class_name HoverLightClickArea extends Area2D

signal interacted

@export var freezing := false:
	set(val):
		freezing = val
		if freezing and touching:
			_on_mouse_exited()

var touching = false
static var _focus_mutex = Mutex.new()
static var current_focusing_item = "":
	set(val):
		current_focusing_item = val
		if GlobalConfig.DEBUG:
			print("HoverLightClickArea current_focusing_item=", current_focusing_item)
static var pending_enter_callables := [] as Array[Callable]

# to pointlight2d
var lights: Array[NodePath] = []


func _ready() -> void:
	for c in get_children():
		if c is PointLight2D:
			lights.append(self.get_path_to(c))
	if lights.is_empty():
		printerr("HoverLightButton has no PointLight2D children. auto freezed name=", name)
		freezing = true
	mouse_entered.connect(_on_mouse_entered)
	mouse_exited.connect(_on_mouse_exited)
	# 默认先熄灭
	_toggle_light(false)


func is_focused() -> bool:
	return current_focusing_item == name


func _on_mouse_entered() -> bool:
	touching = true
	if freezing or not is_visible_in_tree():
		return false
	if is_focused():
		return true
	_focus_mutex.lock()
	# 尝试获得 current_focusing_item
	if current_focusing_item != "":
		if not pending_enter_callables.has(_on_mouse_entered):
			pending_enter_callables.append(_on_mouse_entered)
		_focus_mutex.unlock()
		return false
	current_focusing_item = name
	_focus_mutex.unlock()
	_toggle_light(true)
	return true


func _on_mouse_exited() -> void:
	touching = false
	_focus_mutex.lock()
	pending_enter_callables.erase(_on_mouse_entered)
	# frezzing 不影响 mouse exited
	if is_focused():
		current_focusing_item = ""
		for c in pending_enter_callables:
			if c.call():
				break
	_focus_mutex.unlock()
	_toggle_light(false)


func _toggle_light(on: bool) -> void:
	for l in lights:
		var light = get_node(l) as PointLight2D
		if light:
			light.enabled = on


func _input(event: InputEvent) -> void:
	if freezing or Engine.is_editor_hint() or not is_visible_in_tree():
		return
	if event is InputEventMouseButton:
		if event.button_index == MOUSE_BUTTON_LEFT and event.pressed:
			# get_viewport().set_input_as_handled()
			if is_focused():
				interacted.emit()