#if TOOLS


using System.Security.Cryptography.X509Certificates;

[Tool]
public partial class TerrainPlugin
	: EditorPlugin
{
	public override bool _Handles(GodotObject @object)
		=> @object is Terrain;

	public override void _EnterTree()
	{
		// Initialization of the plugin goes here.
	}

	public override void _ExitTree()
	{
		// Clean-up of the plugin goes here.
	}

	Terrain _previousTerrain = null;
	public override int _Forward3DGuiInput(Camera3D viewportCamera, InputEvent @event)
	{
		if (@event is not InputEventMouse) return (int)AfterGuiInput.Pass;

		if (!IsInstanceValid(_previousTerrain))
			_previousTerrain = null;

		if (RayCastTerrain(viewportCamera) is var (terrain, pos, normal, shape)) {
			if (_previousTerrain != terrain) {
				_previousTerrain?._MouseExit();
				terrain._MouseEnter();
				_previousTerrain = terrain;
			}
			terrain._InputEvent(viewportCamera, @event, pos, normal, shape);
			return viewportCamera.GetViewport().IsInputHandled()
				? (int)AfterGuiInput.Stop : (int)AfterGuiInput.Pass;
		} else {
			_previousTerrain?._MouseExit();
			_previousTerrain = null;
			return (int)AfterGuiInput.Pass;
		}
	}

	(Terrain Terrain, Vector3 Position, Vector3 Normal, int Shape)? RayCastTerrain(Camera3D camera)
	{
		var viewport = camera.GetViewport();
		var mouse    = viewport.GetMousePosition();
		if (!viewport.GetVisibleRect().HasPoint(mouse)) return null;

		var from = camera.ProjectRayOrigin(mouse);
		var to   = from + camera.ProjectRayNormal(mouse) * camera.Far;

		var space  = camera.GetWorld3D().DirectSpaceState;
		var query  = new PhysicsRayQueryParameters3D { From = from, To = to };
		var result = space.IntersectRay(query);
		if (result.Count == 0) return null;

		if ((GodotObject)result["collider"] is not Terrain terrain) return null;
		return (terrain, (Vector3)result["position"], (Vector3)result["normal"], (int)result["shape"]);
	}
}
#endif