#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2010 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.Windows.Forms;
using HeuristicLab.Collections;
using HeuristicLab.Common;
using HeuristicLab.Core.Views;
using HeuristicLab.MainForm;
using HeuristicLab.MainForm.WindowsForms;

namespace HeuristicLab.Clients.Hive.Views {
  [View("ItemTree View")]
  [Content(typeof(IItemTree), IsDefaultView = false)]
  public sealed partial class ItemTreeView : ItemView {
    public new IItemTree Content {
      get { return (IItemTree)base.Content; }
      set { base.Content = value; }
    }

    public ItemTreeView() {
      InitializeComponent();
    }

    protected override void DeregisterContentEvents() {
      foreach (TreeNode node in treeView.Nodes) {
        DeregisterContentEvents((IItemTree)node.Tag, node);
      }
      base.DeregisterContentEvents();
    }

    private void DeregisterContentEvents(IItemTree item, TreeNode node) {
      item.ItemsAdded -= new CollectionItemsChangedEventHandler<IItemTree>(item_ItemsAdded);
      item.ItemsRemoved -= new CollectionItemsChangedEventHandler<IItemTree>(item_ItemsRemoved);
      item.CollectionReset -= new CollectionItemsChangedEventHandler<IItemTree>(item_CollectionReset);
      item.ToStringChanged -= new EventHandler(item_ToStringChanged);
      item.ItemImageChanged -= new EventHandler(item_ItemImageChanged);
      foreach (TreeNode childNode in node.Nodes) {
        DeregisterContentEvents((IItemTree)childNode.Tag, childNode);
      }
    }

    protected override void RegisterContentEvents() {
      base.RegisterContentEvents();
      foreach (TreeNode node in treeView.Nodes) {
        RegisterContentEvents((IItemTree)node.Tag, node);
      }
    }

    private void RegisterContentEvents(IItemTree item, TreeNode node) {
      item.ItemsAdded += new CollectionItemsChangedEventHandler<IItemTree>(item_ItemsAdded);
      item.ItemsRemoved += new CollectionItemsChangedEventHandler<IItemTree>(item_ItemsRemoved);
      item.CollectionReset += new CollectionItemsChangedEventHandler<IItemTree>(item_CollectionReset);
      item.ToStringChanged += new EventHandler(item_ToStringChanged);
      item.ItemImageChanged += new EventHandler(item_ItemImageChanged);
      foreach (TreeNode childNode in node.Nodes) {
        RegisterContentEvents((IItemTree)childNode.Tag, childNode);
      }
    }

    #region Event Handlers (Content)
    private void item_ItemsAdded(object sender, CollectionItemsChangedEventArgs<IItemTree> e) {
      if (InvokeRequired) {
        Invoke(new CollectionItemsChangedEventHandler<IItemTree>(item_ItemsAdded), sender, e);
      } else {
        TreeNode node = GetNodeByItem(sender as IItemTree);
        if (node != null) {
          foreach (IItemTree item in e.Items) {
            AddChildNodes(item, node.Nodes, true);
            node.ExpandAll();
            UpdateNodeItemImage(node);
          }
        }
      }
    }

    private void item_ItemsRemoved(object sender, CollectionItemsChangedEventArgs<IItemTree> e) {
      if (InvokeRequired) {
        Invoke(new CollectionItemsChangedEventHandler<IItemTree>(item_ItemsRemoved), sender, e);
      } else {
        TreeNode node = GetNodeByItem(sender as IItemTree);
        if (node != null) {
          foreach (IItemTree item in e.Items) {
            RemoveChildNodes(item, node.Nodes);
          }
          RebuildImageList();
        }
      }
    }

    private void item_CollectionReset(object sender, CollectionItemsChangedEventArgs<IItemTree> e) {
      if (InvokeRequired) {
        Invoke(new CollectionItemsChangedEventHandler<IItemTree>(item_CollectionReset), sender, e);
      } else {
        TreeNode node = GetNodeByItem(sender as IItemTree);
        if (node != null) {
          foreach (IItemTree item in e.OldItems) {
            RemoveChildNodes(item, node.Nodes);
          }
          RebuildImageList();
          foreach (IItemTree item in e.Items) {
            AddChildNodes(item, node.Nodes, true);
          }
        }
      }
    }

    private void item_ToStringChanged(object sender, EventArgs e) {
      if (InvokeRequired) {
        Invoke(new EventHandler(item_ToStringChanged), sender, e);
      } else {
        var item = sender as IItemTree;
        TreeNode node = GetNodeByItem(item);
        if(node != null)
          node.Text = item.ToString();
      }
    }

    private void item_ItemImageChanged(object sender, EventArgs e) {
      if (InvokeRequired) {
        Invoke(new EventHandler(item_ItemImageChanged), sender, e);
      } else {
        var item = sender as IItemTree;
        TreeNode node = GetNodeByItem(item);
        if(node != null)
          UpdateNodeItemImage(node);
      }
    }

    private void treeView_DoubleClick(object sender, EventArgs e) {
      if (InvokeRequired) {
        Invoke(new EventHandler(treeView_DoubleClick), sender, e);
      } else {
        if (treeView.SelectedNode != null) {
          var item = treeView.SelectedNode.Tag as IItemTree;
          if (item != null) {
            IContentView view = MainFormManager.MainForm.ShowContent(item);
            if (view != null) {
              view.ReadOnly = ReadOnly;
              view.Locked = Locked;
            }
          }
        }
      }
    }
    #endregion

    protected override void OnContentChanged() {
      base.OnContentChanged();
      if (Content == null) {
        // Add code when content has been changed and is null
        ClearNodes();
        detailsViewHost.Content = null;
      } else {
        // Add code when content has been changed and is not null
        ClearNodes();
        AddChildNodes(Content, treeView.Nodes, false);
        foreach (TreeNode node in treeView.Nodes) {
          UpdateNodeItemImage(node);
        }
      }
    }

    private void ClearNodes() {
      treeView.Nodes.Clear();
    }

    private void AddChildNodes(IItemTree item, TreeNodeCollection nodes, bool registerEvents) {
      TreeNode node = CreateTreeViewNode(item);
      nodes.Add(node);
      RebuildImageList(node);
      RegisterContentEvents(item, node); 
      var childItems = item.GetChildItems();
      foreach (var childItem in childItems) {
        AddChildNodes(childItem, node.Nodes, registerEvents);
      }
      node.ExpandAll();
    }

    private void RemoveChildNodes(IItemTree item, TreeNodeCollection treeNodeCollection) {
      int idx = -1;
      for (int i = 0; i < treeNodeCollection.Count; i++) {
        if (treeNodeCollection[i].Tag == item) {
          idx = i; break;
        }
      }
      DeregisterContentEvents(item, treeNodeCollection[idx]);
      treeNodeCollection.RemoveAt(idx);
    }
    
    private TreeNode GetNodeByItem(IItemTree item) {
      TreeNode found = null;
      foreach (TreeNode node in treeView.Nodes) {
        found = GetNodeByItem(node, item);
        if (found != null)
          return found;
      }
      return null;
    }

    private TreeNode GetNodeByItem(TreeNode node, IItemTree item) {
      if (node.Tag == item)
        return node;
      TreeNode found = null;
      foreach (TreeNode childNode in node.Nodes) {
        found = GetNodeByItem(childNode, item);
        if (found != null)
          return found;
      }
      return null;
    }

    private TreeNode CreateTreeViewNode(IItemTree item) {
      var node = new TreeNode(item.ToString());
      node.Tag = item;
      return node;
    }

    private void UpdateNodeItemImage(TreeNode node) {
      if (node == null) throw new ArgumentNullException();
      var item = node.Tag as IItemTree;
      int i = node.ImageIndex;
      this.imageList.Images[i] = item == null ? HeuristicLab.Common.Resources.VSImageLibrary.Nothing : item.ItemImage;
      node.ImageIndex = -1;
      node.ImageIndex = i;
      node.SelectedImageIndex = node.ImageIndex;
      foreach (TreeNode childNode in node.Nodes) {
        UpdateNodeItemImage(childNode);
      }
    }

    protected override void SetEnabledStateOfControls() {
      base.SetEnabledStateOfControls();
      // Enable or disable controls based on whether the content is null or the view is set readonly
    }

    #region Event Handlers (child controls)
    // Put event handlers of child controls here.
    private void treeView_AfterSelect(object sender, TreeViewEventArgs e) {
      detailsViewHost.Content = (IContent)treeView.SelectedNode.Tag;
    }
    #endregion

    private void RebuildImageList() {
      treeView.ImageList.Images.Clear();
      foreach (TreeNode node in treeView.Nodes) {
        RebuildImageList(node);
      }
    }

    private void RebuildImageList(TreeNode node) {
      var item = node.Tag as IItemTree;
      treeView.ImageList.Images.Add(item == null ? HeuristicLab.Common.Resources.VSImageLibrary.Nothing : item.ItemImage);
      node.ImageIndex = treeView.ImageList.Images.Count - 1;
      node.SelectedImageIndex = node.ImageIndex;
      foreach (TreeNode childNode in node.Nodes) {
        RebuildImageList(childNode);
      }
    }
  }
}