/* -*- Mode: IDL; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsISupports.idl"

interface nsIMsgNewsFolder;
interface nsINntpUrl;
interface nsIMsgWindow;

/**
 * A utility class for nsINNTPProtocol that handles the list of new headers.
 */
[scriptable, uuid(579aa17b-4c77-465d-8eb6-feaa927cb19c)]
interface nsINNTPNewsgroupList : nsISupports {
  
  void initialize(in nsINntpUrl runningURL, in nsIMsgNewsFolder newsFolder);
  
  long getRangeOfArtsToDownload(in nsIMsgWindow aMsgWindow, in long first_message,
                                in long last_message,
                                in long maxextra,
                                out long real_first_message,
                                out long real_last_message);
  
  void addToKnownArticles(in long first_message, in long last_message);

  /**
   * Initializes the internal state to get the messages.
   *
   * This method should be called before sending the line
   * <tt>XOVER @arg first_message-@arg last_message</tt> to the server.
   *
   * @param first_message  The first message of the download range.
   * @param last_message   The last message of the download range.
   */
  void initXOVER(in long first_message, in long last_message);  
  void processXOVERLINE(in string line, out unsigned long status);
  void resetXOVER();
  void finishXOVERLINE(in long status, out long newstatus);

  /**
   * Initalizes the state in preparation for a call to XHDR.
   *
   * @return               The next header to get, or an empty string if done.
   */
  ACString initXHDR();
  /**
   * Processes a line of the server's response to XHDR.
   *
   * It will calculate the message number and other information itself, so the
   * unadulterated line itself should be sent.
   *
   * @param aLine          The line as sent from the server.
   */
  void processXHDRLine(in ACString aLine);

  /**
   * Initalizes the internal state to process a HEAD command.
   *
   * This method should be called before sending the line
   * <tt>HEAD @arg aMessage</tt> to the server.
   *
   * @param aMessage       The message number that will be sent.
   */
  void initHEAD(in long aMessage);
  /**
   * Processes a line of the server's response to HEAD.
   *
   * This will not check for a quoted '.' at the beginning.
   *
   * @param aLine          The line the server sent.
   */
  void processHEADLine(in ACString aLine);
  /**
   * Manages the internal state if the call to HEAD failed.
   *
   * @param aMessage       The message key that caused the HEAD failure.
   */
  void HEADFailed(in long aMessage);

  /**
   * Calls the filters after all messages have been processed.
   *
   * This method also cleans out some internal state relating to the messages
   * that have been processed, so it should always be called at the end of
   * XOVER/XHDR/HEAD processing.
   */
  void callFilters();

  attribute boolean getOldMessages;
};