class_name InteractableComponent
extends Node

# 可挂载于任意 Node2D 宿主的交互组件。
# 它统一负责交互锚点、距离过滤、白圈位置和静态动作；复杂宿主可通过
# build_interaction_actions(component, player) 返回多个 InteractionAction。
const GROUP: StringName = &"whaletown_interactable_component"

@export_category("Interaction")
@export var interaction_id: String = ""
@export var interaction_title: String = ""
@export var interaction_priority: int = 100
@export var interaction_distance: float = 150.0
@export var activation_method: StringName = &""
@export var show_marker: bool = true

@export_category("Anchor")
@export var anchor_path: NodePath = NodePath("")

var _host: Node2D

func _ready() -> void:
	_host = get_parent() as Node2D
	if _host == null:
		push_error("InteractableComponent 必须挂在 Node2D 宿主下：%s" % get_path())
		return
	add_to_group(GROUP)

func get_actions(player: Node2D) -> Array[InteractionAction]:
	var actions: Array[InteractionAction] = []
	if player == null or not is_interaction_active():
		return actions
	var distance: float = get_anchor_position().distance_to(player.global_position)
	if distance > interaction_distance:
		return actions
	if _host != null and _host.has_method("build_interaction_actions"):
		var actions_variant: Variant = _host.call("build_interaction_actions", self, player)
		if actions_variant is Array:
			for action_variant: Variant in actions_variant as Array:
				if action_variant is InteractionAction:
					var action: InteractionAction = action_variant as InteractionAction
					if action.is_valid():
						action.distance = distance
						actions.append(action)
			return actions
	var default_action: InteractionAction = _create_default_action()
	if default_action != null:
		default_action.distance = distance
		actions.append(default_action)
	return actions

func get_marker_positions() -> Array[Vector2]:
	if not show_marker or not is_interaction_active():
		return []
	return [get_anchor_position()]

func get_anchor_position() -> Vector2:
	var anchor: Node2D = _resolve_anchor()
	if anchor == null:
		return Vector2.ZERO
	var collision_shape: CollisionShape2D = _first_enabled_collision_shape(anchor)
	return collision_shape.global_position if collision_shape != null else anchor.global_position

func is_interaction_active() -> bool:
	if _host == null:
		return false
	if _host.has_method("is_interaction_active"):
		return bool(_host.call("is_interaction_active", self))
	return true

func _create_default_action() -> InteractionAction:
	if _host == null or activation_method.is_empty() or interaction_id.strip_edges().is_empty() or interaction_title.strip_edges().is_empty():
		return null
	if not _host.has_method(activation_method):
		push_warning("InteractableComponent: %s 不存在方法 %s" % [_host.get_path(), activation_method])
		return null
	return InteractionAction.create(interaction_id, interaction_title, interaction_priority, Callable(_host, activation_method))

func _resolve_anchor() -> Node2D:
	if _host == null:
		return null
	if not anchor_path.is_empty():
		var explicit_anchor: Node2D = _host.get_node_or_null(anchor_path) as Node2D
		if explicit_anchor != null:
			return explicit_anchor
	return _host

func _first_enabled_collision_shape(anchor: Node2D) -> CollisionShape2D:
	var direct_shape: CollisionShape2D = anchor as CollisionShape2D
	if direct_shape != null and not direct_shape.disabled and direct_shape.shape != null:
		return direct_shape
	for child: Node in anchor.get_children():
		var collision_shape: CollisionShape2D = child as CollisionShape2D
		if collision_shape != null and not collision_shape.disabled and collision_shape.shape != null:
			return collision_shape
	return null