@tool

class_name PPTHelper
extends Node2D

signal slide_changed(new_slide_index: int)
signal presentation_finished

## 转场配置数组，按顺序播放
@export var configs: Array[PPTHelperConfig] = []
## 如果为 true, 将在场景加载完成后自动播放
@export var auto_start := true
## 如果为 true, 播放到结尾后将从头开始
@export var loop := false

## 当前激活的配置索引
var current_index := -1
## 动画播放锁，防止在转场时重复触发
var is_playing := false

## 编辑器工具按钮：自动配置 Slides
@export_tool_button("自动配置 Slides") var auto_config_slides = _auto_config_slides


func _ready() -> void:
	if Engine.is_editor_hint():
		return
	if auto_start:
		play()


## 开始或重新开始播放
## @param start_index 从指定的索引开始播放
func play(start_index := 0) -> void:
	if configs.is_empty():
		printerr("PPTHelper: No configs to play.")
		return
	if start_index < 0 or start_index >= configs.size():
		printerr("PPTHelper: 'start_index' is out of bounds.")
		return

	# 重置状态
	is_playing = false
	current_index = -1
	# 隐藏所有页面，准备从头开始
	for config in configs:
		if config and config.canvas_item:
			var node := get_node_or_null(config.canvas_item) as CanvasItem
			if is_instance_valid(node):
				node.modulate.a = 0.0

	# 开始播放指定的页面
	_transition_to(start_index)


## 手动切换到下一个页面
func next() -> void:
	if is_playing or current_index == -1:
		return
	var next_index := current_index + 1
	if next_index >= configs.size():
		if loop:
			next_index = 0
		else:
			presentation_finished.emit()
			print("PPTHelper: Reached the end of the presentation.")
			return
	_transition_to(next_index)


## 跳转到指定的页面
func goto(target_index: int) -> void:
	if target_index < 0 or target_index >= configs.size():
		printerr("PPTHelper: 'target_index' for goto() is out of bounds.")
		return
	if target_index == current_index or is_playing:
		return
	_transition_to(target_index)


# 核心转换函数
func _transition_to(target_index: int) -> void:
	if is_playing:
		return
	is_playing = true
	var from_index := current_index
	var tween: Tween = create_tween()
	tween.set_parallel(true)  # 并行处理 in 和 out 动画
	# --- 处理上一页的 "Ease Out" ---
	if from_index != -1:
		var from_config := configs[from_index]
		var from_node := get_node_or_null(from_config.canvas_item) as CanvasItem
		if is_instance_valid(from_node):
			if from_config.ease_out_duration > 0:
				(
					tween
					. tween_property(from_node, "modulate:a", 0.0, from_config.ease_out_duration)
					. set_trans(_get_trans_type(from_config.ease_out_trans_type))
					. set_ease(_get_ease_type(from_config.ease_out_type))
				)
			else:
				from_node.modulate.a = 0.0
		else:
			printerr("PPTHelper: Invalid node for ease out at index %d." % from_index)

	# --- 处理目标页的 "Ease In" ---
	var target_config := configs[target_index]
	var target_node := get_node_or_null(target_config.canvas_item) as CanvasItem
	if is_instance_valid(target_node):
		if target_config.ease_in_duration > 0:
			target_node.modulate.a = 0.0  # 确保开始时透明
			(
				tween
				. tween_property(target_node, "modulate:a", 1.0, target_config.ease_in_duration)
				. set_trans(_get_trans_type(target_config.ease_in_trans_type))
				. set_ease(_get_ease_type(target_config.ease_in_type))
			)
		else:
			target_node.modulate.a = 1.0
	else:
		printerr("PPTHelper: Invalid node for ease in at index %d." % target_index)
		is_playing = false  # 如果节点无效，立即解锁
		return

	tween.tween_interval(0.001)  # 最小延迟防止无效
	await tween.finished

	# --- 更新状态并检查自动播放下一个 ---
	current_index = target_index
	is_playing = false
	slide_changed.emit(current_index)  # 发射信号

	# 如果配置为自动转到下一个，等待指定时间后执行
	if target_config.ease_out_to_next:
		if target_config.ease_out_wait_time > 0.0:
			await Util.wait(target_config.ease_out_wait_time)
		next()
	else:
		presentation_finished.emit()


# 辅助函数：将字符串映射到 Tween.TransitionType
func _get_trans_type(trans_str: String) -> Tween.TransitionType:
	match trans_str.to_lower():
		"linear":
			return Tween.TRANS_LINEAR
		"sine":
			return Tween.TRANS_SINE
		"cubic":
			return Tween.TRANS_CUBIC
		"quart":
			return Tween.TRANS_QUART
		"quint":
			return Tween.TRANS_QUINT
		"expo":
			return Tween.TRANS_EXPO
		"elastic":
			return Tween.TRANS_ELASTIC
		"bounce":
			return Tween.TRANS_BOUNCE
		"spring":
			return Tween.TRANS_SPRING
		_:
			return Tween.TRANS_LINEAR


# 辅助函数：将字符串映射到 Tween.EaseType
func _get_ease_type(ease_str: String) -> Tween.EaseType:
	match ease_str.to_lower():
		"in":
			return Tween.EASE_IN
		"out":
			return Tween.EASE_OUT
		"inout":
			return Tween.EASE_IN_OUT
		_:
			return Tween.EASE_IN_OUT


#### TOOL BUTTON
func _auto_config_slides() -> void:
	if not Engine.is_editor_hint():
		return  # 只在编辑器中运行
	# 清空现有配置
	configs = []
	# 获取所有直接子节点
	var children := get_children()
	if children.is_empty():
		printerr("PPTHelper: No child nodes found for auto-configuration.")
		notify_property_list_changed()
		return

	# 从下到上配置（反转数组）
	children.reverse()
	var configured_count := 0
	for child in children:
		if child is CanvasItem:
			var config := PPTHelperConfig.new()
			config.canvas_item = get_path_to(child)  # 设置 NodePath 到子节点
			# 其他属性使用默认值（如 ease_in_duration = 0.0 等），可手动调整
			configs.append(config)
			configured_count += 1
		else:
			print("PPTHelper: Skipping non-CanvasItem child: %s" % child.name)

	if configured_count > 0:
		print("PPTHelper: Auto-configured %d slides from child nodes." % configured_count)
	else:
		printerr("PPTHelper: No valid CanvasItem children found for auto-configuration.")

	# 刷新编辑器属性以显示更新
	notify_property_list_changed()