public static void loadFromJSON()
{
if (failedToWrite)
{
return;
}
Chess.board.clear();
string jsonString = File.ReadAllText(Chess.currentGameFile);
var json = Json.Decode(jsonString);
var listOfPieces = json["chess"]["pieces"];
foreach (var piece in listOfPieces)
{
String color = piece.color;
String type = piece.type;
Position position = new Position(piece.Position.x, piece.Position.y);
int moves = piece.moves;
Piece p = new Piece(type, color, position, moves);
Chess.board.set(position, p);
}
Chess.turn = json["chess"]["turn"];
}
private static int lowestThreathener(Position position, string color)
{
List<Piece> pieces;
if (color == "white")
{
pieces = Chess.whitePieces();
}
else
{
pieces = Chess.blackPieces();
}
int value = 123456789;
Chess.checkingOwn = true;
foreach (Piece p in pieces)
{
if (Rules.validMove(p, position))
{
if (p.getValue() < value)
{
value = p.getValue();
}
}
}
Chess.checkingOwn = false;
return value;
}
/*
* Create a new chess piece.
* Types available are: King, Queen, Rook, Bishop, Knight and Pawn
* Colors available are: White, Black
*/
public Piece(string type, string color, Position position, int numberOfMoves = 0)
{
this.type = type;
this.color = color;
this.numberOfMoves = numberOfMoves;
this.position = position;
}
private static bool rookValid(Piece p, Position from, Position to)
{
int xDist = to.x - from.x;
int yDist = to.y - from.y;
if (!(xDist == 0 || yDist == 0))
{
return false;
}
int yDirection = yDist == 0 ? 0 : yDist < 0 ? -1 : 1;
int xDirection = xDist == 0 ? 0 : xDist < 0 ? -1 : 1;
int x = from.x + xDirection;
int y = from.y + yDirection;
Position current = new Position(x, y);
while (!current.Equals(to))
{
if (!Chess.IsEmpty(current))
{
return false;
}
current.x += xDirection;
current.y += yDirection;
}
return !Chess.IsSame(p, to);
}
public Piece(Piece piece)
{
this.type = piece.getType();
this.color = piece.getColor();
this.position = piece.getPosition();
this.numberOfMoves = piece.numberOfMoves;
}
public Board()
{
board = new Dictionary<Position, Piece>();
for (int y = 0; y < 8; y++)
{
for (int x = 0; x < 8; ++x)
{
Position p = new Position(x, y);
board[p] = new Piece("blank", "none", p);
}
}
string color = "black";
for (int y = 1; y < 7; y += 5)
{
for (int x = 0; x < 8; ++x)
{
Position p = new Position(x, y);
board[p] = new Piece("pawn", color, p);
}
color = "white";
}
color = "black";
for (int y = 0; y < 8; y += 7)
{
Position p = new Position(0, y);
board[p] = new Piece("rook", color, p);
p = new Position(1, y);
board[p] = new Piece("knight", color, p);
p = new Position(2, y);
board[p] = new Piece("bishop", color, p);
p = new Position(3, y);
board[p] = new Piece("queen", color, p);
p = new Position(4, y);
board[p] = new Piece("king", color, p);
p = new Position(5, y);
board[p] = new Piece("bishop", color, p);
p = new Position(6, y);
board[p] = new Piece("knight", color, p);
p = new Position(7, y);
board[p] = new Piece("rook", color, p);
color = "white";
}
}
public void clear()
{
for (int y = 0; y < 8; y++)
{
for (int x = 0; x < 8; ++x)
{
Position p = new Position(x, y);
board[p] = new Piece("blank", "none", p);
}
}
}
public static bool validMove(Piece p, Position to)
{
if (p.getPosition().Equals(to)) return false;
String type = p.getType();
switch (type)
{
case "pawn":
return pawnValid(p, p.getPosition(), to);
case "knight":
return knightValid(p, p.getPosition(), to);
case "bishop":
return bishopValid(p, p.getPosition(), to);
case "rook":
return rookValid(p, p.getPosition(), to);
case "queen":
return queenValid(p, p.getPosition(), to);
case "king":
return kingValid(p, p.getPosition(), to);
default:
return false;
}
}
private static bool kingValid(Piece p, Position from, Position to)
{
int xDist = to.x - from.x;
int yDist = to.y - from.y;
//Check for valid castling
if (p.numberOfMoves == 0 && yDist == 0 && (xDist == 2 || xDist == -2))
{
int direction = xDist == 2 ? 1 : -2;
Piece p2 = Chess.board.at(new Position(to.x + direction, from.y));
if (Chess.IsSame(p, p2.getPosition()) && p2.getType() == "rook" && p2.numberOfMoves == 0 && !Chess.IsChecked(p.getColor()))
{
return rookValid(p, from, to);
}
}
if (!((xDist * xDist) <= 1 && (yDist * yDist) <= 1))
{
return false;
}
return !Chess.IsSame(p, to);
}
private static void move(Position from, Position to, bool realMove){
lastMove = new ChessMove(from, to);
Piece p1 = board.at(from);
Piece p2 = board.at(to);
pieceRemoved = p2;
int xDiff = to.x - from.x;
if (p1.getType() == "king" && Math.Abs(xDiff) > 1 && realMove)
{
int xDir = xDiff < 0 ? -2 : 1;
Position rook = new Position(to.x + xDir, to.y);
xDir = xDiff < 0 ? 1 : -1;
board.at(rook).debug();
move(rook, new Position(to.x + xDir, to.y));
}
board.set(from, new Piece("blank", "none", from));
p1.numberOfMoves++;
if (p1.getType() == "pawn" && Math.Abs(to.y - from.y) == 2)
{
p1.numberOfMoves++;
}
p1.setPosition(to);
if (p1.getType() == "pawn" && (to.y == 0 || to.y == 7))
{
p1 = new Piece("queen", p1.getColor(), p1.getPosition(), p1.getNumberOfMoves());
}
board.set(to, p1);
}
public static bool hasMoves()
{
for (int x = 0; x < 8; ++x)
{
for (int y = 0; y < 8; ++y)
{
Piece p = board.at(new Position(x, y));
if (p.getColor() != turn && p.getType() != "blank")
{
Position pos = new Position(x, y);
Dictionary<Position, bool?> moves = Chess.validMoves(p);
foreach (KeyValuePair<Position, bool?> kvp in moves)
{
if (kvp.Value != false)
{
return true;
}
}
}
}
}
return false;
}
public static bool IsChecked(string color)
{
Position kingPos = board.findKing(color);
Piece king = board.at(kingPos);
for (int x = 0; x < 8; ++x)
{
for (int y = 0; y < 8; ++y)
{
Position from = new Position(x, y);
Piece p = board.at(from);
if (p.getColor() != king.getColor())
{
if (Rules.validMove(p, kingPos))
{
return true;
}
}
}
}
return false;
}
public static bool IsSame(Piece p, Position pos)
{
return p.getColor() == board.at(pos).getColor() && !checkingOwn;
}
public static bool IsEmpty(Position pos)
{
Debug.WriteLine(pos.x + "," + pos.y);
return board.at(pos).getType() == "blank";
}
private static bool isThreatened(Position position)
{
return canMoveTo(position, "white");
}
public static Dictionary<Position, bool?> validMoves(Piece toBeMoved)
{
Dictionary<Position, bool?> moves = new Dictionary<Position, bool?>();
for (int x = 0; x < 8; ++x)
{
for (int y = 0; y < 8; ++y)
{
Position to = new Position(x, y);
Piece moveTo = board.at(to);
bool? valid = Rules.validMove(toBeMoved, to);
if (valid == true && moveTo.getType() != "blank")
{
valid = null;
}
if (valid != false)
{
move(toBeMoved.getPosition(), moveTo.getPosition(), false);
if (IsChecked(toBeMoved.getColor()))
{
valid = false;
}
undo();
}
moves.Add(to, valid);
}
}
return moves;
}
private static bool isProtected(Position position)
{
return canMoveTo(position, "black");
}
private static bool queenValid(Piece p, Position from, Position to)
{
return rookValid(p, from, to) || bishopValid(p, from, to);
}
private static bool canMoveTo(Position position, string color){
List<Piece> pieces;
if (color == "white")
{
pieces = Chess.whitePieces();
}
else
{
pieces = Chess.blackPieces();
}
Chess.checkingOwn = true;
foreach (Piece p in pieces)
{
if (Rules.validMove(p, position))
{
Chess.checkingOwn = false;
return true;
}
}
Chess.checkingOwn = false;
return false;
}
private static List<Piece> getPieces(string color)
{
List<Piece> pieces = new List<Piece>();
for (int x = 0; x < 8; ++x)
{
for (int y = 0; y < 8; ++y)
{
Position pos = new Position(x, y);
Piece p = board.at(pos);
if (p.getColor().Equals(color))
{
pieces.Add(p);
}
}
}
return pieces;
}
public static void move(Position from, Position to)
{
if (!Rules.validMove(board.at(from), to))
{
throw new Exception("InvalidMoveError");
}
move(from, to, true);
}
public void set(Position position, Piece piece)
{
board[position] = piece;
}
public Piece at(Position p)
{
return board[p];
}
public static void tempMove(Position from, Position to)
{
move(from, to, false);
}
private static bool knightValid(Piece p, Position from, Position to)
{
int xDist = from.x - to.x;
int yDist = from.y - to.y;
return !Chess.IsSame(p, to) && xDist * xDist + yDist * yDist == 5;
}
public ChessMove(Position from, Position to, int value = 0)
{
this.from = from;
this.to = to;
this.value = value;
}
private static bool pawnValid(Piece p, Position from, Position to)
{
int xDist = from.x - to.x;
int yDist = from.y - to.y;
int direction = p.getColor() == "white" ? -1 : 1;
if (from.y + direction > 7 || from.y + direction < 0) return false;
if (from.y + direction != to.y && ((from.y + 2 * direction != to.y && p.getNumberOfMoves() == 0) || !Chess.IsEmpty(new Position(from.x, from.y + direction)) || p.getNumberOfMoves() > 0))
{
return false;
}
if (xDist < -1 || xDist > 1)
{
return false;
}
if (xDist == 0 && !Chess.IsEmpty(to))
{
return false;
}
if (xDist * xDist == 1 && yDist * yDist != 1)
{
return false;
}
if (xDist != 0 && (Chess.IsEmpty(to) || Chess.IsSame(p, to)))
{
return false;
}
return true;
}
public bool Equals(Position other)
{
if (ReferenceEquals(null, other)) return false;
if (ReferenceEquals(this, other)) return true;
return other.x == x && other.y == y;
}
public void setPosition(Position position)
{
this.position = position;
}