using System;

 using System.Collections.Generic;

 using System.Text;

 using System.Collections.ObjectModel;

 namespace Aga.Controls.Tree

 {

 	/// <summary>

 	/// Provides a simple ready to use implementation of <see cref="ITreeModel"/>. Warning: this class is not optimized 

 	/// to work with big amount of data. In this case create you own implementation of <c>ITreeModel</c>, and pay attention

 	/// on GetChildren and IsLeaf methods.

 	/// </summary>

 	public class TreeModel : ITreeModel

 	{

 		private Node _root;

 		public Node Root

 		{

 			get { return _root; }

 		}

 		public Collection<Node> Nodes

 		{

 			get { return _root.Nodes; }

 		}

 		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 Node FindNode(TreePath path)

 		{

 			if (path.IsEmpty())

 				return _root;

 			else

 				return FindNode(_root, path, 0);

 		}

 		private Node FindNode(Node root, TreePath path, int level)

 		{

 			foreach (Node node in root.Nodes)

 				if (node == path.FullPath[level])

 				{

 					if (level == path.FullPath.Length - 1)

 						return node;

 					else

 						return FindNode(node, path, level + 1);

 				}

 			return null;

 		}

 		#region ITreeModel Members

 		public System.Collections.IEnumerable GetChildren(TreePath treePath)

 		{

 			Node node = FindNode(treePath);

 			if (node != null)

 				foreach (Node n in node.Nodes)

 					yield return n;

 			else

 				yield break;

 		}

 		public bool IsLeaf(TreePath treePath)

 		{

 			Node node = FindNode(treePath);

 			if (node != null)

 				return node.IsLeaf;

 			else

 				throw new ArgumentException("treePath");

 		}

 		public event EventHandler<TreeModelEventArgs> NodesChanged;

 		internal void OnNodesChanged(TreeModelEventArgs args)

 		{

 			if (NodesChanged != null)

 				NodesChanged(this, args);

 		}

 		public event EventHandler<TreePathEventArgs> StructureChanged;

 		public void OnStructureChanged(TreePathEventArgs args)

 		{

 			if (StructureChanged != null)

 				StructureChanged(this, args);

 		}

 		public event EventHandler<TreeModelEventArgs> NodesInserted;

 		internal 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 event EventHandler<TreeModelEventArgs> NodesRemoved;

 		internal 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);

 			}

 		}

 		#endregion

 	}

 }