internal static void Create(List<Move> moves, Field node, Move move, Direction direction)
{
Field near = node[direction];
if (near == null) return;
Field far = near[direction];
if (far == null) return;
if (node.CanUse() && near.CanFree() && far.CanFree())
{
Append(moves, move, move.Create(node, near, far));
}
}
internal bool Exists(Move move, Field near, Field far)
{
bool result = false;
if (move.Hash == 0)
{
if (!CanMove(near, far))
throw new InvalidOperationException();
{
Use();
near.Free();
far.Free();
}
result = move.Update(board);
{
Free();
near.Use();
far.Use();
}
return result;
}
return board.Exists(move.Hash);
}
internal bool DoMove(Move move, Field near, Field far)
{
if (!CanMove(near, far)) return false;
if (Use() && near.Free() && far.Free())
{
board.DoMove(this, near, far, move);
return true;
}
return false;
}
internal bool CanUndoMove(Field near, Field far)
{
return CanFree() && near.CanUse() && far.CanUse();
}
private static IEnumerable<Move> Create(Field node, Move move)
{
List<Move> moves = new List<Move>();
Create(moves, node, move, Direction.Left);
Create(moves, node, move, Direction.Top);
Create(moves, node, move, Direction.Right);
Create(moves, node, move, Direction.Bottom);
return moves;
}
internal void UndoMove(Field node, Field near, Field far, Move move)
{
//data.Remove(hash);
empty.Add(node);
empty.Remove(near);
empty.Remove(far);
history.UndoMove(move);
}
internal void DoMove(Field node, Field near, Field far, Move move)
{
hashSet.Add(hash);
empty.Remove(node);
empty.Add(near);
empty.Add(far);
history.DoMove(move);
}