using System;

namespace Netron.Diagramming.Core.Analysis {
  /// <summary>
  /// This interface describes the additional members useful if the underlying graph is a tree.
  /// </summary>
  public interface ITree : IGraph {

    /// <summary>
    /// Gets or sets a value indicating whether this tree is directed.
    /// </summary>
    /// <value>
    /// 	<c>true</c> if this instance is directed; otherwise, <c>false</c>.
    /// </value>
    new bool IsDirected { get; set; }
    /// <summary>
    /// Gets or sets the root of the tree
    /// </summary>
    INode Root { get; set; }
    /// <summary>
    /// Gets the children of the given node in the tree hierarchy.
    /// </summary>
    /// <param name="node"></param>
    /// <returns></returns>
    CollectionBase<INode> Children(INode node);
    /// <summary>
    /// Gets the edges connecting the children of the given node.
    /// </summary>
    /// <param name="node"></param>
    /// <returns></returns>
    CollectionBase<IEdge> ChildEdges(INode node);

    /// <summary>
    /// Returns the next sibling node of the given node.
    /// </summary>
    /// <param name="node">The node.</param>
    /// <returns></returns>
    INode NextSibling(INode node);

    /// <summary>
    /// Returns the previous sibling node of the given node.
    /// </summary>
    /// <param name="node">The node.</param>
    /// <returns></returns>
    INode PreviousSibling(INode node);

    /// <summary>
    /// Returns the last child of the given node.
    /// </summary>
    /// <param name="node">The node.</param>
    /// <returns></returns>
    INode LastChild(INode node);

    /// <summary>
    /// Returns the first child of the given node.
    /// </summary>
    /// <param name="node">The node.</param>
    /// <returns></returns>
    INode FirstChild(INode node);
    /// <summary>
    /// Returns how many children the given node has.
    /// </summary>
    /// <param name="node">The node.</param>
    /// <returns></returns>
    int ChildCount(INode node);
    /// <summary>
    /// Returns the depth the specified node.
    /// </summary>
    /// <param name="node">The node.</param>
    /// <returns></returns>
    int Depth(INode node);
    /// <summary>
    /// Returns the parent edge of the given node.
    /// </summary>
    /// <param name="node">The node.</param>
    /// <returns></returns>
    IEdge ParentEdge(INode node);
    /// <summary>
    /// Executes a the given <see cref="System.Action"/> on each node, starting from the given node, by means of a traversal
    /// </summary>
    /// <param name="action">The action.</param>
    /// <param name="startNode">The start node.</param>
    void ForEach<T>(Action<T> action, INode startNode) where T : INode;
  }
}