/*
 
  This Source Code Form is subject to the terms of the Mozilla Public
  License, v. 2.0. If a copy of the MPL was not distributed with this
  file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
  Copyright (C) 2009-2010 Michael Möller <mmoeller@openhardwaremonitor.org>
	
*/

using System;
using System.Collections;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using Aga.Controls.Tree;

namespace OpenHardwareMonitor.GUI {
  public class TreeModel : ITreeModel {

    private Node root;
    private bool forceVisible = false;

    public TreeModel() {
      root = new Node();
      root.Model = this;
    }

    public TreePath GetPath(Node node) {
      if (node == root)
        return TreePath.Empty;
      else {
        Stack<object> stack = new Stack<object>();
        while (node != root) {
          stack.Push(node);
          node = node.Parent;
        }
        return new TreePath(stack.ToArray());
      }
    }

    public Collection<Node> Nodes {
      get { return root.Nodes; }
    }

    private Node GetNode(TreePath treePath) {
      Node parent = root;
      foreach (object obj in treePath.FullPath) {
        Node node = obj as Node;
        if (node == null || node.Parent != parent)
          return null;
        parent = node;
      }
      return parent;
    }

    public IEnumerable GetChildren(TreePath treePath) {
      Node node = GetNode(treePath);
      if (node != null) {
        foreach (Node n in node.Nodes)
          if (forceVisible || n.IsVisible)
            yield return n;
      } else {
        yield break;
      }
    }

    public bool IsLeaf(TreePath treePath) {
      return false;
    }

    public bool ForceVisible {
      get {
        return forceVisible;
      }
      set {
        if (value != forceVisible) {
          forceVisible = value;
          OnStructureChanged(root);
        }
      }
    }

    #pragma warning disable 67
    public event EventHandler<TreeModelEventArgs> NodesChanged;
    public event EventHandler<TreePathEventArgs> StructureChanged;
    public event EventHandler<TreeModelEventArgs> NodesInserted;
    public event EventHandler<TreeModelEventArgs> NodesRemoved;
    #pragma warning restore 67

    public void OnNodeChanged(Node parent, int index, Node node) {
      if (NodesChanged != null && parent != null) {
        TreePath path = GetPath(parent);
        if (path != null) 
          NodesChanged(this, new TreeModelEventArgs(
            path, new int[] { index }, new object[] { node }));
      }
    }

    public void OnStructureChanged(Node node) {
      if (StructureChanged != null)
        StructureChanged(this,
          new TreeModelEventArgs(GetPath(node), new object[0]));
    }

    public void OnNodeInserted(Node parent, int index, Node node) {
      if (NodesInserted != null) {
        TreeModelEventArgs args = new TreeModelEventArgs(GetPath(parent),
          new int[] { index }, new object[] { node });
        NodesInserted(this, args);
      }

    }

    public void OnNodeRemoved(Node parent, int index, Node node) {
      if (NodesRemoved != null) {
        TreeModelEventArgs args = new TreeModelEventArgs(GetPath(parent), 
          new int[] { index }, new object[] { node });
        NodesRemoved(this, args);
      }
    }

  }
}