///////////////////////////////////////////////////////////////////////
///  NavigateWithDelegates.cs - Navigates a Directory Subtree,      ///
///  ver 1.1       displaying files and some of their properties    ///
///                                                                 ///
///  Language:     Visual C#                                        ///
///  Platform:     Dell Dimension 8100, Windows Pro 2000, SP2       ///
///  Application:  CSE681 Example                                   ///
///  Author:       Jim Fawcett, CST 2-187, Syracuse Univ.           ///
///                (315) 443-3948, jfawcett@twcny.rr.com            ///
///////////////////////////////////////////////////////////////////////
/*
 *  Module Operations:
 *  ==================
 *  Recursively displays the contents of a directory tree
 *  rooted at a specified path, with specified file pattern.
 *
 *  This version uses delegates to avoid embedding application
 *  details in the Navigator.  Navigate now is reusable.  Clients
 *  simply register event handlers for Navigate events newDir
 *  and newFile.
 *
 *  Public Interface:
 *  =================
 *  Navigate nav = new Navigate();
 *  nav.go("c:\temp","*.cs");
 *  nav.newDir += new Navigate.newDirHandler(OnDir);
 *  nav.newFile += new Navigate.newFileHandler(OnFile);
 *
 *  Maintenance History:
 *  ====================
 *  ver 1.3 : 19 Aug 2018
 *  - converted public delegate (common practice) to a
 *    public property with private backing store
 *  ver 1.2 : 09 Aug 2018
 *  - added multiple pattern handling and modified comments
 *  ver 1.1 : 04 Sep 2006
 *  - added file pattern as argument to member function go()
 *  ver 1.0 : 25 Sep 2003
 *  - first release
 */
//
using System;
using System.IO;
using System.Collections.Generic;

namespace Navig
{
  ///////////////////////////////////////////////////////////////////
  // Navigate class
  // - uses public event properties to avoid binding directly
  //   to application processing

  public class Navigate
  {
    // define public delegate type
    public delegate void newDirHandler(string dir);

    // define public delegate property with private backing store
    event newDirHandler newDir_;  // private backing store

    public newDirHandler newDir { // public delegate property
      get { return newDir_; }     // getter's logic can be changed without
                                  // changing user interface
      set { newDir_ = value; }    // same for setter
    }

    public delegate void newFileHandler(string file);
    event newFileHandler newFile_;
    public newFileHandler newFile { get; set; }  // short-hand notation

    private List<string> patterns_ = new List<string>();

    public Navigate()
    {
      patterns_.Add("*.*");
    }

    public void Add(string pattern)
    {
      if(patterns_.Count == 1 && patterns_[0] == "*.*")
      {
        patterns_.Clear();
      }
      patterns_.Add(pattern);
    }
    ///////////////////////
    // The go function has no application specific code.
    // It just invokes its event delegate to notify clients.
    // The clients take care of all the application specific stuff.

    public void go(string path)
    {
      path = Path.GetFullPath(path);

      if(newDir != null)
        newDir.Invoke(path);

      foreach(string patt in patterns_)
      {
        string[] files = Directory.GetFiles(path, patt);
        foreach (string file in files)
        {
          if (newFile != null)
            newFile.Invoke(file);
        }
      }
      string[] dirs = Directory.GetDirectories(path);
      foreach(string dir in dirs)
        go(dir);
    }
  }
}