#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2015 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.IO;
using System.Linq;
using System.Reflection;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;
using HeuristicLab.PluginInfrastructure.Manager;

namespace HeuristicLab.PluginInfrastructure.UI {
  /// <summary>
  /// The starter form is responsible for initializing the plugin infrastructure
  /// and shows a list of installed applications.
  /// </summary>
  public partial class StarterForm : Form {
    private const string pluginManagerItemName = "Plugins";
    // private const string updatePluginsItemName = "Updates Available";
    private const string optimizerItemName = "Optimizer"; // TODO: encoding a specific name of an application here is problematic (applications are discovered dynamically)

    private readonly ICommandLineArgument[] arguments;

    private ListViewItem pluginManagerListViewItem;
    private bool abortRequested; // TODO: necessary?
    private PluginManager pluginManager;
    private SplashScreen splashScreen;

    /// <summary>
    /// Initializes an instance of the starter form.
    /// The starter form shows a splashscreen and initializes the plugin infrastructure.
    /// </summary>
    public StarterForm()
      : base() {
      InitializeComponent();
      largeImageList.Images.Add(Resources.HeuristicLab.ToBitmap());
      smallImageList.Images.Add(Resources.HeuristicLab.ToBitmap());
      Text = "HeuristicLab " + AssemblyExtensions.GetFileVersion(GetType().Assembly);

      string pluginPath = Path.GetFullPath(Application.StartupPath);
      pluginManager = new PluginManager(pluginPath);
      splashScreen = new SplashScreen(pluginManager, 1000);
      splashScreen.VisibleChanged += new EventHandler(splashScreen_VisibleChanged);
      splashScreen.Show(this, "Loading HeuristicLab...");

      pluginManager.DiscoverAndCheckPlugins();
      UpdateApplicationsList();
    }

    /// <summary>
    /// Creates a new StarterForm and passes the arguments in <paramref name="args"/>.
    /// </summary>
    /// <param name="args">The arguments that should be processed</param>
    public StarterForm(string[] args)
      : this() {
      arguments = CommandLineArgumentHandling.GetArguments(args);
    }

    protected override void SetVisibleCore(bool value) {
      value &= !(arguments.OfType<HideStarterArgument>().Any() || arguments.OfType<OpenArgument>().Any());
      if (!value) HandleArguments();
      base.SetVisibleCore(value);
    }

    #region Events
    private void StarterForm_Load(object sender, EventArgs e) {
      HandleArguments();
    }

    private void StarterForm_FormClosing(object sender, FormClosingEventArgs e) {
      splashScreen.Close();
      abortRequested = true;
    }

    private void applicationsListView_SelectedIndexChanged(object sender, EventArgs e) {
      startButton.Enabled = applicationsListView.SelectedItems.Count > 0;
    }

    private void applicationsListView_ItemActivate(object sender, EventArgs e) {
      if (applicationsListView.SelectedItems.Count > 0) {
        ListViewItem selected = applicationsListView.SelectedItems[0];
        if (selected.Text == pluginManagerItemName) {
          try {
            Cursor = Cursors.AppStarting;
            using (var form = new PluginInformationDialog(pluginManager.Plugins)) {
              form.ShowDialog(this);
            }
          } finally {
            Cursor = Cursors.Arrow;
          }
        } else {
          ApplicationDescription app = (ApplicationDescription)applicationsListView.SelectedItems[0].Tag;
          StartApplication(app, arguments);
        }
      }
    }

    private void largeIconsButton_Click(object sender, EventArgs e) {
      applicationsListView.View = View.LargeIcon;
    }

    private void detailsButton_Click(object sender, EventArgs e) {
      applicationsListView.View = View.Details;
      foreach (ColumnHeader column in applicationsListView.Columns) {
        if (applicationsListView.Items.Count > 0)
          column.AutoResize(ColumnHeaderAutoResizeStyle.ColumnContent);
        else column.AutoResize(ColumnHeaderAutoResizeStyle.HeaderSize);
      }
    }

    private void aboutButton_Click(object sender, EventArgs e) {
      List<IPluginDescription> plugins = new List<IPluginDescription>(pluginManager.Plugins.OfType<IPluginDescription>());
      using (var dialog = new AboutDialog(plugins, Assembly.GetEntryAssembly())) {
        dialog.ShowDialog();
      }
    }

    private void splashScreen_VisibleChanged(object sender, EventArgs e) {
      // close hidden starter form
      if (!splashScreen.Visible && arguments != null &&
           (arguments.OfType<HideStarterArgument>().Any() || arguments.OfType<OpenArgument>().Any()))
        Close();
    }
    #endregion

    #region Helpers
    private void UpdateApplicationsList() {
      if (InvokeRequired) Invoke((Action)UpdateApplicationsList);
      else {
        applicationsListView.Items.Clear();
        AddPluginManagerItem();

        foreach (ApplicationDescription info in pluginManager.Applications) {
          ListViewItem item = new ListViewItem(info.Name, 0);
          item.Tag = info;
          item.Group = applicationsListView.Groups["Applications"];
          item.SubItems.Add(new ListViewItem.ListViewSubItem(item, info.Version.ToString()));
          item.SubItems.Add(new ListViewItem.ListViewSubItem(item, info.Description));
          item.ToolTipText = info.Description;
          applicationsListView.Items.Add(item);
        }
        foreach (ColumnHeader column in applicationsListView.Columns) {
          if (applicationsListView.Items.Count > 0)
            column.AutoResize(ColumnHeaderAutoResizeStyle.ColumnContent);
          else column.AutoResize(ColumnHeaderAutoResizeStyle.HeaderSize);
        }
      }
    }

    private void AddPluginManagerItem() {
      pluginManagerListViewItem = new ListViewItem(pluginManagerItemName, 0);
      pluginManagerListViewItem.Group = applicationsListView.Groups["Plugin Information"];
      pluginManagerListViewItem.SubItems.Add(new ListViewItem.ListViewSubItem(pluginManagerListViewItem, AssemblyExtensions.GetFileVersion(GetType().Assembly)));
      pluginManagerListViewItem.SubItems.Add(new ListViewItem.ListViewSubItem(pluginManagerListViewItem, "Show detailed plugin information"));
      pluginManagerListViewItem.ToolTipText = "Show detailed plugin information";

      applicationsListView.Items.Add(pluginManagerListViewItem);
    }

    private void HandleArguments() {
      try {
        if (arguments.OfType<OpenArgument>().Any() && !arguments.OfType<StartArgument>().Any()) {
          InitiateApplicationStart(optimizerItemName);
        }
        foreach (var argument in arguments) {
          if (argument is StartArgument) {
            var arg = (StartArgument)argument;
            InitiateApplicationStart(arg.Value);
          }
        }
      } catch (AggregateException ex) {
        ShowErrorDialog(ex);
      }
    }

    private void InitiateApplicationStart(string appName) {
      var appDesc = (from desc in pluginManager.Applications
                     where desc.Name.Equals(appName)
                     select desc).SingleOrDefault();
      if (appDesc != null) {
        StartApplication(appDesc, arguments);
      } else {
        MessageBox.Show("Cannot start application " + appName + ".",
                        "HeuristicLab",
                        MessageBoxButtons.OK,
                        MessageBoxIcon.Warning);
      }
    }

    private void StartApplication(ApplicationDescription app, ICommandLineArgument[] args) {
      splashScreen.Show("Loading " + app.Name);
      // STAThread is necessary for a UI component we are using in the application
      var t = new Thread(() => pluginManager.Run(app, args));
      t.SetApartmentState(ApartmentState.STA);
      t.Start();
    }
    #endregion

    private void ShowErrorDialog(Exception exception) {
      MessageBox.Show(exception.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
    }
  }
}