private static Board _With(LogicalPiece played, LogicalPiece bound, Board board)
{
// this looks like shit I'm sorry: This advances from one step in the direction of to
int Step(int from, int to) => from + (from < to ? 1 : to == from ? 0 : -1);
Func <PlayerColor, LogicalPiece> StepTowards(LogicalPiece origin, LogicalPiece destination) =>
playerColor => new LogicalPiece(Step(origin.X, destination.X), Step(origin.Z, destination.Z), playerColor);
LogicalPiece next = played;
var currentBoard = board;
while (!next.Equals(bound))
{
var advanceOneStepToBoundIn = StepTowards(next, bound);
LogicalPiece toRemove = advanceOneStepToBoundIn(played.Color.Opposing());
LogicalPiece toAdd = advanceOneStepToBoundIn(played.Color);
currentBoard = currentBoard
.Without(toRemove)
.With(toAdd);
next = toAdd;
}
return(currentBoard);
}
private static IReadOnlyList <Piece> AddToGameObjectState(LogicalPiece piece, IReadOnlyList <Piece> gameObjectState)
{
List <Piece> intermediatePhysicalState = new List <Piece>(gameObjectState);
intermediatePhysicalState.Add(InstantiateAsPiece(piece));
return(intermediatePhysicalState.AsReadOnly());
}
private static IReadOnlyList <LogicalPiece> RemoveFromLogicalState(LogicalPiece piece, IReadOnlyList <LogicalPiece> state)
{
List <LogicalPiece> intermediateLogicalState = new List <LogicalPiece>(state);
intermediateLogicalState.Remove(piece);
return(intermediateLogicalState.AsReadOnly());
}
private static IReadOnlyList <LogicalPiece> AddToLogicalState(LogicalPiece piece, IReadOnlyList <LogicalPiece> state)
{
List <LogicalPiece> intermediateLogicalState = new List <LogicalPiece>(state);
intermediateLogicalState.Add(piece);
return(intermediateLogicalState.AsReadOnly());
}
private static IReadOnlyList <Piece> RemoveFromGameObjectState(LogicalPiece piece, IReadOnlyList <Piece> gameObjectState)
{
Piece toRemove = gameObjectState.First(physical => physical.ToLogicalPiece().Equals(piece));
Object.Destroy(toRemove.gameObject);
List <Piece> intermediatePhysicalState = new List <Piece>(gameObjectState);
intermediatePhysicalState.RemoveAll(physical => physical.ToLogicalPiece().Equals(piece));
return(intermediatePhysicalState.AsReadOnly());
}
private Board _Without(LogicalPiece piece, Board board)
{
if (!board.LogicalState.Contains(piece))
{
return(board);
}
var logicalState = RemoveFromLogicalState(piece, board.LogicalState);
return(_isReal ?
new Board(logicalState, RemoveFromGameObjectState(piece, board._physicalState)) :
new Board(logicalState));
}
private Board _With(LogicalPiece piece, Board board)
{
if (board.LogicalState.Contains(piece))
{
return(board);
}
var logicalState = AddToLogicalState(piece, board.LogicalState);
return(_isReal ?
new Board(logicalState, AddToGameObjectState(piece, board._physicalState)) :
new Board(logicalState));
}
private static Piece InstantiateAsPiece(LogicalPiece piece)
{
// this has the very intended sideeffect of actually creating the Piece in the GameWorld.
// Should be I/O but it isn't
return(Object
.Instantiate(
Game.Instance.GetPrefForColor(piece.Color),
new Vector3(piece.X, 0f, piece.Z),
Quaternion.identity
)
.AddComponent <Piece>()
.Init(piece));
}
public Board Without(LogicalPiece piece) => _Without(piece, this);
public Piece Init(LogicalPiece piece)
{
_underlying = piece;
return(this);
}