@tool
class_name Sign extends TextureRect

# @export var texture: Texture:
# 	set(val):
# 		texture = val
# 		sprite2d.texture = texture
# # @export var base_scale := Vector2.ONE:
# # 	set(val):
# # 		base_scale = val
# # 		sprite2d.scale = base_scale
@export var show_sign := true:
	set(val):
		show_sign = val
		if val:
			modulate.a = 1.0
		else:
			modulate.a = 0.0

signal interacted
signal cancel

# 同时只能有一个物品被激活交互态，其他物品进入等待队列
static var occupied: NodePath
static var _pending_activate_sign := [] as Array[NodePath]
# 使用互斥锁保证线程安全。在操作 occupied 或 _pending_activate_sign 时需要先锁定，操作完成后解锁
static var mutex = Mutex.new()

var activated = false
# var sprite2d = Sprite2D.new()
var base_scale = Vector2.ONE


func _ready() -> void:
	base_scale = scale
	# layer = GlobalConfig.CANVAS_LAYER_FG
	var point_light = get_node_or_null("../PointLight2D")
	if point_light:
		point_light.energy = 0.0
	var area2d = get_node_or_null("../Area2D")
	if area2d:
		area2d.body_entered.connect(activate)
		area2d.body_exited.connect(disactivate)
	if not Engine.is_editor_hint():
		modulate.a = 0


# func _load_sprite() -> void:
# 	sprite2d.texture = texture
# 	sprite2d.scale = base_scale


func activate(_body: Node2D) -> void:
	# point_light.energy = 1.0
	if not is_node_ready():
		await ready
	var path := get_path()
	mutex.lock()
	if occupied and occupied != path:
		_pending_activate_sign.append(path)
		mutex.unlock()
		return
	else:
		occupied = path
		activated = true
	mutex.unlock()
	if activated and show_sign:
		var tween = create_tween()
		tween.tween_property(self, "modulate:a", 1.0, 0.2)
		var p_tween = tween.parallel()
		p_tween.tween_property(self, "scale", base_scale * Vector2(1.2, 1.2), 0.3)
		p_tween.tween_property(self, "scale", base_scale, 0.1)
	# if activated:
		# focus_mode = FOCUS_ALL
		# grab_focus()


func disactivate(_body: Node2D) -> void:
	# release_focus()
	mutex.lock()
	if activated:
		activated = false
		occupied = ""
		while _pending_activate_sign.size() > 0:
			var path = _pending_activate_sign.pop_front()
			var _sign = get_node_or_null(path)
			if _sign:
				_sign.activate(null)
				break
	else:
		# make sure the sign is not in the pending list
		_pending_activate_sign.erase(get_path())
		# double check. because the sign may be activated by other body
		if activated:
			disactivate(_body)
	mutex.unlock()
	# point_light.energy = 0.0
	if show_sign:
		create_tween().tween_property(self, "modulate:a", 0.0, 0.2)


func _unhandled_input(event: InputEvent) -> void:
	if activated:
		if event.is_action_pressed("interact"):
			interacted.emit()
		elif event.is_action_pressed("cancel"):
			cancel.emit()
		get_viewport().set_input_as_handled()