using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Threading;
using ICPDAS.SmartQ;


namespace WCSMixPubSub
{
    public delegate void ShowRecevieMsgDelegate(string topic,string data);

    public partial class MainForm : Form
    {      
        /*
         * If application must publish or subscribe at the same time
         * the programe must has two PSPARMS structures , 
         * one responses publish works, another responses subscribe works.
         */
        private PSPARMS psparms;

        private Thread subThread;
        private bool subscribing = false;
        private bool threadrunning = false;
        private bool connecting = false;

        //private PSPARMS psp for initial 
        private string clientid = "Client_PC";
        private string pBroker = "192.168.100.58";
        private int port = 1883;
        private string Topic = "MyTopic";
        private ushort keepAliveTime = 32000;
        private int qos = 1;
        private int retain = 0;
        private string lwtTopic = "MyTopic";
        private int lwtQos = 1;
        private int lwtRetain = 0;
        private string lwtData = "Client_PC";
        private string persistDir = "C:\\temp\\wmqtt";

        public MainForm()
        {
            InitializeComponent();

        }

        private void InitializeCustomization()
        {
            //pub structure initialization
            
            psparms = new PSPARMS();
            psparms.clientID = clientid + " pub";
            psparms.pBroker = pBroker;
            psparms.port = port;
            psparms.Topic = "";
            psparms.keepAliveTime = keepAliveTime;
            psparms.qos = qos;
            psparms.retain = retain;
            psparms.lwtTopic = lwtTopic;
            psparms.lwtQos = lwtQos;
            psparms.lwtRetain = lwtRetain;
            psparms.lwtData = lwtData + " pub terminated.";
            psparms.persistDir = persistDir;
            psparms.timeout = 10;

            //subscribe thread initialization
            subThread = new Thread(new ThreadStart(SubscribeThreadWorker));
            subThread.Name = "Subscriber";
            subThread.IsBackground = true;          
        }

        #region Controls Event Handle
        private void MainForm_Load(object sender, EventArgs e)
        {
            InitializeCustomization();
            clientIDTxt.Text = clientid;
            QpIpTxt.Text = pBroker;
            subTopicTxt.Text = Topic;
            pubTopicTxt.Text = Topic;
        }

        private void MainForm_Closing(object sender, CancelEventArgs e)
        {
            //stop receiving
            if (subscribing)
            {
                subscribing = false;
            }
            Thread.Sleep(1000);

            if (connecting)
            {
                /* Disconnect the protocol*/
                MQTTDotNet.ICPDAS_MQIsdpDisconnect(ref psparms);
            }

            /*Close Subscribe Thread*/
            threadrunning = false;
            subThread.Abort();

            /* Terminate and Release memory */
            MQTTDotNet.ICPDAS_MQIsdpTerminate(ref psparms);
        }

        private void ConnBt_Click(object sender, EventArgs e)
        {
            if (!string.IsNullOrEmpty(clientIDTxt.Text) && !string.IsNullOrEmpty(QpIpTxt.Text))
            {
                
                psparms.clientID = clientIDTxt.Text + " pub";
                psparms.pBroker = QpIpTxt.Text;
                psparms.persistDir = persistDir;

                /* Connect to QP-500 */
                if (!connecting)
                {
                    int returncode = MQTTDotNet.ICPDAS_MQIsdpConnect(ref psparms);
                    if (returncode != 0)
                    {
                        MessageBox.Show("Failed to connnect to QP-500 When pubclient connect.\n");
                        return;
                    }
                    MessageBox.Show("Connected to QP-500 Successfully.");
                    connecting = true;
                }
            }            
        }

        private void DisconnBt_Click(object sender, EventArgs e)
        {
            /*Suspend subscribe thread*/
            if (connecting)
            {
                if (subscribing)
                {
                    subscribing = false;
                }
                Thread.Sleep(1000);

                /* Disconnect the protocol*/
                MQTTDotNet.ICPDAS_MQIsdpDisconnect(ref psparms);
                MessageBox.Show("Disconnect to QP-500.");
                connecting = false;
            }
        }

        private void PublishBt_Click(object sender, EventArgs e)
        {
            if (!string.IsNullOrEmpty(pubTopicTxt.Text) && !string.IsNullOrEmpty(pubDataTxt.Text))
            {
                psparms.Topic = pubTopicTxt.Text;
                string pubdata = pubDataTxt.Text;
                MQTTDotNet.ICPDAS_MQIsdpPublish(ref psparms, pubdata, pubdata.Length);
            }
        }

        private void SubBt_Click(object sender, EventArgs e)
        {
            if (!string.IsNullOrEmpty(subTopicTxt.Text))
            {
                psparms.Topic = subTopicTxt.Text;
                MQTTDotNet.ICPDAS_MQIsdpSubscribe(ref psparms);
                MessageBox.Show("Subscribe topic: " + psparms.Topic);
                if (!subscribing)
                {
                    if(subThread!=null && !threadrunning)
                        subThread.Start();
                    subscribing = true;
                }
            }
        }

        private void UnSubBt_Click(object sender, EventArgs e)
        {
            if (!string.IsNullOrEmpty(subTopicTxt.Text))
            {
                psparms.Topic = subTopicTxt.Text;
                MQTTDotNet.ICPDAS_MQIsdpUnsubscribe(ref psparms);
                MessageBox.Show("Unsubscribe topic: " + psparms.Topic);
            }
        }
        #endregion

        private void SubscribeThreadWorker()
        {
            int buffersize = 1024;
            byte[] topicBytes;
            byte[] dataBytes;
            Encoding strencoding = Encoding.UTF8;
            threadrunning = true;
            //MessageBox.Show("Subscribe Thread worker start.");

            while (threadrunning)
            {
                if (subscribing)
                {
                    //this.BeginInvoke(new ShowRecevieMsgDelegate(ShowReceiveMsg), "", "sub thread working");

                    topicBytes = new byte[buffersize];
                    dataBytes = new byte[buffersize];
                    int returncode = MQTTDotNet.ICPDAS_MQIsdpReceive(ref psparms, topicBytes, dataBytes);

                    if (topicBytes[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');
                        this.BeginInvoke(new ShowRecevieMsgDelegate(ShowReceiveMsg), rcvTopic, rcvData);
                    }
                    
                    Thread.Sleep(100);
                }
                else
                {
                    //this.BeginInvoke(new ShowRecevieMsgDelegate(ShowReceiveMsg), "", "Sub Thread sleeping");
                    Thread.Sleep(1000);
                }
            }            
            //MessageBox.Show("Subscribe Thread worker end.");
        }

        private void ShowReceiveMsg(string topic, string data)
        {
            rcvTopicTxt.Text = topic;
            rcvDataTxt.Text = data;
            this.Update();
        }




    }
}