class_name SaveGameList extends CenterContainer

signal _picked(save_game: SaveGame)

@export var saves: Array[SaveGame]
var save_buttons: Array[SaveGameDisplay]
@export var update_display: bool:
	set(value):
		_load_games()
var scroll_container: ScrollContainer

func _validate_property(property: Dictionary) -> void:
	if property.name == "saves":
		property.usage = PROPERTY_USAGE_READ_ONLY + PROPERTY_USAGE_SCRIPT_VARIABLE + PROPERTY_USAGE_EDITOR


func _ready() -> void:
	get_parent_control().visible = false
	_load_games()

func _ensure_directory() -> void:
	var dir := DirAccess.open(State.user_saves_path)

	# Create dir if needed.
	if DirAccess.get_open_error() == ERR_INVALID_PARAMETER:
		dir = DirAccess.open("user://")
		dir.make_dir_recursive(State.user_saves_path)

	if DirAccess.get_open_error() != OK:
		printerr("Error while opening User Save Directory: %s" % error_string(DirAccess.get_open_error()))


func _load_games():
	_ensure_directory()
	saves = []
	var save_game_dir := DirAccess.open(State.user_saves_path)
	var filepaths: PackedStringArray = save_game_dir.get_files()

	for path in filepaths:
		if path.ends_with(".json"):
			saves.append(SaveGame.new("%s/%s" % [State.user_saves_path, path.get_basename()]))

	saves.append(SaveGame.new())

	_sort_saves()
	_rebuild_buttons()


func _sort_saves() -> void:
	saves.sort_custom(func(a: SaveGame, b: SaveGame) -> int:
		if a.last_saved > b.last_saved:
			return -1
		elif a.last_saved < b.last_saved:
			return 1
		else:
			return 0
	)

func _rebuild_buttons() -> void:
	save_buttons = []
	if scroll_container != null:
		scroll_container.queue_free()

	scroll_container = ScrollContainer.new()

	scroll_container.horizontal_scroll_mode = ScrollContainer.SCROLL_MODE_DISABLED
	scroll_container.custom_minimum_size = Vector2(0, ProjectSettings.get_setting("display/window/size/viewport_height") - 256)
	add_child(scroll_container)

	var save_box := VBoxContainer.new()
	save_box.add_theme_constant_override("separation", 16)
	scroll_container.add_child(save_box)

	for i in range(saves.size()):
		var new_button := SaveGameDisplay.new(saves[i], i+1)
		save_box.add_child(new_button)
		save_buttons.append(new_button)
		new_button.pressed.connect(func(): _on_game_picked(i))


func _on_game_picked(id: int) -> void:
	_picked.emit(saves[id] if id >= 0 && id < saves.size() else SaveGame.new())


func get_most_recent_save() -> SaveGame:
	_sort_saves()
	return saves[0] if saves.size() > 0 else SaveGame.new()

func has_existing_saves() -> bool:
	return saves.size() > 1

func _input(event: InputEvent) -> void:
	if event.is_action_pressed("ui_cancel"):
		cancel()

func cancel()->void:
	get_parent_control().visible = false
	visible = false
	_on_game_picked(-1)

# This function is called when the user us supposed to choose a slot to load or create a new game.
func pick_save_slot() -> SaveGame:
	get_parent_control().visible = true
	visible = true
	save_buttons[0].grab_focus()
	var result = await _picked
	get_parent_control().visible = false
	visible = false
	return result