/*  
  Copyright 2007-2013 The NGenerics Team
 (https://github.com/ngenerics/ngenerics/wiki/Team)

 This program is licensed under the GNU Lesser General Public License (LGPL).  You should 
 have received a copy of the license along with the source code.  If not, an online copy
 of the license can be found at http://www.gnu.org/copyleft/lesser.html.
*/

using System;

namespace NGenerics.DataStructures.Trees {
    /// <summary>
    /// An interface for the tree data structure
    /// </summary>
    /// <typeparam name="T">The type of elements in the tree.</typeparam>
    public interface ITree<T> {
        /// <summary>
        /// Adds the specified child to the tree.
        /// </summary>
        /// <param name="child">The child to add..</param>
        void Add(ITree<T> child);

        /// <summary>
        /// Gets the data held in this node.
        /// </summary>
        /// <value>The data.</value>
        T Data { get; }

        /// <summary>
        /// Gets the degree of this node.
        /// </summary>
        /// <value>The degree of this node.</value>
        int Degree { get; }

        /// <summary>
        /// Gets the child at the specified index.
        /// </summary>
        /// <param name="index">The index.</param>
        /// <returns>The child at the specified index.</returns>
        ITree<T> GetChild(int index);

        /// <summary>
        /// Gets the height of this tree.
        /// </summary>
        /// <value>The height of this tree.</value>
        int Height { get; }

        /// <summary>
        /// Gets a value indicating whether this instance is leaf node.
        /// </summary>
        /// <value>
        /// 	<c>true</c> if this instance is leaf node; otherwise, <c>false</c>.
        /// </value>
        bool IsLeafNode { get; }

        /// <summary>
        /// Removes the specified child.
        /// </summary>
        /// <param name="child">The child.</param>
        /// <returns>An indication of whether the child was found (and removed) from this tree.</returns>
        bool Remove(ITree<T> child);

        /// <summary>
        /// Finds the node for which the given predicate holds true.
        /// </summary>
        /// <param name="condition">The condition to test on the data item.</param>
        /// <returns>The fist node that matches the condition if found, otherwise null.</returns>
        ITree<T> FindNode(Predicate<T> condition);

        /// <summary>
        /// Gets the parent of the current node.
        /// </summary>
        /// <value>The parent of the current node.</value>
        ITree<T> Parent { get;}
    }
}