/// <summary>
/// Tells the opening book what move did the oponent played , so the opening book could update itself.
/// </summary>
/// <param name="move">The move the opponent played</param>
static internal void MoveApplied(Move move)
{
//if not in book, break away.
if (!IsInBook)
{
return;
}
//look for such a move
OpeningMove applied = CurrentMove.Responses.FirstOrDefault(x => x.Move.EqualMove(move));
//if not found, we are leaving the book, otherwise we apply move and check if we will then be leaving the book.
if (applied == null)
{
IsInBook = false;
}
else
{
if (applied.Responses.Count == 0)
{
IsInBook = false;
}
CurrentMove = applied;
}
}
/// <summary>
/// Resets to the starting position
/// </summary>
static internal void ResetBook()
{
if (m_Root != null)
{
IsInBook = true;
}
//root is always the starting position
CurrentMove = m_Root;
}
/// <summary>
/// Provides a random move out of the valid opening moves availible at the current node.
/// First try excellent moves, then good, and so forth.
/// </summary>
/// <returns>The returned move, must be played.</returns>
internal static Move GetRandomMove()
{
//we always make sure we are still inside the book
if (IsInBook == false)
{
return(null);
}
Random rand = new Random();
//look for excellent moves
var GreatResponses = CurrentMove.Responses.Where(x => x.MoveType == OpeningMoveType.Excellent);
//if no such exists, look for good move.
if (GreatResponses.Count() == 0)
{
GreatResponses = CurrentMove.Responses.Where(x => x.MoveType == OpeningMoveType.Good);
}
//if no such exists, look for any move (I don't load bad moves at all)
if (GreatResponses.Count() == 0)
{
GreatResponses = CurrentMove.Responses;
}
//pick one randomly , perheps as a more balanced move, the random distribution should corraspond to the probability of node.
int movePosition = rand.Next(0, GreatResponses.Sum(x => x.Count) - 1);
//now we pick one according to the probability
int counter = 0;
foreach (OpeningMove openingMove in GreatResponses)
{
counter += openingMove.Count;
if (movePosition < counter)
{
CurrentMove = openingMove;
break;
}
}
//if the found move would draw us out of the book, make sure the user won't ask for another move in the future.
if (CurrentMove.Responses.Count == 0)
{
IsInBook = false;
}
return(CurrentMove.Move);
}
static OpeningBook()
{
try
{
//CreateOpeningBooks();
Generic <OpeningMove> .LoadFromDisk(out m_Root, "ChessEngineBook.xml");
CurrentMove = m_Root;
IsInBook = false;
}
catch (Exception ex)
{
IsInBook = false;
Global.WriteToLog(ex.Message + ex.StackTrace);
}
}
/// <summary>
/// Parses PGN files and saves them to the 'ChessEngineBook.xml' file.
/// NOTE: we should also zip the files to conserve space.
/// </summary>
private static void CreateOpeningBooks()
{
List <string> m_OpeningBookLocations = new List <string>
{
//"RJF60.pgn",
"strong.PGN",
"CMX.PGN",
};
OpeningMove startingPoint = new OpeningMove();
foreach (string openingBookLocation in m_OpeningBookLocations)
{
TextReader tr = null;
tr = new StreamReader(openingBookLocation);
string book = tr.ReadToEnd();
tr.Close();
AnalyzeBook(book, startingPoint);
}
Generic <OpeningMove> .SaveToDisk(startingPoint, "ChessEngineBook.xml");
}
/// <summary>
/// Parses one single move.
/// </summary>
/// <param name="_board">The current board , current opening book's game board</param>
/// <param name="_pgnMove">the move's PGN notation</param>
/// <param name="moves">A list of all availible moves</param>
/// <returns>An opening move represents the parsed response.</returns>
private static OpeningMove PGNMoveParser(Board _board, string _pgnMove, List <Move> moves)
{
bool isCapture = _pgnMove.Contains('x');
bool test = false;
if (test)
{
moves = MovesGenerator.GetLegalMoves(_board);
}
OpeningMove move = new OpeningMove();
try
{
//first check if it is castle
if (_pgnMove.StartsWith("O-O-O"))
{
move.Move = moves.First(x => x.MoveType == MoveTypes.CastleQueenSide);
}
else if (_pgnMove.StartsWith("O-O"))
{
move.Move = moves.First(x => x.MoveType == MoveTypes.CastleKingSide);
}
else
{
int piece = PGNletterToPieceParser(_pgnMove[0], _board.CurrentPlayer);
var pieceMoves = moves.Where(x => x.MovingPiece == piece);
if (pieceMoves.Count() == 1)
{
move.Move = pieceMoves.ElementAt(0);
}
else
{
if (piece == Piece.BlackPawn || piece == Piece.WhitePawn)
{
var sourceMoves = pieceMoves.Where(x => x.SourceFile == _pgnMove[0]);
if (sourceMoves.Count() == 1)
{
move.Move = sourceMoves.ElementAt(0);
}
else
{
if (isCapture)
{
string dest = _pgnMove.Substring(_pgnMove.IndexOf('x') + 1, 2);
move.Move = sourceMoves.First(x => x.DestinationSquareString == dest);
}
else
{
string dest = _pgnMove.Substring(0, 2);
move.Move = sourceMoves.First(x => x.DestinationSquareString.StartsWith(dest));
}
}
}
else
{
IEnumerable <Move> destMoves;
if (isCapture)
{
string dest = _pgnMove.Substring(_pgnMove.IndexOf('x') + 1, 2);
destMoves = pieceMoves.Where(x => x.DestinationSquareString == dest);
}
else
{
int indexDestRank = _pgnMove.LastIndexOfAny(new char[] { '1', '2', '3', '4', '5', '6', '7', '8', '9' });
string dest = _pgnMove.Substring(indexDestRank - 1, 2);
destMoves = pieceMoves.Where(x => x.DestinationSquareString == dest);
}
switch (destMoves.Count())
{
case 1:
move.Move = destMoves.ElementAt(0);
break;
case 2:
//either rank or file ambiguity
if (_pgnMove[1] >= '1' && _pgnMove[1] <= '9')
{
//rank ambiguity
move.Move = destMoves.First(x => x.SourceRank == _pgnMove[1]);
}
else
{
move.Move = destMoves.First(x => x.SourceFile == _pgnMove[1]);
}
break;
case 3:
move.Move = destMoves.First(x => x.SourceSquareString == _pgnMove.Substring(1, 2));
break;
}
}
}
//now get move type
if (_pgnMove.Contains("!!"))
{
move.MoveType = OpeningMoveType.Excellent;
}
else if (_pgnMove.Contains("!?"))
{
move.MoveType = OpeningMoveType.Interesting;
}
else if (_pgnMove.Contains("?!"))
{
move.MoveType = OpeningMoveType.Dubious;
}
else if (_pgnMove.Contains("!"))
{
move.MoveType = OpeningMoveType.Good;
}
else if (_pgnMove.Contains("??"))
{
move.MoveType = OpeningMoveType.Blunder;
}
else if (_pgnMove.Contains("?"))
{
move.MoveType = OpeningMoveType.Bad;
}
}
if (move.Move == null)
{
throw new System.Exception("not found");
}
return(move);
}
catch (Exception ex)
{
throw ex;
}
}
/// <summary>
/// Parses the book string in the standard PGN format, and inserts it into the starting position node
/// </summary>
/// <param name="book">A standard PGN formatted string</param>
/// <param name="startingPoint">The starting node to add responses to</param>
private static void AnalyzeBook(string book, OpeningMove startingPoint)
{
try
{
string[] tags = book.Replace("\r\n", " ").Split(new string[] { "[" }, StringSplitOptions.RemoveEmptyEntries);
for (int i = 6; i < tags.Length; i += 7)
{
string movesString = tags[i].Substring(tags[i].IndexOf(']') + 1);
string[] movesArray = movesString.Split(new string[] { " " }, StringSplitOptions.RemoveEmptyEntries);
Board board = new Board();
board.StartingPosition();
//parentMove will slide, containing the parent to the move.
OpeningMove parentMove = startingPoint;
bool abortMatch = false;
for (int j = 0; j < movesArray.Length && !abortMatch; j++)
{
if (j % 3 == 0)
{
continue;
}
if (parentMove.LegalMoves == null)
{
parentMove.LegalMoves = MovesGenerator.GetLegalMoves(board);
}
OpeningMove move = PGNMoveParser(board, movesArray[j], parentMove.LegalMoves);
if (move.MoveType != OpeningMoveType.Excellent && move.MoveType != OpeningMoveType.Good)
{
abortMatch = true;
break;
}
//to avoid duplicate entries problem, we make sure to use same instance of a move.
OpeningMove storedSameMove = parentMove.Responses.FirstOrDefault(x => x.Move.EqualMove(move.Move));
if (storedSameMove == null)
{
move.Count = 1;
parentMove.Responses.Add(move);
}
else
{
parentMove.Count++;
move = storedSameMove;
}
parentMove = move;
board.ApplyMove(move.Move);
}
}
}
catch (Exception ex)
{
throw ex;
}
}