#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2018 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.Linq;
using System.Windows.Forms;
using HeuristicLab.PluginInfrastructure.Manager;

namespace HeuristicLab.PluginInfrastructure.Advanced {
  internal partial class AvailablePluginsView : InstallationManagerControl {
    private class RefreshBackgroundWorkerResult {
      public IEnumerable<IPluginDescription> RemotePlugins { get; set; }
      public IEnumerable<DeploymentService.ProductDescription> RemoteProducts { get; set; }
    }
    private class UpdateOrInstallPluginsBackgroundWorkerArgument {
      public IEnumerable<IPluginDescription> PluginsToUpdate { get; set; }
      public IEnumerable<IPluginDescription> PluginsToInstall { get; set; }
    }
    private const string PluginDiscoveryMessage = "Looking for new plugins...";
    private BackgroundWorker refreshServerPluginsBackgroundWorker;
    private BackgroundWorker updateOrInstallPluginsBackgroundWorker;

    private IEnumerable<DeploymentService.ProductDescription> products;
    private IEnumerable<IPluginDescription> plugins;

    private IEnumerable<IPluginDescription> CheckedPlugins {
      get {
        return (from item in pluginsListView.Items.OfType<ListViewItem>()
                where item.Checked
                let plugin = item.Tag as IPluginDescription
                where plugin != null
                select plugin).ToList();
      }
    }

    private InstallationManager installationManager;
    public InstallationManager InstallationManager {
      get { return installationManager; }
      set { installationManager = value; }
    }
    private PluginManager pluginManager;
    public PluginManager PluginManager {
      get { return pluginManager; }
      set { pluginManager = value; }
    }
    public AvailablePluginsView() {
      InitializeComponent();
      productImageList.Images.Add(HeuristicLab.PluginInfrastructure.Resources.Setup_Install);
      productLargeImageList.Images.Add(HeuristicLab.PluginInfrastructure.Resources.Setup_Install);
      pluginsImageList.Images.Add(HeuristicLab.PluginInfrastructure.Resources.Plugin);
      refreshServerPluginsBackgroundWorker = new BackgroundWorker();
      refreshServerPluginsBackgroundWorker.DoWork += new DoWorkEventHandler(refreshServerPluginsBackgroundWorker_DoWork);
      refreshServerPluginsBackgroundWorker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(refreshServerPluginsBackgroundWorker_RunWorkerCompleted);

      updateOrInstallPluginsBackgroundWorker = new BackgroundWorker();
      updateOrInstallPluginsBackgroundWorker.DoWork += new DoWorkEventHandler(updateOrInstallPluginsBackgroundWorker_DoWork);
      updateOrInstallPluginsBackgroundWorker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(updateOrInstallPluginsBackgroundWorker_RunWorkerCompleted);
    }


    #region event handlers for refresh server plugins background worker
    void refreshServerPluginsBackgroundWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e) {
      if (e.Error != null) {
        StatusView.ShowError("Connection Error",
          "There was an error while connecting to the server." + Environment.NewLine +
          "Please check your connection settings and user credentials.");
      } else {
        RefreshBackgroundWorkerResult refreshResult = (RefreshBackgroundWorkerResult)e.Result;
        products = refreshResult.RemoteProducts;
        plugins = refreshResult.RemotePlugins;
        UpdateControl();
      }
      StatusView.UnlockUI();
      StatusView.RemoveMessage(PluginDiscoveryMessage);
      StatusView.HideProgressIndicator();
    }

    void refreshServerPluginsBackgroundWorker_DoWork(object sender, DoWorkEventArgs e) {
      RefreshBackgroundWorkerResult result = new RefreshBackgroundWorkerResult();
      result.RemotePlugins = installationManager.GetRemotePluginList();
      result.RemoteProducts = installationManager.GetRemoteProductList();
      e.Result = result;
    }
    #endregion
    #region event handlers for plugin update background worker
    void updateOrInstallPluginsBackgroundWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e) {
      if (e.Error != null) {
        StatusView.ShowError("Connection Error",
          "There was an error while connecting to the server." + Environment.NewLine +
          "Please check your connection settings and user credentials.");
      } else {
        UpdateControl();
      }
      StatusView.UnlockUI();
      StatusView.HideProgressIndicator();
    }

    void updateOrInstallPluginsBackgroundWorker_DoWork(object sender, DoWorkEventArgs e) {
      UpdateOrInstallPluginsBackgroundWorkerArgument info = (UpdateOrInstallPluginsBackgroundWorkerArgument)e.Argument;
      bool cancelled = false;
      if (info.PluginsToInstall.Count() > 0)
        installationManager.Install(info.PluginsToInstall, out cancelled);
      if (info.PluginsToUpdate.Count() > 0)
        installationManager.Update(info.PluginsToUpdate, out cancelled);

      if (!cancelled && (info.PluginsToInstall.Count() > 0 || info.PluginsToUpdate.Count() > 0))
        pluginManager.DiscoverAndCheckPlugins();
    }
    #endregion


    #region button events
    private void refreshRemoteButton_Click(object sender, EventArgs e) {
      StatusView.LockUI();
      StatusView.ShowProgressIndicator();
      StatusView.ShowMessage(PluginDiscoveryMessage);
      refreshServerPluginsBackgroundWorker.RunWorkerAsync();
    }
    private void installPluginsButton_Click(object sender, EventArgs e) {
      StatusView.LockUI();
      StatusView.ShowProgressIndicator();
      var updateOrInstallInfo = new UpdateOrInstallPluginsBackgroundWorkerArgument();
      // if there is a local plugin with same name and same major and minor version then it's an update
      var pluginsToUpdate = from remotePlugin in CheckedPlugins
                            let matchingLocalPlugins = from localPlugin in pluginManager.Plugins
                                                       where localPlugin.Name == remotePlugin.Name
                                                       where localPlugin.Version.Major == remotePlugin.Version.Major
                                                       where localPlugin.Version.Minor == remotePlugin.Version.Minor
                                                       where IsNewerThan(remotePlugin, localPlugin)
                                                       select localPlugin
                            where matchingLocalPlugins.Count() > 0
                            select remotePlugin;

      // otherwise install a new plugin
      var pluginsToInstall = CheckedPlugins.Except(pluginsToUpdate);

      updateOrInstallInfo.PluginsToInstall = pluginsToInstall;
      updateOrInstallInfo.PluginsToUpdate = pluginsToUpdate;
      updateOrInstallPluginsBackgroundWorker.RunWorkerAsync(updateOrInstallInfo);
    }
    private void installProductsButton_Click(object sender, EventArgs e) {
      StatusView.LockUI();
      StatusView.ShowProgressIndicator();
      var updateOrInstallInfo = new UpdateOrInstallPluginsBackgroundWorkerArgument();
      var selectedProduct = (DeploymentService.ProductDescription)productsListView.SelectedItems[0].Tag;
      // if there is a local plugin with same name and same major and minor version then it's an update
      var pluginsToUpdate = from plugin in selectedProduct.Plugins
                            let matchingLocalPlugins = from localPlugin in pluginManager.Plugins
                                                       where localPlugin.Name == plugin.Name
                                                       where localPlugin.Version.Major == plugin.Version.Major
                                                       where localPlugin.Version.Minor == plugin.Version.Minor
                                                       where IsNewerThan(plugin, localPlugin)
                                                       select localPlugin
                            where matchingLocalPlugins.Count() > 0
                            select plugin;

      // otherwise install a new plugin
      var pluginsToInstall = selectedProduct.Plugins.Except(pluginsToUpdate);

      updateOrInstallInfo.PluginsToInstall =
        pluginsToInstall
        .Cast<IPluginDescription>()
        .ToList();
      updateOrInstallInfo.PluginsToUpdate =
        pluginsToUpdate
        .Cast<IPluginDescription>()
        .ToList();
      updateOrInstallPluginsBackgroundWorker.RunWorkerAsync(updateOrInstallInfo);
    }

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

    private void showDetailsButton_CheckedChanged(object sender, EventArgs e) {
      productsListView.View = View.Details;
    }

    #endregion

    private void UpdateControl() {
      // clear products view
      List<ListViewItem> productItemsToDelete = new List<ListViewItem>(productsListView.Items.OfType<ListViewItem>());
      productItemsToDelete.ForEach(item => productsListView.Items.Remove(item));

      // populate products list view
      foreach (var product in products) {
        var item = CreateListViewItem(product);
        productsListView.Items.Add(item);
      }
      var allPluginsListViewItem = new ListViewItem();
      allPluginsListViewItem.Text = "All Plugins";
      allPluginsListViewItem.ImageIndex = 0;
      productsListView.Items.Add(allPluginsListViewItem);
      Util.ResizeColumns(productsListView.Columns.OfType<ColumnHeader>());
    }

    private void UpdatePluginsList() {
      pluginsListView.Items.Clear();

      // populate plugins list
      if (productsListView.SelectedItems.Count > 0) {
        pluginsListView.SuppressItemCheckedEvents = true;

        var selectedItem = productsListView.SelectedItems[0];
        if (selectedItem.Text == "All Plugins") {
          foreach (var plugin in plugins) {
            var item = CreateListViewItem(plugin);
            pluginsListView.Items.Add(item);
          }
        } else {
          var selectedProduct = (DeploymentService.ProductDescription)productsListView.SelectedItems[0].Tag;
          foreach (var plugin in selectedProduct.Plugins) {
            var item = CreateListViewItem(plugin);
            pluginsListView.Items.Add(item);
          }
        }

        Util.ResizeColumns(pluginsListView.Columns.OfType<ColumnHeader>());
        pluginsListView.SuppressItemCheckedEvents = false;
      }
    }

    private ListViewItem CreateListViewItem(DeploymentService.ProductDescription product) {
      ListViewItem item = new ListViewItem(new string[] { product.Name, product.Version.ToString() });
      item.Tag = product;
      item.ImageIndex = 0;
      return item;
    }

    private ListViewItem CreateListViewItem(IPluginDescription plugin) {
      ListViewItem item = new ListViewItem(new string[] { plugin.Name, plugin.Version.ToString(), plugin.Description });
      item.Tag = plugin;
      item.ImageIndex = 0;
      return item;
    }

    #region products list view events
    private void productsListView_SelectedIndexChanged(object sender, EventArgs e) {
      UpdatePluginsList();
      installProductsButton.Enabled = (productsListView.SelectedItems.Count > 0 &&
        productsListView.SelectedItems[0].Text != "All Plugins");
    }
    #endregion

    #region item checked event handler
    private void remotePluginsListView_ItemChecked(object sender, ItemCheckedEventArgs e) {
      foreach (ListViewItem item in pluginsListView.SelectedItems) {
        IPluginDescription plugin = (IPluginDescription)item.Tag;
        if (e.Item.Checked)
          HandlePluginChecked(plugin);
        else
          HandlePluginUnchecked(plugin);
      }
      installPluginsButton.Enabled = pluginsListView.CheckedItems.Count > 0;
    }

    private void HandlePluginUnchecked(IPluginDescription plugin) {
      // also uncheck all dependent plugins
      List<ListViewItem> modifiedItems = new List<ListViewItem>();
      modifiedItems.AddRange(FindItemsForPlugin(plugin));
      var dependentPlugins = Util.GetAllDependents(plugin, plugins);
      foreach (var dependentPlugin in dependentPlugins) {
        // there can be multiple entries for a single plugin in different groups
        foreach (var item in FindItemsForPlugin(dependentPlugin)) {
          if (item != null && item.Checked) {
            if (!modifiedItems.Contains(item))
              modifiedItems.Add(item);
          }
        }
      }
      pluginsListView.UncheckItems(modifiedItems);
    }

    private void HandlePluginChecked(IPluginDescription plugin) {
      // also check all dependencies
      List<ListViewItem> modifiedItems = new List<ListViewItem>();
      modifiedItems.AddRange(FindItemsForPlugin(plugin));
      foreach (var dep in Util.GetAllDependencies(plugin)) {
        // there can be multiple entries for a single plugin in different groups
        foreach (ListViewItem item in FindItemsForPlugin(dep)) {
          if (item != null && !item.Checked) {
            if (!modifiedItems.Contains(item))
              modifiedItems.Add(item);
          }
        }
      }
      pluginsListView.CheckItems(modifiedItems);
    }

    #endregion

    #region helper methods
    private IEnumerable<ListViewItem> FindItemsForPlugin(IPluginDescription plugin) {
      return (from item in pluginsListView.Items.OfType<ListViewItem>()
              let otherPlugin = item.Tag as IPluginDescription
              where otherPlugin != null && otherPlugin.Name == plugin.Name && otherPlugin.Version == plugin.Version
              select item);
    }

    // compares for two plugins with same major and minor version if plugin1 is newer than plugin2
    private static bool IsNewerThan(IPluginDescription plugin1, IPluginDescription plugin2) {
      // newer: build version is higher, or if build version is the same revision is higher
      return plugin1.Version.Build > plugin2.Version.Build ||
        (plugin1.Version.Build == plugin2.Version.Build && plugin1.Version.Revision > plugin2.Version.Revision);
    }
    #endregion

  }
}