using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;
using HeuristicLab.Collections;
using HeuristicLab.Core;
using HeuristicLab.Core.Views;
using HeuristicLab.MainForm;
using HeuristicLab.PluginInfrastructure;

namespace HeuristicLab.Encodings.ParameterConfigurationEncoding.Views {

  [View("ItemDictionaryView")]
  [Content(typeof(ItemDictionary<,>), IsDefaultView = false)]
  public partial class ItemDictionaryView<K, T> : ItemView
    where K : class, IItem
    where T : class, IItem {
    protected Dictionary<KeyValuePair<K, T>, List<ListViewItem>> itemListViewItemMapping;
    protected TypeSelectorDialog typeSelectorDialog;

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

    public ListView ItemsListView {
      get { return itemsListView; }
    }

    public ItemDictionaryView() {
      InitializeComponent();
      itemListViewItemMapping = new Dictionary<KeyValuePair<K, T>, List<ListViewItem>>();
    }

    protected override void Dispose(bool disposing) {
      if (disposing) {
        if (typeSelectorDialog != null) typeSelectorDialog.Dispose();
        if (components != null) components.Dispose();
      }
      base.Dispose(disposing);
    }

    protected override void DeregisterContentEvents() {
      Content.ItemsAdded -= new CollectionItemsChangedEventHandler<KeyValuePair<K, T>>(Content_ItemsAdded);
      Content.ItemsRemoved -= new CollectionItemsChangedEventHandler<KeyValuePair<K, T>>(Content_ItemsRemoved);
      Content.CollectionReset -= new CollectionItemsChangedEventHandler<KeyValuePair<K, T>>(Content_CollectionReset);
      foreach (KeyValuePair<K, T> item in itemListViewItemMapping.Keys) {
        DeregisterItemEvents(item);
      }
      base.DeregisterContentEvents();
    }
    protected override void RegisterContentEvents() {
      base.RegisterContentEvents();
      Content.ItemsAdded += new CollectionItemsChangedEventHandler<KeyValuePair<K, T>>(Content_ItemsAdded);
      Content.ItemsRemoved += new CollectionItemsChangedEventHandler<KeyValuePair<K, T>>(Content_ItemsRemoved);
      Content.CollectionReset += new CollectionItemsChangedEventHandler<KeyValuePair<K, T>>(Content_CollectionReset);
    }
    protected virtual void DeregisterItemEvents(KeyValuePair<K, T> item) {
      item.Value.ItemImageChanged -= new EventHandler(Item_ItemImageChanged);
      item.Key.ToStringChanged -= new EventHandler(Item_ToStringChanged);
    }
    protected virtual void RegisterItemEvents(KeyValuePair<K, T> item) {
      item.Value.ItemImageChanged += new EventHandler(Item_ItemImageChanged);
      item.Key.ToStringChanged += new EventHandler(Item_ToStringChanged);
    }

    protected override void OnContentChanged() {
      base.OnContentChanged();
      itemsListView.Items.Clear();
      itemListViewItemMapping.Clear();
      RebuildImageList();
      viewHost.Content = null;
      if (Content != null) {
        Caption += " (" + Content.GetType().Name + ")";
        foreach (KeyValuePair<K, 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 = !ReadOnly;
        sortAscendingButton.Enabled = itemsListView.Items.Count > 1;
        sortDescendingButton.Enabled = itemsListView.Items.Count > 1;
        removeButton.Enabled = !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(KeyValuePair<K, T> item) {
      ListViewItem listViewItem = new ListViewItem();
      listViewItem.Text = item.Key.ToString();
      listViewItem.ToolTipText = item.Key.ItemName + ": " + item.Key.ItemDescription;
      itemsListView.SmallImageList.Images.Add(item.Value.ItemImage);
      listViewItem.ImageIndex = itemsListView.SmallImageList.Images.Count - 1;
      listViewItem.Tag = item;
      return listViewItem;
    }
    protected virtual void AddListViewItem(ListViewItem listViewItem) {
      KeyValuePair<K, T> item = (KeyValuePair<K, T>)listViewItem.Tag;
      itemsListView.Items.Add(listViewItem);
      if (!itemListViewItemMapping.ContainsKey(item)) {
        RegisterItemEvents(item);
        itemListViewItemMapping.Add(item, new List<ListViewItem>());
      }
      itemListViewItemMapping[item].Add(listViewItem);
      sortAscendingButton.Enabled = itemsListView.Items.Count > 1;
      sortDescendingButton.Enabled = itemsListView.Items.Count > 1;
    }
    protected virtual void RemoveListViewItem(ListViewItem listViewItem) {
      KeyValuePair<K, T> item = (KeyValuePair<K, T>)listViewItem.Tag;
      itemListViewItemMapping[item].Remove(listViewItem);
      if (itemListViewItemMapping[item].Count == 0) {
        itemListViewItemMapping.Remove(item);
        DeregisterItemEvents(item);
      }
      listViewItem.Remove();
      sortAscendingButton.Enabled = itemsListView.Items.Count > 1;
      sortDescendingButton.Enabled = itemsListView.Items.Count > 1;
    }
    protected virtual void UpdateListViewItemImage(ListViewItem listViewItem) {
      KeyValuePair<K, T> item = (KeyValuePair<K, T>)listViewItem.Tag;
      int i = listViewItem.ImageIndex;
      listViewItem.ImageList.Images[i] = item.Value.ItemImage;
      listViewItem.ImageIndex = -1;
      listViewItem.ImageIndex = i;
    }
    protected virtual void UpdateListViewItemText(ListViewItem listViewItem) {
      KeyValuePair<K, T> item = (KeyValuePair<K, T>)listViewItem.Tag;
      listViewItem.Text = item.Key.ToString();
      listViewItem.ToolTipText = item.Value.ItemName + ": " + item.Value.ItemDescription;
    }
    protected virtual IEnumerable<ListViewItem> GetListViewItemsForItem(KeyValuePair<K, T> item) {
      List<ListViewItem> listViewItems = null;
      itemListViewItemMapping.TryGetValue(item, out listViewItems);
      return listViewItems == null ? Enumerable.Empty<ListViewItem>() : listViewItems;
    }

    #region ListView Events
    protected virtual void itemsListView_SelectedIndexChanged(object sender, EventArgs e) {
      removeButton.Enabled = (Content != null) && !ReadOnly && itemsListView.SelectedItems.Count > 0;
      AdjustListViewColumnSizes();
      if (showDetailsCheckBox.Checked) {
        if (itemsListView.SelectedItems.Count == 1) {
          KeyValuePair<K, T> item = (KeyValuePair<K, T>)itemsListView.SelectedItems[0].Tag;
          detailsGroupBox.Enabled = true;
          viewHost.Content = item.Value;
        } 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) && !ReadOnly) {
          foreach (ListViewItem item in itemsListView.SelectedItems)
            Content.Remove(((KeyValuePair<K, T>)item.Tag).Key);
        }
      }
    }
    protected virtual void itemsListView_DoubleClick(object sender, EventArgs e) {
      if (itemsListView.SelectedItems.Count == 1) {
        KeyValuePair<K, T> item = (KeyValuePair<K, T>)itemsListView.SelectedItems[0].Tag;
        IContentView view = MainFormManager.MainForm.ShowContent(item.Value);
        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;
        KeyValuePair<K, T> item = (KeyValuePair<K, T>)listViewItem.Tag;
        DataObject data = new DataObject();
        data.SetData("Type", item.GetType());
        data.SetData("Value", item);
        if (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.Key);
        }
      }
    }
    protected virtual void itemsListView_DragEnterOver(object sender, DragEventArgs e) {
      e.Effect = DragDropEffects.None;
      Type type = e.Data.GetData("Type") as Type;
      if (!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) {
      //  K item = e.Data.GetData("Value") as K;
      //  if ((e.Effect & DragDropEffects.Copy) == DragDropEffects.Copy) item = (T)item.Clone();
      //  Content.Add(item);
      //}
      throw new NotImplementedException();
    }
    #endregion

    #region Button Events
    protected virtual void addButton_Click(object sender, EventArgs e) {
      //T item = CreateItem();
      //if (item != null)
      //  Content.Add(item);
      throw new NotImplementedException();
    }
    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(((KeyValuePair<K, T>)item.Tag).Key);
        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 ? ((KeyValuePair<K, T>)itemsListView.SelectedItems[0].Tag).Value : null;
      } else {
        splitContainer.Panel2Collapsed = true;
        viewHost.Content = null;
      }
    }
    #endregion

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

    }
    protected virtual void Content_ItemsRemoved(object sender, CollectionItemsChangedEventArgs<KeyValuePair<K, T>> e) {
      if (InvokeRequired)
        Invoke(new CollectionItemsChangedEventHandler<KeyValuePair<K, T>>(Content_ItemsRemoved), sender, e);
      else {
        foreach (KeyValuePair<K, 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<KeyValuePair<K, T>> e) {
      if (InvokeRequired)
        Invoke(new CollectionItemsChangedEventHandler<KeyValuePair<K, T>>(Content_CollectionReset), sender, e);
      else {
        foreach (KeyValuePair<K, 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 (KeyValuePair<K, 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 {
        KeyValuePair<K, T> item = (KeyValuePair<K, 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 {
        KeyValuePair<K, T> item = (KeyValuePair<K, 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);
      }
    }
    protected virtual void RebuildImageList() {
      itemsListView.SmallImageList.Images.Clear();
      foreach (ListViewItem listViewItem in itemsListView.Items) {
        KeyValuePair<K, T> item = (KeyValuePair<K, T>)listViewItem.Tag;
        itemsListView.SmallImageList.Images.Add(item.Value.ItemImage);
        listViewItem.ImageIndex = itemsListView.SmallImageList.Images.Count - 1;
      }
    }
    #endregion
  }
}