class_name AutoloadSnapshot
extends RefCounted
## Saves and restores the script variables of autoloads such as Settings and Playlist,
## so a test that changes global state does not leak into the next test.

var _values: Dictionary = {}


## Records the current values of every script variable on [param autoloads].
static func take(autoloads: Array[Node]) -> AutoloadSnapshot:
	var snapshot: AutoloadSnapshot = AutoloadSnapshot.new()
	for autoload: Node in autoloads:
		var values: Dictionary = {}
		for property: Dictionary in autoload.get_property_list():
			if property.usage & PROPERTY_USAGE_SCRIPT_VARIABLE:
				var value: Variant = autoload.get(property.name)
				values[property.name] = (value.duplicate()
						if value is Array || value is Dictionary else value)
		snapshot._values[autoload] = values
	return snapshot


## Puts back the values recorded by [method take].
func restore() -> void:
	for autoload: Node in _values:
		var values: Dictionary = _values[autoload]
		for property_name: String in values:
			autoload.set(property_name, values[property_name])