/// <summary>
/// Checks the endgame.
/// </summary>
/// <param name="oppositePlayer">The opposite player.</param>
/// <returns>
/// <c>GameEventType.None</c> if there were no threats from either side.
/// <c>GameEventType.Check</c> if there was a check from the opposing side.
/// <c>GameEventType.Checkmate</c> if there was a checkmate from the opposing side.
/// <c>GameEventType.Stalemate</c> if there is a stalemate.
/// </returns>
public override GameEventType CheckEndgame(PlayerBase oppositePlayer)
{
List<Position> oppositeKingMoves;
List<Position> attacks;
GameEventType endgame = GameEventType.None;
if (oppositePlayer == null || !(oppositePlayer is PlayerChess))
{
throw new Exception("oppositePlayer is not of PlayerChess type");
}
oppositeKingMoves = ((PlayerChess)oppositePlayer).King.AllMoveOptions;
foreach (IPiece piece in this.PieceList)
{
attacks = piece.AttackOptions;
foreach (Position target in attacks)
{
if (this.gameboard.Figures[target] != null && this.gameboard.Figures[target] is King)
{
endgame = GameEventType.Check;
break;
}
}
}
// If there is no Check and no Checkmate, check for Stalemate.
List<Position> posList = new List<Position>();
bool isStalemate = false;
// Aggregate all the possible moves from this player's pieces
foreach (IPiece piece in this.PieceList)
{
posList.AddRange(piece.AllMoveOptions.ToList());
posList.Add(piece.Position);
}
// Check each possible move of the opposite king's moves
foreach (Position position in oppositeKingMoves)
{
isStalemate = true;
if (!posList.Contains(position))
{
isStalemate = false;
break;
}
}
if (isStalemate)
{
if (endgame == GameEventType.Check)
{
return GameEventType.Checkmate;
}
// else
// {
// return GameEventType.Stalemate;
// }
}
return endgame;
}