namespace AibisDream
{
    /// <summary>
    /// 放置验证结果
    /// </summary>
    public enum PlacementResult
    {
        Success,           // 可以放置
        OutOfBounds,       // 超出边界
        Overlap,           // 与已有块重叠
        InvalidPosition    // 无效位置
    }

    /// <summary>
    /// 放置检测接口
    /// 负责验证形状是否可以放置在指定位置
    /// </summary>
    public interface IPlacementValidator
    {
        /// <summary>
        /// 检查形状是否可以放置在指定位置
        /// </summary>
        /// <param name="grid">网格系统</param>
        /// <param name="shape">要放置的形状</param>
        /// <param name="gridX">网格X坐标（形状左下角位置）</param>
        /// <param name="gridY">网格Y坐标（形状左下角位置）</param>
        /// <returns>放置验证结果</returns>
        PlacementResult CanPlace(IBlockPuzzleGrid grid, IBlockShape shape, int gridX, int gridY);

        /// <summary>
        /// 检查形状是否可以放置在指定位置（详细版本）
        /// </summary>
        /// <param name="grid">网格系统</param>
        /// <param name="shape">要放置的形状</param>
        /// <param name="gridX">网格X坐标（形状左下角位置）</param>
        /// <param name="gridY">网格Y坐标（形状左下角位置）</param>
        /// <param name="failureReason">失败原因（如果返回false）</param>
        /// <returns>是否可以放置</returns>
        bool CanPlaceDetailed(IBlockPuzzleGrid grid, IBlockShape shape, int gridX, int gridY, out PlacementResult failureReason);

        /// <summary>
        /// 获取形状在指定位置的所有占用格子坐标
        /// </summary>
        /// <param name="shape">形状</param>
        /// <param name="gridX">网格X坐标（形状左下角位置）</param>
        /// <param name="gridY">网格Y坐标（形状左下角位置）</param>
        /// <returns>占用格子的网格坐标数组</returns>
        (int x, int y)[] GetOccupiedCells(IBlockShape shape, int gridX, int gridY);
    }
}