MoonTools.ECS/src/FilterBuilder.cs

namespace MoonTools.ECS;

public struct FilterBuilder
{
	private ComponentDepot ComponentDepot;
	private HashSet<Type> Included;
	private HashSet<Type> Excluded;

	internal FilterBuilder(ComponentDepot componentDepot)
	{
		ComponentDepot = componentDepot;
		Included = new HashSet<Type>();
		Excluded = new HashSet<Type>();
	}

	private FilterBuilder(ComponentDepot componentDepot, HashSet<Type> included, HashSet<Type> excluded)
	{
		ComponentDepot = componentDepot;
		Included = included;
		Excluded = excluded;
	}

	public FilterBuilder Include<TComponent>() where TComponent : struct
	{
		ComponentDepot.Register<TComponent>();
		Included.Add(typeof(TComponent));
		return new FilterBuilder(ComponentDepot, Included, Excluded);
	}

	public FilterBuilder Exclude<TComponent>() where TComponent : struct
	{
		ComponentDepot.Register<TComponent>();
		Excluded.Add(typeof(TComponent));
		return new FilterBuilder(ComponentDepot, Included, Excluded);
	}

	public Filter Build()
	{
		return ComponentDepot.CreateFilter(Included, Excluded);
	}
}