namespace Shogi.Domain.Other;

/// <summary>
/// </summary>
/// <typeparam name="TPiece"></typeparam>
/// <param name="boardState">A 2D array of pieces, representing your board. Indexed as [x, y].</param>
public class BoardRules<TPiece>(TPiece?[,] boardState) where TPiece : IRulesLifecycle<TPiece>
{
	private readonly Vector2 MaxIndex = new(boardState.GetLength(0) - 1, boardState.GetLength(1) - 1);

	/// <summary>
	/// Validates a move, invoking the <see cref="IRulesLifecycle{TPiece}.OnMoveValidation(MoveValidationContext{TPiece})"/> callback which you should implement.
	/// A move is considered valid if it could be made legally, ignoring check or check-mate rules.
	/// Check and check-mate verifying happens in a different lifecycle callback.
	/// </summary>
	/// <param name="from">The position of the piece being moved.</param>
	/// <param name="to">The desired destination of the piece being moved.</param>
	/// <param name="isPromotion">TODO</param>
	/// <returns></returns>
	public RulesLifecycleResult ValidateMove(Vector2 from, Vector2 to, bool isPromotion)
	{
		if (IsWithinBounds(from) && IsWithinBounds(to))
		{
			var piece = boardState[(int)from.X, (int)from.Y];
			if (piece == null)
			{
				return new RulesLifecycleResult(IsError: true, $"There is no piece at position {from}.");
			}

			return piece.OnMoveValidation(new MoveValidationContext<TPiece>(from, to, isPromotion, boardState));
		}

		return new RulesLifecycleResult(IsError: true, "test message");
	}


	//foreach (var piece in boardState)
	//{
	//	if (piece != null)
	//	{
	//		var result = piece.OnMoveValidation(new MoveValidationContext<TPiece>(from, to, isPromotion, boardState));
	//		if (result.IsError)
	//		{
	//			return result;
	//		}
	//	}
	//}

	//public int ValidateMove(Vector2 start, Vector2 end)
	//{
	//	if (board.GetLength(0) != boardSize.X || board.GetLength(1) != boardSize.Y)
	//	{
	//		throw new ArgumentException($"2D array dimensions must match boardSize given during {nameof(CreateNewRules)} method.", nameof(board));
	//	}
	//	if (start - start != Vector2.Zero)
	//	{
	//		throw new ArgumentException("Negative values not allowed.", nameof(start));
	//	}
	//	if (end - end != Vector2.Zero)
	//	{
	//		throw new ArgumentException("Negative values not allowed.", nameof(end));
	//	}
	//	if (start.X >= boardSize.X || start.Y >= boardSize.Y)
	//	{
	//		throw new ArgumentException("Start position must be within the given boardSize.", nameof(start));
	//	}
	//	if (end.X >= boardSize.X || end.Y >= boardSize.Y)
	//	{
	//		throw new ArgumentException("End position must be within the given boardSize.", nameof(end));
	//	}

	//	return 0;
	//}

	private bool IsWithinBounds(Vector2 position)
	{
		var isPositive = position - position == Vector2.Zero;
		return isPositive && position.X <= MaxIndex.X && position.Y <= MaxIndex.Y;
	}
}