/*
  This program was written by S. Tanaka, E-mail: tanaka@nuee.nagoya-u.ac.jp
*/

import java.io.*; 
import java.net.*;

public class FTPServer extends Thread {
  public static void main(String[] args)
      {
           if(args.length != 0) {
            //  System.out.println(args[0]);
                r = args[0];}
           else{ r = "c:";}
           int i = 1;
           try
              { ServerSocket s = new ServerSocket(21);

                    for(;;)
                    { Socket incoming = s.accept();
                      new FTPServer(incoming,i).start();
                      i++;
                    }
               }
            catch(Exception e){}
      }

       public FTPServer(Socket income, int c)
           { incoming = income; counter = c; }


       public void run()
       {  int lng,lng1,lng2,i,ip1,ip2,ip = 1,h1;
          String a1,a2,di,str1,user="",host,dir;
          System.out.println(r);
          dir = r;
          InetAddress inet;
          InetAddress localip;
          try
            { inet = incoming.getInetAddress();
              localip = inet.getLocalHost();
              host = inet.toString();
              h1 = host.indexOf("/");
              host = host.substring(h1 + 1);
              // System.out.println(host);
              BufferedReader in
               = new BufferedReader(new InputStreamReader(incoming.getInputStream()));
              PrintWriter out
               = new PrintWriter(incoming.getOutputStream(),true);

              out.println("220 MyFtp server ready.\r");

              boolean done = false;
              while(!done)
                 {  a1 = "";
                    a2 = "";
                    String str = in.readLine();
          if(str.startsWith("RETR")){
                        out.println("150 Binary data connection");
                        str = str.substring(4);
                        str = str.trim();
                        System.out.println(str);
                        System.out.println(dir);
                        RandomAccessFile outFile = new
                        RandomAccessFile(dir+"/"+str,"r");

                        Socket t = new Socket(host,ip);
                        OutputStream out2
                           = t.getOutputStream();
                        byte bb[] = new byte[1024];
                        int amount;
                       try{
                        while((amount = outFile.read(bb)) != -1){
                              out2.write(bb, 0, amount);

                          }
                        out2.close();
                        out.println("226 transfer complete");
                        outFile.close();
                        t.close();
                       }
                        catch(IOException e){}
                  }

          if(str.startsWith("STOR")){
                        out.println("150 Binary data connection");
                        str = str.substring(4);
                        str = str.trim();
                        System.out.println(str);
                        System.out.println(dir);
                        RandomAccessFile inFile = new
                        RandomAccessFile(dir+"/"+str,"rw");
                        Socket t = new Socket(host,ip);
                        InputStream in2
                           = t.getInputStream();
                        byte bb[] = new byte[1024];
                        int amount;
                       try{
                        while((amount = in2.read(bb)) != -1){
                              inFile.write(bb, 0, amount);
                          }
                        in2.close();
                        out.println("226 transfer complete");
                        inFile.close();
                        t.close();
                       }
                        catch(IOException e){}
                  }


          if(str.startsWith("TYPE")){
                        out.println("200 type set");}
          if(str.startsWith("DELE")){
                        str = str.substring(4);
                        str = str.trim();
                        File f = new File(dir,str);
                        boolean del = f.delete();
                        out.println("250 delete command successful");}

          if(str.startsWith("CDUP")){
                        int n = dir.lastIndexOf("/");
                        dir = dir.substring(0,n);
                        out.println("250 CWD command succesful");
                                     }
          if(str.startsWith("CWD")){
                        str1 = str.substring(3);
                        dir = dir+"/"+str1.trim();
                        out.println("250 CWD command succesful");
                                     }
          if(str.startsWith("QUIT")) {
                        out.println("GOOD BYE");
                        done = true; }
          if(str.startsWith("USER")){
                        user = str.substring(4);
                        user = user.trim();
                        out.println("331 Password");}
          if(str.startsWith("PASS")) out.println("230 User "+user+" logged in.");
          if(str.startsWith("PWD")){
                        out.println("257 \""+dir+"\" is current directory");
            }
          if(str.startsWith("SYS"))  out.println("500 SYS not understood");
          if(str.startsWith("PORT")) {
                        out.println("200 PORT command successful");
                        lng = str.length() - 1;
                        lng2 = str.lastIndexOf(",");
                        lng1 = str.lastIndexOf(",",lng2-1);
                        for(i=lng1+1;i<lng2;i++){
                              a1 = a1 + str.charAt(i);}
                        for(i=lng2+1;i<=lng;i++){
                              a2 = a2 + str.charAt(i); }
                        ip1 = Integer.parseInt(a1);
                        ip2 =Integer.parseInt(a2);
                        ip = ip1 * 16 *16 + ip2;

                                       }
          if(str.startsWith("LIST")) {
                        try
                        {  out.println("150 ASCII data");
                           Socket t = new Socket(host,ip);
                           PrintWriter out2
                             = new PrintWriter(t.getOutputStream(),true);

                           File f = new File(dir);
                           String[] a = new String[10];
                           String d,e;
                           int i1,j1;
                           a = f.list();
                           j1 = a.length;
                           d = f.getName();
                           for(i1=0;i1<j1;i1++)
                             {   if( a[i1].indexOf(".") == -1)    // DIR
                                 { di = "d ";}
                                 else
                                 { di = "- ";}
                           out2.println(di+a[i1]);
                             }
                           t.close();
                           out.println("226 transfer complete");
                           }
                           catch(IOException e){}
                                       }

          }
          incoming.close();
        }
        catch (Exception e)
        { // System.out.println(e);
        }
	   }
private Socket incoming; 
private int counter; 
private static String r;

}