using System;
using System.Numerics;

namespace gaemstone.Bloxel;

public readonly struct BlockPos
	: IEquatable<BlockPos>
{
	public static readonly BlockPos Origin = default;

	public int X { get; }
	public int Y { get; }
	public int Z { get; }

	public BlockPos(int x, int y, int z) => (X, Y, Z) = (x, y, z);
	public void Deconstruct(out int x, out int y, out int z) => (x, y, z) = (X, Y, Z);

	public Vector3 GetOrigin() => new(X, Y, Z);
	public Vector3 GetCenter() => new(X + 0.5f, Y + 0.5f, Z + 0.5f);


	public BlockPos Add(int x, int y, int z) => new(X + x, Y + y, Z + z);
	public BlockPos Add(in BlockPos other)   => new(X + other.X, Y + other.Y, Z + other.Z);

	public BlockPos Add(BlockFacing facing)
		{ var (x, y, z) = facing; return Add(x, y, z); }
	public BlockPos Add(BlockFacing facing, int factor)
		{ var (x, y, z) = facing; return Add(x * factor, y * factor, z * factor); }

	public BlockPos Add(Neighbor neighbor)
		{ var (x, y, z) = neighbor; return Add(x, y, z); }
	public BlockPos Add(Neighbor neighor, int factor)
		{ var (x, y, z) = neighor; return Add(x * factor, y * factor, z * factor); }


	public BlockPos Subtract(int x, int y, int z) => new(X - x, Y - y, Z - z);
	public BlockPos Subtract(in BlockPos other)   => new(X - other.X, Y - other.Y, Z - other.Z);

	public BlockPos Subtract(BlockFacing facing)
		{ var (x, y, z) = facing; return Subtract(x, y, z); }
	public BlockPos Subtract(BlockFacing facing, int factor)
		{ var (x, y, z) = facing; return Subtract(x * factor, y * factor, z * factor); }

	public BlockPos Subtract(Neighbor neighbor)
		{ var (x, y, z) = neighbor; return Subtract(x, y, z); }
	public BlockPos Subtract(Neighbor neighor, int factor)
		{ var (x, y, z) = neighor; return Subtract(x * factor, y * factor, z * factor); }


	public bool Equals(BlockPos other)
		=> (X == other.X) && (Y == other.Y) && (Z == other.Z);
	public override bool Equals(object? obj)
		=> (obj is BlockPos pos) && Equals(pos);

	public override int GetHashCode() => HashCode.Combine(X, Y, Z);
	public override string ToString() => $"BlockPos({X}:{Y}:{Z})";
	public string ToShortString() => $"{X}:{Y}:{Z}";


	public static BlockPos operator +(BlockPos left, BlockPos right) => left.Add(right);
	public static BlockPos operator -(BlockPos left, BlockPos right) => left.Subtract(right);
	public static BlockPos operator +(BlockPos left, BlockFacing right) => left.Add(right);
	public static BlockPos operator -(BlockPos left, BlockFacing right) => left.Subtract(right);
	public static BlockPos operator +(BlockPos left, Neighbor right) => left.Add(right);
	public static BlockPos operator -(BlockPos left, Neighbor right) => left.Subtract(right);

	public static bool operator ==(BlockPos left, BlockPos right) => left.Equals(right);
	public static bool operator !=(BlockPos left, BlockPos right) => !left.Equals(right);
}

public static class BlockPosExtensions
{
	public static BlockPos ToBlockPos(this Vector3 self)
		=> new((int)MathF.Floor(self.X), (int)MathF.Floor(self.Y), (int)MathF.Floor(self.Z));
}