/* -*- Mode: C++; tab-width: 2; 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 nsIProtocolHandler;
interface nsIChannel;
interface nsIURI;
interface nsIFile;

/**
 * nsIIOService provides a set of network utility functions.  This interface
 * duplicates many of the nsIProtocolHandler methods in a protocol handler
 * independent way (e.g., NewURI inspects the scheme in order to delegate
 * creation of the new URI to the appropriate protocol handler).  nsIIOService
 * also provides a set of URL parsing utility functions.  These are provided
 * as a convenience to the programmer and in some cases to improve performance
 * by eliminating intermediate data structures and interfaces.
 */
[scriptable, uuid(bddeda3f-9020-4d12-8c70-984ee9f7935e)]
interface nsIIOService : nsISupports
{
    /**
     * Returns a protocol handler for a given URI scheme.
     *
     * @param aScheme the URI scheme
     * @return reference to corresponding nsIProtocolHandler
     */
    nsIProtocolHandler getProtocolHandler(in string aScheme);

    /**
     * Returns the protocol flags for a given scheme.
     *
     * @param aScheme the URI scheme
     * @return value of corresponding nsIProtocolHandler::protocolFlags
     */
    unsigned long getProtocolFlags(in string aScheme);

    /**
     * This method constructs a new URI by determining the scheme of the
     * URI spec, and then delegating the construction of the URI to the
     * protocol handler for that scheme. QueryInterface can be used on
     * the resulting URI object to obtain a more specific type of URI.
     *
     * @see nsIProtocolHandler::newURI
     */
    nsIURI newURI(in AUTF8String aSpec,
                  in string aOriginCharset,
                  in nsIURI aBaseURI);

    /**
     * This method constructs a new URI from a nsIFile.
     *
     * @param aFile specifies the file path
     * @return reference to a new nsIURI object
     *
     * Note: in the future, for perf reasons we should allow 
     * callers to specify whether this is a file or directory by
     * splitting this  into newDirURI() and newActualFileURI().
     */
    nsIURI newFileURI(in nsIFile aFile);

    /**
     * Creates a channel for a given URI.
     *
     * @param aURI nsIURI from which to make a channel
     * @return reference to the new nsIChannel object
     */
    nsIChannel newChannelFromURI(in nsIURI aURI);

    /**
     * Equivalent to newChannelFromURI(newURI(...))
     */
    nsIChannel newChannel(in AUTF8String aSpec,
                          in string aOriginCharset,
                          in nsIURI aBaseURI);

    /**
     * Returns true if networking is in "offline" mode. When in offline mode, 
     * attempts to access the network will fail (although this does not 
     * necessarily correlate with whether there is actually a network 
     * available -- that's hard to detect without causing the dialer to 
     * come up).
     *
     * Changing this fires observer notifications ... see below.
     */
    attribute boolean offline;

    /**
     * Checks if a port number is banned. This involves consulting a list of
     * unsafe ports, corresponding to network services that may be easily
     * exploitable. If the given port is considered unsafe, then the protocol
     * handler (corresponding to aScheme) will be asked whether it wishes to
     * override the IO service's decision to block the port. This gives the
     * protocol handler ultimate control over its own security policy while
     * ensuring reasonable, default protection.
     *
     * @see nsIProtocolHandler::allowPort
     */
    boolean allowPort(in long aPort, in string aScheme);

    /**
     * Utility to extract the scheme from a URL string, consistently and
     * according to spec (see RFC 2396).
     *
     * NOTE: Most URL parsing is done via nsIURI, and in fact the scheme
     * can also be extracted from a URL string via nsIURI.  This method
     * is provided purely as an optimization.
     *
     * @param aSpec the URL string to parse
     * @return URL scheme
     *
     * @throws NS_ERROR_MALFORMED_URI if URL string is not of the right form.
     */
    ACString extractScheme(in AUTF8String urlString);
};

%{C++
/**
 * We send notifications through nsIObserverService with topic
 * NS_IOSERVICE_GOING_OFFLINE_TOPIC and data NS_IOSERVICE_OFFLINE
 * when 'offline' has changed from false to true, and we are about
 * to shut down network services such as DNS. When those
 * services have been shut down, we send a notification with
 * topic NS_IOSERVICE_OFFLINE_STATUS_TOPIC and data
 * NS_IOSERVICE_OFFLINE.
 *
 * When 'offline' changes from true to false, then after
 * network services have been restarted, we send a notification
 * with topic NS_IOSERVICE_OFFLINE_STATUS_TOPIC and data
 * NS_IOSERVICE_ONLINE.
 */
#define NS_IOSERVICE_GOING_OFFLINE_TOPIC  "network:offline-about-to-go-offline"
#define NS_IOSERVICE_OFFLINE_STATUS_TOPIC "network:offline-status-changed"
#define NS_IOSERVICE_OFFLINE              "offline"
#define NS_IOSERVICE_ONLINE               "online"
%}
