#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.Collections.Generic;
using System.Linq;
using System.Windows.Forms;
using HeuristicLab.Collections;
using HeuristicLab.MainForm;
using HeuristicLab.MainForm.WindowsForms;
using HeuristicLab.PluginInfrastructure;

namespace HeuristicLab.Core.Views {
  [View("ItemCollection View")]
  [Content(typeof(ItemCollection<>), true)]
  [Content(typeof(IItemCollection<>), false)]
  public partial class ItemCollectionView<T> : ItemView where T : class, IItem {
    private Dictionary<T, List<ListViewItem>> listViewItemMapping;
    protected TypeSelectorDialog typeSelectorDialog;

    public new IItemCollection<T> Content {
      get { return (IItemCollection<T>)base.Content; }
      set { base.Content = value; }
    }

    public ListView ItemsListView {
      get { return itemsListView; }
    }

    public ItemCollectionView() {
      InitializeComponent();
      listViewItemMapping = new Dictionary<T, List<ListViewItem>>();
    }

    protected override void DeregisterContentEvents() {
      Content.ItemsAdded -= new CollectionItemsChangedEventHandler<T>(Content_ItemsAdded);
      Content.ItemsRemoved -= new CollectionItemsChangedEventHandler<T>(Content_ItemsRemoved);
      Content.CollectionReset -= new CollectionItemsChangedEventHandler<T>(Content_CollectionReset);
      foreach (T item in listViewItemMapping.Keys) {
        item.ItemImageChanged -= new EventHandler(Item_ItemImageChanged);
        item.ToStringChanged -= new EventHandler(Item_ToStringChanged);
      }
      base.DeregisterContentEvents();
    }
    protected override void RegisterContentEvents() {
      base.RegisterContentEvents();
      Content.ItemsAdded += new CollectionItemsChangedEventHandler<T>(Content_ItemsAdded);
      Content.ItemsRemoved += new CollectionItemsChangedEventHandler<T>(Content_ItemsRemoved);
      Content.CollectionReset += new CollectionItemsChangedEventHandler<T>(Content_CollectionReset);
    }

    protected override void OnContentChanged() {
      base.OnContentChanged();
      while (itemsListView.Items.Count > 0) RemoveListViewItem(itemsListView.Items[0]);
      RebuildImageList();
      viewHost.Content = null;
      if (Content != null) {
        Caption += " (" + Content.GetType().Name + ")";
        foreach (T item in Content)
          AddListViewItem(CreateListViewItem(item));
        AdjustListViewColumnSizes();
        SortItemsListView(SortOrder.Ascending);
      }
    }

    protected override void SetEnabledStateOfControls() {
      base.SetEnabledStateOfControls();
      if (Content == null) {
        addButton.Enabled = false;
        sortAscendingButton.Enabled = false;
        sortDescendingButton.Enabled = false;
        removeButton.Enabled = false;
        itemsListView.Enabled = false;
        detailsGroupBox.Enabled = false;
      } else {
        addButton.Enabled = !Content.IsReadOnly && !ReadOnly;
        sortAscendingButton.Enabled = itemsListView.Items.Count > 1;
        sortDescendingButton.Enabled = itemsListView.Items.Count > 1;
        removeButton.Enabled = !Content.IsReadOnly && !ReadOnly && itemsListView.SelectedItems.Count > 0;
        itemsListView.Enabled = true;
        detailsGroupBox.Enabled = itemsListView.SelectedItems.Count == 1;
      }
    }

    protected virtual T CreateItem() {
      if (typeSelectorDialog == null) {
        typeSelectorDialog = new TypeSelectorDialog();
        typeSelectorDialog.Caption = "Select Item";
        typeSelectorDialog.TypeSelector.Caption = "Available Items";
        typeSelectorDialog.TypeSelector.Configure(typeof(T), false, true);
      }

      if (typeSelectorDialog.ShowDialog(this) == DialogResult.OK) {
        try {
          return (T)typeSelectorDialog.TypeSelector.CreateInstanceOfSelectedType();
        } catch (Exception ex) {
          ErrorHandling.ShowErrorDialog(this, ex);
        }
      }
      return null;
    }
    protected virtual ListViewItem CreateListViewItem(T item) {
      ListViewItem listViewItem = new ListViewItem();
      listViewItem.Text = item.ToString();
      listViewItem.ToolTipText = item.ItemName + ": " + item.ItemDescription;
      listViewItem.Tag = item;
      itemsListView.SmallImageList.Images.Add(item.ItemImage);
      listViewItem.ImageIndex = itemsListView.SmallImageList.Images.Count - 1;
      return listViewItem;
    }
    protected virtual void AddListViewItem(ListViewItem listViewItem) {
      T item = (listViewItem.Tag as T);
      itemsListView.Items.Add(listViewItem);
      if (!listViewItemMapping.ContainsKey(item)) {
        item.ItemImageChanged += new EventHandler(Item_ItemImageChanged);
        item.ToStringChanged += new EventHandler(Item_ToStringChanged);
        listViewItemMapping.Add(item, new List<ListViewItem>());
      }
      listViewItemMapping[item].Add(listViewItem);
      sortAscendingButton.Enabled = itemsListView.Items.Count > 1;
      sortDescendingButton.Enabled = itemsListView.Items.Count > 1;
    }
    protected virtual void RemoveListViewItem(ListViewItem listViewItem) {
      T item = (listViewItem.Tag as T);
      listViewItemMapping[item].Remove(listViewItem);
      if (listViewItemMapping[item].Count == 0) {
        listViewItemMapping.Remove(item);
        item.ItemImageChanged -= new EventHandler(Item_ItemImageChanged);
        item.ToStringChanged -= new EventHandler(Item_ToStringChanged);
      }
      listViewItem.Remove();
      sortAscendingButton.Enabled = itemsListView.Items.Count > 1;
      sortDescendingButton.Enabled = itemsListView.Items.Count > 1;
    }
    protected virtual void UpdateListViewItemImage(ListViewItem listViewItem) {
      int i = listViewItem.ImageIndex;
      listViewItem.ImageList.Images[i] = ((T)listViewItem.Tag).ItemImage;
      listViewItem.ImageIndex = -1;
      listViewItem.ImageIndex = i;
    }
    protected virtual void UpdateListViewItemText(ListViewItem listViewItem) {
      if (!listViewItem.Text.Equals(listViewItem.Tag.ToString()))
        listViewItem.Text = listViewItem.Tag.ToString();
    }
    protected virtual IEnumerable<ListViewItem> GetListViewItemsForItem(T item) {
      return listViewItemMapping[item];
    }

    #region ListView Events
    protected virtual void itemsListView_SelectedIndexChanged(object sender, EventArgs e) {
      removeButton.Enabled = (Content != null) && !Content.IsReadOnly && !ReadOnly && itemsListView.SelectedItems.Count > 0;
      AdjustListViewColumnSizes();
      if (showDetailsCheckBox.Checked) {
        if (itemsListView.SelectedItems.Count == 1) {
          T item = (T)itemsListView.SelectedItems[0].Tag;
          detailsGroupBox.Enabled = true;
          viewHost.Content = item;
        } else {
          viewHost.Content = null;
          detailsGroupBox.Enabled = false;
        }
      }
    }
    protected virtual void itemsListView_KeyDown(object sender, KeyEventArgs e) {
      if (e.KeyCode == Keys.Delete) {
        if ((itemsListView.SelectedItems.Count > 0) && !Content.IsReadOnly && !ReadOnly) {
          foreach (ListViewItem item in itemsListView.SelectedItems)
            Content.Remove((T)item.Tag);
        }
      }
    }
    protected virtual void itemsListView_DoubleClick(object sender, EventArgs e) {
      if (itemsListView.SelectedItems.Count == 1) {
        T item = (T)itemsListView.SelectedItems[0].Tag;
        IContentView view = MainFormManager.MainForm.ShowContent(item);
        if (view != null) {
          view.ReadOnly = ReadOnly;
          view.Locked = Locked;
        }
      }
    }
    protected virtual void itemsListView_ItemDrag(object sender, ItemDragEventArgs e) {
      if (!Locked) {
        ListViewItem listViewItem = (ListViewItem)e.Item;
        T item = (T)listViewItem.Tag;
        DataObject data = new DataObject();
        data.SetData("Type", item.GetType());
        data.SetData("Value", item);
        if (Content.IsReadOnly || ReadOnly) {
          DoDragDrop(data, DragDropEffects.Copy | DragDropEffects.Link);
        } else {
          DragDropEffects result = DoDragDrop(data, DragDropEffects.Copy | DragDropEffects.Link | DragDropEffects.Move);
          if ((result & DragDropEffects.Move) == DragDropEffects.Move)
            Content.Remove(item);
        }
      }
    }
    protected virtual void itemsListView_DragEnterOver(object sender, DragEventArgs e) {
      e.Effect = DragDropEffects.None;
      Type type = e.Data.GetData("Type") as Type;
      if (!Content.IsReadOnly && !ReadOnly && (type != null) && (typeof(T).IsAssignableFrom(type))) {
        if ((e.KeyState & 32) == 32) e.Effect = DragDropEffects.Link;  // ALT key
        else if ((e.KeyState & 4) == 4) e.Effect = DragDropEffects.Move;  // SHIFT key
        else if ((e.AllowedEffect & DragDropEffects.Copy) == DragDropEffects.Copy) e.Effect = DragDropEffects.Copy;
        else if ((e.AllowedEffect & DragDropEffects.Move) == DragDropEffects.Move) e.Effect = DragDropEffects.Move;
        else if ((e.AllowedEffect & DragDropEffects.Link) == DragDropEffects.Link) e.Effect = DragDropEffects.Link;
      }
    }
    protected virtual void itemsListView_DragDrop(object sender, DragEventArgs e) {
      if (e.Effect != DragDropEffects.None) {
        T item = e.Data.GetData("Value") as T;
        if ((e.Effect & DragDropEffects.Copy) == DragDropEffects.Copy) item = (T)item.Clone();
        Content.Add(item);
      }
    }
    #endregion

    #region Button Events
    protected virtual void addButton_Click(object sender, EventArgs e) {
      T item = CreateItem();
      if (item != null)
        Content.Add(item);
    }
    protected virtual void sortAscendingButton_Click(object sender, EventArgs e) {
      SortItemsListView(SortOrder.Ascending);
    }
    protected virtual void sortDescendingButton_Click(object sender, EventArgs e) {
      SortItemsListView(SortOrder.Descending);
    }
    protected virtual void removeButton_Click(object sender, EventArgs e) {
      if (itemsListView.SelectedItems.Count > 0) {
        foreach (ListViewItem item in itemsListView.SelectedItems)
          Content.Remove((T)item.Tag);
        itemsListView.SelectedItems.Clear();
      }
    }
    #endregion

    #region CheckBox Events
    protected virtual void showDetailsCheckBox_CheckedChanged(object sender, EventArgs e) {
      if (showDetailsCheckBox.Checked) {
        splitContainer.Panel2Collapsed = false;
        detailsGroupBox.Enabled = itemsListView.SelectedItems.Count == 1;
        viewHost.Content = itemsListView.SelectedItems.Count == 1 ? (T)itemsListView.SelectedItems[0].Tag : null;
      } else {
        splitContainer.Panel2Collapsed = true;
        viewHost.Content = null;
      }
    }
    #endregion

    #region Content Events
    protected virtual void Content_ItemsAdded(object sender, CollectionItemsChangedEventArgs<T> e) {
      if (InvokeRequired)
        Invoke(new CollectionItemsChangedEventHandler<T>(Content_ItemsAdded), sender, e);
      else {
        foreach (T item in e.Items)
          AddListViewItem(CreateListViewItem(item));
        AdjustListViewColumnSizes();
      }

    }
    protected virtual void Content_ItemsRemoved(object sender, CollectionItemsChangedEventArgs<T> e) {
      if (InvokeRequired)
        Invoke(new CollectionItemsChangedEventHandler<T>(Content_ItemsRemoved), sender, e);
      else {
        foreach (T item in e.Items) {
          //remove only the first matching ListViewItem, because the IItem could be contained multiple times in the ItemCollection
          ListViewItem listviewItem = GetListViewItemsForItem(item).FirstOrDefault();
          if (listviewItem != null) RemoveListViewItem(listviewItem);
        }
        RebuildImageList();
      }
    }
    protected virtual void Content_CollectionReset(object sender, CollectionItemsChangedEventArgs<T> e) {
      if (InvokeRequired)
        Invoke(new CollectionItemsChangedEventHandler<T>(Content_CollectionReset), sender, e);
      else {
        foreach (T item in e.OldItems) {
          //remove only the first matching ListViewItem, because the IItem could be contained multiple times in the ItemCollection
          ListViewItem listviewItem = GetListViewItemsForItem(item).FirstOrDefault();
          if (listviewItem != null) RemoveListViewItem(listviewItem);
        }
        RebuildImageList();
        foreach (T item in e.Items)
          AddListViewItem(CreateListViewItem(item));
      }
    }
    #endregion

    #region Item Events
    protected virtual void Item_ItemImageChanged(object sender, EventArgs e) {
      if (InvokeRequired)
        Invoke(new EventHandler(Item_ItemImageChanged), sender, e);
      else {
        T item = (T)sender;
        foreach (ListViewItem listViewItem in GetListViewItemsForItem(item))
          UpdateListViewItemImage(listViewItem);
      }
    }
    protected virtual void Item_ToStringChanged(object sender, EventArgs e) {
      if (InvokeRequired)
        Invoke(new EventHandler(Item_ToStringChanged), sender, e);
      else {
        T item = (T)sender;
        foreach (ListViewItem listViewItem in GetListViewItemsForItem(item))
          UpdateListViewItemText(listViewItem);
      }
    }
    #endregion

    #region Helpers
    protected virtual void SortItemsListView(SortOrder sortOrder) {
      itemsListView.Sorting = SortOrder.None;
      itemsListView.Sorting = sortOrder;
      itemsListView.Sorting = SortOrder.None;
    }
    protected virtual void AdjustListViewColumnSizes() {
      if (itemsListView.Items.Count > 0) {
        for (int i = 0; i < itemsListView.Columns.Count; i++)
          itemsListView.Columns[i].AutoResize(ColumnHeaderAutoResizeStyle.ColumnContent);
      }
    }
    private void RebuildImageList() {
      itemsListView.SmallImageList.Images.Clear();
      foreach (ListViewItem item in itemsListView.Items) {
        itemsListView.SmallImageList.Images.Add(((T)item.Tag).ItemImage);
        item.ImageIndex = itemsListView.SmallImageList.Images.Count - 1;
      }
    }
    #endregion
  }
}