#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2014 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.Drawing;
using System.Linq;
using System.Text.RegularExpressions;
using System.Windows.Forms;
using HeuristicLab.Collections;
using HeuristicLab.Common;
using HeuristicLab.Core;
using HeuristicLab.Core.Views;
using HeuristicLab.MainForm;
using HeuristicLab.MainForm.WindowsForms;
using HeuristicLab.Persistence.Core;
using HeuristicLab.Persistence.Default.Xml;
using HeuristicLab.PluginInfrastructure;

namespace HeuristicLab.Scripting.Views {
  [View("ItemCollection View")]
  [Content(typeof(VariableStore), true)]
  public partial class VariableStoreView : AsynchronousContentView {
    protected readonly Dictionary<string, ListViewItem> itemListViewItemMapping;
    protected readonly Dictionary<Type, bool> serializableLookup;
    protected TypeSelectorDialog typeSelectorDialog;
    protected bool validDragOperation;

    public new VariableStore Content {
      get { return (VariableStore)base.Content; }
      set { base.Content = value; }
    }

    public ListView ItemsListView {
      get { return variableListView; }
    }

    public VariableStoreView() {
      InitializeComponent();
      itemListViewItemMapping = new Dictionary<string, ListViewItem>();
      serializableLookup = new Dictionary<Type, bool>();
      variableListView.SmallImageList.Images.AddRange(new Image[] {
        HeuristicLab.Common.Resources.VSImageLibrary.Error,
        HeuristicLab.Common.Resources.VSImageLibrary.Warning,
        HeuristicLab.Common.Resources.VSImageLibrary.Object,
        HeuristicLab.Common.Resources.VSImageLibrary.Nothing
      });
    }

    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 -= Content_ItemsAdded;
      Content.ItemsReplaced -= Content_ItemsReplaced;
      Content.ItemsRemoved -= Content_ItemsRemoved;
      Content.CollectionReset -= Content_CollectionReset;
      base.DeregisterContentEvents();
    }
    protected override void RegisterContentEvents() {
      base.RegisterContentEvents();
      Content.ItemsAdded += Content_ItemsAdded;
      Content.ItemsReplaced += Content_ItemsReplaced;
      Content.ItemsRemoved += Content_ItemsRemoved;
      Content.CollectionReset += Content_CollectionReset;
    }

    protected override void OnContentChanged() {
      base.OnContentChanged();
      variableListView.Items.Clear();
      itemListViewItemMapping.Clear();
      if (Content != null) {
        Caption += " (" + Content.GetType().Name + ")";
        foreach (var item in Content)
          AddVariable(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;
        variableListView.Enabled = false;
      } else {
        addButton.Enabled = !Locked && !ReadOnly;
        sortAscendingButton.Enabled = variableListView.Items.Count > 1;
        sortDescendingButton.Enabled = variableListView.Items.Count > 1;
        removeButton.Enabled = !Locked && !ReadOnly && variableListView.SelectedItems.Count > 0;
        variableListView.Enabled = true;
        variableListView.LabelEdit = !Locked && !ReadOnly;
      }
    }

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

      if (typeSelectorDialog.ShowDialog(this) == DialogResult.OK) {
        try {
          return (object)typeSelectorDialog.TypeSelector.CreateInstanceOfSelectedType();
        } catch (Exception ex) {
          ErrorHandling.ShowErrorDialog(this, ex);
        }
      }
      return null;
    }

    protected virtual void AddVariable(KeyValuePair<string, object> variable) {
      if (string.IsNullOrEmpty(variable.Key)) throw new ArgumentException("The variable must have a name.", "variable");
      string value = (variable.Value ?? "null").ToString();
      string type = variable.Value == null ? "null" : variable.Value.GetType().ToString();
      bool serializable = IsSerializable(variable);
      var listViewItem = new ListViewItem(new[] { variable.Key, value, type }) { ToolTipText = GetToolTipText(variable, serializable), Tag = variable };
      bool validIdentifier = SafeVariableNameRegex.IsMatch(variable.Key);
      if (!serializable) listViewItem.ImageIndex = 0;
      else if (!validIdentifier) listViewItem.ImageIndex = 1;
      else if (variable.Value != null) listViewItem.ImageIndex = 2;
      else listViewItem.ImageIndex = 3;
      variableListView.Items.Add(listViewItem);
      itemListViewItemMapping[variable.Key] = listViewItem;
      sortAscendingButton.Enabled = variableListView.Items.Count > 1;
      sortDescendingButton.Enabled = variableListView.Items.Count > 1;
      var item = variable.Value as IItem;
      if (item != null) item.ToStringChanged += item_ToStringChanged;
    }

    protected virtual void RemoveVariable(KeyValuePair<string, object> variable) {
      if (string.IsNullOrEmpty(variable.Key)) throw new ArgumentException("The variable must have a name.", "variable");
      ListViewItem listViewItem;
      if (itemListViewItemMapping.TryGetValue(variable.Key, out listViewItem)) {
        itemListViewItemMapping.Remove(variable.Key);
        variableListView.Items.Remove(listViewItem);
        sortAscendingButton.Enabled = variableListView.Items.Count > 1;
        sortDescendingButton.Enabled = variableListView.Items.Count > 1;
        var item = variable.Value as IItem;
        if (item != null) item.ToStringChanged -= item_ToStringChanged;
      }
    }

    protected virtual void UpdateVariable(KeyValuePair<string, object> variable) {
      if (string.IsNullOrEmpty(variable.Key)) throw new ArgumentException("The variable must have a name.", "variable");
      ListViewItem listViewItem;
      if (itemListViewItemMapping.TryGetValue(variable.Key, out listViewItem)) {
        string value = (variable.Value ?? "null").ToString();
        string type = variable.Value == null ? "null" : variable.Value.GetType().ToString();
        bool serializable = IsSerializable(variable);
        bool validIdentifier = SafeVariableNameRegex.IsMatch(variable.Key);
        if (!serializable) listViewItem.ImageIndex = 0;
        else if (!validIdentifier) listViewItem.ImageIndex = 1;
        else if (variable.Value != null) listViewItem.ImageIndex = 2;
        else listViewItem.ImageIndex = 3;
        listViewItem.SubItems[1].Text = value;
        listViewItem.SubItems[2].Text = type;
        listViewItem.ToolTipText = GetToolTipText(variable, serializable);
        listViewItem.Tag = variable;
      } else throw new ArgumentException("A variable with the specified name does not exist.", "variable");
    }

    #region ListView Events
    protected virtual void variableListView_SelectedIndexChanged(object sender, EventArgs e) {
      removeButton.Enabled = (Content != null) && !Locked && !ReadOnly && variableListView.SelectedItems.Count > 0;
      AdjustListViewColumnSizes();
    }
    protected virtual void variableListView_KeyDown(object sender, KeyEventArgs e) {
      switch (e.KeyCode) {
        case Keys.Delete:
          if ((variableListView.SelectedItems.Count > 0) && !Locked && !ReadOnly) {
            foreach (ListViewItem item in variableListView.SelectedItems)
              Content.Remove(item.Text);
          }
          break;
        case Keys.F2:
          var focusedItem = variableListView.FocusedItem;
          if (variableListView.LabelEdit && focusedItem.Selected)
            focusedItem.BeginEdit();
          break;
        case Keys.A:
          if (e.Modifiers.HasFlag(Keys.Control)) {
            foreach (ListViewItem item in variableListView.Items)
              item.Selected = true;
          }
          break;
      }
    }
    protected virtual void variableListView_DoubleClick(object sender, EventArgs e) {
      if (variableListView.SelectedItems.Count == 1) {
        var item = variableListView.SelectedItems[0].Tag as KeyValuePair<string, object>?;
        if (item != null) {
          var value = item.Value.Value as IContent;
          if (value != null) {
            IContentView view = MainFormManager.MainForm.ShowContent(value);
            if (view != null) {
              view.ReadOnly = ReadOnly;
              view.Locked = Locked;
            }
          }
        }
      }
    }
    protected virtual void variableListView_ItemDrag(object sender, ItemDragEventArgs e) {
      if (!Locked && variableListView.SelectedItems.Count == 1) {
        var listViewItem = variableListView.SelectedItems[0];
        var item = (KeyValuePair<string, object>)listViewItem.Tag;
        var data = new DataObject(HeuristicLab.Common.Constants.DragDropDataFormat, item.Value);
        DoDragDrop(data, DragDropEffects.Copy);
      }
    }
    protected virtual void variableListView_DragEnter(object sender, DragEventArgs e) {
      validDragOperation = !Locked && !ReadOnly && e.Data.GetData(HeuristicLab.Common.Constants.DragDropDataFormat) != null;
    }
    protected virtual void variableListView_DragOver(object sender, DragEventArgs e) {
      e.Effect = DragDropEffects.None;
      if (validDragOperation) {
        if (e.AllowedEffect.HasFlag(DragDropEffects.Copy)) e.Effect = DragDropEffects.Copy;
      }
    }
    protected virtual void variableListView_DragDrop(object sender, DragEventArgs e) {
      if (e.Effect == DragDropEffects.Copy) {
        object item = e.Data.GetData(HeuristicLab.Common.Constants.DragDropDataFormat);
        var cloner = new Cloner();
        var dc = item as IDeepCloneable;
        if (dc != null) item = cloner.Clone(dc);
        var namedItem = item as INamedItem;
        bool nameValid = namedItem != null && !string.IsNullOrEmpty(namedItem.Name);
        string name = nameValid ? GenerateNewVariableName(namedItem.Name, false) : GenerateNewVariableName();
        Content.Add(name, item);
        var listViewItem = variableListView.FindItemWithText(name);
        if (!nameValid) listViewItem.BeginEdit();
      }
    }

    private readonly Regex SafeVariableNameRegex = new Regex("^[@]?[_a-zA-Z][_a-zA-Z0-9]*$");
    private const string DefaultVariableName = "enter_name";

    private void variableListView_AfterLabelEdit(object sender, LabelEditEventArgs e) {
      string name = e.Label;
      if (!string.IsNullOrEmpty(name) && SafeVariableNameRegex.IsMatch(name)) {
        var variable = (KeyValuePair<string, object>)variableListView.Items[e.Item].Tag;
        if (!Content.ContainsKey(name)) {
          Content.Remove(variable.Key);
          Content.Add(name, variable.Value);
        }
      }
      e.CancelEdit = true;
    }
    #endregion

    #region Button Events
    protected virtual void addButton_Click(object sender, EventArgs e) {
      object newVar = CreateItem();
      if (newVar != null) {
        string name = GenerateNewVariableName();
        Content.Add(name, newVar);
        var item = variableListView.FindItemWithText(name);
        item.BeginEdit();
      }
    }
    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 (variableListView.SelectedItems.Count > 0) {
        foreach (ListViewItem item in variableListView.SelectedItems)
          Content.Remove(item.Text);
        variableListView.SelectedItems.Clear();
      }
    }
    #endregion

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

    protected virtual void Content_ItemsReplaced(object sender, CollectionItemsChangedEventArgs<KeyValuePair<string, object>> e) {
      if (InvokeRequired)
        Invoke(new CollectionItemsChangedEventHandler<KeyValuePair<string, object>>(Content_ItemsReplaced), sender, e);
      else {
        foreach (var item in e.Items)
          UpdateVariable(item);
        AdjustListViewColumnSizes();
      }
    }

    protected virtual void Content_ItemsRemoved(object sender, CollectionItemsChangedEventArgs<KeyValuePair<string, object>> e) {
      if (InvokeRequired)
        Invoke(new CollectionItemsChangedEventHandler<KeyValuePair<string, object>>(Content_ItemsRemoved), sender, e);
      else {
        foreach (var item in e.Items)
          RemoveVariable(item);
        AdjustListViewColumnSizes();
      }
    }
    protected virtual void Content_CollectionReset(object sender, CollectionItemsChangedEventArgs<KeyValuePair<string, object>> e) {
      if (InvokeRequired)
        Invoke(new CollectionItemsChangedEventHandler<KeyValuePair<string, object>>(Content_CollectionReset), sender, e);
      else {
        foreach (var item in e.OldItems)
          RemoveVariable(item);
        foreach (var item in e.Items)
          AddVariable(item);
        AdjustListViewColumnSizes();
      }
    }

    private void item_ToStringChanged(object sender, EventArgs e) {
      foreach (ListViewItem item in variableListView.Items) {
        var variable = item.Tag as KeyValuePair<string, object>?;
        if (variable != null && variable.Value.Value == sender) {
          string value = (variable.Value.Value ?? "null").ToString();
          item.SubItems[1].Text = value;
          item.SubItems[2].Text = variable.Value.Value.GetType().ToString();
          item.ToolTipText = GetToolTipText(variable.Value, item.ImageIndex != 0);
        }
      }
    }
    #endregion

    #region Helpers
    protected virtual void SortItemsListView(SortOrder sortOrder) {
      variableListView.Sorting = SortOrder.None;
      variableListView.Sorting = sortOrder;
      variableListView.Sorting = SortOrder.None;
    }
    protected virtual void AdjustListViewColumnSizes() {
      foreach (ColumnHeader ch in variableListView.Columns)
        ch.Width = -2;
    }

    private string GetToolTipText(KeyValuePair<string, object> variable, bool serializable) {
      if (string.IsNullOrEmpty(variable.Key)) throw new ArgumentException("The variable must have a name.", "variable");
      string value = (variable.Value ?? "null").ToString();
      string type = variable.Value == null ? "null" : variable.Value.GetType().ToString();
      string[] lines = {
        "Name: " + variable.Key,
        "Value: " + value,
        "Type: " + type
      };
      string toolTipText = string.Join(Environment.NewLine, lines);
      if (!SafeVariableNameRegex.IsMatch(variable.Key))
        toolTipText = "Caution: Identifier is no valid C# identifier!" + Environment.NewLine + toolTipText;
      if (!serializable)
        toolTipText = "Caution: Type is not serializable!" + Environment.NewLine + toolTipText;
      return toolTipText;
    }

    private string GenerateNewVariableName(string defaultName = DefaultVariableName, bool generateValidIdentifier = true) {
      if (generateValidIdentifier && !SafeVariableNameRegex.IsMatch(defaultName))
        defaultName = DefaultVariableName;
      if (Content.ContainsKey(defaultName)) {
        int i = 1;
        string formatString = generateValidIdentifier ? "{0}{1}" : "{0} ({1})";
        string newName;
        do {
          newName = string.Format(formatString, defaultName, i++);
        } while (Content.ContainsKey(newName));
        return newName;
      }
      return defaultName;
    }

    private bool IsSerializable(KeyValuePair<string, object> variable) {
      var type = variable.Value.GetType();
      bool serializable;
      if (serializableLookup.TryGetValue(type, out serializable))
        return serializable;
      var ser = new Serializer(variable, ConfigurationService.Instance.GetDefaultConfig(new XmlFormat()), "ROOT", true);
      try {
        return serializableLookup[type] = ser.Count() > 0;
      } catch (PersistenceException) {
        return serializableLookup[type] = false;
      }
    }
    #endregion
  }
}