gaemstone.ECS/src/gaemstone.ECS/Entity+Bare.cs

using System;
using static flecs_hub.flecs;

namespace gaemstone.ECS;

public readonly partial struct Entity
	: IEquatable<Entity>
{
	public static readonly Entity None = default;

	public readonly ecs_entity_t Value;
	public uint NumericId => (uint)Value.Data;

	public bool IsSome => Value.Data != 0;
	public bool IsNone => Value.Data == 0;

	public Entity(ecs_entity_t value) => Value = value;

	public bool Equals(Entity other) => Value.Data == other.Value.Data;
	public override bool Equals(object? obj) => (obj is Entity other) && Equals(other);
	public override int GetHashCode() => Value.Data.GetHashCode();
	public override string? ToString()
		=> IsSome ? $"Entity({Value.Data.Data})"
		          :  "Entity.None";

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

	public static implicit operator Id          (Entity e) => new(e.Value.Data);
	public static implicit operator ecs_entity_t(Entity e) => e.Value;
	public static implicit operator ecs_id_t    (Entity e) => e.Value.Data;

	public static implicit operator Term  (Entity entity) => new(entity);
	public static implicit operator TermId(Entity entity) => new(entity);
}