path: root/embed/mozilla/MozDownload.cpp

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* ***** 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 © 2002
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *  Conrad Carlen <ccarlen@netscape.com>
 * 
 * Adapted for epiphany by Marco Pesenti Gritti <marco@gnome.org>
 *
 * 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"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK *****
 *
 * $Id$
 */

#include "mozilla-config.h"
#include "config.h"

#include <stdlib.h>

#include <glib/gi18n.h>
#include <gio/gdesktopappinfo.h>
#include <gio/gio.h>

#include <nsStringAPI.h>

#include <nsComponentManagerUtils.h>
#include <nsICancelable.h>
#include <nsIChannel.h>
#include <nsIDOMDocument.h>
#include <nsIFileURL.h>
#include <nsIIOService.h>
#include <nsILocalFile.h>
#include <nsIMIMEInfo.h>
#include <nsIMIMEService.h>
#include <nsIObserver.h>
#include <nsIRequest.h>
#include <nsIURI.h>
#include <nsIWritablePropertyBag2.h>
#include <nsIWebBrowserPersist.h>

#include <nsMemory.h>
#include <nsNetError.h>
#include <nsServiceManagerUtils.h>

#ifndef HAVE_GECKO_1_9
#include "EphyBadCertRejector.h"
#endif

#include "EphyUtils.h"

#include "eel-gconf-extensions.h"
#include "ephy-debug.h"
#include "ephy-file-helpers.h"
#include "ephy-prefs.h"
#include "mozilla-download.h"

#include "MozDownload.h"

/* Minimum time between progress updates */
#define PROGRESS_RATE 500000 /* microsec */

const char* const persistContractID = "@mozilla.org/embedding/browser/nsWebBrowserPersist;1";

MozDownload::MozDownload() :
    mTotalProgress(-1),
    mCurrentProgress(0),
    mMaxSize(-1),
    mAddToRecent(PR_TRUE),
    mStatus(NS_OK),
    mEmbedPersist(nsnull),
    mDownloadState(EPHY_DOWNLOAD_INITIALISING)
{
    LOG ("MozDownload ctor (%p)", (void *) this);
}

MozDownload::~MozDownload()
{
    LOG ("MozDownload dtor (%p)", (void *) this);

    NS_ASSERTION (!mEphyDownload, "MozillaDownload still alive!");
}

NS_IMPL_ISUPPORTS4 (MozDownload,
            nsIWebProgressListener,
            nsIWebProgressListener2,
            nsITransfer,
            nsIInterfaceRequestor)

nsresult
MozDownload::InitForEmbed (nsIURI *aSource, nsIURI *aTarget, const nsAString &aDisplayName,
                   nsIMIMEInfo *aMIMEInfo, PRTime aStartTime, nsILocalFile *aTempFile,
               nsICancelable *aCancelable, MozillaEmbedPersist *aEmbedPersist,
               PRInt64 aMaxSize)
{
    mEmbedPersist = aEmbedPersist;
    mMaxSize = aMaxSize;
    return Init (aSource, aTarget, aDisplayName, aMIMEInfo, aStartTime, aTempFile, aCancelable);
}

/* void init (in nsIURI aSource, in nsIURI aTarget, in AString aDisplayName, in nsIMIMEInfo aMIMEInfo, in PRTime startTime, in nsILocalFile aTempFile, in nsICancelable aCancelable); */
NS_IMETHODIMP
MozDownload::Init (nsIURI *aSource,
           nsIURI *aTarget,
           const nsAString &aDisplayName,
           nsIMIMEInfo *aMIMEInfo,
           PRTime aStartTime,
           nsILocalFile *aTempFile,
           nsICancelable *aCancelable)
{
    PRBool addToView = PR_TRUE;

    if (mEmbedPersist)
    {
        EphyEmbedPersistFlags flags;

        flags = ephy_embed_persist_get_flags (EPHY_EMBED_PERSIST (mEmbedPersist));

        addToView = !(flags & EPHY_EMBED_PERSIST_NO_VIEW);
    }

    mSource = aSource;
    mDestination = aTarget;
    mStartTime = aStartTime;
    mTotalProgress = 0;
    mCurrentProgress = 0;
    mPercentComplete = 0;
    mInterval = PROGRESS_RATE;
    mLastUpdate = mStartTime;
    mMIMEInfo = aMIMEInfo;
    mAddToRecent = addToView;

    /* This will create a refcount cycle, which needs to be broken in ::OnStateChange */
    mCancelable = aCancelable;

    if (addToView)
    { 
        DownloaderView *dview;
        EphyDownload **cache_ptr;
        dview = EPHY_DOWNLOADER_VIEW
            (ephy_embed_shell_get_downloader_view (embed_shell));
        mEphyDownload = mozilla_download_new (this);
        cache_ptr = &mEphyDownload;
        g_object_add_weak_pointer (G_OBJECT (mEphyDownload),
                       (gpointer *) cache_ptr);
        downloader_view_add_download (dview, mEphyDownload);
        g_object_unref (mEphyDownload);
    }
    else
    {
        mEphyDownload = nsnull;
    }

    return NS_OK;
}

NS_IMETHODIMP
MozDownload::GetSource(nsIURI **aSource)
{
    NS_ENSURE_ARG_POINTER(aSource);
    NS_IF_ADDREF(*aSource = mSource);

    return NS_OK;
}

NS_IMETHODIMP
MozDownload::GetTargetFile (nsILocalFile** aTargetFile)
{
    nsresult rv;
                                                                                                                              
    nsCOMPtr<nsIFileURL> fileURL = do_QueryInterface(mDestination, &rv);
    if (NS_FAILED(rv)) return rv;
                                                                                                                              
    nsCOMPtr<nsIFile> file;
    rv = fileURL->GetFile(getter_AddRefs(file));
    if (NS_SUCCEEDED(rv))
        rv = CallQueryInterface(file, aTargetFile);
    return rv;
}

NS_IMETHODIMP
MozDownload::GetPercentComplete(PRInt32 *aPercentComplete)
{
    NS_ENSURE_ARG_POINTER(aPercentComplete);
    *aPercentComplete = mPercentComplete;

    return NS_OK;
}

NS_IMETHODIMP
MozDownload::GetTotalProgress(PRInt64 *aTotalProgress)
{
    NS_ENSURE_ARG_POINTER(aTotalProgress);
    *aTotalProgress = mTotalProgress;

    return NS_OK;
}

NS_IMETHODIMP
MozDownload::GetCurrentProgress(PRInt64 *aCurrentProgress)
{
    NS_ENSURE_ARG_POINTER(aCurrentProgress);
    *aCurrentProgress = mCurrentProgress;

    return NS_OK;
}

NS_IMETHODIMP
MozDownload::GetState(EphyDownloadState *aDownloadState)
{
    NS_ENSURE_ARG_POINTER(aDownloadState);
    *aDownloadState = mDownloadState;

    return NS_OK;
}

NS_IMETHODIMP
MozDownload::GetElapsedTime(PRInt64 *aElapsedTime)
{
    NS_ENSURE_ARG_POINTER(aElapsedTime);
    *aElapsedTime = PR_Now() - mStartTime;

    return NS_OK;
}

NS_IMETHODIMP
MozDownload::GetMIMEInfo(nsIMIMEInfo **aMIMEInfo)
{
        NS_ENSURE_ARG_POINTER(aMIMEInfo);
    NS_IF_ADDREF(*aMIMEInfo = mMIMEInfo);

    return NS_OK;
}

NS_IMETHODIMP 
MozDownload::OnStateChange (nsIWebProgress *aWebProgress, nsIRequest *aRequest,
                PRUint32 aStateFlags, nsresult aStatus)
{
    nsresult rv;

    if (NS_FAILED(aStatus) && NS_SUCCEEDED(mStatus))
            mStatus = aStatus;

    if (aStateFlags & STATE_START)
    {
        mDownloadState = EPHY_DOWNLOAD_DOWNLOADING;

        if (mEphyDownload)
        {
            g_signal_emit_by_name (mEphyDownload, "changed");
        }
    }

    /* We will get this even in the event of a cancel */
    /* Due to a mozilla bug [https://bugzilla.mozilla.org/show_bug.cgi?id=304353],
     * we'll only get STATE_STOP if we're driven from external app handler; elsewhere
     * we get STATE_STOP | STATE_IS_NETWORK | STATE_IS_REQUEST. So check first if 
     * STATE_IS_REQUEST is set.
     */
    /* Be careful that download is only completed when STATE_IS_NETWORK is set
     * and many lonely STOP events may be triggered before.
     */
#ifdef GNOME_ENABLE_DEBUG
{
    nsCString spec;
    if (mSource) mSource->GetSpec(spec);

    LOG ("url %s, status %x, state %x (is-stop:%s, is-network:%s, is-request:%s)",
         spec.get(), aStatus, aStateFlags,
         aStateFlags & STATE_STOP ? "t" : "f",
         aStateFlags & STATE_IS_NETWORK ? "t" : "f",
         aStateFlags & STATE_IS_REQUEST ? "t" : "f");
}
#endif

    if (((aStateFlags & STATE_IS_REQUEST) &&
         (aStateFlags & STATE_IS_NETWORK) &&
         (aStateFlags & STATE_STOP)) ||
        aStateFlags == STATE_STOP)
    {
        LOG ("STATE_STOP");

        /* Keep us alive */
        nsCOMPtr<nsITransfer> kungFuDeathGrip(this);

        mDownloadState = NS_SUCCEEDED (aStatus) ? EPHY_DOWNLOAD_COMPLETED : EPHY_DOWNLOAD_FAILED;
        if (mEphyDownload)
        {
            g_signal_emit_by_name (mEphyDownload, "changed");
        }

        /* break refcount cycle */
        mCancelable = nsnull;
        
        nsCString destSpec;
        nsCString mimeType;

        mDestination->GetSpec (destSpec);

        if (NS_SUCCEEDED (aStatus) && mMIMEInfo)
        {
            rv = mMIMEInfo->GetMIMEType (mimeType);
            NS_ENSURE_SUCCESS (rv, NS_ERROR_FAILURE);
        }

        if (mAddToRecent)
        {
            ephy_file_add_recent_item (destSpec.get(), mimeType.get());
        }

        if (mEmbedPersist)
        {
            if (NS_SUCCEEDED (aStatus))
            {
                mozilla_embed_persist_completed (mEmbedPersist);
            }
            else
            {
                mozilla_embed_persist_cancelled (mEmbedPersist);
            }
        }
        else if (NS_SUCCEEDED (aStatus))
        {
            /* see http://bugzilla.gnome.org/show_bug.cgi?id=456945 */
#ifdef HAVE_GECKO_1_9
            return NS_OK;
#else
            GDesktopAppInfo *helperApp;
            NS_ENSURE_TRUE (mMIMEInfo, NS_ERROR_FAILURE);

            nsString description;
            mMIMEInfo->GetApplicationDescription (description);

            nsCString cDesc;
            NS_UTF16ToCString (description, NS_CSTRING_ENCODING_UTF8, cDesc);

            /* HACK we use the application description to decide
               if we have to open the saved file */
            if (g_str_has_prefix (cDesc.get(), "gnome-default:"))
            {
                /* Format gnome-default:<usertime>:<helperapp id> */
                char **str = g_strsplit (cDesc.get(), ":", -1);
                g_return_val_if_fail (g_strv_length (str) == 3, NS_ERROR_FAILURE);

                char *end;
                guint32 user_time = strtoul (str[1], &end, 0);

                helperApp = g_desktop_app_info_new (str[2]);
                if (!helperApp) return NS_ERROR_FAILURE;

                nsCString aDest;
                rv = mDestination->GetSpec (aDest);
                NS_ENSURE_SUCCESS (rv, NS_ERROR_FAILURE);
                
                GFile* file;
                GList* list = NULL;

                file = g_file_new_for_uri (destSpec.get ());
                list = g_list_append (list, file);
                ephy_file_launch_application (G_APP_INFO (helperApp), list, user_time, NULL);

                g_list_free (list);
                g_object_unref (file);
                g_strfreev (str);
            }
            else if (g_str_has_prefix (cDesc.get(), "gnome-browse-to-file:"))
            {
                /* Format gnome-browse-to-file:<usertime> */
                char **str = g_strsplit (cDesc.get(), ":", -1);
                g_return_val_if_fail (g_strv_length (str) == 2, NS_ERROR_FAILURE);

                char *end;
                guint32 user_time = strtoul (str[1], &end, 0);

                nsCString aDest;
                rv = mDestination->GetSpec (aDest);
                NS_ENSURE_SUCCESS (rv, NS_ERROR_FAILURE);

                GFile *dest;
                dest = g_file_new_for_uri (aDest.get ());
                ephy_file_browse_to (dest, user_time);

                g_object_unref (dest);
                g_strfreev (str);
            }
#endif /* HAVE_GECKO_1_9 */
        }
    }
        
    return NS_OK; 
}

NS_IMETHODIMP
MozDownload::OnProgressChange (nsIWebProgress *aWebProgress,
                   nsIRequest *aRequest,
                   PRInt32 aCurSelfProgress,
                   PRInt32 aMaxSelfProgress,
                   PRInt32 aCurTotalProgress,
                   PRInt32 aMaxTotalProgress)
{
    return OnProgressChange64 (aWebProgress, aRequest,
                   aCurSelfProgress, aMaxSelfProgress,
                   aCurTotalProgress, aMaxTotalProgress);
}

/* void onProgressChange64 (in nsIWebProgress aWebProgress, in nsIRequest aRequest, in long long aCurSelfProgress, in long long aMaxSelfProgress, in long long aCurTotalProgress,
 in long long aMaxTotalProgress); */
NS_IMETHODIMP
MozDownload::OnProgressChange64 (nsIWebProgress *aWebProgress,
                 nsIRequest *aRequest,
                 PRInt64 aCurSelfProgress,
                 PRInt64 aMaxSelfProgress,
                 PRInt64 aCurTotalProgress,
                 PRInt64 aMaxTotalProgress)
{
    if (mMaxSize >= 0 &&
        ((aMaxTotalProgress > 0 && mMaxSize < aMaxTotalProgress) ||
         mMaxSize < aCurTotalProgress))
    {
        Cancel ();
    }

    if (!mRequest)
        mRequest = aRequest;

    PRInt64 now = PR_Now ();

    if ((now - mLastUpdate < mInterval) &&
        (aMaxTotalProgress == -1 || aCurTotalProgress < aMaxTotalProgress))
        return NS_OK;

    mLastUpdate = now;

    if (aMaxTotalProgress <= 0)
    {
            mPercentComplete = -1;
    }
    else
    {
        /* Make sure not to round up, so we don't display 100% unless
         * it's really finished! 
         */
            mPercentComplete = (PRInt32)(((float)aCurTotalProgress / (float)aMaxTotalProgress) * 100.0);
    }

    mTotalProgress = aMaxTotalProgress;
    mCurrentProgress = aCurTotalProgress;

    if (mEphyDownload)
    {
        g_signal_emit_by_name (mEphyDownload, "changed");
    }

    return NS_OK;
}

#ifdef HAVE_GECKO_1_9
/* boolean onRefreshAttempted (in nsIWebProgress aWebProgress, in nsIURI aRefreshURI, in long aDelay, in boolean aSameURI); */
NS_IMETHODIMP
MozDownload::OnRefreshAttempted(nsIWebProgress *aWebProgress,
                                nsIURI *aUri,
                                PRInt32 aDelay,
                                PRBool aSameUri,
                                PRBool *allowRefresh)
{
        *allowRefresh = PR_TRUE;
        return NS_OK;
}
#endif

NS_IMETHODIMP
MozDownload::OnLocationChange (nsIWebProgress *aWebProgress, nsIRequest *aRequest, nsIURI *location)
{
    return NS_OK;
}

NS_IMETHODIMP 
MozDownload::OnStatusChange (nsIWebProgress *aWebProgress, nsIRequest *aRequest,
                 nsresult aStatus, const PRUnichar *aMessage)
{
    return NS_OK;
}

NS_IMETHODIMP 
MozDownload::OnSecurityChange (nsIWebProgress *aWebProgress, nsIRequest *aRequest, PRUint32 state)
{
    return NS_OK;
}

/* void getInterface (in nsIIDRef uuid, [iid_is (uuid), retval] out nsQIResult result); */
NS_IMETHODIMP
MozDownload::GetInterface(const nsIID & uuid, void * *result)
{
#ifndef HAVE_GECKO_1_9
    if (uuid.Equals (NS_GET_IID (nsIBadCertListener)) &&
        mEmbedPersist)
    {
        EphyEmbedPersistFlags flags;

        g_object_get (mEmbedPersist, "flags", &flags, (char *) NULL);

        if (flags & EPHY_EMBED_PERSIST_NO_CERTDIALOGS)
        {
            nsIBadCertListener *badCertRejector = new EphyBadCertRejector ();
            if (!badCertRejector) return NS_ERROR_OUT_OF_MEMORY;

            *result = badCertRejector;
            NS_ADDREF (badCertRejector);

            return NS_OK;
        }
    }
#endif
    return NS_ERROR_NO_INTERFACE;
}

void
MozDownload::Cancel()
{
    if (mDownloadState != EPHY_DOWNLOAD_DOWNLOADING &&
        mDownloadState != EPHY_DOWNLOAD_PAUSED)
    {
        return;
    }

    if (mCancelable)
    {
        /* FIXME: error code? */
        mCancelable->Cancel (NS_BINDING_ABORTED);
    }
}

void
MozDownload::Pause()
{
    if (mRequest)
    {
        mRequest->Suspend ();
        mDownloadState = EPHY_DOWNLOAD_PAUSED;
    }
}

void
MozDownload::Resume()
{
    if (mRequest)
    {
        mRequest->Resume ();
        mDownloadState = EPHY_DOWNLOAD_DOWNLOADING;
    }
}

nsresult InitiateMozillaDownload (nsIDOMDocument *domDocument, nsIURI *sourceURI,
                  nsILocalFile* inDestFile, const char *contentType,
                  nsIURI* inOriginalURI, MozillaEmbedPersist *embedPersist,
                  nsIInputStream *postData, nsISupports *aCacheKey,
                  PRInt64 aMaxSize)
{
    nsresult rv = NS_OK;

    EphyEmbedPersistFlags ephy_flags;
    ephy_flags = ephy_embed_persist_get_flags (EPHY_EMBED_PERSIST (embedPersist));

    if (!ephy_embed_persist_get_dest (EPHY_EMBED_PERSIST (embedPersist)))
    {
        nsCString cPath;
        inDestFile->GetNativePath (cPath);

        ephy_embed_persist_set_dest (EPHY_EMBED_PERSIST (embedPersist),
                cPath.get());
    }
    
    nsCOMPtr<nsIMIMEService> mimeService (do_GetService ("@mozilla.org/mime;1"));
    nsCOMPtr<nsIMIMEInfo> mimeInfo;
    if (mimeService)
    {
        mimeService->GetFromTypeAndExtension (nsCString(contentType),
                              nsCString(),
                              getter_AddRefs (mimeInfo));
    }

    PRBool isHTML = (contentType &&
            (strcmp (contentType, "text/html") == 0 ||
             strcmp (contentType, "text/xml") == 0 ||
             strcmp (contentType, "application/xhtml+xml") == 0));

    nsCOMPtr<nsIWebBrowserPersist> webPersist (do_CreateInstance(persistContractID, &rv));
    NS_ENSURE_SUCCESS (rv, rv);
  
    PRInt64 timeNow = PR_Now();
  
    nsString fileDisplayName;
    inDestFile->GetLeafName(fileDisplayName);

    nsCOMPtr<nsIIOService> ioService;
    rv = EphyUtils::GetIOService (getter_AddRefs (ioService));
    NS_ENSURE_SUCCESS (rv, rv);

    nsCOMPtr<nsIURI> destURI;
    ioService->NewFileURI (inDestFile, getter_AddRefs(destURI));

    MozDownload *downloader = new MozDownload ();
    /* dlListener attaches to its progress dialog here, which gains ownership */
    /* FIXME is that still true? */
    rv = downloader->InitForEmbed (inOriginalURI, destURI, fileDisplayName,
                       mimeInfo, timeNow, nsnull, webPersist, embedPersist, aMaxSize);
    NS_ENSURE_SUCCESS (rv, rv);

    rv = webPersist->SetProgressListener (downloader);
    NS_ENSURE_SUCCESS (rv, rv);

    PRInt32 flags = nsIWebBrowserPersist::PERSIST_FLAGS_REPLACE_EXISTING_FILES;

    if (!domDocument && !isHTML && !(ephy_flags & EPHY_EMBED_PERSIST_COPY_PAGE) &&
        !(ephy_flags & EPHY_EMBED_PERSIST_DO_CONVERSION))
    {
        flags |= nsIWebBrowserPersist::PERSIST_FLAGS_NO_CONVERSION;
    }
    if (ephy_flags & EPHY_EMBED_PERSIST_COPY_PAGE)
    {
        flags |= nsIWebBrowserPersist::PERSIST_FLAGS_FROM_CACHE;
    }
    webPersist->SetPersistFlags(flags);

    /* Create a new tagged channel if we need to block cookies from server */
    if (ephy_flags & EPHY_EMBED_PERSIST_NO_COOKIES)
    {
        nsCOMPtr<nsIChannel> tmpChannel;
        rv = ioService->NewChannelFromURI (sourceURI, getter_AddRefs (tmpChannel));
        NS_ENSURE_SUCCESS (rv, rv);

        nsCOMPtr<nsIWritablePropertyBag2> props = do_QueryInterface(tmpChannel);
        rv = props->SetPropertyAsBool (NS_LITERAL_STRING("epiphany-blocking-cookies"), PR_TRUE);
        NS_ENSURE_SUCCESS (rv, rv);
    
        rv = webPersist->SaveChannel (tmpChannel, inDestFile);
    }
    else if (!domDocument || !isHTML || ephy_flags & EPHY_EMBED_PERSIST_COPY_PAGE)
    {
        rv = webPersist->SaveURI (sourceURI, aCacheKey, nsnull,
                      postData, nsnull, inDestFile);
    }
    else
    {
        PRInt32 encodingFlags = 0;
        nsCOMPtr<nsILocalFile> filesFolder;

        /**
         * Construct a directory path to hold the associated files; mozilla
         * will create the directory as needed.
         */

        nsCString cPath;
        inDestFile->GetNativePath (cPath);

        char *basename = g_path_get_basename (cPath.get());
        char *dirname = g_path_get_dirname (cPath.get());
        char *dot_pos = strchr (basename, '.');
        if (dot_pos)
        {
            *dot_pos = 0;
        }
        /* translators: this is the directory name to store auxilary files when saving html files */
        char *new_basename = g_strdup_printf (_("%s Files"), basename);
        char *new_path = g_build_filename (dirname, new_basename, NULL);
        g_free (new_basename);
        g_free (basename);
        g_free (dirname);
      
        filesFolder = do_CreateInstance ("@mozilla.org/file/local;1");
        filesFolder->InitWithNativePath (nsCString(new_path));

        g_free (new_path);

        rv = webPersist->SaveDocument (domDocument, inDestFile, filesFolder,
                           contentType, encodingFlags, 80);
    }
  
    return rv;
}

static char*
GetFilePath (const char *filename)
{
    const char *home_dir;
    char *download_dir, *path;

    download_dir = ephy_file_get_downloads_dir ();

    if (ephy_ensure_dir_exists (download_dir, NULL))
    {
        path = g_build_filename (download_dir, filename, (char *) NULL);
    }
    else
    {
        home_dir = g_get_home_dir ();
        path = g_build_filename (home_dir ? home_dir : "/", filename, (char *) NULL);
    }
    g_free (download_dir);
    
    return path;
}

static const char*
file_is_compressed (const char *filename)
{
        int i;
        static const char * const compression[] = {".gz", ".bz2", ".Z", ".lz", NULL};

        for (i = 0; compression[i] != NULL; i++)
        {
                if (g_str_has_suffix (filename, compression[i]))
                        return compression[i];
        }

        return NULL;
}

static const char*
parse_extension (const char *filename)
{
        const char *compression;

        compression = file_is_compressed (filename);

        /* If the file is compressed we might have a double extension */
        if (compression != NULL)
        {
                int i;
                static const char * const extensions[] = {"tar", "ps", "xcf", "dvi", "txt", "text", NULL};

                for (i = 0; extensions[i] != NULL; i++)
                {
                        char *suffix;
                        suffix = g_strdup_printf (".%s%s", extensions[i],
                                                  compression);

                        if (g_str_has_suffix (filename, suffix))
                        {
                                char *p;

                                p = g_strrstr (filename, suffix);
                                g_free (suffix);

                                return p;
                        }

                        g_free (suffix);
                }
        }
        
        /* default case */
        return g_strrstr (filename, ".");
}

nsresult BuildDownloadPath (const char *defaultFileName, nsILocalFile **_retval)
{
    char *path;

    path = GetFilePath (defaultFileName);
    
    if (g_file_test (path, G_FILE_TEST_EXISTS))
    {
        int i = 1;
        const char *dot_pos;
                char *serial = NULL;
        GString *tmp_path;
        gssize position;

                dot_pos = parse_extension (defaultFileName);
        if (dot_pos)
        {
            position = dot_pos - defaultFileName;
        }
        else
        {
            position = strlen (defaultFileName);
        }
        tmp_path = g_string_new (NULL);

        do {
            g_free (path);
            g_string_assign (tmp_path, defaultFileName);
            serial = g_strdup_printf ("(%d)", i++);
            g_string_insert (tmp_path, position, serial);
            g_free (serial);
            path = GetFilePath (tmp_path->str);
            
        } while (g_file_test (path, G_FILE_TEST_EXISTS));
        
        g_string_free (tmp_path, TRUE);
    }

    nsCOMPtr <nsILocalFile> destFile (do_CreateInstance(NS_LOCAL_FILE_CONTRACTID));
    NS_ENSURE_TRUE (destFile, NS_ERROR_FAILURE);

    destFile->InitWithNativePath (nsCString (path));
    g_free (path);

    NS_IF_ADDREF (*_retval = destFile);
    return NS_OK;
}