extends Camera3D

## Owns dart input. The camera does the raycast because the raycast IS a
## camera operation — projecting a screen point into the world.
##
## The dart exposes begin_drag / update_drag / release_drag and never looks
## for the camera itself. This script decides who to call them on.

const RAY_LENGTH := 1000.0

var _held_dart: Dart = null


func _unhandled_input(event: InputEvent) -> void:
	if event is InputEventMouseButton:
		var mb := event as InputEventMouseButton
		if mb.button_index != MOUSE_BUTTON_LEFT:
			return
		if mb.pressed:
			_try_grab(mb.position)
		else:
			_release()

	elif event is InputEventMouseMotion and _held_dart != null:
		_held_dart.update_drag(self, (event as InputEventMouseMotion).position)


func _try_grab(screen_pos: Vector2) -> void:
	var hit := _raycast(screen_pos)
	if hit.is_empty():
		return

	var body = hit.get("collider")
	if body is Dart:
		_held_dart = body as Dart
		# NOTE: two args, not three. The old start_drag(camera, mouse_pos, point)
		# passed mouse_pos but never used it — begin_drag only needs the hit point.
		_held_dart.begin_drag(self, hit["position"])


func _release() -> void:
	if _held_dart == null:
		return
	_held_dart.release_drag()
	_held_dart = null


func _raycast(screen_pos: Vector2) -> Dictionary:
	var params := PhysicsRayQueryParameters3D.create(
		project_ray_origin(screen_pos),
		project_ray_origin(screen_pos) + project_ray_normal(screen_pos) * RAY_LENGTH
	)
	if _held_dart != null:
		params.exclude = [_held_dart.get_rid()]

	return get_world_3d().direct_space_state.intersect_ray(params)