/// <summary> /// Plays for a specific turn. /// </summary> /// <param name="turn"></param> /// <returns></returns> public abstract Action Play(Turn turn);
/// <summary>
/// Plays for a specific turn.
/// </summary>
/// <param name="turn"></param>
/// <returns></returns>
public override Action Play(Turn turn)
{
throw new NotImplementedException();
}
/// <summary>
/// Instantiates the next <see cref="Turn"/> by playing an <paramref name="action"/>.
/// The returned new <see cref="Turn"/> is null if the <paramref name="action"/> breaks the rules.
/// </summary>
/// <param name="action"></param>
/// <returns>The next <see cref="Turn"/> can be null if <paramref name="action"/> breaks the rules.</returns>
public Turn NextTurn(Action action)
{
if (action == null)
{
return(null);
}
if (action.Player != CurrentPlayer)
{
return(null);
}
if (action is PassHand)
{
return(initializeNextTurn());
}
else if (action is PlaceStone)
{
var placeStone = action as PlaceStone;
var stone = placeStone.Stone;
if (!FreePositions.Contains(stone.Position))
{
return(null);
}
Turn nextTurn = initializeNextTurn();
// Remove captured groups
for (int g = 0; g < nextTurn._groups.Count; g++)
{
var group = nextTurn._groups.ElementAt(g);
if (group.Player != stone.Player)
{
var f = GetFreedoms(group);
if (f.Count() == 1 && f.Contains(stone.Position))
{
nextTurn._groups.Remove(group);
g--;
}
}
}
// Create a new group with the new stone
Group newGroup = new Group(stone);
// Merge adjacent groups
for (int g = 0; g < nextTurn._groups.Count; g++)
{
var group = nextTurn._groups.ElementAt(g);
if (group.Player == stone.Player && group.AdjacentPositions.Contains(stone.Position))
{
newGroup += group;
nextTurn._groups.Remove(group);
g--;
}
}
nextTurn._groups.Add(newGroup);
// Check that newGroup hast freedom in nextTurn
if (!nextTurn.GetFreedoms(newGroup).Any())
{
return(null);
}
// Check Ko rule
if (nextTurn.isSameState(Previous))
{
return(null);
}
// Action is valid, nextTurn is well created
return(nextTurn);
}
else
{
throw new ArgumentException("Action expected to be PlaceStone or PassHand.");
}
}