class_name ConversationTurn
extends RefCounted

var _conversation_id: StringName
var _revision := 0
var _speaker: WorldEntityRef
var _listener: WorldEntityRef
var _act: ConversationAct
var _options: Array[ConversationOption] = []
var _causal_topic_ids: Array[StringName] = []
var _reason_trace: Array[StringName] = []
var _terminal := false


func _init(
	conversation_id: StringName = &"",
	revision: int = 0,
	speaker: WorldEntityRef = null,
	listener: WorldEntityRef = null,
	act: ConversationAct = null,
	options: Array[ConversationOption] = [],
	causal_topic_ids: Array[StringName] = [],
	reason_trace: Array[StringName] = [],
	terminal: bool = false
) -> void:
	_conversation_id = conversation_id
	_revision = revision
	_speaker = ConversationSemantic.duplicate_entity(speaker)
	_listener = ConversationSemantic.duplicate_entity(listener)
	_act = act.copy() if act != null else null
	for option in options:
		_options.append(option.copy() if option != null else null)
	_causal_topic_ids = causal_topic_ids.duplicate()
	_reason_trace = reason_trace.duplicate()
	_terminal = terminal


func is_valid() -> bool:
	if (
		not ConversationSemantic.is_valid_id(_conversation_id)
		or _revision <= 0
		or _speaker == null
		or not _speaker.is_valid()
		or _listener == null
		or not _listener.is_valid()
		or _speaker.equals(_listener)
		or _act == null
		or not _act.is_valid()
		or not _act.get_speaker().equals(_speaker)
		or not _act.get_listener().equals(_listener)
		or ConversationSemantic.normalize_id_array(_causal_topic_ids) == null
		or ConversationSemantic.normalize_trace(_reason_trace) == null
	):
		return false
	var seen: Dictionary = {}
	for option in _options:
		if option == null or not option.is_valid() or seen.has(option.get_option_id()):
			return false
		if not option.get_speaker().equals(_listener) or not option.get_listener().equals(_speaker):
			return false
		seen[option.get_option_id()] = true
	return not _terminal or _options.is_empty()


func get_conversation_id() -> StringName:
	return _conversation_id


func get_revision() -> int:
	return _revision


func get_speaker() -> WorldEntityRef:
	return ConversationSemantic.duplicate_entity(_speaker)


func get_listener() -> WorldEntityRef:
	return ConversationSemantic.duplicate_entity(_listener)


func get_act() -> ConversationAct:
	return _act.copy() if _act != null else null


func get_options() -> Array[ConversationOption]:
	var result: Array[ConversationOption] = []
	for option in _options:
		result.append(option.copy())
	return result


func get_option(option_id: StringName) -> ConversationOption:
	for option in _options:
		if option.get_option_id() == option_id:
			return option.copy()
	return null


func get_causal_topic_ids() -> Array[StringName]:
	return _causal_topic_ids.duplicate()


func get_reason_trace() -> Array[StringName]:
	return _reason_trace.duplicate()


func is_terminal() -> bool:
	return _terminal


func copy() -> ConversationTurn:
	return ConversationTurn.new(
		_conversation_id,
		_revision,
		_speaker,
		_listener,
		_act,
		_options,
		_causal_topic_ids,
		_reason_trace,
		_terminal
	)