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/* vim:set ts=4 sw=4 sts=4 et: */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Darin Fisher <darin@meer.net>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
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 * ***** END LICENSE BLOCK ***** */

#include "nsISupports.idl"

interface nsIProxyInfo;
interface nsIChannel;
interface nsIURI;

/**
 * nsIProtocolProxyService provides methods to access information about
 * various network proxies.
 */
[scriptable, uuid(ec2da5ae-eb2e-11d8-9782-0004e22243f8)]
interface nsIProtocolProxyService : nsISupports
{
    /**
     * This attribute indicates whether or not support for proxies is enabled.
     */
    readonly attribute PRBool proxyEnabled;

    /**
     * This method returns a nsIProxyInfo instance that identifies a proxy to
     * be used for loading the given URL.  Otherwise, this method returns null
     * indicating that a direct connection should be used.
     *
     * @param aURI
     *        The URI to test.
     *
     * NOTE: If this proxy is unavailable, getFailoverForProxy may be called
     * to determine the correct secondary proxy to be used.
     *
     * NOTE: If the protocol handler for the given URI supports
     * nsIProxiedProtocolHandler, then the nsIProxyInfo instance returned
     * from examineForProxy may be passed to the newProxiedChannel method
     * to create a nsIChannel to the given URI that uses the specified proxy.
     *
     * NOTE: However, if the nsIProxyInfo type is "HTTP", then it means that
     * the given URI should be loaded using the HTTP protocol handler, which
     * also supports nsIProxiedProtocolHandler.
     *
     * @see nsIProxiedProtocolHandler::newProxiedChannel 
     */
    nsIProxyInfo examineForProxy(in nsIURI aURI);

    /**
     * This method may be called to construct a nsIProxyInfo instance from
     * the given parameters.  This method may be useful in conjunction with
     * nsISocketTransportService::createTransport for creating, for example,
     * a SOCKS connection.
     *
     * @param aType
     *        The proxy type.  This is a string value that identifies the proxy
     *        type.  Standard values include:
     *          "HTTP"   - specifies a HTTP proxy
     *          "SOCKS"  - specifies a SOCKS version 5 proxy
     *          "SOCKS4" - specifies a SOCKS version 4 proxy
     *        The type name is case insensitive.  Other string values may be
     *        possible.
     * @param aHost
     *        The proxy hostname or IP address.
     * @param aPort
     *        The proxy port.
     * @param aFlags
     *        Flags associated with this connection.  See nsIProxyInfo.idl
     *        for currently defined flags.
     */
    nsIProxyInfo newProxyInfo(in ACString aType, in AUTF8String aHost,
                              in long aPort, in unsigned long aFlags);

    /**
     * This method may be called to re-configure proxy settings given a URI
     * to a new proxy auto config file.  This method may return before the
     * configuration actually takes affect (i.e., the URI may be loaded
     * asynchronously).
     *
     * @param aURI
     *        The location of the PAC file to load.
     */
    void configureFromPAC(in AUTF8String aURI);

    /**
     * If the proxy identified by aProxyInfo is unavailable for some reason,
     * this method may be called to access an alternate proxy that may be used
     * instead.  As a side-effect, this method may affect future return values
     * from examineForProxy as well as from getFailoverProxy.
     *
     * @param aProxyInfo
     *        The proxy that was unavailable.
     * @param aURI
     *        The URI that was originally passed to ExamineForProxy.
     * @param aReason
     *        The error code corresponding to the proxy failure.  This value
     *        may be used to tune the delay before this proxy is used again.
     *
     * @throw NS_ERROR_NOT_AVAILABLE if there is no alternate proxy available.
     */
    nsIProxyInfo getFailoverForProxy(in nsIProxyInfo aProxyInfo,
                                     in nsIURI       aURI,
                                     in nsresult     aReason);
};
