AzureIoTResult_t AzureIoTHubClient_UnsubscribeCloudToDeviceMessage()

in source/azure_iot_hub_client.c [987:1025]
35 lines of code
3 McCabe index (conditional complexity)

AzureIoTResult_t AzureIoTHubClient_UnsubscribeCloudToDeviceMessage( AzureIoTHubClient_t * pxAzureIoTHubClient )
{
    AzureIoTMQTTSubscribeInfo_t xMqttSubscription = { 0 };
    AzureIoTMQTTResult_t xMQTTResult;
    AzureIoTResult_t xResult;
    uint16_t usSubscribePacketIdentifier;
    AzureIoTHubClientReceiveContext_t * pxContext;

    if( pxAzureIoTHubClient == NULL )
    {
        AZLogError( ( "AzureIoTHubClient_UnsubscribeCloudToDeviceMessage failed: invalid argument" ) );
        xResult = eAzureIoTErrorInvalidArgument;
    }
    else
    {
        pxContext = &pxAzureIoTHubClient->_internal.xReceiveContext[ azureiothubRECEIVE_CONTEXT_INDEX_C2D ];
        xMqttSubscription.xQoS = eAzureIoTMQTTQoS1;
        xMqttSubscription.pcTopicFilter = ( const uint8_t * ) AZ_IOT_HUB_CLIENT_C2D_SUBSCRIBE_TOPIC;
        xMqttSubscription.usTopicFilterLength = ( uint16_t ) sizeof( AZ_IOT_HUB_CLIENT_C2D_SUBSCRIBE_TOPIC ) - 1;
        usSubscribePacketIdentifier = AzureIoTMQTT_GetPacketId( &( pxAzureIoTHubClient->_internal.xMQTTContext ) );

        AZLogDebug( ( "Attempting to unsubscribe from the MQTT topic: %s", AZ_IOT_HUB_CLIENT_C2D_SUBSCRIBE_TOPIC ) );

        if( ( xMQTTResult = AzureIoTMQTT_Unsubscribe( &( pxAzureIoTHubClient->_internal.xMQTTContext ),
                                                      &xMqttSubscription, 1,
                                                      usSubscribePacketIdentifier ) ) != eAzureIoTMQTTSuccess )
        {
            AZLogError( ( "Cloud to device unsubscribe failed: MQTT error=0x%08x", xMQTTResult ) );
            xResult = eAzureIoTErrorUnsubscribeFailed;
        }
        else
        {
            memset( pxContext, 0, sizeof( AzureIoTHubClientReceiveContext_t ) );
            xResult = eAzureIoTSuccess;
        }
    }

    return xResult;
}