extends Reference
class_name PolyServiceBuilder

## https://xmpp.org/extensions/xep-0030.html

func request(connection: Connections.Connection) -> Sums.Promise:
    return connection.promise_iq(connection.domain, "get",
        Stanza.disco_items_queury,
        _service_discovery(connection))

func _service_discovery(connection: Connections.Connection) -> Sums.Result:
    var response = yield()
    if not response.is_ok:
        return response

    var query := Stanza.unwrap_query_result(response.value)
    if not query.is_ok:
        return query.value

    var poly_services := Array()
    for item in query.value.children:
        # todo: Do this at the same time, in separate coroutines.
        if not item.is_element() or item.name != "item":
            continue

        var poly_service = load("res://scenes/PolyService.gd").new()
        poly_service.jid = item.attributes["jid"]
        if "name" in item.attributes:
            poly_service.name = item.attributes["name"]

        poly_services.push_back(poly_service)

        var feature_promise = connection.promise_iq(
            item.attributes["jid"], "get", 
            Stanza.disco_info_queury,
            Stanza.yield_as_is())

        if not feature_promise.is_done:
            yield(feature_promise, "done")

        # todo: Propagate error if it's unrelated to service discovery itself.
        if feature_promise.is_ok:
            # If features arrived, - populate services.
            var jid = feature_promise.value.attributes["from"]

            var features := Stanza.unwrap_query_result(feature_promise.value)
            if not features.is_ok:
                # todo: Propagate the error.
                continue

            poly_service.muc = load("res://scenes/MucService.gd").new().try_init(
                connection, jid, features.value)

    return Sums.Result.make_value(poly_services)