/*
 * $Id: FingerConnection.java,v 1.1 2004/06/07 20:12:50 dog Exp $
 * Copyright (C) 2003 The Free Software Foundation
 * 
 * This file is part of GNU inetlib, a library.
 * 
 * GNU inetlib 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 2 of the License, or
 * (at your option) any later version.
 * 
 * GNU inetlib 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 library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * As a special exception, if you link this library with other files to
 * produce an executable, this library does not by itself cause the
 * resulting executable to be covered by the GNU General Public License.
 * This exception does not however invalidate any other reasons why the
 * executable file might be covered by the GNU General Public License.
 */
package gnu.inet.finger;

import java.io.BufferedOutputStream;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.net.Socket;

/**
 * A client for the finger protocol described in RFC 1288.
 *
 * @author <a href='mailto:dog@gnu.org'>Chris Burdess</a>
 */
public class FingerConnection
{

  /**
   * The default finger port.
   */
  public static final int DEFAULT_PORT = 79;

  /*
   * The US-ASCII encoding.
   */
  private static final String US_ASCII = "US-ASCII";

  /**
   * The underlying socket used for communications.
   */
  protected Socket socket;

  /**
   * If we want a verbose response.
   */
  protected boolean verbose;

  /**
   * Creates a new finger connection.
   * @param host the name of the internet host to connect to
   */
  public FingerConnection (String host)
    throws IOException
    {
      this (host, DEFAULT_PORT);
    }

  /**
   * Creates a new finger connection.
   * @param host the name of the internet host to connect to
   * @param port the port to connect to
   */
  public FingerConnection (String host, int port)
    throws IOException
    {
      socket = new Socket (host, port);
    }

  /**
   * Retrieves the verbose flag.
   * If true, the server should provide more output.
   */
  public boolean isVerbose ()
    {
      return verbose;
    }

  /**
   * Sets the verbose flag.
   * If true, the server should provide more output.
   * @param verbose true for more verbose, false otherwise
   */
  public void setVerbose (boolean verbose)
    {
      this.verbose = verbose;
    }

  /**
   * Lists the available users.
   */
  public String list ()
    throws IOException
    {
      return finger (null, null);
    }

  /**
   * Fingers the specified user.
   * @param username the user to finger
   * @return information about all matching users
   */
  public String finger (String username)
    throws IOException
    {
      return finger (username, null);
    }

  /**
   * Fingers the specified user at the specified host.
   * @param username the user to finger (null for any user)
   * @param hostname the domain of the user (null for any domain)
   * @return information about all matching users
   */
  public String finger (String username, String hostname)
    throws IOException
    {
      // Send the command
      OutputStream out = socket.getOutputStream ();
      out = new BufferedOutputStream (out);
      if (verbose)
        {
          out.write ('/');
          out.write ('W');
          if (username != null || hostname != null)
            {
              out.write (' ');
            }
        }
      if (username != null)
        {
          out.write (username.getBytes (US_ASCII));
        }
      if (hostname != null)
        {
          out.write ('@');
          out.write (hostname.getBytes (US_ASCII));
        }
      out.write ('\r');
      out.write ('\n');
      out.flush ();
      
      // Read the response
      InputStream in = socket.getInputStream ();
      ByteArrayOutputStream acc = new ByteArrayOutputStream ();
      byte[] buf = new byte[4096];
      for (int len = in.read (buf); len != -1; len = in.read (buf))
        {
          acc.write (buf, 0, len);
        }
      return acc.toString (US_ASCII);
    }

}