/*

 *   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.util.io;

import java.io.BufferedOutputStream;

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;

import java.io.UnsupportedEncodingException;

import java.net.Socket;

import java.net.UnknownHostException;

import org.sonews.storage.Article;

/**

 * Posts an Article to a NNTP server using the POST command.

 * @author Christian Lins

 * @since sonews/0.5.0

 */

public class ArticleWriter 

{

  private BufferedOutputStream out;

  private BufferedReader       inr;

  public ArticleWriter(String host, int port)

    throws IOException, UnknownHostException

  {

    // Connect to NNTP server

    Socket socket = new Socket(host, port);

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

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

    String line = inr.readLine();

    if(line == null || !line.startsWith("200 "))

    {

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

    }

  }

  public void close()

    throws IOException, UnsupportedEncodingException

  {

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

    this.out.flush();

  }

  protected void finishPOST()

    throws IOException

  {

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

    this.out.flush();

    String line = inr.readLine();

    if(line == null || !line.startsWith("240 ") || !line.startsWith("441 "))

    {

      throw new IOException(line);

    }

  }

  protected void preparePOST()

    throws IOException

  {

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

    this.out.flush();

    String line = this.inr.readLine();

    if(line == null || !line.startsWith("340 "))

    {

      throw new IOException(line);

    }

  }

  public void writeArticle(Article article)

    throws IOException, UnsupportedEncodingException

  {

    byte[] buf = new byte[512];

    ArticleInputStream in = new ArticleInputStream(article);

    preparePOST();

    int len = in.read(buf);

    while(len != -1)

    {

      writeLine(buf, len);

      len = in.read(buf);

    }

    finishPOST();

  }

  /**

   * Writes the raw content of an article to the remote server. This method

   * does no charset conversion/handling of any kind so its the preferred

   * method for sending an article to remote peers.

   * @param rawArticle

   * @throws IOException

   */

  public void writeArticle(byte[] rawArticle)

    throws IOException

  {

    preparePOST();

    writeLine(rawArticle, rawArticle.length);

    finishPOST();

  }

  /**

   * Writes the given buffer to the connect remote server.

   * @param buffer

   * @param len

   * @throws IOException

   */

  protected void writeLine(byte[] buffer, int len)

    throws IOException

  {

    this.out.write(buffer, 0, len);

    this.out.flush();

  }

}