#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2015 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.Windows.Forms;
using HeuristicLab.Core;
using HeuristicLab.PluginInfrastructure;

namespace HeuristicLab.Optimizer {
  internal partial class NewItemDialog : Form {
    private bool isInitialized;

    private List<TreeNode> treeNodes;
    private string currentSearchString;

    private Type selectedType;
    public Type SelectedType {
      get { return selectedType; }
      private set {
        if (value != selectedType) {
          selectedType = value;
          OnSelectedTypeChanged();
        }
      }
    }

    private IItem item;
    public IItem Item {
      get { return item; }
    }

    public NewItemDialog() {
      InitializeComponent();
      treeNodes = new List<TreeNode>();
      currentSearchString = string.Empty;
      item = null;
      SelectedTypeChanged += this_SelectedTypeChanged;
    }

    private void NewItemDialog_Load(object sender, EventArgs e) {
      if (isInitialized) return;

      var categories =
        from t in ApplicationManager.Manager.GetTypes(typeof(IItem))
        where CreatableAttribute.IsCreatable(t)
        orderby CreatableAttribute.GetCategory(t), ItemAttribute.GetName(t), ItemAttribute.GetVersion(t) ascending
        group t by CreatableAttribute.GetCategory(t) into c
        select c;

      imageList.Images.Add(HeuristicLab.Common.Resources.VSImageLibrary.Class);      // default icon
      imageList.Images.Add(HeuristicLab.Common.Resources.VSImageLibrary.Namespace);  // plugins

      foreach (var category in categories) {
        var categoryNode = new TreeNode(category.Key) {
          ImageIndex = 1,
          Tag = category.Key,
        };
        categoryNode.SelectedImageIndex = categoryNode.ImageIndex;

        foreach (var creatable in category) {
          string name = ItemAttribute.GetName(creatable);

          var itemNode = new TreeNode(name) {
            ImageIndex = 0,
            Tag = creatable
          };
          categoryNode.Nodes.Add(itemNode);
          var image = ItemAttribute.GetImage(creatable);
          if (image != null) {
            imageList.Images.Add(image);
            itemNode.ImageIndex = imageList.Images.Count - 1;
          }
          itemNode.SelectedImageIndex = itemNode.ImageIndex;
        }
        if (categoryNode.Nodes.Count > 0)
          treeNodes.Add(categoryNode);
      }
      foreach (var node in treeNodes)
        typesTreeView.Nodes.Add((TreeNode)node.Clone());
      isInitialized = true;
    }
    private void NewItemDialog_Shown(object sender, EventArgs e) {
      searchTextBox.Text = string.Empty;
      searchTextBox.Focus();
    }

    public virtual void Filter(string searchString) {
      if (InvokeRequired) {
        Invoke(new Action<string>(Filter), searchString);
      } else {
        searchString = searchString.ToLower();

        if (!searchString.Contains(currentSearchString)) {
          typesTreeView.BeginUpdate();
          // expand saerch -> restore all tree nodes
          var selectedNode = typesTreeView.SelectedNode;
          typesTreeView.Nodes.Clear();
          foreach (TreeNode node in treeNodes)
            typesTreeView.Nodes.Add((TreeNode)node.Clone());
          RestoreSelectedNode(selectedNode);
          typesTreeView.EndUpdate();
        }

        // remove nodes
        typesTreeView.BeginUpdate();
        int i = 0;
        var searchTokens = searchString.Split(' ');
        while (i < typesTreeView.Nodes.Count) {
          int j = 0;
          while (j < typesTreeView.Nodes[i].Nodes.Count) {
            if (searchTokens.Any(searchToken => !typesTreeView.Nodes[i].Nodes[j].Text.ToLower().Contains(searchToken))) {
              if ((typesTreeView.Nodes[i].Nodes[j].Tag as Type).Equals(SelectedType))
                SelectedType = null;
              typesTreeView.Nodes[i].Nodes[j].Remove();
            } else
              j++;
          }
          if (typesTreeView.Nodes[i].Nodes.Count == 0)
            typesTreeView.Nodes[i].Remove();
          else
            i++;
        }
        typesTreeView.EndUpdate();
        currentSearchString = searchString;

        // if there is just one type node left, select by default
        if (typesTreeView.Nodes.Count == 1) {
          if (typesTreeView.Nodes[0].Nodes.Count == 1) {
            typesTreeView.SelectedNode = typesTreeView.Nodes[0].Nodes[0];
          }
        }

        if (typesTreeView.Nodes.Count == 0) {
          SelectedType = null;
          typesTreeView.Enabled = false;
        } else {
          SetTreeNodeVisibility();
          typesTreeView.Enabled = true;
        }
        UpdateDescription();
      }
    }

    protected virtual void UpdateDescription() {
      descriptionTextBox.Text = string.Empty;

      if (typesTreeView.SelectedNode != null) {
        string category = typesTreeView.SelectedNode.Tag as string;
        if (category != null) {
          descriptionTextBox.Text = category;
          pluginTextBox.Text = string.Empty;
          versionTextBox.Text = string.Empty;
        }
        Type type = typesTreeView.SelectedNode.Tag as Type;
        if (type != null) {
          string description = ItemAttribute.GetDescription(type);
          var version = ItemAttribute.GetVersion(type);
          var plugin = ApplicationManager.Manager.GetDeclaringPlugin(type);
          if (description != null)
            descriptionTextBox.Text = description;
          if (plugin != null)
            pluginTextBox.Text = plugin.Name;
          if (version != null)
            versionTextBox.Text = version.ToString();
        }
      } else if (typesTreeView.Nodes.Count == 0) {
        descriptionTextBox.Text = "No types found";
        pluginTextBox.Text = string.Empty;
        versionTextBox.Text = string.Empty;
      }
    }

    #region Events
    public event EventHandler SelectedTypeChanged;
    protected virtual void OnSelectedTypeChanged() {
      if (SelectedTypeChanged != null)
        SelectedTypeChanged(this, EventArgs.Empty);
    }
    #endregion

    #region Control Events
    protected virtual void searchTextBox_TextChanged(object sender, EventArgs e) {
      Filter(searchTextBox.Text);
    }

    protected virtual void itemsTreeView_AfterSelect(object sender, TreeViewEventArgs e) {
      if (typesTreeView.SelectedNode == null) SelectedType = null;
      else SelectedType = typesTreeView.SelectedNode.Tag as Type;
      UpdateDescription();
    }

    protected virtual void itemsTreeView_VisibleChanged(object sender, EventArgs e) {
      if (Visible) SetTreeNodeVisibility();
    }
    #endregion

    #region Helpers
    private void RestoreSelectedNode(TreeNode selectedNode) {
      if (selectedNode != null) {
        foreach (TreeNode node in typesTreeView.Nodes) {
          if (node.Text.Equals(selectedNode.Text)) typesTreeView.SelectedNode = node;
          foreach (TreeNode child in node.Nodes) {
            if ((child.Text.Equals(selectedNode.Text)) && (child.Tag == selectedNode.Tag))
              typesTreeView.SelectedNode = child;
          }
        }
        if (typesTreeView.SelectedNode == null) SelectedType = null;
      }
    }
    private void SetTreeNodeVisibility() {
      TreeNode selectedNode = typesTreeView.SelectedNode;
      if (string.IsNullOrEmpty(currentSearchString) && (typesTreeView.Nodes.Count > 1)) {
        typesTreeView.CollapseAll();
        if (selectedNode != null) typesTreeView.SelectedNode = selectedNode;
      } else {
        typesTreeView.ExpandAll();
      }
      if (selectedNode != null) selectedNode.EnsureVisible();
    }
    #endregion

    private void okButton_Click(object sender, EventArgs e) {
      if (SelectedType != null) {
        item = (IItem)Activator.CreateInstance(SelectedType);
        DialogResult = DialogResult.OK;
        Close();
      }
    }
    private void itemTreeView_DoubleClick(object sender, EventArgs e) {
      if (SelectedType != null) {
        item = (IItem)Activator.CreateInstance(SelectedType);
        DialogResult = DialogResult.OK;
        Close();
      }
    }
    private void this_SelectedTypeChanged(object sender, EventArgs e) {
      okButton.Enabled = SelectedType != null;
    }

    private void expandAllButton_Click(object sender, EventArgs e) {
      typesTreeView.ExpandAll();
    }
    private void collapseAllButton_Click(object sender, EventArgs e) {
      typesTreeView.CollapseAll();
    }

    private TreeNode toolStripMenuNode = null;
    private void typesTreeView_MouseDown(object sender, MouseEventArgs e) {
      if (e.Button == MouseButtons.Right) {
        Point coordinates = typesTreeView.PointToClient(Cursor.Position);
        toolStripMenuNode = typesTreeView.GetNodeAt(coordinates);

        if (toolStripMenuNode != null && coordinates.X >= toolStripMenuNode.Bounds.Left &&
            coordinates.X <= toolStripMenuNode.Bounds.Right) {
          typesTreeView.SelectedNode = toolStripMenuNode;

          expandToolStripMenuItem.Enabled =
            expandToolStripMenuItem.Visible = !toolStripMenuNode.IsExpanded && toolStripMenuNode.Nodes.Count > 0;
          collapseToolStripMenuItem.Enabled = collapseToolStripMenuItem.Visible = toolStripMenuNode.IsExpanded;
        } else {
          expandToolStripMenuItem.Enabled = expandToolStripMenuItem.Visible = false;
          collapseToolStripMenuItem.Enabled = collapseToolStripMenuItem.Visible = false;
        }
        expandAllToolStripMenuItem.Enabled =
          expandAllToolStripMenuItem.Visible =
            !typesTreeView.Nodes.OfType<TreeNode>().All(x => TreeNodeIsFullyExpanded(x));
        collapseAllToolStripMenuItem.Enabled =
          collapseAllToolStripMenuItem.Visible = typesTreeView.Nodes.OfType<TreeNode>().Any(x => x.IsExpanded);
        if (contextMenuStrip.Items.Cast<ToolStripMenuItem>().Any(item => item.Enabled))
          contextMenuStrip.Show(Cursor.Position);
      }
    }
    private bool TreeNodeIsFullyExpanded(TreeNode node) {
      return (node.Nodes.Count == 0) || (node.IsExpanded && node.Nodes.OfType<TreeNode>().All(x => TreeNodeIsFullyExpanded(x)));
    }

    private void expandToolStripMenuItem_Click(object sender, EventArgs e) {
      if (toolStripMenuNode != null) toolStripMenuNode.ExpandAll();
    }
    private void expandAllToolStripMenuItem_Click(object sender, EventArgs e) {
      typesTreeView.ExpandAll();
    }
    private void collapseToolStripMenuItem_Click(object sender, EventArgs e) {
      if (toolStripMenuNode != null) toolStripMenuNode.Collapse();
    }
    private void collapseAllToolStripMenuItem_Click(object sender, EventArgs e) {
      typesTreeView.CollapseAll();
    }
  }
}