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

public class JPOP {

   String nl = "\n";
   String host;
   String user;
   String password;
   int   port;
   int   status;
   /*
         -1 : Errore
          0 : Pronto
          1 : Connesso all'host
          2 : Connesso al POP server
   */
   Socket sock;
   BufferedInputStream in;
   BufferedOutputStream out;
   int tot_msg;

   int IN_DEBUG = 0;

 public JPOP() {
      host="";
      user="";
      password="";
      port=110;
      status=0;
      tot_msg=0;
      set_newline();
   }

   public JPOP(String phost, String puser, String ppassword) {
     host=phost;
     user=puser;
     password=ppassword;
     port=110;
     status=0;
     tot_msg=0;
     set_newline();
   }

public JPOP(String phost, String puser, String ppassword,int pport) {
  host=phost;
  user=puser;
  password=ppassword;
  status=0;
  tot_msg=0;
  set_newline();
  if (pport>0 && pport<=65535) port=pport;
  else status=-1;
}

public boolean is_ready() {
  return (status==0) ? true : false;
}

public boolean is_error() {
 return (status==-1) ? true : false;
}

public boolean is_host_connected() {
 return (status==1) ? true : false;
}

public boolean is_pop_connected() {
 return (status==2) ? true : false;
}

public void host_connect() {
   if (!is_ready()) {
     status = -1;
     return;
   }
   status = -1;
   try {
     sock = new Socket(InetAddress.getByName(host), port);
   }
   catch (Exception ex) {
      return;
   }
   status = 1;
   return;
}

public void pop_connect() {
   if (!is_host_connected()) {
     status = -1;
     return;
   }
   try {
       in = new BufferedInputStream(sock.getInputStream());
       out = new BufferedOutputStream(sock.getOutputStream());
       String data = "";
       data = get_line();
       if (data.charAt(0) != '+')
         throw new Exception();
   }
   catch (Exception ex) {
     close();
     System.out.println("Errore di comunicazione con il server ");
     return;
   }
   String data;
   System.out.println("Invio User "+user);
   try { put_line("USER "+user); }
     catch (Exception ex) { close(); return; }
   System.out.println("In attesa di risposta...");
   try { data=get_line(); }
     catch (Exception ex) { close(); return; }
   System.out.println("Risposta: "+data);
   if (data.indexOf("+")!=0) { close(); return;}
   System.out.println("Invio Password "+password);
   try { put_line("PASS "+password); }
     catch (Exception ex) { close(); return; }
   System.out.println("In attesa di risposta...");
   try { data=get_line(); }
     catch (Exception ex) { close(); return; }
   System.out.println("Risposta: "+data);
   if (data.indexOf("+")!=0) { close(); return;}
   // se sono qui vuol dire che il login e' andato a buon fine :-)
   String dat[];
   try {
     dat = data.split(" ");
     tot_msg = Integer.parseInt(dat[1]);
     status = 2;
   }
   catch (Exception ex) {
     status = -1;
     close();
   }
}

public int get_tot_msg() {
 if (is_pop_connected())
    return tot_msg;
 else
    return -1;
}

public String get_msg(int number) throws Exception {
 String messaggio="";
 String linea="";
 if (!is_pop_connected() || tot_msg<=0 || number>tot_msg || number<0) return "";
 else {
     put_line("RETR "+number);
     linea = get_line();
     if (linea.charAt(0)!='+') throw new Exception();
     while (true) {
       linea = get_line(); //System.out.println("Linea: '"+linea+"'");
       if (linea.length()==1 && linea.charAt(0)=='.')
         break;
       else
          messaggio+=nl+linea;
     }
 }
 return messaggio;
}

public String get_head(int number) throws Exception {
 String head="";
 String linea="";
 if (!is_pop_connected() || tot_msg<=0 || number>tot_msg || number<0) return "";
 else {
     put_line("TOP "+number+" 0");
     linea = get_line();
     if (linea.charAt(0)!='+') throw new Exception();
     while (true) {
       linea = get_line(); //System.out.println("Linea: '"+linea+"'");
       if (linea.length()==1 && linea.charAt(0)=='.')
         break;
       else
          head+=nl+linea;
     }
 }
 return head;
}

public String get_host_connection_data() {
   return "'"+host+":"+port+"'";
}

public String get_pop_connection_data() {
   return "user: '"+user+"', password: '"+password+"'";
}

public void close() {
  try {
    if (is_pop_connected())
      out.write(("QUIT\n").getBytes());
      out.flush();
  } catch (Exception ex1) {};
  try {
    out.close();
    in.close();
  }
 catch (Exception ex2) {};
 try {
   if (sock.isConnected())
     sock.close();
 }
 catch (Exception ex3) {};
  status = -1;
}

public String get_line() throws Exception {
    if (!is_host_connected() && !is_pop_connected()) {
      return "";
    }
    String str="";
    int ch;
    ch=0;
    while (ch!=13) {
       //if (IN_DEBUG==1) System.out.print(ch+" ");
       ch=in.read();
       if (ch==-1) throw new Exception(); // break;
       if (ch==10) continue;
       if (ch!=13) str=str+(char)ch;
    }
    return str;
}

public void put_line(String str) throws Exception {
    if (!is_host_connected() && !is_pop_connected()) {
      return;
    }
   out.write((str+"\n").getBytes());
   out.flush();
}

  void set_newline() {
    String os;
    os = System.getProperty("os.name");
    System.out.println("OS : "+os);
    os = os.toUpperCase();
    if (os.indexOf("WINDOWS")>=0)
       nl = "\n\r";
    if (os.indexOf("WIN")>=0)
       nl = "\n\r";
    else
      nl = "\n";
  }

}