class_name PropInventory extends Resource

signal current_item_changed(prop_key: String)

# prop_空手 默认就存在，并且不可删除
@export var enabled_items := ["prop_空手"]
@export var current_index := 0:
	set(val):
		if current_index != val:
			val = wrapi(val, 0, enabled_items.size())
			current_index = val
			current_item_changed.emit(enabled_items[current_index])


func current_item_key():
	if enabled_items.size() == 0:
		return null
	return enabled_items[current_index]


func enable_item(prop_key: String) -> void:
	if not enabled_items.has(prop_key):
		enabled_items.append(prop_key)
	# 新增后直接选中
	current_index = enabled_items.find(prop_key)


func disable_item(prop_key: String) -> void:
	if prop_key == "prop_空手":
		printerr("Cannot disable prop_空手")
		return
	# if enabled_items.has(prop_key):
	enabled_items.erase(prop_key)
	# wrap index
	current_index = wrapi(current_index, 0, enabled_items.size())


# return true if the index changed
func index_wrap_add(delta: int) -> bool:
	# auto wrapped in setter
	current_index += delta
	return not enabled_items.is_empty()