extends CanvasLayer

## 生命值归零后的死亡界面：画面渐黑 + 重新开始按钮。
## 只负责显示和重启，死亡状态由玩家（is_dead）决定。

signal restart_requested

@export var fade_time: float = 1.0
## 渐黑完成后再过多久显示标题和按钮
@export var button_delay: float = 0.4

var _player: Node = null
var _fade: ColorRect = null
var _center: CenterContainer = null
var _button: Button = null
var _elapsed: float = 0.0
var _dying: 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/RestartButton")
	if _button != null:
		_button.pressed.connect(restart)
	if _fade != null:
		_fade.color = Color(0.0, 0.0, 0.0, 0.0)
	if _center != null:
		_center.visible = false


func _process(delta: float) -> void:
	if not _dying:
		if _player == null or not is_instance_valid(_player):
			_player = get_tree().get_first_node_in_group("player")
			if _player == null:
				return
		if bool(_player.is_dead):
			_dying = true
			visible = true
		else:
			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 _dying:
		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:
			restart()


func restart() -> void:
	restart_requested.emit()
	get_tree().paused = false
	get_tree().reload_current_scene()