#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2008 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
 *
 * This file is part of HeuristicLab.
 *
 * HeuristicLab is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * HeuristicLab is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
 */
#endregion

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Timers;
using HeuristicLab.Hive.Slave.Common;
using HeuristicLab.Hive.Slave.Communication;
using System.Diagnostics;
using HeuristicLab.Hive.Contracts.BusinessObjects;
using HeuristicLab.Hive.Contracts;
using HeuristicLab.Hive.Slave.Core.ConfigurationManager;
using HeuristicLab.Hive.Slave.Communication.ServerService;
using HeuristicLab.Tracing;
using System.Threading;
//using BO = HeuristicLab.Hive.Contracts.BusinessObjects;

namespace HeuristicLab.Hive.Slave.Core {
  /// <summary>
  /// Heartbeat class. It sends every x ms a heartbeat to the server and receives a Message
  /// </summary>
  public class Heartbeat {

    private bool offline;

    public TimeSpan Interval { get; set; }

    private Thread heartBeatThread;

    private static object locker = new object();

    public Heartbeat() {
      Interval = new TimeSpan(0,0,10);
    }

    public Heartbeat(TimeSpan interval) {
      Interval = interval;
    }

    private WcfService wcfService;

    private bool abortThreadPending;

    /// <summary>
    /// Starts the Heartbeat signal.
    /// </summary>
    public void StartHeartbeat() {
      wcfService = WcfService.Instance;
      wcfService.ProcessHeartBeatCompleted += new EventHandler<ProcessHeartBeatCompletedEventArgs>(wcfService_ProcessHeartBeatCompleted);
      abortThreadPending = false;
      heartBeatThread = GetHeartBeatThread();
      heartBeatThread.Start();
    }

    private Thread GetHeartBeatThread() {
      return new Thread(() => {
        while (!abortThreadPending) {
          lock (locker) {
            // check if cwfService is disconnected for any reason (should happen at first heartbeat)
            // [chn] TODO: Client should always send heartbeats. when calendar disallows he should tell the server he does not want to compute anything
            if (wcfService.ConnState == NetworkEnum.WcfConnState.Disconnected) {
              wcfService.Connect();
            }

            if (wcfService.ConnState == NetworkEnum.WcfConnState.Loggedin) {

              // client is allowed to calculate stuff
              ClientDto info = ConfigManager.Instance.GetClientInfo();
              
              HeartBeatData heartBeatData = new HeartBeatData {
                SlaveId = info.Id,
                FreeCores = info.NrOfCores - ConfigManager.Instance.GetUsedCores(),
                FreeMemory = GetFreeMemory(),
                JobProgress = ConfigManager.Instance.GetProgressOfAllJobs(),
                IsAllowedToCalculate = UptimeManager.Instance.IsOnline() && UptimeManager.Instance.CalendarAvailable
              };

              if (!heartBeatData.IsAllowedToCalculate) {
                // stop all running jobs and send snapshots to server
                MessageQueue.GetInstance().AddMessage(MessageContainer.MessageType.UptimeLimitDisconnect);
              }

              Logger.Debug("Sending Heartbeat: " + heartBeatData);
              wcfService.ProcessHeartBeatAsync(heartBeatData);
            }

          } // lock
          Thread.Sleep(Interval);
        } // while
        abortThreadPending = false;
      });
    }

    private int GetFreeMemory() {
      PerformanceCounter counter = new PerformanceCounter("Memory", "Available Bytes", true);
      int mb = (int)(counter.NextValue() / 1024 / 1024);
      return mb;
    }

    void wcfService_ProcessHeartBeatCompleted(object sender, ProcessHeartBeatCompletedEventArgs e) {
      Logger.Debug("Heartbeat Response received");
      e.Result.ActionRequest.ForEach(mc => MessageQueue.GetInstance().AddMessage(mc));
    }

    public void StopHeartBeat() {
      abortThreadPending = true;
    }
  }
}