//      Author: Bill Farley
//      Date: 4/8/2001
//      Time: 11:58:06 AM

//Compile: csc /r:System.Net.dll /r:System.IO.dll /r:message.dll /target:library POP3.cs


using System.Net.Sockets;
using System.Collections;
using System.IO;
using System.Net;
using System;

public class POP3
{
    string POPServer;
    string user;
    string pwd;
	NetworkStream ns;
	StreamReader sr;

    public POP3(){}

    public POP3(string server, string _user, string _pwd)
    {
        POPServer = server;
        user = _user;
        pwd = _pwd;
    }

    private void Connect()
	{
		TCPClient sender = new TCPClient(POPServer,110);
        Byte[] outbytes;
        string input;

        try{
			ns = sender.GetStream();
            sr = new StreamReader(ns);
 
			sr.ReadLine();
            //Console.WriteLine(sr.ReadLine() );

            input = "user " + user + "\r\n";
            outbytes = System.Text.Encoding.ASCII.GetBytes(input.ToCharArray());
		    ns.Write(outbytes,0,outbytes.Length) ;
			sr.ReadLine();
            //Console.WriteLine(sr.ReadLine() );

            input = "pass " + pwd + "\r\n";
            outbytes = System.Text.Encoding.ASCII.GetBytes(input.ToCharArray());
			ns.Write(outbytes,0,outbytes.Length) ;
			sr.ReadLine();
            //Console.WriteLine(sr.ReadLine() );
 
        }
		catch(InvalidOperationException ioe){
			Console.WriteLine("Could not connect to mail server");
		}
    }

	private void Disconnect()
	{
            string input = "quit" + "\r\n";
            Byte[] outbytes = System.Text.Encoding.ASCII.GetBytes(input.ToCharArray());
		    ns.Write(outbytes,0,outbytes.Length);
			//Console.WriteLine(sr.ReadLine() );
			ns.Close();
	}

    public int GetNumberOfNewMessages()
    {
        Byte[] outbytes;
        string input;

        try{
 			Connect();

            input = "stat" + "\r\n";
            outbytes = System.Text.Encoding.ASCII.GetBytes(input.ToCharArray());
		    ns.Write(outbytes,0,outbytes.Length);
			string resp = sr.ReadLine();
			//Console.WriteLine(resp);
			string[] tokens = resp.Split(new Char[] {' '});

            Disconnect();

			return tokens[1].ToInt32();
        }
		catch(InvalidOperationException ioe){
			Console.WriteLine("Could not connect to mail server");
			return 0;
		}
   }
    public ArrayList GetNewMessages(string subj)
    {

		int newcount;
		ArrayList newmsgs = new ArrayList();

        try{
			newcount = GetNumberOfNewMessages();
			Connect();
	
			for(int n=1; n<newcount+1; n++){
				ArrayList msglines = GetRawMessage(n);
				string msgsubj = GetMessageSubject(msglines);
				if(msgsubj.CompareTo(subj) == 0){
					Message msg = new Message();
					msg.Subject = msgsubj;
					msg.From = GetMessageFrom(msglines);
					msg.Body = GetMessageBody(msglines);
					newmsgs.Add(msg);
					DeleteMessage(n);
				}
			}

			Disconnect();
			return newmsgs;
        }
		catch(Exception e){
			Console.WriteLine(e.ToString() );
			Console.ReadLine();
			return newmsgs;
		}
   }
   private ArrayList GetRawMessage (int messagenumber)
   {
    	Byte[] outbytes;
        string input;
		string line = "";
 
		input = "retr " + messagenumber.ToString() + "\r\n";
        outbytes = System.Text.Encoding.ASCII.GetBytes(input.ToCharArray());
		ns.Write(outbytes,0,outbytes.Length);
	
		ArrayList msglines = new ArrayList();
		do{
			line = sr.ReadLine();
			msglines.Add(line);
		  } while (line != ".");
		msglines.RemoveAt(msglines.Count-1);

		return msglines;
   }
   private string GetMessageSubject(ArrayList msglines)
   {
		string[] tokens;
   		IEnumerator msgenum = msglines.GetEnumerator();
		while (msgenum.MoveNext() ){
			string line = (string)msgenum.Current;
			if(line.StartsWith("Subject:") ){
				tokens = line.Split(new Char[] {' '});
				return tokens[1].Trim();
			}
		}
		return "None";
   }
   private string GetMessageFrom (ArrayList msglines)
   {
   		string[] tokens;
		IEnumerator msgenum = msglines.GetEnumerator();
		while (msgenum.MoveNext() ){
			string line = (string)msgenum.Current;
			if(line.StartsWith("Return-Path:") ){
				tokens = line.Split(new Char[] {'<'});
				return tokens[1].Trim(new Char[] {'<','>'});
			}
		}
		return "None";
   }
   private string GetMessageBody(ArrayList msglines)
   {
		string body = "";
		string line = " ";
   		IEnumerator msgenum = msglines.GetEnumerator();
	
   		while(line.CompareTo("") != 0){
			msgenum.MoveNext();
			line = (string)msgenum.Current;
		}

		while (msgenum.MoveNext() ){
			body = body + (string)msgenum.Current + "\r\n";
		}
		return body;
   }
   private void DeleteMessage(int messagenumber)
   {
    	Byte[] outbytes;
        string input;
 
		try{
			input = "dele " + messagenumber.ToString() + "\r\n";
        	outbytes = System.Text.Encoding.ASCII.GetBytes(input.ToCharArray());
			ns.Write(outbytes,0,outbytes.Length);
		}
		catch(Exception e){
			Console.WriteLine(e.ToString() );
			Console.ReadLine();
		}
	
   }

}