namespace MinecraftClient.Pathing.Core
{
    /// <summary>
    /// A* search node. Stored in the open/closed sets during pathfinding.
    /// </summary>
    public sealed class PathNode
    {
        public readonly int X;
        public readonly int Y;
        public readonly int Z;

        public double GCost;
        public double HCost;
        public double FCost => GCost + HCost;

        public PathNode? Parent;
        public MoveType MoveUsed;

        public int HeapIndex;
        public bool IsOpen;
        public bool IsClosed;

        public PathNode(int x, int y, int z)
        {
            X = x;
            Y = y;
            Z = z;
        }

        public long PackedPosition => Pack(X, Y, Z);

        public static long Pack(int x, int y, int z)
        {
            // 26 bits for X (0..60M), 26 bits for Z (0..60M), 12 bits for Y (-2048..2047)
            long px = (long)(x + 30_000_000) & 0x3FFFFFF;
            long pz = (long)(z + 30_000_000) & 0x3FFFFFF;
            long py = (long)(y + 2048) & 0xFFF;
            return (px << 38) | (pz << 12) | py;
        }
    }
}