extends DeckNode

var expr = Expression.new()

func _init():
	name = "Expression"
	node_type = name.to_snake_case()
	description = "A node returning the result of a mathematical expression."
	category = "general"

	props_to_serialize = []

	# TODO: order of ports is changed
	# due to https://github.com/godotengine/godot/issues/85558
	# when it's fixed, switch it back
	add_input_port(
		DeckType.Types.DICTIONARY,
		"Expression Input"
	)

	add_output_port(
		DeckType.Types.ANY,
		"Expression Text",
		"codeblock"
	)



func _value_request(_from_port : int) -> Variant:

	var text = get_output_ports()[0].value_callback.call()

	var err = expr.parse(text, ["deck_var", "input"])
	if err != OK:

		DeckHolder.logger.log_node("Expression parse failed: %s" % err, Logger.LogType.ERROR)
		printerr(err)
		return null


	var res = expr.execute([_belonging_to.variable_stack, request_value(0)])
	if expr.has_execute_failed():

		DeckHolder.logger.log_node("Expression Execution Failed: %s" % text, Logger.LogType.ERROR)
		return null


	return res