#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2012 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.ComponentModel;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Reflection;
using HeuristicLab.PluginInfrastructure;
using HeuristicLab.DataImporter.DbExplorer.Interfaces;
using HeuristicLab.DataImporter.Data;
using HeuristicLab.DataImporter.Data.CommandBase;
using HeuristicLab.DataImporter.Data.Model;
using HeuristicLab.DataImporter.Data.View;
using HeuristicLab.DataImporter.DataProcessor.Command;
using System.Xml;
using HeuristicLab.Persistence.Default.Xml;

namespace HeuristicLab.DataImporter.DataProcessor {
  public partial class DataProcessorView : Form {
    private DataSetView dataSetView;
    private BackgroundWorker backgroundWorker;
    private string lastSavedFile;
    private ICommand lastSavedCommand;
    private ProgressDialog progressDlg;

    private DataProcessorView() {
      InitializeComponent();
      this.HScroll = false;
      this.HorizontalScroll.Visible = false;
      backgroundWorker = new BackgroundWorker();
      backgroundWorker.WorkerReportsProgress = true;
      backgroundWorker.DoWork += new DoWorkEventHandler(backgroundWorker_DoWork);
      backgroundWorker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(backgroundWorker_RunWorkerCompleted);
      backgroundWorker.ProgressChanged += new ProgressChangedEventHandler(backgroundWorker_ProgressChanged);
    }

    public DataProcessorView(DataProcessor dataProcessor)
      : this() {
      this.dataProcessor = dataProcessor;
      this.dataProcessor.CommandChain.Changed += this.CommandChainChanged;
      this.dataSetView = new DataSetView(this.dataProcessor.DataSet, this.dataProcessor.CommandChain);
      this.dataSetView.StateChanged += new EventHandler(DataSetStateChanged);
      this.dataSetView.Dock = DockStyle.Fill;
      this.dataSetView.ColumnGroupMaxWidth = this.splitContainer1.Panel2.Width;
      this.splitContainer1.Panel2.Controls.Add(this.dataSetView);
      this.splitContainer1.Panel2.Resize += new EventHandler(Panel2_Resize);
      FillItemList();

      IDbExplorer[] explorers = ApplicationManager.Manager.GetInstances<IDbExplorer>().ToArray();
      ToolStripItem item;
      foreach (IDbExplorer exp in explorers) {
        item = new ToolStripMenuItem();
        item.Text = exp.MenuItemDescription;
        item.Tag = exp;
        item.Click += new EventHandler(setGenericDBConnectionToolStripMenuItem_Click);
        databaseToolStripMenuItem.DropDownItems.Add(item);
      }
    }

    private DataProcessor dataProcessor;
    public DataProcessor DataProcessor {
      get { return this.dataProcessor; }
    }

    private bool UndoEnabled {
      get { return this.undoToolStripButton.Enabled; }
      set { this.undoToolStripButton.Enabled = value; this.undoToolStripMenuItem.Enabled = value; }
    }
    private bool RedoEnabled {
      get { return this.redoToolStripButton.Enabled; }
      set { this.redoToolStripButton.Enabled = value; this.redoToolStripMenuItem.Enabled = value; }
    }

    private bool SaveCommandChainEnabled {
      get { return this.saveCommandChainToolStripButton.Enabled; }
      set { this.saveCommandChainToolStripButton.Enabled = value; }
    }

    #region CommandList

    private void listCommands_MouseDoubleClick(object sender, MouseEventArgs e) {
      ListViewItem item = listCommands.HitTest(e.Location).Item;
      if (item != null) {
        ICommandGenerator generator = (ICommandGenerator)listCommands.FocusedItem;
        if (generator.Enabled(dataSetView.State)) {
          ICommand cmd = ((ICommandGenerator)generator).GenerateCommand(dataProcessor.DataSet);
          if (cmd != null) {
            try {
              dataProcessor.CommandChain.Add(cmd);
            }
            catch (CommandExecutionException cee) {
              MessageBox.Show(cee.Message, cee.Command.Description);
            }
          }
        }
      }
      item.Selected = false;
    }

    private void FillItemList() {
      //sort after ViewableCommandInfoAttribute
      IEnumerable<Type> commands = ApplicationManager.Manager.GetTypes(typeof(ICommand)).Select(t => new {
        Command = t,
        Attribute = (ViewableCommandInfoAttribute)Attribute.GetCustomAttribute(t, typeof(ViewableCommandInfoAttribute))
      })
         .Where(t => t.Attribute != null && !t.Command.IsAbstract)
        .OrderBy(t => t.Attribute, new AttributeComparer())
        .Select(t => t.Command);
      ListViewItem item = null;
      bool addGroup;
      foreach (Type t in commands) {
        item = (ListViewItem)Activator.CreateInstance(typeof(CommandListViewItem<>).MakeGenericType(t));
        addGroup = true;
        foreach (ListViewGroup grp in listCommands.Groups)
          if (grp.Name == item.Group.Name) {
            item.Group = grp;
            addGroup = false;
            break;
          }
        if (addGroup) {
          listCommands.Groups.Add(item.Group);
        }
        listCommands.Items.Add(item);
      }
      UpdateListViewItems();
    }

    public void DataSetStateChanged(object sender, EventArgs e) {
      UpdateListViewItems();
    }

    private void UpdateListViewItems() {
      foreach (ICommandGenerator generator in listCommands.Items) {
        if (generator.Enabled(dataSetView.State))
          ((ListViewItem)generator).ForeColor = Color.Black;
        else
          ((ListViewItem)generator).ForeColor = Color.LightGray;
      }
    }
    #endregion

    private void CommandChainChanged(object sender, EventArgs e) {
      #region undo & redo updates
      this.UndoEnabled = !this.dataProcessor.CommandChain.FirstCommandReached;
      this.RedoEnabled = !this.dataProcessor.CommandChain.LastCommandReached;
      this.SaveCommandChainEnabled = !this.dataProcessor.CommandChain.FirstCommandReached;
      this.undoToolStripButton.ToolTipText = this.dataProcessor.CommandChain.PreviousCommandDescription;
      this.redoToolStripButton.ToolTipText = this.dataProcessor.CommandChain.NextCommandDescription;

      //needed to update tooltip if it is currently being shown - taken from 
      //http://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=167320
      System.Reflection.FieldInfo f = this.toolStrip.GetType().GetField("currentlyActiveTooltipItem", System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic);
      if (object.ReferenceEquals(f.GetValue(this.toolStrip), this.undoToolStripButton)) {
        // Need to set currentlyActiveTooltipItem to null, so the call to UpdateToolTip actually does the update
        f.SetValue(this.toolStrip, null);
        System.Reflection.MethodInfo m = this.toolStrip.GetType().GetMethod("UpdateToolTip", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance);
        m.Invoke(this.toolStrip, new object[] { this.undoToolStripButton });
      }
      f = this.toolStrip.GetType().GetField("currentlyActiveTooltipItem", System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic);
      if (object.ReferenceEquals(f.GetValue(this.toolStrip), this.redoToolStripButton)) {
        // Need to set currentlyActiveTooltipItem to null, so the call to UpdateToolTip actually does the update
        f.SetValue(this.toolStrip, null);
        System.Reflection.MethodInfo m = this.toolStrip.GetType().GetMethod("UpdateToolTip", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance);
        m.Invoke(this.toolStrip, new object[] { this.redoToolStripButton });
      }
      #endregion

      #region macro recording
      Bitmap image;
      string toolTipText;
      if (dataProcessor.CommandChain.IsMacroRecording) {
        image = Properties.Resources.StopHS;
        toolTipText = "Stop Macro recording";
      } else {
        image = Properties.Resources.RecordHS;
        toolTipText = "Start Macro recording";
      }

      recordMacroToolStripButton.Image = image;
      recordMacroToolStripButton.ToolTipText = toolTipText;
      f = this.toolStrip.GetType().GetField("currentlyActiveTooltipItem", System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic);
      if (object.ReferenceEquals(f.GetValue(this.toolStrip), this.recordMacroToolStripButton)) {
        // Need to set currentlyActiveTooltipItem to null, so the call to UpdateToolTip actually does the update
        f.SetValue(this.toolStrip, null);
        System.Reflection.MethodInfo m = this.toolStrip.GetType().GetMethod("UpdateToolTip", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance);
        m.Invoke(this.toolStrip, new object[] { this.recordMacroToolStripButton });
      }
      #endregion

      if (!string.IsNullOrEmpty(lastSavedFile)) {
        if (lastSavedCommand != this.dataProcessor.CommandChain.LastExecutedCommand && !lastSavedFile.Contains('*'))
          this.Text = "Data Importer - " + lastSavedFile + "*";
        else
          this.Text = "Data Importer - " + lastSavedFile;
      }
    }

    private void chbReorderColumns_CheckedChanged(object sender, EventArgs e) {
      this.dataSetView.AllowReorderColumns = chbReorder.CheckBoxControl.Checked;

      if (chbReorder.CheckBoxControl.Checked) {
        foreach (ListViewItem item in listCommands.Items)
          item.ForeColor = Color.LightGray;
        listCommands.Enabled = false;
      } else {
        Dictionary<string, int[]> dictionary = new Dictionary<string, int[]>();
        int[] displayIndices;
        for (int i = this.dataSetView.Controls.Count - 1; i >= 0; i--) {
          displayIndices = ((ColumnGroupView)this.dataSetView.Controls[i]).DisplayIndexes;
          //check if displayIndices are ordered, otherwise the array is added to the list
          for (int j = 0; j < displayIndices.Length; j++) {
            if (j != 0 && ((displayIndices[j] - displayIndices[j - 1]) != 1)) {
              ColumnGroup columnGroup = this.dataSetView.DataSet.ColumnGroups.ElementAt(this.dataSetView.Controls.Count - 1 - i);
              dictionary[columnGroup.Name] = displayIndices;
              break;
            }
          }
        }
        if (dictionary.Count != 0)
          this.dataProcessor.CommandChain.Add(new ReorderColumnsCommand(this.dataProcessor.DataSet, dictionary));

        listCommands.Enabled = true;
        UpdateListViewItems();
      }
    }

    private void UpdateDataSetView() {
      this.dataSetView.Dispose();
      this.dataSetView = new DataSetView(this.dataProcessor.DataSet, this.dataProcessor.CommandChain);
      this.dataSetView.StateChanged += new EventHandler(DataSetStateChanged);
      UpdateListViewItems();

      this.dataSetView.Dock = DockStyle.Fill;
      this.splitContainer1.Panel2.Controls.Clear();
      this.splitContainer1.Panel2.Controls.Add(this.dataSetView);
      this.dataSetView.ColumnGroupMaxWidth = this.splitContainer1.Panel2.Width;
      this.dataProcessor.CommandChain.Changed += this.CommandChainChanged;
      GC.Collect();
    }

    private void Panel2_Resize(object sender, EventArgs e) {
      this.dataSetView.ColumnGroupMaxWidth = this.splitContainer1.Panel2.Width;
    }


    #region BackgroundWorker
    private void backgroundWorker_DoWork(object sender, DoWorkEventArgs e) {
      CommandChain temp = (CommandChain)e.Argument;
      int i = 0;
      int max = temp.CommandsCount;
      foreach (DataSetCommandBase cmd in temp) {
        //update description
        backgroundWorker.ReportProgress(i * 100 / max, cmd.Description);
        cmd.DataSet = dataProcessor.DataSet;
        if (cmd is DatabaseCommandBase)
          ((DatabaseCommandBase)cmd).DbExplorer = this.dataProcessor.DatabaseExplorer;
        this.dataProcessor.CommandChain.Add(cmd, false);
        i++;
      }
    }

    private void backgroundWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e) {
      progressDlg.ProgressBar.Value = 100;
      progressDlg.Refresh();
      this.Enabled = true;
      UpdateDataSetView();
      progressDlg.Close();
      if (e.Error != null) {
        string message = e.Error.Message;
        if (e.Error is CommandExecutionException)
          message += Environment.NewLine + "Command: " +
            ((CommandExecutionException)e.Error).Command.GetType().ToString();
        MessageBox.Show(message, "Error occured during loading of command chain");
      }
      this.dataProcessor.CommandChain.FireChanged();
    }

    private void backgroundWorker_ProgressChanged(object sender, ProgressChangedEventArgs e) {
      progressDlg.Label.Text = (string)e.UserState;
      progressDlg.ProgressBar.Value = e.ProgressPercentage;
      progressDlg.Refresh();
    }
    #endregion

    #region GUI actions
    private void NewFile() {
      if (!CheckUnsavedChanges())
        return;
      this.DataProcessor.Reset();
      this.lastSavedFile = "";
      this.Text = "Data Importer";
      UpdateDataSetView();
    }

    private void Open() {
      if (!CheckUnsavedChanges())
        return;
      OpenFileDialog dlg = new OpenFileDialog();
      dlg.Filter = "DataImporter file (*.dhl)|*.dhl|All files (*.*)|*.*";
      dlg.RestoreDirectory = true;
      if (dlg.ShowDialog() == DialogResult.OK) {
        try {
          DataProcessor dp = (DataProcessor)XmlParser.Deserialize(dlg.FileName);
          dp.DatabaseExplorer = this.dataProcessor.DatabaseExplorer;
          this.lastSavedFile = dlg.FileName;
          this.Text = "Data Importer - " + lastSavedFile;
          this.dataProcessor.Reset();
          this.dataProcessor = dp;
        }
        catch (XmlException e) {
          MessageBox.Show(e.Message, "Error occured during file open.");
        }
        finally {
          this.lastSavedCommand = null;
          UpdateDataSetView();
          this.dataProcessor.CommandChain.FireChanged();
        }
      }
    }

    private bool CheckUnsavedChanges() {
      if (this.lastSavedCommand != this.dataProcessor.CommandChain.LastExecutedCommand) {
        DialogResult result = MessageBox.Show("Save changes (Yes), discard changes (No) or cancel the current action (Cancel)?", "Warning", MessageBoxButtons.YesNoCancel);
        if (result == DialogResult.Yes)
          this.Save();
        else if (result == DialogResult.Cancel)
          return false;
      }
      return true;
    }

    private void Save() {
      if (string.IsNullOrEmpty(this.lastSavedFile))
        this.SaveAs();
      else
        this.Save(this.lastSavedFile);
    }

    private void Save(string filename) {
      try {
        this.Cursor = Cursors.WaitCursor;
        XmlGenerator.Serialize(this.dataProcessor, filename,9);
        this.Cursor = Cursors.Default;
        this.Text = "Data Importer - " + lastSavedFile;
        this.lastSavedCommand = this.dataProcessor.CommandChain.LastExecutedCommand;
      }
      finally {
        this.Cursor = Cursors.Default;
      }
    }

    private void SaveAs() {
      SaveFileDialog saveFileDialog = new SaveFileDialog();
      saveFileDialog.AddExtension = true;
      saveFileDialog.RestoreDirectory = true;
      saveFileDialog.DefaultExt = "dhl";
      saveFileDialog.Filter = "DataImporter file (*.dhl)|*.dhl|All files (*.*)|*.*";

      if (saveFileDialog.ShowDialog() == DialogResult.OK) {
        this.lastSavedFile = saveFileDialog.FileName;
        this.Save(this.lastSavedFile);
      }
    }

    private void RecordMacro() {
      if (dataProcessor.CommandChain.IsMacroRecording)
        this.SaveCommandChain();
      this.dataProcessor.CommandChain.ToggleMacroRecording();
    }

    private void OpenCommandChain() {
      OpenFileDialog dlg = new OpenFileDialog();
      dlg.Filter = "DataImporter Command file (*.dhlcmd)|*.dhlcmd|All files (*.*)|*.*";
      dlg.RestoreDirectory = true;
      if (dlg.ShowDialog() == DialogResult.OK) {
        this.dataSetView.Dispose();
        this.Cursor = Cursors.WaitCursor;
        this.Enabled = false;
        try {
          CommandChain temp = (CommandChain)XmlParser.Deserialize(dlg.FileName);
          progressDlg = new ProgressDialog();
          progressDlg.DesktopLocation = new Point(this.Location.X + this.Width / 2 - progressDlg.Width / 2, this.Location.Y + this.Height / 2 - progressDlg.Height / 2);
          backgroundWorker.RunWorkerAsync(temp);
          progressDlg.ShowDialog();
          this.Refresh();
        }
        finally {
          this.Enabled = true;
          this.Cursor = Cursors.Default;
        }
      }
    }

    private void SaveCommandChain() {
      SaveFileDialog saveFileDialog = new SaveFileDialog();
      saveFileDialog.AddExtension = true;
      saveFileDialog.RestoreDirectory = true;
      saveFileDialog.DefaultExt = "dhlcmd";
      saveFileDialog.Filter = "DataImporter Command file (*.dhlcmd)|*.dhlcmd|All files (*.*)|*.*";

      if (saveFileDialog.ShowDialog() == DialogResult.OK) {
        try {
          this.Cursor = Cursors.WaitCursor;
          XmlGenerator.Serialize(this.dataProcessor.CommandChain, saveFileDialog.FileName,9);
        }
        finally {
          this.Cursor = Cursors.Default;
        }
      }
    }

    private void Export() {
      ExportDialog exportDlg = new ExportDialog(this.dataProcessor.DataSet);
      exportDlg.StartPosition = FormStartPosition.CenterParent;
      exportDlg.ShowDialog(this);
    }

    private void Import() {
      ImportDialog importDlg = new ImportDialog(this.dataProcessor.DataSet, this.dataProcessor.CommandChain);
      importDlg.StartPosition = FormStartPosition.CenterParent;
      importDlg.ShowDialog(this);
    }

    private void Undo() {
      this.dataProcessor.CommandChain.Undo();
      this.Focus();
    }

    private void Redo() {
      this.dataProcessor.CommandChain.Redo();
      this.Focus();
    }

    private void AddTables() {
      if (dataProcessor.DatabaseExplorer == null || !dataProcessor.DatabaseExplorer.IsConnected) {
        MessageBox.Show("Not connected to database!");
        return;
      }
      DbTablesView tablesForm = new DbTablesView();
      tablesForm.DbExplorer = dataProcessor.DatabaseExplorer;
      tablesForm.SetTables(dataProcessor.DatabaseExplorer.AllTables);
      tablesForm.StartPosition = FormStartPosition.CenterParent;
      if (tablesForm.ShowDialog(this) == DialogResult.OK) {
        progressDlg = new ProgressDialog();
        progressDlg.Label.Text = "Loading data from database";
        progressDlg.Show(this);
        progressDlg.DesktopLocation = new Point(this.Location.X + this.Width / 2 - progressDlg.Width / 2, this.Location.Y + this.Height / 2 - progressDlg.Height / 2);
        this.Refresh();
        this.dataProcessor.CommandChain.Add(new LoadColumnGroupsFromDBCommand(this.dataProcessor.DataSet, this.dataProcessor.DatabaseExplorer,
          tablesForm.SelectedTables));
        progressDlg.Close();
      }
    }

    private void DatabaseExplorer_NewRowLoaded(object sender, ProgressChangedEventArgs e) {
      progressDlg.ProgressBar.Value = e.ProgressPercentage;
      progressDlg.Label.Text = (string)e.UserState;
      progressDlg.Refresh();
    }

    private void AddTablesWithSQLCommand() {
      CommandViewDialog dlg = new CommandViewDialog();
      dlg.StartPosition = FormStartPosition.CenterParent;
      SqlCommandView cmdView = new SqlCommandView();
      dlg.Panel.Controls.Add(cmdView);
      dlg.Panel.Size = cmdView.Size;
      dlg.ShowDialog(this);
      if (dlg.DialogResult == DialogResult.OK) {
        this.dataProcessor.CommandChain.Add(new LoadColumnGroupWithSqlStringFromDBCommand(this.dataProcessor.DataSet, this.dataProcessor.DatabaseExplorer, cmdView.SqlCommand));
      }
    }

    private void SetDbConnection() {
      dataProcessor.DatabaseExplorer.ShowDbConnectionWizard();
      if (dataProcessor.DatabaseExplorer.IsConnected) {
        this.lblConnectionStatus.Text = "Successfully connected to database!";
        this.lblConnectionStatus.BackColor = Color.LightGreen;
      } else {
        this.lblConnectionStatus.Text = "Not connected to database!";
        this.lblConnectionStatus.BackColor = Color.FromArgb(255, 128, 128); //light red
      }
    }
    #endregion

    #region GUI ClickEvents - menuitems, toolbarbuttons

    private void DataProcessorView_FormClosing(object sender, FormClosingEventArgs e) {
      if (!CheckUnsavedChanges())
        e.Cancel = true;
    }

    #region MenuItems
    private void newToolStripMenuItem_Click(object sender, EventArgs e) {
      this.NewFile();
    }

    private void openToolStripMenuItem_Click(object sender, EventArgs e) {
      this.Open();
    }

    private void saveToolStripMenuItem_Click(object sender, EventArgs e) {
      this.Save();
    }

    private void saveAsToolStripMenuItem_Click(object sender, EventArgs e) {
      this.SaveAs();
    }

    private void importToolStripMenuItem_Click(object sender, EventArgs e) {
      this.Import();
    }

    private void exportToolStripMenuItem_Click(object sender, EventArgs e) {
      this.Export();
    }

    private void exitToolStripMenuItem_Click(object sender, EventArgs e) {
      this.Close();
    }

    private void undoToolStripMenuItem_Click(object sender, EventArgs e) {
      this.Undo();
    }

    private void redoToolStripMenuItem_Click(object sender, EventArgs e) {
      this.Redo();
    }

    private void addTablesToolStripMenuItem_Click(object sender, EventArgs e) {
      this.AddTables();
    }

    private void addTablesWithSqlStringToolStripMenuItem_Click(object sender, EventArgs e) {
      this.AddTablesWithSQLCommand();
    }

    private void setGenericDBConnectionToolStripMenuItem_Click(object sender, EventArgs e) {
      this.dataProcessor.DatabaseExplorer = (IDbExplorer)((ToolStripMenuItem)sender).Tag;
      this.dataProcessor.DatabaseExplorer.NewRowLoaded += new ProgressChangedEventHandler(DatabaseExplorer_NewRowLoaded);
      this.SetDbConnection();
    }
    #endregion

    #region ToolbarButtons
    private void newToolStripButton_Click(object sender, EventArgs e) {
      this.NewFile();
    }

    private void openToolStripButton_Click(object sender, EventArgs e) {
      this.Open();
    }

    private void saveToolStripButton_Click(object sender, EventArgs e) {
      this.Save();
    }

    private void recordMacroToolStripButton_Click(object sender, EventArgs e) {
      this.RecordMacro();
    }

    private void openCommandChainToolStripButton_Click(object sender, EventArgs e) {
      this.OpenCommandChain();
    }

    private void saveCommandChaingToolStripButton_Click(object sender, EventArgs e) {
      this.SaveCommandChain();
    }

    private void undoToolStripButton_Click(object sender, EventArgs e) {
      this.Undo();
    }

    private void redoToolStripButton_Click(object sender, EventArgs e) {
      this.Redo();
    }
    #endregion
    #endregion

    private class AttributeComparer : IComparer<ViewableCommandInfoAttribute> {
      public int Compare(ViewableCommandInfoAttribute x, ViewableCommandInfoAttribute y) {
        int cmpResult = x.GroupName.CompareTo(y.GroupName);
        if (cmpResult != 0)
          return cmpResult;
        cmpResult = x.Position.CompareTo(y.Position);
        if (cmpResult != 0)
          return cmpResult;
        return x.Name.CompareTo(y.Name);
      }
    }
  }
}