class_name World extends Node
## Access and flow control for the game world.

@export var pause_enabled := true
@export var save_path := "user://save_state.res"

@export var manager: WorldManager
@export var spook_manager: SpookManager

@export_category("Game Scenes")
@export var initial_level: PackedScene

@export var pause_scene: PackedScene

@export var kill_screen_scene: PackedScene

var current_level: PackedScene

@onready var level_root: Node3D = %LevelRoot
@onready var ui_root: Control = %UIRoot
@onready var save_icon: MarginContainer = %SaveIcon

static var instance: World


func _ready() -> void:
	World.instance = self
	manager.alert_raised.connect(spook_manager.on_alert_raised)
	manager.alert_cleared.connect(spook_manager.on_alert_cleared)
	manager.player_dead.connect(on_player_death)
	load_level(initial_level)


func _unhandled_input(event: InputEvent) -> void:
	if event.is_action_pressed("pause") and pause_enabled:
		pause()


func pause() -> void:
	get_tree().paused = true
	var pause_menu: Control = pause_scene.instantiate()
	ui_root.add_child(pause_menu)
	pause_menu.tree_exiting.connect(unpause)


func unpause() -> void:
	get_tree().paused = false


func load_level(level: PackedScene, save: SaveState = null) -> void:
	for c: Node in level_root.get_children():
		c.queue_free()
		level_root.remove_child(c)
	current_level = level
	print("Instantiating level from ", level.resource_path)
	var level_instance := level.instantiate()
	level_root.add_child(level_instance)
	if save:
		save.load_to_world(self)
	print("Done!")


func on_player_death() -> void:
	var kill_screen: Control = kill_screen_scene.instantiate()
	kill_screen.tree_exiting.connect(on_game_over)
	ui_root.add_child(kill_screen)


func _reload_saved(save: SaveState) -> void:
	load_level(current_level, save)


func on_game_over() -> void:
	# reload the level from the last save
	if ResourceLoader.exists(save_path):
		Game.instance.queue_load(save_path).finally(_reload_saved)
	else:
		load_level(current_level)


func save_progress() -> void:
	print("Preparing save state...")
	save_icon.show()
	var save := SaveState.serialize(self)
	print("Writing save to ", save_path)
	ResourceSaver.save(save, save_path)
	save_icon.hide()
	print("Done!")