/*

 *   SONEWS News Server

 *   see AUTHORS for the list of contributors

 *

 *   This program is free software: you can redistribute it and/or modify

 *   it under the terms of the GNU General Public License as published by

 *   the Free Software Foundation, either version 3 of the License, or

 *   (at your option) any later version.

 *

 *   This program is distributed in the hope that it will be useful,

 *   but WITHOUT ANY WARRANTY; without even the implied warranty of

 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 *   GNU General Public License for more details.

 *

 *   You should have received a copy of the GNU General Public License

 *   along with this program.  If not, see <http://www.gnu.org/licenses/>.

 */

package org.sonews.mlgw;

import java.io.BufferedOutputStream;

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;

import java.net.Socket;

import java.net.UnknownHostException;

import org.sonews.config.Config;

import org.sonews.storage.Article;

import org.sonews.util.io.ArticleInputStream;

/**

 * Connects to a SMTP server and sends a given Article to it.

 * @author Christian Lins

 * @since sonews/1.0

 */

class SMTPTransport

{

  protected BufferedReader       in;

  protected BufferedOutputStream out;

  protected Socket               socket;

  public SMTPTransport(String host, int port)

    throws IOException, UnknownHostException

  {

    socket = new Socket(host, port);

    this.in  = new BufferedReader(new InputStreamReader(socket.getInputStream()));

    this.out = new BufferedOutputStream(socket.getOutputStream());

    // Read helo from server

    String line = this.in.readLine();

    if(line == null || !line.startsWith("220 "))

    {

      throw new IOException("Invalid helo from server: " + line);

    }

    // Send HELO to server

    this.out.write(

      ("HELO " + Config.inst().get(Config.HOSTNAME, "localhost") + "\r\n").getBytes("UTF-8"));

    this.out.flush();

    line = this.in.readLine();

    if(line == null || !line.startsWith("250 "))

    {

      throw new IOException("Unexpected reply: " + line);

    }

  }

  public SMTPTransport(String host)

    throws IOException

  {

    this(host, 25);

  }

  public void close()

    throws IOException

  {

    this.out.write("QUIT".getBytes("UTF-8"));

    this.out.flush();

    this.in.readLine();

    this.socket.close();

  }

  public void send(Article article, String mailFrom, String rcptTo)

    throws IOException

  {

    assert(article != null);

    assert(mailFrom != null);

    assert(rcptTo != null);

    this.out.write(("MAIL FROM: " + mailFrom).getBytes("UTF-8"));

    this.out.flush();

    String line = this.in.readLine();

    if(line == null || !line.startsWith("250 "))

    {

      throw new IOException("Unexpected reply: " + line);

    }

    this.out.write(("RCPT TO: " + rcptTo).getBytes("UTF-8"));

    this.out.flush();

    line  = this.in.readLine();

    if(line == null || !line.startsWith("250 "))

    {

      throw new IOException("Unexpected reply: " + line);

    }

    this.out.write("DATA".getBytes("UTF-8"));

    this.out.flush();

    line = this.in.readLine();

    if(line == null || !line.startsWith("354 "))

    {

      throw new IOException("Unexpected reply: " + line);

    }

    ArticleInputStream   artStream = new ArticleInputStream(article);

    for(int b = artStream.read(); b >= 0; b = artStream.read())

    {

      this.out.write(b);

    }

    // Flush the binary stream; important because otherwise the output

    // will be mixed with the PrintWriter.

    this.out.flush();

    this.out.write("\r\n.\r\n".getBytes("UTF-8"));

    this.out.flush();

    line = this.in.readLine();

    if(line == null || !line.startsWith("250 "))

    {

      throw new IOException("Unexpected reply: " + line);

    }

  }

}