/*
 *
 *   Copyright (c) 1999 - 2011 my-Channels Ltd
 *   Copyright (c) 2012 - 2017 Software AG, Darmstadt, Germany and/or Software AG USA Inc., Reston, VA, USA, and/or its subsidiaries and/or its affiliates and/or their licensors.
 *
 *   Use, reproduction, transfer, publication or disclosure is prohibited except as specifically provided for in your License Agreement with Software AG.
 *
 */
using System;
using com.pcbsys.nirvana.client;

namespace com.pcbsys.nirvana.apps
{
    /// <summary>
    /// This sample demonstrates how an nDataStreamListener application can be created. It simply calls the nSession.init passing in the nDataStreamListener instance
    /// and implements the onMessage callback.
    /// </summary>
    class DataStreamListener : nSampleApp, nDataStreamListener
    {

        private static System.Text.UTF8Encoding encoding = new System.Text.UTF8Encoding();

        private long lastEID = 0;
        private DateTime startTime;
        private long byteCount = 0;

        private int logLevel = 0;
        private int count = -1;
        private int totalMsgs = 0;
        private int reportCount = 10000;

        private static DataStreamListener mySelf = null;

        /**
         * This method demonstrates the Nirvana API calls necessary to consume data from nDataGroup objects
         * 
         * It is called after all command line arguments have been received and
         * validated
         *
         * @param realmDetails a String[] containing the possible RNAME values
         * @param loglvl the specified log level
         * @param repCount the specified report count
         */
        private void doit(String[] realmDetails, int loglvl, int repCount)
        {
            mySelf.constructSession(realmDetails, this);

            logLevel = loglvl;
            reportCount = repCount;

            try
            {
                //Stay subscribed until the user presses any key
                Console.WriteLine("Press any key to quit !");
                try
                {
                    Console.Read();
                }
                catch (Exception ) { } //Ignore this

                Console.WriteLine("Finished. Consumed total of " + totalMsgs);
                //Close the session we opened
                try
                {
                    nSessionFactory.close(mySession);
                }
                catch (Exception ) { }
                //Close any other sessions so that we can exit
                nSessionFactory.shutdown();

            }
            catch (nSessionPausedException )
            {
                Console.WriteLine("Session has been paused, please resume the session");
                Environment.Exit(1);
            }
            catch (nSecurityException )
            {
                Console.WriteLine("Unsufficient permissions for the requested operation.");
                Console.WriteLine("Please check the ACL settings on the server.");
                Environment.Exit(1);
            }
            catch (nSessionNotConnectedException )
            {
                Console.WriteLine("The session object used is not physically connected to the Nirvana realm.");
                Console.WriteLine("Please ensure the realm is up and check your RNAME value.");
                Environment.Exit(1);
            }
            catch (nUnexpectedResponseException )
            {
                Console.WriteLine("The Nirvana REALM has returned an unexpected response.");
                Console.WriteLine("Please ensure the Nirvana REALM and client API used are compatible.");
                Environment.Exit(1);
            }
            catch (nRequestTimedOutException )
            {
                Console.WriteLine("The requested operation has timed out waiting for a response from the REALM.");
                Console.WriteLine("If this is a very busy REALM ask your administrator to increase the client timeout values.");
                Environment.Exit(1);
            }
        }


        protected override void processArgs(String[] args)
        {
            //
            // Need a min of 1, rname
            if (args.Length < 1)
            {
                Usage();
                Environment.Exit(2);
            }
            String RNAME = args[0]; ;

            var loglvl = 3;
            if (args.Length > 1)
            {
                loglvl = Convert.ToInt32(args[1]);
            }
            //
            // Optional Parameters
            //
            var report = 1000;
            //Check for a selector message filter value
            if (args.Length > 2)
            {
                report = Convert.ToInt32(args[2]);
            }
            //
            // Run the sample app
            //
            mySelf.doit(parseRealmProperties(RNAME), loglvl, report);
        }


        public static void Main(String[] args)
        {

            //Create an instance for this class
            mySelf = new DataStreamListener();

            //Process command line arguments

            mySelf.processArgs(args);
        }

        /**
         * Prints the usage message for this class
         */
        private static void Usage()
        {
            Console.WriteLine("Usage ...\n");
            Console.WriteLine("DataGroupListener <rname> [debug] [count] \n");

            Console.WriteLine(
              "<Required Arguments> \n");
            Console.WriteLine(
              "<rname> - the rname of the server to connect to");
            Console.WriteLine(
              "\n[Optional Arguments] \n");
            Console.WriteLine(
              "[debug] - The level of output from each event, 0 - none, 1 - summary, 2 - EIDs, 3 - All");
            Console.WriteLine(
              "[count] - The number of events to wait before printing out summary information");
        }

        /**
         * A callback is received by the API to this method each time an event is received from
         * the nirvana channel. Be carefull not to spend too much time processing the message
         * inside this method, as until it exits the next message can not be pushed.
         *
         * @param evt An nConsumeEvent object containing the message received from the channel
         */
        public void onMessage(nConsumeEvent evt)
        {
            //If this is the first message we receive
            if (count == -1)
            {
                //Get a timestamp to be used for message rate calculations
                startTime = DateTime.Now;
                count = 0;
            }

            //Increment he counter
            count++;
            totalMsgs++;

            //Have we reached the point where we need to report the rates?
            if (count == reportCount)
            {

                //Reset the counter
                count = 0;

                //Get a timestampt to calculate the rates
                DateTime end = DateTime.Now;

                // Does the specified log level permits us to print on the screen?
                if (logLevel >= 1)
                {

                    //Dump the rates on the screen
                    if (!end.Equals(startTime))
                    {
                        TimeSpan ts = end - startTime;
                        double milli = ts.TotalMilliseconds;
                        Console.WriteLine("Received " + reportCount + " in " + (milli) + " Evt/Sec = " + ((reportCount * 1000) / (milli)) + " Bytes/sec=" + ((byteCount * 1000) / (milli)));
                        Console.WriteLine("Bandwidth data : Bytes Tx [" + mySession.getOutputByteCount() + "] Bytes Rx [" + mySession.getInputByteCount() + "]");
                    }
                    else
                    {
                        Console.WriteLine("Received " + reportCount + " faster than the system millisecond counter");
                    }
                }
                //Set the startTime for the next report equal to the end timestamp for the previous one
                startTime = end;

                //Reset the byte counter
                byteCount = 0;
            }

            //If the last EID counter is not equal to the current event ID
            if (lastEID != evt.getEventID())
            {
                //If yes, maybe we have missed an event, so print a message on the screen.
                //This message could be printed for a number of other reasons.
                //One of them would be someone purging a range creating an 'eid gap'.
                //As eids are never reused within a channel you could have a situation
                //where this gets printed but nothing is missed.
                Console.WriteLine("Expired event range " + (lastEID) + " - " + (evt.getEventID() - 1));
                //Reset the last eid counter
                lastEID = evt.getEventID() + 1;
            }
            else
            {

                //Increment the last eid counter
                lastEID++;
            }
            //Get the data of the message
            byte[] buffer = evt.getEventData();
            if (buffer != null)
            {
                //Add its length to the byte counter
                byteCount += buffer.Length;
            }
            //If the loglevel permits printing on the screen
            if (logLevel >= 2)
            {
                //Print the eid
                Console.WriteLine("Event id : " + evt.getEventID());
                if (evt.isEndOfChannel())
                {
                    Console.WriteLine("End of channel reached");
                }
                //If the loglevel permits printing on the screen
                if (logLevel >= 3)
                {
                    //Print the message tag
                    Console.WriteLine("Event tag : " + evt.getEventTag());
                    //Print the message data
                    Console.WriteLine("Event data : " + encoding.GetString(evt.getEventData()));
                    if (evt.hasAttributes())
                    {
                        displayEventAttributes(evt.getAttributes());
                    }

                    nEventProperties prop = evt.getProperties();
                    if (prop != null)
                    {
                        displayEventProperties(prop);
                    }
                }
            }
        }
    }
}