#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2011 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.Security.Principal;
using System.ServiceProcess;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Windows.Forms.DataVisualization.Charting;
using HeuristicLab.Common;
using HeuristicLab.Core.Views;
using HeuristicLab.MainForm;


namespace HeuristicLab.Clients.Hive.SlaveCore.Views {

  [View("HeuristicLab Slave View")]
  [Content(typeof(SlaveItem), IsDefaultView = true)]
  public partial class SlaveView : ItemView {

    public new SlaveItem Content {
      get { return (SlaveItem)base.Content; }
      set {
        if (base.Content != value) {
          base.Content = value;
        }
      }
    }

    public SlaveView() {
      InitializeComponent();

      if (!CheckRunAsAdmin())
        btnRestartService.Enabled = false;
      btnRestart.Enabled = false;

    }

    #region Register Content Events
    protected override void DeregisterContentEvents() {
      Content.SlaveMessageLogged -= new System.EventHandler<EventArgs<string>>(Content_SlaveMessageLogged);
      Content.SlaveShutdown -= new System.EventHandler(Content_SlaveShutdown);
      Content.SlaveStatusChanged -= new System.EventHandler<EventArgs<StatusCommons>>(Content_SlaveStatusChanged);

      base.DeregisterContentEvents();
    }

    protected override void RegisterContentEvents() {
      base.RegisterContentEvents();

      Content.SlaveMessageLogged += new System.EventHandler<EventArgs<string>>(Content_SlaveMessageLogged);
      Content.SlaveShutdown += new System.EventHandler(Content_SlaveShutdown);
      Content.SlaveStatusChanged += new System.EventHandler<EventArgs<StatusCommons>>(Content_SlaveStatusChanged);
    }
    #endregion

    protected override void OnContentChanged() {
      base.OnContentChanged();
      if (Content == null) {
        //nothing to do...        
      } else {
        //try to establish a connection to the slave service 
        if (base.Content != null) {
          ((SlaveItem)base.Content).Open();
          Task.Factory.StartNew(Connector);
        }
      }
    }

    private void Connector() {
      bool connected = false;
      while (!connected) {
        this.Invoke(new Func<bool>(() => connected = ((SlaveItem)base.Content).ReconnectToSlaveCore()));

        if (!connected) {
          Thread.Sleep(1000);
        }
      }
      this.Invoke(new Action(SetEnabledStateOfControls));
    }

    protected override void SetEnabledStateOfControls() {
      base.SetEnabledStateOfControls();
      //do nothing at the moment, we have nothing editable
    }

    #region Event Handlers
    void Content_SlaveStatusChanged(object sender, EventArgs<StatusCommons> e) {
      RenderChart(e.Value);
    }

    void Content_SlaveShutdown(object sender, System.EventArgs e) {
      txtLog.AppendText("Slave did shutdown" + Environment.NewLine);
      Task.Factory.StartNew(Connector);
    }

    void Content_SlaveMessageLogged(object sender, EventArgs<string> e) {
      txtLog.AppendText(e.Value + Environment.NewLine);
    }
    #endregion

    private void RenderChart(StatusCommons status) {
      jobChart.Series[0].Points.Clear();

      DataPoint pJobs = new DataPoint(status.Jobs.Count, status.Jobs.Count);
      DataPoint pJobsAborted = new DataPoint(status.JobsAborted, status.JobsAborted);
      DataPoint pJobsDone = new DataPoint(status.JobsFinished, status.JobsFinished);
      DataPoint pJobsFetched = new DataPoint(status.JobsFetched, status.JobsFetched);

      pJobs.LegendText = "Current jobs: " + status.Jobs.Count;
      pJobs.Color = System.Drawing.Color.Orange;
      pJobsAborted.LegendText = "Aborted jobs: " + status.JobsAborted;
      pJobsAborted.Color = System.Drawing.Color.Red;
      pJobsDone.LegendText = "Finished jobs: " + status.JobsFinished;
      pJobsDone.Color = System.Drawing.Color.Green;
      pJobsFetched.LegendText = "Fetched jobs: " + status.JobsFetched;
      pJobsFetched.Color = System.Drawing.Color.Blue;

      jobChart.Series[0].Points.Add(pJobs);
      jobChart.Series[0].Points.Add(pJobsAborted);
      jobChart.Series[0].Points.Add(pJobsDone);
      jobChart.Series[0].Points.Add(pJobsFetched);
    }

    private void btnSoftPause_Click(object sender, System.EventArgs e) {
      if (Content != null)
        Content.PauseAll();
    }

    private void btnHardPause_Click(object sender, System.EventArgs e) {
      if (Content != null)
        Content.StopAll();
    }

    private void btnRestart_Click(object sender, System.EventArgs e) {
      if (Content != null) {
        Content.RestartCore();
        btnRestart.Enabled = false;
        btnSleep.Enabled = true;
      }
    }

    private void btnSleep_Click(object sender, System.EventArgs e) {
      if (Content != null) {
        Content.Sleep();
        btnRestart.Enabled = true;
        btnSleep.Enabled = false;
      }
    }

    private void btnAbout_Click(object sender, System.EventArgs e) {
      SlaveAboutDialog diag = new SlaveAboutDialog();
      diag.ShowDialog();
    }

    private void btnRestartService_Click(object sender, EventArgs e) {
      if (CheckRunAsAdmin()) {
        RestartService();
      } else {
        MessageBox.Show("You need to run this application as Administrator to restart the service");
      }
    }

    private bool CheckRunAsAdmin() {
      bool isRunAsAdmin = false;
      WindowsIdentity user = WindowsIdentity.GetCurrent();
      WindowsPrincipal principal = new WindowsPrincipal(user);

      try {
        isRunAsAdmin = principal.IsInRole(WindowsBuiltInRole.Administrator);
      }
      catch { }
      return isRunAsAdmin;
    }

    private void RestartService() {
      string serviceName = "HeuristicLab.Clients.Hive.SlaveCore.SlaveWindowsService";
      TimeSpan timeout = TimeSpan.FromMilliseconds(5000);

      ServiceController service = new ServiceController(serviceName);
      try {
        if (service.Status == ServiceControllerStatus.Running) {
          service.Stop();
          service.WaitForStatus(ServiceControllerStatus.Stopped, timeout);
        }

        service.Start();
        service.WaitForStatus(ServiceControllerStatus.Running, timeout);
      }
      catch (InvalidOperationException ex) {
        MessageBox.Show("Error starting service: Hive Slave Service not found!" + Environment.NewLine + ex.ToString());
      }
      catch (Exception ex) {
        MessageBox.Show("Error starting service, exception is: " + Environment.NewLine + ex.ToString());
      }
    }
  }
}