@tool
extends Node

signal archive_loaded

static var archive: AssembledArchive
# current archive
static var user_root_dir := "user://data/"  # must end with "/"
static var archive_dir := "user://data/archives/"
static var archive_prefix := "save"

var archives := {}

var autosave_timer := Timer.new()


func _ready() -> void:
	# 禁用默认退出行为，在 _notification 处理 NOTIFICATION_WM_CLOSE_REQUEST 时保存数据
	get_tree().set_auto_accept_quit(false)
	if not _check_dirs_and_archives():
		_handle_load_error("存档目录", "读写")
		return
	autosave_timer.timeout.connect(_try_auto_save)
	autosave_timer.stop()
	add_child(autosave_timer)
	# config should be loaded first
	load_config()
	# 在 debug or editor 模式下，直接保证有 archive
	if GlobalConfig.DEBUG or Engine.is_editor_hint():
		if archives.size() == 0:
			create_and_use_new_archive()
		else:
			# debug 模式下默认使用 0 号存档
			GlobalConfigManager.config.current_selected_archive_id = 0


func _notification(what):
	# handle window close request
	if what == NOTIFICATION_WM_CLOSE_REQUEST:
		save_all()
		if has_node("/root/Main"):
			print("Saved all success before Quit")
			# 已保存所有数据 [ID:ui_saved_all]
			SceneManager.pop_notification(tr("ui_saved_all"))
			var tree = get_tree()
			tree.create_timer(1.5).timeout.connect(tree.quit)
		else:
			get_tree().quit()


func _on_archive_id_changed():
	var selected_id = GlobalConfigManager.config.current_selected_archive_id
	if selected_id < 0:
		return
	if archive:
		if selected_id != archive.archive_id:
			ResourceSaver.save(archive)
			archive = null
		else:
			return
	if not archives.has(selected_id):
		create_and_use_new_archive(selected_id)
		# 已创建新存档 [ID:ui_new_archive]
		SceneManager.pop_notification(tr("ui_new_archive"))
	else:
		load_archive()


func check_autosave_options():
	if (
		GlobalConfigManager.config.auto_save_enabled
		and archive
		and GlobalConfigManager.config.auto_save_seconds > 1
	):
		# reset left time
		autosave_timer.stop()
		autosave_timer.one_shot = false
		autosave_timer.wait_time = GlobalConfigManager.config.auto_save_seconds
		autosave_timer.start()
	else:
		autosave_timer.stop()

	if GlobalConfig.DEBUG:
		print(
			"check_autosave_option: ",
			GlobalConfigManager.config.auto_save_enabled,
			" wait_time=",
			autosave_timer.wait_time
		)


func _try_auto_save():
	if GlobalConfig.DEBUG:
		print("Auto save")
	if archive and GlobalConfigManager.config.auto_save_seconds > 1:
		save_all()
		# 自动保存成功 [ID:ui_auto_saved]
		SceneManager.pop_notification(tr("ui_auto_saved"))


func _check_dirs_and_archives() -> bool:
	if !DirAccess.dir_exists_absolute(user_root_dir):
		DirAccess.make_dir_recursive_absolute(user_root_dir)
		print("Create user_root_dir:", user_root_dir)
	# Check if the archive directory is accessible
	if !DirAccess.dir_exists_absolute(archive_dir):
		DirAccess.make_dir_recursive_absolute(archive_dir)
		print("Create archive_dir:", archive_dir)
	var archive_dir_access = DirAccess.open(archive_dir)
	if !archive_dir_access:
		_handle_load_error("存档目录", "读取")
		# TODO pop up a dialog to inform the user
		return false
	var files = archive_dir_access.get_files()
	files.sort()
	# get archive number
	for file in files:
		if file.begins_with(archive_prefix) and file.ends_with(GlobalConfig.RES_FILE_FORMAT):
			var id_str = file.get_basename().substr(archive_prefix.length())
			# 低于三位数的 id 会被忽略
			if id_str.length() < 3:
				continue
			var id = int(id_str)
			# 读取范围是 0-99
			if id < 0 or id > 99:
				continue
			var path = archive_dir + file
			if not archives.has(id):
				archives[id] = ResourceLoader.load(
					path, "AssembledArchive", ResourceLoader.CACHE_MODE_REPLACE_DEEP
				)
	return true


# id = -1 means create a new archive, otherwise create an archive with the given id
func create_and_use_new_archive(id := -1) -> void:
	_check_dirs_and_archives()
	var archive_path = _get_archive_path(id)
	if id < 0:
		# 如果 id 小于 0，找到一个新的 id，创建新存档
		id = 0
		# find a new id
		archive_path = _get_archive_path(id)
		while FileAccess.file_exists(archive_path):
			id += 1
			archive_path = _get_archive_path(id)
		_create_and_save_new_archive_resoure(id)
	else:
		# 如果 id 大于等于 0，创建指定 id 的存档
		if FileAccess.file_exists(archive_path):
			_create_and_save_new_archive_resoure(id, true)
		else:
			_create_and_save_new_archive_resoure(id)
	archives[id] = archive
	# this will auto trigger signal and load the new archive
	GlobalConfigManager.config.current_selected_archive_id = id


func _create_and_save_new_archive_resoure(id, take_over_path = false) -> void:
	var archive_path = _get_archive_path(id)
	archive = AssembledArchive.new() as Resource
	if take_over_path:
		archive.take_over_path(archive_path)
	else:
		archive.resource_path = archive_path
	archive.archive_id = id
	archive.created_time = Time.get_datetime_string_from_system(false, true)
	ResourceSaver.save(archive, archive_path)


# 超过 999 个存档会出问题；不过这个游戏不会有这么多存档
func _get_archive_path(id: int) -> String:
	var id_str := ""
	if id < 10:
		id_str = "00" + str(id)
	elif id < 100:
		id_str = "0" + str(id)
	else:
		id_str = str(id)
	return archive_dir + archive_prefix + id_str + GlobalConfig.RES_FILE_FORMAT


func save_all() -> void:
	# save config
	var config = GlobalConfigManager.config
	if config:
		ResourceSaver.save(config)

	# player_global_position
	var player = SceneManager.get_player() as MainPlayer
	# 在此处保存 player 的位置信息
	if archive and player:
		archive.player_global_position_x = player.global_position.x
		archive.player_direction = player.facing_direction
	if archive:
		ResourceSaver.save(archive)
	# reset autosave timer
	check_autosave_options()


func load_config() -> void:
	if GlobalConfigManager.config:
		return
	var path = user_root_dir + "config" + GlobalConfig.RES_FILE_FORMAT
	if FileAccess.file_exists(path):
		var config = ResourceLoader.load(path)
		GlobalConfigManager.config = config
	else:
		var config = GlobalConfig.new()
		GlobalConfigManager.config = config
		ResourceSaver.save(config, path)
	GlobalConfigManager.config.resource_path = path
	if Engine.is_editor_hint():
		return
	# connect signals
	GlobalConfigManager.config.current_selected_archive_id_changed.connect(_on_archive_id_changed)
	GlobalConfigManager.config.auto_save_seconds_changed.connect(check_autosave_options)
	GlobalConfigManager.config.auto_save_enabled_changed.connect(check_autosave_options)


func load_archive() -> void:
	_check_dirs_and_archives()
	var selected_id = GlobalConfigManager.config.current_selected_archive_id
	if archive and selected_id == archive.archive_id:
		return
	if not archives.has(selected_id):
		_handle_load_error(str(selected_id) + " 号存档", "查找")
		return
	archive = archives[selected_id]
	# emit signal
	archive_loaded.emit()
	check_autosave_options()


func _handle_load_error(target, action) -> void:
	var msg = str(target) + " " + str(action) + " 失败，请检查文件访问权限"
	SceneManager.pop_notification(msg)
	printerr(msg)
	# TODO handle error