using Arch.Core;
using TheLivingWorld.Core.Ecs;
using TheLivingWorld.Core.Geo;
using TheLivingWorld.Core.Worlds;

namespace TheLivingWorld.Core.Systems;

/// <summary>Fills every feature's cached world-space extent from the geometry it points at.</summary>
public sealed class ComputeBoundsSystem : IWorldSystem
{
    private static readonly QueryDescription AreaFeatures = new QueryDescription().WithAll<Outline, Bounds>();
    private static readonly QueryDescription LineFeatures = new QueryDescription().WithAll<Polyline, Bounds>();

    public string Name => nameof(ComputeBoundsSystem);

    public void Execute(GameWorld world)
    {
        var shapes = world.Shapes;

        // Holes are contained by their outline, so the outline alone determines the extent.
        world.Ecs.Query(in AreaFeatures, (ref Outline outline, ref Bounds bounds) =>
        {
            bounds.Value = RectBounds.FromPoints(shapes.Get(outline.ShapeId));
        });

        world.Ecs.Query(in LineFeatures, (ref Polyline line, ref Bounds bounds) =>
        {
            bounds.Value = RectBounds.FromPoints(shapes.Get(line.ShapeId));
        });
    }
}