# (c) 2023-present Eroax
# (c) 2023-present Yagich
# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
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."

	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 parse(input: Dictionary) -> 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, input])
	if expr.has_execute_failed():

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

	return res

func _value_request(_from_port : int) -> Variant:
	var input = await request_value_async(0)
	return parse(input)


func _receive(_on_input_port: int, data: Variant) -> void:
	send(0, parse(data))