int mqtt_client_disconnect()

in src/mqtt_client.c [1317:1379]
55 lines of code
6 McCabe index (conditional complexity)

int mqtt_client_disconnect(MQTT_CLIENT_HANDLE handle, ON_MQTT_DISCONNECTED_CALLBACK callback, void* ctx)
{
    int result;
    MQTT_CLIENT* mqtt_client = (MQTT_CLIENT*)handle;
    if (mqtt_client == NULL)
    {
        /*Codes_SRS_MQTT_CLIENT_07_010: [If the parameters handle is NULL then mqtt_client_disconnect shall return a non-zero value.]*/
        result = MU_FAILURE;
    }
    else
    {
        if (mqtt_client->mqtt_status & MQTT_STATUS_CLIENT_CONNECTED)
        {
            BUFFER_HANDLE disconnectPacket = mqtt_codec_disconnect();
            if (disconnectPacket == NULL)
            {
                /*Codes_SRS_MQTT_CLIENT_07_011: [If any failure is encountered then mqtt_client_disconnect shall return a non-zero value.]*/
                LogError("Error: mqtt_client_disconnect failed");
                mqtt_client->packetState = PACKET_TYPE_ERROR;
                result = MU_FAILURE;
            }
            else
            {
                /* Codes_SRS_MQTT_CLIENT_07_037: [ if callback is not NULL callback shall be called once the mqtt connection has been disconnected ] */
                mqtt_client->disconnect_cb = callback;
                mqtt_client->disconnect_ctx = ctx;
                mqtt_client->packetState = DISCONNECT_TYPE;

                size_t size = BUFFER_length(disconnectPacket);
                /*Codes_SRS_MQTT_CLIENT_07_012: [On success mqtt_client_disconnect shall send the MQTT DISCONNECT packet to the endpoint.]*/
                if (sendPacketItem(mqtt_client, BUFFER_u_char(disconnectPacket), size) != 0)
                {
                    /*Codes_SRS_MQTT_CLIENT_07_011: [If any failure is encountered then mqtt_client_disconnect shall return a non-zero value.]*/
                    LogError("Error: mqtt_client_disconnect send failed");
                    result = MU_FAILURE;
                }
                else
                {
                    if (is_trace_enabled(mqtt_client))
                    {
                        STRING_HANDLE trace_log = STRING_construct("DISCONNECT");
                        log_outgoing_trace(mqtt_client, trace_log);
                        STRING_delete(trace_log);
                    }
                    result = 0;
                }
                BUFFER_delete(disconnectPacket);
            }
            clear_mqtt_options(mqtt_client);
        }
        else
        {
            // If the client is not connected then just close the underlying socket
            mqtt_client->disconnect_cb = callback;
            mqtt_client->disconnect_ctx = ctx;

            close_connection(mqtt_client);
            clear_mqtt_options(mqtt_client);
            result = 0;
        }
    }
    return result;
}