using System;
using System.Collections.Generic;
using System.Text;
using System.Threading;
using ICPDAS.SmartQ;  /*WMQTT includ*/

namespace CSSubExample
{
    class Subscribe
    {
        static void Main(string[] args)
        {
            try
            {
                /* Initial Setting */
                PSPARMS psparms = new PSPARMS();

                long clienidMaxlength = MQTTDotNet.CLIENT_ID_MAXLENGTH;
                string idstr = "Client_Sub_PC";
                if (idstr.Length < clienidMaxlength)
                {
                    psparms.clientID = idstr;
                }
                else
                {
                    throw new Exception("clientID is too long.");
                }                
                psparms.pBroker = "127.0.0.1";
                psparms.port = 1883;
                psparms.Topic = "MyTopic";
                psparms.keepAliveTime = 32000;
                psparms.qos = 1;
                psparms.retain = 0;
                psparms.lwtTopic = "MyTopic";
                psparms.lwtQos = 1;
                psparms.lwtRetain = 0;
                psparms.lwtData = "Client_Sub terminated.";
                psparms.persistDir = "C:\\temp\\wmqtt";
                psparms.timeout = 10000;

                /* Output predefined info */
                Console.WriteLine("ClientID  : " + psparms.clientID.ToString());
                Console.WriteLine("QP-500    : " + psparms.pBroker);
                Console.WriteLine("Port      : " + psparms.port);
                Console.WriteLine("Topic     : " + psparms.Topic);
                Console.WriteLine("QoS       : " + psparms.qos);
                Console.WriteLine("Timeout   : " + psparms.timeout);
                Console.WriteLine("LWTTopic  : " + psparms.lwtTopic);
                Console.WriteLine("LWTQos    : " + psparms.lwtQos);
                Console.WriteLine("LWTRetain : " + ((psparms.retain == 1) ? "true" : "false"));
                Console.WriteLine("******************************************************");

                /* Connect to QP-500 */
                if (MQTTDotNet.ICPDAS_MQIsdpConnect(ref psparms) != 0)
                {
                    Console.WriteLine("Failed to connnect to QP-500\n");
                    string s = Console.ReadLine();
                    return;
                }
                Console.WriteLine("Connect to QP-500 Successfully.");

                /* Subscribe to the specified topic */
                MQTTDotNet.ICPDAS_MQIsdpSubscribe(ref psparms);
                Console.WriteLine("The subscribed topic: {0}", psparms.Topic);
                Thread.Sleep(500);
                
                /* Receive data which is subscribed */
                int buffersize = 1024;
                bool flag = true;
                byte[] topicBytes;
                byte[] dataBytes;
                Encoding strencoding = Encoding.UTF8;

                while (flag)
                {
                    topicBytes = new byte[buffersize];
                    dataBytes = new byte[buffersize];
                    MQISDP rc = (MQISDP)MQTTDotNet.ICPDAS_MQIsdpReceive(ref psparms, topicBytes, dataBytes);
                    if (rc == MQISDP.ConnectionBroken)
                        break;
                    else if ((rc == MQISDP.PubsAvailable) || (rc == MQISDP.Ok))
                    {
                        if (dataBytes[0] != strencoding.GetBytes("\0")[0])
                        {
                            string rcvData = strencoding.GetString(dataBytes, 0, dataBytes.Length).TrimEnd('\0');
                            string rcvTopic = strencoding.GetString(topicBytes, 0, topicBytes.Length).TrimEnd('\0');
                            Console.WriteLine("The received message: TOPIC: " + rcvTopic + ", DATA: " + rcvData);
                        }
                        else    // empty string for exit
                        {
                            flag = false;
                        }
                    }
                }

                /* Unsubscribe */
                MQTTDotNet.ICPDAS_MQIsdpUnsubscribe(ref psparms);
                
                /* Disconnect the protocol*/
                MQTTDotNet.ICPDAS_MQIsdpDisconnect(ref psparms);
                Console.WriteLine("Disconnect to QP-500.");
                
                /* Terminate and Release memory */
                MQTTDotNet.ICPDAS_MQIsdpTerminate(ref psparms);
                
                /* Wait for ending */
                Console.Write("\nWait a second to exit...\n");
                Thread.Sleep(1000);
                return;
            }
            catch (Exception ex)
            {
                Console.WriteLine("****************************EXCEPION MESSAGE**************************");
                Console.WriteLine(ex.Message);
                Console.WriteLine(ex.Data);
                Console.WriteLine(ex.Source);
                Console.WriteLine(ex.StackTrace);
                Console.WriteLine(ex.TargetSite);
                string str = Console.ReadLine();
                return;
            }
        }
    }
}