/* 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 nsIURI;
interface nsIDOMWindow;
interface nsIChannel;

/**
 * Utility functions for determining whether a given URI, channel, or window
 * hierarchy is third party with respect to a known URI.
 */
[scriptable, uuid(b711bd7f-0674-49be-ae77-f221db5f7b6c)]
interface mozIThirdPartyUtil : nsISupports
{
  /**
   * isThirdPartyURI
   *
   * Determine whether two URIs are third party with respect to each other.
   * This is determined by computing the base domain for both URIs. If they can
   * be determined, and the base domains match, the request is defined as first
   * party. If it cannot be determined because one or both URIs do not have a
   * base domain (for instance, in the case of IP addresses, host aliases such
   * as 'localhost', or a file:// URI), an exact string comparison on host is
   * performed.
   *
   * For example, the URI "http://mail.google.com/" is not third party with
   * respect to "http://images.google.com/", but "http://mail.yahoo.com/" and
   * "http://192.168.1.1/" are.
   *
   * @return true if aFirstURI is third party with respect to aSecondURI.
   *
   * @throws if either URI is null, has a malformed host, or has an empty host
   *         and is not a file:// URI.
   */
  boolean isThirdPartyURI(in nsIURI aFirstURI, in nsIURI aSecondURI);

  /**
   * isThirdPartyWindow
   *
   * Determine whether the given window hierarchy is third party. This is done
   * as follows:
   *
   * 1) Obtain the URI of the principal associated with 'aWindow'. Call this the
   *    'bottom URI'.
   * 2) If 'aURI' is provided, determine if it is third party with respect to
   *    the bottom URI. If so, return.
   * 3) Find the same-type parent window, if there is one, and its URI.
   *    Determine whether it is third party with respect to the bottom URI. If
   *    so, return.
   *
   * Therefore, each level in the window hierarchy is tested. (This means that
   * nested iframes with different base domains, even though the bottommost and
   * topmost URIs might be equal, will be considered third party.)
   *
   * @param aWindow
   *        The bottommost window in the hierarchy.
   * @param aURI
   *        A URI to test against. If null, the URI of the principal
   *        associated with 'aWindow' will be used.
   *
   * For example, if 'aURI' is "http://mail.google.com/", 'aWindow' has a URI
   * of "http://google.com/", and its parent is the topmost content window with
   * a URI of "http://mozilla.com", the result will be true.
   *
   * @return true if 'aURI' is third party with respect to any of the URIs
   *         associated with aWindow and its same-type parents.
   *
   * @throws if aWindow is null; the same-type parent of any window in the
   *         hierarchy cannot be determined; or the URI associated with any
   *         window in the hierarchy is null, has a malformed host, or has an
   *         empty host and is not a file:// URI.
   *
   * @see isThirdPartyURI
   */
  boolean isThirdPartyWindow(in nsIDOMWindow aWindow, [optional] in nsIURI aURI);

  /**
   * isThirdPartyChannel
   *
   * Determine whether the given channel and its content window hierarchy is
   * third party. This is done as follows:
   *
   * 1) If 'aChannel' is an nsIHttpChannel and has the
   *    'forceAllowThirdPartyCookie' property set, then:
   *    a) If 'aURI' is null, return false.
   *    b) Otherwise, find the URI of the channel, determine whether it is
   *       foreign with respect to 'aURI', and return.
   * 2) Find the URI of the channel and determine whether it is third party with
   *    respect to the URI of the channel. If so, return.
   * 3) Obtain the bottommost nsIDOMWindow, and its same-type parent if it
   *    exists, from the channel's notification callbacks. Then:
   *    a) If the parent is the same as the bottommost window, and the channel
   *       has the LOAD_DOCUMENT_URI flag set, return false. This represents the
   *       case where a toplevel load is occurring and the window's URI has not
   *       yet been updated. (We have already checked that 'aURI' is not foreign
   *       with respect to the channel URI.)
   *    b) Otherwise, return the result of isThirdPartyWindow with arguments
   *       of the channel's bottommost window and the channel URI, respectively.
   *
   * Therefore, both the channel's URI and each level in the window hierarchy
   * associated with the channel is tested.
   *
   * @param aChannel
   *        The channel associated with the load.
   * @param aURI
   *        A URI to test against. If null, the URI of the channel will be used.
   *
   * For example, if 'aURI' is "http://mail.google.com/", 'aChannel' has a URI
   * of "http://google.com/", and its parent is the topmost content window with
   * a URI of "http://mozilla.com", the result will be true.
   *
   * @return true if aURI is third party with respect to the channel URI or any
   *         of the URIs associated with the same-type window hierarchy of the
   *         channel.
   *
   * @throws if 'aChannel' is null; the channel has no notification callbacks or
   *         an associated window; or isThirdPartyWindow throws.
   *
   * @see isThirdPartyWindow
   */
  boolean isThirdPartyChannel(in nsIChannel aChannel, [optional] in nsIURI aURI);

  /**
   * getBaseDomain
   *
   * Get the base domain for aHostURI; e.g. for "www.bbc.co.uk", this would be
   * "bbc.co.uk". Only properly-formed URI's are tolerated, though a trailing
   * dot may be present. If aHostURI is an IP address, an alias such as
   * 'localhost', an eTLD such as 'co.uk', or the empty string, aBaseDomain will
   * be the exact host. The result of this function should only be used in exact
   * string comparisons, since substring comparisons will not be valid for the
   * special cases elided above.
   *
   * @param aHostURI
   *        The URI to analyze.
   *
   * @return the base domain.
   */
  AUTF8String getBaseDomain(in nsIURI aHostURI);

  /**
   * getURIFromWindow
   *
   * Returns the URI associated with the script object principal for the
   * window.
   */
  nsIURI getURIFromWindow(in nsIDOMWindow aWindow);

  /**
   * getTopWindowForChannel
   *
   * Returns the top-level window associated with the given channel.
   */
  nsIDOMWindow getTopWindowForChannel(in nsIChannel aChannel);
};

%{ C++
/**
 * The mozIThirdPartyUtil implementation is an XPCOM service registered
 * under the ContractID:
 */
#define THIRDPARTYUTIL_CONTRACTID "@mozilla.org/thirdpartyutil;1"
%}

