Piece.java

package com.example.paktalin.agilejava_exercises;

import android.support.annotation.NonNull;

import com.example.paktalin.agilejava_exercises.moves.KingMoveStrategy;
import com.example.paktalin.agilejava_exercises.moves.MoveStrategy;
import com.example.paktalin.agilejava_exercises.moves.QueenMoveStrategy;

import java.util.List;

/**
 * Created by Paktalin on 23/05/2018.
 */

public class Piece implements Comparable<Piece> {

    public enum Color {White, Black}

    private Type type;
    private Color color;

    private double strength;
    private Position position;
    private MoveStrategy moveStrategy;

    private Piece() {}

    private Piece(final Color color, final Type type) {
        this.color = color;
        this.type = type;
    }

    public enum Type {
        Pawn(1, 'p'),
        Knight(2.5, 'n'),
        Rook(5, 'r'),
        Bishop(3, 'b'),
        Queen(9, 'q', new QueenMoveStrategy()),
        King(0, 'k', new KingMoveStrategy());

        private double strength;
        private char representation;
        private MoveStrategy moveStrategy;

        Type(double strength, char representation, MoveStrategy moveStrategy) {
            this.strength = strength;
            this.representation = representation;
            this.moveStrategy = moveStrategy;
        }

        Type(double strength, char representation) {
            this.strength = strength;
            this.representation = representation;
        }

        public char getRepresentation() {
            return representation;
        }

        public double getStrength() {
            return strength;
        }

        public MoveStrategy getMoveStrategy() {
            return moveStrategy;
        }
    }

    public void setPosition(Position position) {
        this.position = position;
    }

    char getRepresentation() {
        char representation = this.type.getRepresentation();
        if (this.isBlack())
            return Character.toUpperCase(representation);
        return representation;
    }

    void setStrength(double strength) {
        this.strength = strength;
    }

    void setStrength(List<Piece> pieces) {
        if (this.type != Type.Pawn)
            strength = this.type.getStrength();
        else setPawnStrength(this, pieces);
    }

    @Override
    public int compareTo(@NonNull Piece that) {
        if (this.getStrength() > that.getStrength())
            return -1;
        if (this.getStrength() < that.getStrength())
            return 1;
        return 0;
    }

    private static void setPawnStrength(Piece currentPiece, List<Piece> pieces) {
        currentPiece.setStrength(1.0);
        for (Piece piece : pieces) {
            if (pawnsOnSameColumn(currentPiece, piece)) {
                piece.setStrength(0.5);
                currentPiece.setStrength(0.5);
            }
        }
    }

    private static boolean pawnsOnSameColumn(Piece currentPiece, Piece piece) {
        return piece.getPosition().getColumn() == currentPiece.getPosition().getColumn() &&
                piece.getPosition().getRow() != currentPiece.getPosition().getRow() &&
                piece.getType() == currentPiece.getType();
    }

    boolean isMovable(Position from, Position to) {
        return this.getType().getMoveStrategy().isMovable(from, to);
    }

    double getStrength() {
        return strength;
    }
    public Color getColor() {
        return color;
    }
    Type getType() {
        return type;
    }
    public Position getPosition() {
        return position;
    }

    boolean isColor(Color color) {
        return this.color == color;
    }
    boolean isWhite() {
        return isColor(Color.White);
    }
    boolean isBlack() {
        return isColor(Color.Black);
    }
    boolean isType(Piece.Type type) {
        return this.getType() == type;
    }
    public boolean isAtPosition(Position position) {
        return this.position.equals(position);
    }

    static Piece createPawn(Color color) {
        return new Piece(color, Type.Pawn);
    }
    public static Piece createKing(Color color) {
        return new Piece(color, Type.King);
    }
    static Piece createBishop(Color color) {
        return new Piece(color, Type.Bishop);
    }
    static Piece createRook(Color color) {
        return new Piece(color, Type.Rook);
    }
    static Piece createKnight(Color color) {
        return new Piece(color, Type.Knight);
    }
    public static Piece createQueen(Color color) {
        return new Piece(color, Type.Queen);
    }
}