/* 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 nsIDOMWindow;
interface nsIDOMNode;

/**
 * nsISessionStore keeps track of the current browsing state.
 *
 * The nsISessionStore API operates mostly on browser windows and the browser
 * tabs contained in them.
 */

[scriptable, uuid(91eca9cf-6741-4c8f-a3a0-2e957240894d)]
interface nsISessionStore : nsISupports
{
  /**
   * Get the current browsing state.
   * @returns a JSON string representing the session state.
   */
  AString getBrowserState();

  /**
   * Get the number of restore-able tabs for a browser window
   */
  unsigned long getClosedTabCount(in nsIDOMWindow aWindow);

  /**
   * Get closed tab data
   *
   * @param aWindow is the browser window for which to get closed tab data
   * @returns a JS array of closed tabs.
   */
  jsval getClosedTabs(in nsIDOMWindow aWindow);

  /**
   * @param aWindow is the browser window to reopen a closed tab in.
   * @param aIndex  is the index of the tab to be restored (FIFO ordered).
   * @returns a reference to the reopened tab.
   */
  nsIDOMNode undoCloseTab(in nsIDOMWindow aWindow, in unsigned long aIndex);

  /**
   * @param aWindow is the browser window associated with the closed tab.
   * @param aIndex  is the index of the closed tab to be removed (FIFO ordered).
   */
  nsIDOMNode forgetClosedTab(in nsIDOMWindow aWindow, in unsigned long aIndex);

  /**
   * @param aTab is the browser tab to get the value for.
   * @param aKey is the value's name.
   * 
   * @returns A string value or an empty string if none is set.
   */
  AString getTabValue(in jsval aTab, in AString aKey);

  /**
   * @param aTab         is the browser tab to set the value for.
   * @param aKey         is the value's name.
   * @param aStringValue is the value itself (use JSON.stringify/parse before setting JS objects).
   */
  void setTabValue(in jsval aTab, in AString aKey, in AString aStringValue);

  /**
   * @param aTab is the browser tab to get the value for.
   * @param aKey is the value's name.
   */
  void deleteTabValue(in jsval aTab, in AString aKey);

  /**
   * Restores the previous browser session using a fast, lightweight strategy
   * @param aSessionString The session string to restore from. If null, the
   *                       backup session file is read from.
   */
  void restoreLastSession(in AString aSessionString);
};