using gaemstone.ECS;

namespace gaemstone.Flecs;

[Module, Path("/flecs/core")]
public static class Core
{
	// Entity Tags

	[Tag] public struct Name {  }
	[Tag] public struct Symbol {  }
	[Tag] public struct Alias {  }

	[Tag] public struct Module {  }
	[Tag] public struct Prefab {  }
	[Tag] public struct SlotOf {  }
	[Tag] public struct Disabled {  }
	[Tag] public struct Empty {  }

	// Can't be in a module class with the same name.
	[Path("/flecs/system/System")]
	[Tag] public struct System {  }

	// Entities

	[Entity]    public struct World {  }
	[Path("*")] public struct Wildcard {  }
	[Path("_")] public struct Any {  }
	[Entity]    public struct This {  }
	[Path("$")] public struct Variable {  }
	[Entity]    public struct Flag {  }

	// Entity Relationships

	[Relation, Tag] public struct IsA {  }
	[Relation, Tag] public struct ChildOf {  }
	[Relation, Tag] public struct DependsOn {  }

	// Component / Relationship Properties

	[Tag] public struct Transitive {  }
	[Tag] public struct Reflexive {  }
	[Tag] public struct Symmetric {  }
	[Tag] public struct Final {  }
	[Tag] public struct DontInherit {  }
	[Tag] public struct Tag {  }
	[Tag] public struct Union {  }
	[Tag] public struct Exclusive {  }
	[Tag] public struct Acyclic {  }
	[Relation, Tag] public struct With {  }
	[Tag] public struct OneOf {  }

	// Components

	[Component]
	public readonly struct Component
	{
		public int Size { get; }
		public int Alignment { get; }
	}

	[Relation, Component]
	public readonly struct Identifier
	{
#pragma warning disable IDE0051 // Disable "unused" hint.
#pragma warning disable CS0169  // Disable "unused" warning.
#pragma warning disable CS0649  // Disable "never assigned to" warning.
		private unsafe readonly void* _value;
		private readonly nint _length;
		private readonly ulong _hash;
		private readonly ulong _indexHash;
		private unsafe readonly void* _index;
#pragma warning restore

		public override string? ToString() { unsafe {
			if ((_value == null) || (_length == 0)) return null;
			else return new UTF8View(new(_value, (int)_length)).ToString();
		} }

		public static implicit operator string?(Identifier id)
			=> id.ToString();
	}
}