package chess.ai;

import java.util.Arrays;
import java.util.List;

import chess.model.Color;
import chess.model.Coordinate;
import chess.model.Piece;
import chess.model.PieceVisitor;
import chess.model.pieces.Bishop;
import chess.model.pieces.King;
import chess.model.pieces.Knight;
import chess.model.pieces.Pawn;
import chess.model.pieces.Queen;
import chess.model.pieces.Rook;

public class PiecePosCost implements PieceVisitor<List<Float>> {

	/**
	 * Evaluate the cost of position for AI algorithm.
	 */

	private final Color color;

	private static final List<Float> BISHOP = Arrays.asList(
			-2.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -2.0f, 
			-1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, -1.0f,
			-1.0f, 0.0f, 0.5f, 1.0f, 1.0f, 0.5f, 0.0f, -1.0f,
			-1.0f, 0.5f, 0.5f, 1.0f, 1.0f, 0.5f, 0.5f, -1.0f,
			-1.0f, 0.0f, 1.0f, 1.0f, 1.0f, 1.0f, 0.0f, -1.0f,
			-1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, -1.0f,
			-1.0f, 0.5f, 0.0f, 0.0f, 0.0f, 0.0f, 0.5f, -1.0f,
			-2.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -2.0f);

	private static final List<Float> KING = Arrays.asList(
			-3.0f, -4.0f, -4.0f, -5.0f, -5.0f, -4.0f, -4.0f, -3.0f,
			-3.0f, -4.0f, -4.0f, -5.0f, -5.0f, -4.0f, -4.0f, -3.0f,
			-3.0f, -4.0f, -4.0f, -5.0f, -5.0f, -4.0f, -4.0f, -3.0f,
			-3.0f, -4.0f, -4.0f, -5.0f, -5.0f, -4.0f, -4.0f, -3.0f,
			-2.0f, -3.0f, -3.0f, -4.0f, -4.0f, -3.0f, -3.0f, -2.0f,
			-1.0f, -2.0f, -2.0f, -2.0f, -2.0f, -2.0f, -2.0f, -1.0f,
			2.0f, 2.0f, 0.0f, 0.0f, 0.0f, 0.0f, 2.0f, 2.0f,
			2.0f, 3.0f, 1.0f, 0.0f, 0.0f, 1.0f, 3.0f, 2.0f);

	private static final List<Float> KNIGHT = Arrays.asList(
			-5.0f, -4.0f, -3.0f, -3.0f, -3.0f, -3.0f, -4.0f, -5.0f, 
			-4.0f, -2.0f, 0.0f, 0.0f, 0.0f, 0.0f, -2.0f, -4.0f,
			-3.0f, 0.0f, 1.0f, 1.5f, 1.5f, 1.0f, 0.0f, -3.0f,
			-3.0f, 0.5f, 1.5f, 2.0f, 2.0f, 1.5f, 0.5f, -3.0f,
			-3.0f, 0.0f, 1.5f, 2.0f, 2.0f, 1.5f, 0.0f, -3.0f,
			-3.0f, 0.5f, 1.0f, 1.5f, 1.5f, 1.0f, 0.5f, -3.0f,
			-4.0f, -2.0f, 0.0f, 0.5f, 0.5f, 0.0f, -2.0f, -4.0f,
			-5.0f, -4.0f, -3.0f, -3.0f, -3.0f, -3.0f, -4.0f, -5.0f);

	private static final List<Float> PAWN = Arrays.asList(
			0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f,
			5.0f, 5.0f, 5.0f, 5.0f, 5.0f, 5.0f, 5.0f, 5.0f,
			1.0f, 1.0f, 2.0f, 3.0f, 3.0f, 2.0f, 1.0f, 1.0f,
			0.5f, 0.5f, 1.0f, 2.5f, 2.5f, 1.0f, 0.5f, 0.5f,
			0.0f, 0.0f, 1.0f, 2.0f, 2.0f, 1.0f, 0.0f, 0.0f,
			0.5f, -0.5f, -1.0f, 0.0f, 0.0f, -1.0f, -0.5f, 0.5f,
			0.5f, 1.0f, 1.0f, -2.0f, -2.0f, 1.0f, 1.0f, 0.5f,
			0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f);

	private static final List<Float> QUEEN = Arrays.asList(
			-2.0f, -1.0f, -1.0f, -0.5f, -0.5f, -1.0f, -1.0f, -2.0f,
			-1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, -1.0f,
			-1.0f, 0.0f, 0.5f, 0.5f, 0.5f, 0.5f, 0.0f, -1.0f,
			-0.5f, 0.0f, 0.5f, 0.5f, 0.5f, 0.5f, 0.0f, -0.5f,
			0.0f, 0.0f, 0.5f, 0.5f, 0.5f, 0.5f, 0.0f, -0.5f,
			-1.0f, 0.5f, 0.5f, 0.5f, 0.5f, 0.5f, 0.0f, -1.0f,
			-1.0f, 0.0f, 0.5f, 0.0f, 0.0f, 0.0f, 0.0f, -1.0f,
			-2.0f, -1.0f, -1.0f, -0.5f, -0.5f, -1.0f, -1.0f, -2.0f);

	private static final List<Float> ROOK = Arrays.asList(
			0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f,
			0.5f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 0.5f,
			-0.5f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, -0.5f,
			-0.5f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, -0.5f,
			-0.5f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, -0.5f,
			-0.5f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, -0.5f,
			-0.5f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, -0.5f,
			0.0f, 0.0f, 0.0f, 0.5f, 0.5f, 0.0f, 0.0f, 0.0f);

	public PiecePosCost(Color color) {
		this.color = color;
	}

	public float getEvaluation(Piece piece, Coordinate coordinate) {
		if (piece == null)
			return 0;
		List<Float> positions = visit(piece);
		int x = piece.getColor() == Color.Black ? (Coordinate.VALUE_MAX - 1 - coordinate.getX()) : coordinate.getX();
		int y = piece.getColor() == Color.Black ? (Coordinate.VALUE_MAX - 1 - coordinate.getY()) : coordinate.getY();
		Coordinate newCoords = new Coordinate(x, y);
		assert newCoords.isValid();
		float result = positions.get(newCoords.toIndex());
		if (piece.getColor() != color)
			return -result;
		return result;
	}

	@Override
	public List<Float> visitPiece(Bishop bishop) {
		return BISHOP;
	}

	@Override
	public List<Float> visitPiece(King king) {
		return KING;
	}

	@Override
	public List<Float> visitPiece(Knight knight) {
		return KNIGHT;
	}

	@Override
	public List<Float> visitPiece(Pawn pawn) {
		return PAWN;
	}

	@Override
	public List<Float> visitPiece(Queen queen) {
		return QUEEN;
	}

	@Override
	public List<Float> visitPiece(Rook rook) {
		return ROOK;
	}

}