdentifier(game.getPlayerTurn()).isPawn(pawn))
			return CommandResult.NotAllowed;

		int destY = this.pieceCoords.getY();

		int enemyLine = pawn.getColor() == Color.White ? 0 : 7;

		if (destY != enemyLine)
			return CommandResult.NotAllowed;

		this.oldPawn = pawn;
		board.pieceComes(createPiece(this.promoteType, pawn.getColor()), this.pieceCoords);

		outputSystem.onPawnPromoted(this.promoteType);

		// invalidate the last move cache
		board.setLastMove(null);

		return CommandResult.Moved;
	}

	private Piece createPiece(PromoteType promoteType, Color color) {
		switch (promoteType) {
			case Queen:
				return new Queen(color);

			case Bishop:
				return new Bishop(color);

			case Knight:
				return new Knight(color);

			case Rook:
				return new Rook(color);

			default:
				return null;
		}
	}

	@Override
	protected CommandResult undoImpl(Game game, GameListener outputSystem) {
		final ChessBoard board = game.getBoard();

		Piece promoted = board.pieceAt(this.pieceCoords);

		assert promoted != null;

		game.undoTraitPiecesPos();

		board.pieceComes(this.oldPawn, this.pieceCoords);

		game.getLastAction().undo(game, outputSystem);

		return CommandResult.Moved;
	}

	public PromoteType getPromoteType() {
		return promoteType;
	}

}