extends CanvasLayer

## 过关界面：集齐钻石后碰到门显示。
## 显示时把整棵树暂停，所以这一层的 process_mode 设成 ALWAYS（见 .tscn），
## 不然暂停后自己的动画和按钮也会停。

@export var fade_time: float = 0.8
@export var button_delay: float = 0.3
## 点「进入下一关」时加载哪个场景。
## 留空 = 重新加载本关；填 res://scenes/level_2.tscn 之类就跳到下一关。
@export_file("*.tscn") var next_level_scene: String = ""

var _fade: ColorRect = null
var _center: CenterContainer = null
var _button: Button = null
var _title: Label = null
var _subtitle: Label = null
var _elapsed: float = 0.0
var _showing: bool = false


func _ready() -> void:
	visible = false
	_fade = get_node_or_null("Fade")
	_center = get_node_or_null("Center")
	_button = get_node_or_null("Center/VBox/NextButton")
	_title = get_node_or_null("Center/VBox/Title")
	_subtitle = get_node_or_null("Center/VBox/Subtitle")
	if _button != null:
		_button.pressed.connect(next_level)
	if _fade != null:
		_fade.color = Color(0.0, 0.0, 0.0, 0.0)
	if _center != null:
		_center.visible = false
	if next_level_scene.is_empty() and _button != null:
		_button.text = "重新开始  (R)"


func show_clear() -> void:
	if _showing:
		return
	_showing = true
	visible = true
	_elapsed = 0.0
	if _title != null:
		_title.text = "过关！"
	if _subtitle != null:
		var player := get_tree().get_first_node_in_group("player")
		var n: int = 0 if player == null else int(player.diamonds)
		_subtitle.text = "钻石 %d / %d" % [n, n]
	get_tree().paused = true


func _process(delta: float) -> void:
	if not _showing:
		return
	_elapsed += delta
	if _fade != null:
		_fade.color = Color(0.0, 0.0, 0.0, clampf(_elapsed / maxf(fade_time, 0.01), 0.0, 1.0))
	if _center != null and _elapsed >= fade_time + button_delay:
		_center.visible = true


func _unhandled_input(event: InputEvent) -> void:
	if not _showing:
		return
	var key := event as InputEventKey
	if key != null and key.pressed and not key.echo:
		if key.physical_keycode == KEY_R or key.physical_keycode == KEY_ENTER:
			next_level()


func next_level() -> void:
	get_tree().paused = false
	if next_level_scene.is_empty():
		get_tree().reload_current_scene()
	else:
		get_tree().change_scene_to_file(next_level_scene)