path: root/camel/providers/imap/camel-imap-folder.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/* camel-imap-folder.c: class for an imap folder */

/* 
 * Authors:
 *   Dan Winship <danw@ximian.com>
 *   Jeffrey Stedfast <fejj@ximian.com> 
 *
 * Copyright (C) 2000, 2001 Ximian, Inc.
 *
 * This program is free software; you can redistribute it and/or 
 * modify it under the terms of the GNU General Public License as 
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 */

#ifdef HAVE_CONFIG_H
#include <config.h> 
#endif

#include <stdlib.h>
#include <sys/types.h>
#include <dirent.h>
#include <sys/stat.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <fcntl.h>
#include <ctype.h>

#include "camel-imap-folder.h"
#include "camel-imap-command.h"
#include "camel-imap-message-cache.h"
#include "camel-imap-private.h"
#include "camel-imap-search.h"
#include "camel-imap-store.h"
#include "camel-imap-summary.h"
#include "camel-imap-utils.h"
#include "camel-imap-wrapper.h"
#include "camel-data-wrapper.h"
#include "camel-disco-diary.h"
#include "camel-exception.h"
#include "camel-filter-driver.h"
#include "camel-mime-filter-crlf.h"
#include "camel-mime-filter-from.h"
#include "camel-mime-message.h"
#include "camel-mime-utils.h"
#include "camel-multipart.h"
#include "camel-operation.h"
#include "camel-session.h"
#include "camel-stream-buffer.h"
#include "camel-stream-filter.h"
#include "camel-stream-mem.h"
#include "camel-stream.h"
#include "string-utils.h"

#define CF_CLASS(o) (CAMEL_FOLDER_CLASS (CAMEL_OBJECT_GET_CLASS(o)))
static CamelDiscoFolderClass *disco_folder_class = NULL;

static void imap_finalize (CamelObject *object);
static void imap_rescan (CamelFolder *folder, int exists, CamelException *ex);
static void imap_refresh_info (CamelFolder *folder, CamelException *ex);
static void imap_sync_online (CamelFolder *folder, CamelException *ex);
static void imap_sync_offline (CamelFolder *folder, CamelException *ex);
static const char *imap_get_full_name (CamelFolder *folder);
static void imap_expunge_uids_online (CamelFolder *folder, GPtrArray *uids, CamelException *ex);
static void imap_expunge_uids_offline (CamelFolder *folder, GPtrArray *uids, CamelException *ex);
static void imap_expunge_uids_resyncing (CamelFolder *folder, GPtrArray *uids, CamelException *ex);
static void imap_cache_message (CamelDiscoFolder *disco_folder, const char *uid, CamelException *ex);

/* message manipulation */
static CamelMimeMessage *imap_get_message (CamelFolder *folder, const gchar *uid,
                       CamelException *ex);
static void imap_append_online (CamelFolder *folder, CamelMimeMessage *message,
                 const CamelMessageInfo *info, CamelException *ex);
static void imap_append_offline (CamelFolder *folder, CamelMimeMessage *message,
                  const CamelMessageInfo *info, CamelException *ex);
static void imap_append_resyncing (CamelFolder *folder, CamelMimeMessage *message,
                   const CamelMessageInfo *info, CamelException *ex);

static void imap_copy_online (CamelFolder *source, GPtrArray *uids,
                  CamelFolder *destination, CamelException *ex);
static void imap_copy_offline (CamelFolder *source, GPtrArray *uids,
                   CamelFolder *destination, CamelException *ex);
static void imap_copy_resyncing (CamelFolder *source, GPtrArray *uids,
                 CamelFolder *destination, CamelException *ex);
static void imap_move_messages_to (CamelFolder *source, GPtrArray *uids,
                   CamelFolder *destination, CamelException *ex);

/* searching */
static GPtrArray *imap_search_by_expression (CamelFolder *folder, const char *expression, CamelException *ex);
static void       imap_search_free          (CamelFolder *folder, GPtrArray *uids);

static void imap_thaw (CamelFolder *folder);

GData *parse_fetch_response (CamelImapFolder *imap_folder, char *msg_att);

static void
camel_imap_folder_class_init (CamelImapFolderClass *camel_imap_folder_class)
{
    CamelFolderClass *camel_folder_class = CAMEL_FOLDER_CLASS (camel_imap_folder_class);
    CamelDiscoFolderClass *camel_disco_folder_class = CAMEL_DISCO_FOLDER_CLASS (camel_imap_folder_class);

    disco_folder_class = CAMEL_DISCO_FOLDER_CLASS (camel_type_get_global_classfuncs (camel_disco_folder_get_type ()));

    /* virtual method overload */
    camel_folder_class->get_full_name = imap_get_full_name;
    camel_folder_class->get_message = imap_get_message;
    camel_folder_class->move_messages_to = imap_move_messages_to;
    camel_folder_class->search_by_expression = imap_search_by_expression;
    camel_folder_class->search_free = imap_search_free;
    camel_folder_class->thaw = imap_thaw;

    camel_disco_folder_class->refresh_info_online = imap_refresh_info;
    camel_disco_folder_class->sync_online = imap_sync_online;
    camel_disco_folder_class->sync_offline = imap_sync_offline;
    /* We don't sync flags at resync time: the online code will
     * deal with it eventually.
     */
    camel_disco_folder_class->sync_resyncing = imap_sync_offline;
    camel_disco_folder_class->expunge_uids_online = imap_expunge_uids_online;
    camel_disco_folder_class->expunge_uids_offline = imap_expunge_uids_offline;
    camel_disco_folder_class->expunge_uids_resyncing = imap_expunge_uids_resyncing;
    camel_disco_folder_class->append_online = imap_append_online;
    camel_disco_folder_class->append_offline = imap_append_offline;
    camel_disco_folder_class->append_resyncing = imap_append_resyncing;
    camel_disco_folder_class->copy_online = imap_copy_online;
    camel_disco_folder_class->copy_offline = imap_copy_offline;
    camel_disco_folder_class->copy_resyncing = imap_copy_resyncing;
    camel_disco_folder_class->cache_message = imap_cache_message;
}

static void
camel_imap_folder_init (gpointer object, gpointer klass)
{
    CamelImapFolder *imap_folder = CAMEL_IMAP_FOLDER (object);
    CamelFolder *folder = CAMEL_FOLDER (object);
    
    folder->has_summary_capability = TRUE;
    folder->has_search_capability = TRUE;
    
    imap_folder->priv = g_malloc0(sizeof(*imap_folder->priv));
#ifdef ENABLE_THREADS
    imap_folder->priv->search_lock = e_mutex_new(E_MUTEX_SIMPLE);
    imap_folder->priv->cache_lock = e_mutex_new(E_MUTEX_REC);
#endif

    imap_folder->need_rescan = TRUE;
}

CamelType
camel_imap_folder_get_type (void)
{
    static CamelType camel_imap_folder_type = CAMEL_INVALID_TYPE;
    
    if (camel_imap_folder_type == CAMEL_INVALID_TYPE) {
        camel_imap_folder_type =
            camel_type_register (CAMEL_DISCO_FOLDER_TYPE, "CamelImapFolder",
                         sizeof (CamelImapFolder),
                         sizeof (CamelImapFolderClass),
                         (CamelObjectClassInitFunc) camel_imap_folder_class_init,
                         NULL,
                         (CamelObjectInitFunc) camel_imap_folder_init,
                         (CamelObjectFinalizeFunc) imap_finalize);
    }
    
    return camel_imap_folder_type;
}

CamelFolder *
camel_imap_folder_new (CamelStore *parent, const char *folder_name,
               const char *folder_dir, CamelException *ex)
{
    CamelImapStore *imap_store = CAMEL_IMAP_STORE (parent);
    CamelFolder *folder;
    CamelImapFolder *imap_folder;
    const char *short_name;
    char *summary_file;

    if (camel_mkdir_hier (folder_dir, S_IRWXU) != 0) {
        camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                      _("Could not create directory %s: %s"),
                      folder_dir, g_strerror (errno));
        return NULL;
    }

    folder = CAMEL_FOLDER (camel_object_new (camel_imap_folder_get_type ()));
    short_name = strrchr (folder_name, imap_store->dir_sep);
    if (short_name)
        short_name++;
    else
        short_name = folder_name;
    camel_folder_construct (folder, parent, folder_name, short_name);

    summary_file = g_strdup_printf ("%s/summary", folder_dir);
    folder->summary = camel_imap_summary_new (summary_file);
    g_free (summary_file);
    if (!folder->summary) {
        camel_object_unref (CAMEL_OBJECT (folder));
        camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                      _("Could not load summary for %s"),
                      folder_name);
        return NULL;
    }

    imap_folder = CAMEL_IMAP_FOLDER (folder);
    imap_folder->cache = camel_imap_message_cache_new (folder_dir, folder->summary, ex);
    if (!imap_folder->cache) {
        camel_object_unref (CAMEL_OBJECT (folder));
        return NULL;
    }

    if ((imap_store->parameters & IMAP_PARAM_FILTER_INBOX) &&
        !g_strcasecmp (folder_name, "INBOX"))
        imap_folder->do_filtering = TRUE;

    return folder;
}

/* Called with the store's command_lock locked */
void
camel_imap_folder_selected (CamelFolder *folder, CamelImapResponse *response,
                CamelException *ex)
{
    CamelImapFolder *imap_folder = CAMEL_IMAP_FOLDER (folder);
    CamelImapSummary *imap_summary = CAMEL_IMAP_SUMMARY (folder->summary);
    unsigned long exists = 0, validity = 0, val, uid;
    CamelMessageInfo *info;
    GData *fetch_data;
    int i, count;
    char *resp;

    CAMEL_IMAP_STORE_ASSERT_LOCKED (folder->parent_store, command_lock);

    count = camel_folder_summary_count (folder->summary);

    for (i = 0; i < response->untagged->len; i++) {
        resp = response->untagged->pdata[i] + 2;
        if (!g_strncasecmp (resp, "FLAGS ", 6) &&
            !folder->permanent_flags) {
            resp += 6;
            folder->permanent_flags = imap_parse_flag_list (&resp);
        } else if (!g_strncasecmp (resp, "OK [PERMANENTFLAGS ", 19)) {
            resp += 19;
            folder->permanent_flags = imap_parse_flag_list (&resp);
        } else if (!g_strncasecmp (resp, "OK [UIDVALIDITY ", 16)) {
            validity = strtoul (resp + 16, NULL, 10);
        } else if (isdigit ((unsigned char)*resp)) {
            unsigned long num = strtoul (resp, &resp, 10);

            if (!g_strncasecmp (resp, " EXISTS", 7)) {
                exists = num;
                /* Remove from the response so nothing
                 * else tries to interpret it.
                 */
                g_free (response->untagged->pdata[i]);
                g_ptr_array_remove_index (response->untagged, i--);
            }
        }
    }

    if (camel_disco_store_status (CAMEL_DISCO_STORE (folder->parent_store)) == CAMEL_DISCO_STORE_RESYNCING) {
        if (validity != imap_summary->validity) {
            camel_exception_setv (ex, CAMEL_EXCEPTION_FOLDER_SUMMARY_INVALID,
                          _("Folder was destroyed and recreated on server."));
            return;
        }

        /* FIXME: find missing UIDs ? */
        return;
    }

    if (!imap_summary->validity)
        imap_summary->validity = validity;
    else if (validity != imap_summary->validity) {
        imap_summary->validity = validity;
        camel_folder_summary_clear (folder->summary);
        CAMEL_IMAP_FOLDER_LOCK (imap_folder, cache_lock);
        camel_imap_message_cache_clear (imap_folder->cache);
        CAMEL_IMAP_FOLDER_UNLOCK (imap_folder, cache_lock);
        imap_folder->need_rescan = FALSE;
        camel_imap_folder_changed (folder, exists, NULL, ex);
        return;
    }

    /* If we've lost messages, we have to rescan everything */
    if (exists < count)
        imap_folder->need_rescan = TRUE;
    else if (count != 0 && !imap_folder->need_rescan) {
        CamelImapStore *store = CAMEL_IMAP_STORE (folder->parent_store);

        /* Similarly, if the UID of the highest message we
         * know about has changed, then that indicates that
         * messages have been both added and removed, so we
         * have to rescan to find the removed ones. (We pass
         * NULL for the folder since we know that this folder
         * is selected, and we don't want camel_imap_command
         * to worry about it.)
         */
        response = camel_imap_command (store, NULL, ex, "FETCH %d UID", count);
        if (!response)
            return;
        uid = 0;
        for (i = 0; i < response->untagged->len; i++) {
            resp = response->untagged->pdata[i];
            val = strtoul (resp + 2, &resp, 10);
            if (val == 0)
                continue;
            if (!g_strcasecmp (resp, " EXISTS")) {
                /* Another one?? */
                exists = val;
                continue;
            }
            if (uid != 0 || val != count || g_strncasecmp (resp, " FETCH (", 8) != 0)
                continue;

            fetch_data = parse_fetch_response (imap_folder, resp + 7);
            uid = strtoul (g_datalist_get_data (&fetch_data, "UID"), NULL, 10);
            g_datalist_clear (&fetch_data);
        }
        camel_imap_response_free_without_processing (store, response);

        info = camel_folder_summary_index (folder->summary, count - 1);
        val = strtoul (camel_message_info_uid (info), NULL, 10);
        camel_folder_summary_info_free (folder->summary, info);
        if (uid == 0 || uid != val)
            imap_folder->need_rescan = TRUE;
    }

    /* Now rescan if we need to */
    if (imap_folder->need_rescan) {
        imap_rescan (folder, exists, ex);
        return;
    }

    /* If we don't need to rescan completely, but new messages
     * have been added, find out about them.
     */
    if (exists > count)
        camel_imap_folder_changed (folder, exists, NULL, ex);

    /* And we're done. */
}   

static void           
imap_finalize (CamelObject *object)
{
    CamelImapFolder *imap_folder = CAMEL_IMAP_FOLDER (object);

    if (imap_folder->search)
        camel_object_unref (CAMEL_OBJECT (imap_folder->search));
    if (imap_folder->cache)
        camel_object_unref (CAMEL_OBJECT (imap_folder->cache));

#ifdef ENABLE_THREADS
    e_mutex_destroy(imap_folder->priv->search_lock);
    e_mutex_destroy(imap_folder->priv->cache_lock);
#endif
    g_free(imap_folder->priv);
}

static void
imap_refresh_info (CamelFolder *folder, CamelException *ex)
{
    CamelImapStore *imap_store = CAMEL_IMAP_STORE (folder->parent_store);
    CamelImapFolder *imap_folder = CAMEL_IMAP_FOLDER (folder);
    CamelImapResponse *response;

    if (camel_disco_store_status (CAMEL_DISCO_STORE (imap_store)) == CAMEL_DISCO_STORE_OFFLINE)
        return;

    if (camel_folder_is_frozen (folder)) {
        imap_folder->need_refresh = TRUE;
        return;
    }

    /* If the folder isn't selected, select it (which will force
     * a rescan if one is needed.
     */
    if (imap_store->current_folder != folder) {
        response = camel_imap_command (imap_store, folder, ex, NULL);
        camel_imap_response_free (imap_store, response);
        return;
    }

    /* Otherwise, if we need a rescan, do it, and if not, just do
     * a NOOP to give the server a chance to tell us about new
     * messages.
     */
    if (imap_folder->need_rescan)
        imap_rescan (folder, camel_folder_summary_count (folder->summary), ex);
    else {
        response = camel_imap_command (imap_store, folder, ex, "NOOP");
        camel_imap_response_free (imap_store, response);
    }
}

/* Called with the store's command_lock locked */
static void
imap_rescan (CamelFolder *folder, int exists, CamelException *ex)
{
    CamelImapFolder *imap_folder = CAMEL_IMAP_FOLDER (folder);
    CamelImapStore *store = CAMEL_IMAP_STORE (folder->parent_store);
    struct {
        char *uid;
        guint32 flags;
    } *new;
    char *resp;
    CamelImapResponseType type;
    int i, seq, summary_len, summary_got;
    CamelMessageInfo *info;
    CamelImapMessageInfo *iinfo;
    GArray *removed;
    gboolean ok;

    CAMEL_IMAP_STORE_ASSERT_LOCKED (store, command_lock);
    imap_folder->need_rescan = FALSE;

    summary_len = camel_folder_summary_count (folder->summary);
    if (summary_len == 0) {
        if (exists)
            camel_imap_folder_changed (folder, exists, NULL, ex);
        return;
    }

    /* Check UIDs and flags of all messages we already know of. */
    camel_operation_start (NULL, _("Scanning for changed messages"));
    info = camel_folder_summary_index (folder->summary, summary_len - 1);
    ok = camel_imap_command_start (store, folder, ex,
                       "UID FETCH 1:%s (FLAGS)",
                       camel_message_info_uid (info));
    camel_folder_summary_info_free (folder->summary, info);
    if (!ok) {
        camel_operation_end (NULL);
        return;
    }

    new = g_malloc0 (summary_len * sizeof (*new));
    summary_got = 0;
    while ((type = camel_imap_command_response (store, &resp, ex)) == CAMEL_IMAP_RESPONSE_UNTAGGED) {
        GData *data;
        char *uid;
        guint32 flags;

        data = parse_fetch_response (imap_folder, resp);
        g_free (resp);
        if (!data)
            continue;

        seq = GPOINTER_TO_INT (g_datalist_get_data (&data, "SEQUENCE"));
        uid = g_datalist_get_data (&data, "UID");
        flags = GPOINTER_TO_UINT (g_datalist_get_data (&data, "FLAGS"));

        if (!uid || !seq || seq >= summary_len) {
            g_datalist_clear (&data);
            continue;
        }

        camel_operation_progress (NULL, ++summary_got * 100 / summary_len);
        new[seq - 1].uid = g_strdup (uid);
        new[seq - 1].flags = flags;
        g_datalist_clear (&data);
    }

    camel_operation_end (NULL);
    if (type == CAMEL_IMAP_RESPONSE_ERROR) {
        for (i = 0; i < summary_len && new[i].uid; i++)
            g_free (new[i].uid);
        g_free (new);
        return;
    }
    /* Free the final tagged response */
    g_free (resp);

    /* If we find a UID in the summary that doesn't correspond to
     * the UID in the folder, then either: (a) it's a real UID,
     * but the message was deleted on the server, or (b) it's a
     * fake UID, and needs to be removed from the summary in order
     * to sync up with the server. So either way, we remove it
     * from the summary.
     */
    removed = g_array_new (FALSE, FALSE, sizeof (int));
    for (i = 0; i < summary_len && new[i].uid; i++) {
        info = camel_folder_summary_index (folder->summary, i);
        iinfo = (CamelImapMessageInfo *)info;

        if (strcmp (camel_message_info_uid (info), new[i].uid) != 0) {
            camel_folder_summary_info_free(folder->summary, info);
            seq = i + 1;
            g_array_append_val (removed, seq);
            i--;
            summary_len--;
            continue;
        }

        /* Update summary flags */
        if (new[i].flags != iinfo->server_flags) {
            guint32 server_set, server_cleared;

            server_set = new[i].flags & ~iinfo->server_flags;
            server_cleared = iinfo->server_flags & ~new[i].flags;

            info->flags = (info->flags | server_set) & ~server_cleared;
            iinfo->server_flags = new[i].flags;

            camel_object_trigger_event (CAMEL_OBJECT (folder),
                            "message_changed",
                            g_strdup (new[i].uid));
        }

        camel_folder_summary_info_free (folder->summary, info);
        g_free (new[i].uid);
    }

    seq = i + 1;

    /* Free remaining memory. */
    while (i < summary_len && new[i].uid)
        g_free (new[i++].uid);
    g_free (new);

    /* Remove any leftover cached summary messages. (Yes, we
     * repeatedly add the same number to the removed array.
     * See RFC2060 7.4.1)
     */
    for (i = seq; i < summary_len; i++)
        g_array_append_val (removed, seq);

    /* And finally update the summary. */
    camel_imap_folder_changed (folder, exists, removed, ex);
    g_array_free (removed, TRUE);
}

/* Find all messages in @folder with flags matching @flags and @mask.
 * If no messages match, returns %NULL. Otherwise, returns an array of
 * CamelMessageInfo and sets *@set to a message set corresponding the
 * UIDs of the matched messages. The caller must free the infos, the
 * array, and the set string.
 */
static GPtrArray *
get_matching (CamelFolder *folder, guint32 flags, guint32 mask, char **set)
{
    GPtrArray *matches;
    CamelMessageInfo *info;
    int i, max, range;
    GString *gset;

    matches = g_ptr_array_new ();
    gset = g_string_new ("");
    max = camel_folder_summary_count (folder->summary);
    range = -1;
    for (i = 0; i < max; i++) {
        info = camel_folder_summary_index (folder->summary, i);
        if (!info)
            continue;
        if ((info->flags & mask) != flags) {
            camel_folder_summary_info_free (folder->summary, info);
            if (range != -1) {
                if (range != i - 1) {
                    info = matches->pdata[matches->len - 1];
                    g_string_sprintfa (gset, ":%s", camel_message_info_uid (info));
                }
                range = -1;
            }
            continue;
        }

        g_ptr_array_add (matches, info);
        if (range != -1)
            continue;
        range = i;
        if (gset->len)
            g_string_append_c (gset, ',');
        g_string_sprintfa (gset, "%s", camel_message_info_uid (info));
    }
    if (range != -1 && range != max - 1) {
        info = matches->pdata[matches->len - 1];
        g_string_sprintfa (gset, ":%s", camel_message_info_uid (info));
    }

    if (matches->len) {
        *set = gset->str;
        g_string_free (gset, FALSE);
        return matches;
    } else {
        g_string_free (gset, TRUE);
        g_ptr_array_free (matches, TRUE);
        return NULL;
    }
}

static void
imap_sync_offline (CamelFolder *folder, CamelException *ex)
{
    camel_folder_summary_save (folder->summary);
}

static void
imap_sync_online (CamelFolder *folder, CamelException *ex)
{
    CamelImapStore *store = CAMEL_IMAP_STORE (folder->parent_store);
    CamelImapResponse *response = NULL;
    CamelMessageInfo *info;
    GPtrArray *matches;
    char *set, *flaglist;
    int i, j, max;

    CAMEL_IMAP_STORE_LOCK (store, command_lock);

    /* Find a message with changed flags, find all of the other
     * messages like it, sync them as a group, mark them as
     * updated, and continue.
     */
    max = camel_folder_summary_count (folder->summary);
    for (i = 0; i < max; i++) {
        info = camel_folder_summary_index (folder->summary, i);
        if (!info)
            continue;
        if (!(info->flags & CAMEL_MESSAGE_FOLDER_FLAGGED)) {
            camel_folder_summary_info_free (folder->summary, info);
            continue;
        }

        flaglist = imap_create_flag_list (info->flags);
        matches = get_matching (folder, info->flags & (CAMEL_IMAP_SERVER_FLAGS | CAMEL_MESSAGE_FOLDER_FLAGGED),
                    CAMEL_IMAP_SERVER_FLAGS | CAMEL_MESSAGE_FOLDER_FLAGGED, &set);
        camel_folder_summary_info_free (folder->summary, info);

        response = camel_imap_command (store, folder, ex,
                           "UID STORE %s FLAGS.SILENT %s",
                           set, flaglist);
        g_free (set);
        g_free (flaglist);
        if (response)
            camel_imap_response_free (store, response);
        if (!camel_exception_is_set (ex)) {
            for (j = 0; j < matches->len; j++) {
                info = matches->pdata[j];
                info->flags &= ~CAMEL_MESSAGE_FOLDER_FLAGGED;
                ((CamelImapMessageInfo*)info)->server_flags =
                    info->flags & CAMEL_IMAP_SERVER_FLAGS;
            }
            camel_folder_summary_touch (folder->summary);
        }
        for (j = 0; j < matches->len; j++) {
            info = matches->pdata[j];
            camel_folder_summary_info_free (folder->summary, info);
        }
        g_ptr_array_free (matches, TRUE);

        if (camel_exception_is_set (ex)) {
            CAMEL_IMAP_STORE_UNLOCK (store, command_lock);
            return;
        }
    }

    /* Save the summary */
    imap_sync_offline (folder, ex);

    CAMEL_IMAP_STORE_UNLOCK (store, command_lock);
}

static void
imap_expunge_uids_offline (CamelFolder *folder, GPtrArray *uids, CamelException *ex)
{
    int i;

    for (i = 0; i < uids->len; i++) {
        camel_folder_summary_remove_uid (folder->summary, uids->pdata[i]);
        /* We intentionally don't remove it from the cache because
         * the cached data may be useful in replaying a COPY later.
         */
    }
    camel_folder_summary_save (folder->summary);

    camel_disco_diary_log (CAMEL_DISCO_STORE (folder->parent_store)->diary,
                   CAMEL_DISCO_DIARY_FOLDER_EXPUNGE, folder, uids);
}

static void
imap_expunge_uids_online (CamelFolder *folder, GPtrArray *uids, CamelException *ex)
{
    CamelImapStore *store = CAMEL_IMAP_STORE (folder->parent_store);
    CamelImapResponse *response;
    char *set;

    set = imap_uid_array_to_set (folder->summary, uids);
    CAMEL_IMAP_STORE_LOCK (store, command_lock);
    response = camel_imap_command (store, folder, ex,
                       "UID STORE %s +FLAGS.SILENT \\Deleted",
                       set);
    if (response)
        camel_imap_response_free (store, response);
    if (camel_exception_is_set (ex)) {
        CAMEL_IMAP_STORE_UNLOCK (store, command_lock);
        g_free (set);
        return;
    }

    if (store->capabilities & IMAP_CAPABILITY_UIDPLUS) {
        response = camel_imap_command (store, folder, ex,
                           "UID EXPUNGE %s", set);
    } else
        response = camel_imap_command (store, folder, ex, "EXPUNGE");
    if (response)
        camel_imap_response_free (store, response);
    CAMEL_IMAP_STORE_UNLOCK (store, command_lock);
}

static int
uid_compar (const void *va, const void *vb)
{
    const char **sa = (const char **)va, **sb = (const char **)vb;
    unsigned long a, b;

    a = strtoul (*sa, NULL, 10);
    b = strtoul (*sb, NULL, 10);
    if (a < b)
        return -1;
    else if (a == b)
        return 0;
    else
        return 1;
}

static void
imap_expunge_uids_resyncing (CamelFolder *folder, GPtrArray *uids, CamelException *ex)
{
    CamelImapStore *store = CAMEL_IMAP_STORE (folder->parent_store);
    CamelImapResponse *response;
    char *result, *keep_uidset, *mark_uidset;

    if (store->capabilities & IMAP_CAPABILITY_UIDPLUS) {
        imap_expunge_uids_online (folder, uids, ex);
        return;
    }

    /* If we don't have UID EXPUNGE we need to avoid expunging any
     * of the wrong messages. So we search for deleted messages,
     * and any that aren't in our to-expunge list get temporarily
     * marked un-deleted.
     */

    CAMEL_IMAP_STORE_LOCK (store, command_lock);
    response = camel_imap_command (store, folder, ex, "UID SEARCH DELETED");
    if (!response) {
        CAMEL_IMAP_STORE_UNLOCK (store, command_lock);
        return;
    }
    result = camel_imap_response_extract (store, response, "SEARCH", ex);
    if (!result) {
        CAMEL_IMAP_STORE_UNLOCK (store, command_lock);
        return;
    }

    keep_uidset = mark_uidset = NULL;
    if (result[8] == ' ') {
        GPtrArray *keep_uids, *mark_uids;
        char *uid, *lasts = NULL;
        unsigned long euid, kuid;
        int ei, ki;

        keep_uids = g_ptr_array_new ();
        mark_uids = g_ptr_array_new ();

        /* Parse SEARCH response */
        for (uid = strtok_r (result + 9, " ", &lasts); uid; uid = strtok_r (NULL, " ", &lasts))
            g_ptr_array_add (keep_uids, uid);
        qsort (keep_uids->pdata, keep_uids->len,
               sizeof (void *), uid_compar);

        /* Fill in "mark_uids", empty out "keep_uids" as needed */
        for (ei = ki = 0; ei < uids->len; ei++) {
            euid = strtoul (uids->pdata[ei], NULL, 10);

            for (; ki < keep_uids->len; ki++) {
                kuid = strtoul (keep_uids->pdata[ki], NULL, 10);

                if (kuid >= euid)
                    break;
            }

            if (euid == kuid)
                g_ptr_array_remove_index (keep_uids, ki);
            else
                g_ptr_array_add (mark_uids, uids->pdata[ei]);
        }

        if (keep_uids->len)
            keep_uidset = imap_uid_array_to_set (folder->summary, keep_uids);
        g_ptr_array_free (keep_uids, TRUE);

        if (mark_uids->len)
            mark_uidset = imap_uid_array_to_set (folder->summary, mark_uids);
        g_ptr_array_free (mark_uids, TRUE);
    } else {
        /* Empty SEARCH result, meaning nothing is marked deleted
         * on server.
         */
        mark_uidset = imap_uid_array_to_set (folder->summary, uids);
    }
    g_free (result);

    /* Unmark messages to be kept */
    if (keep_uidset) {
        response = camel_imap_command (store, folder, ex,
                           "UID STORE %s -FLAGS.SILENT \\Deleted",
                           keep_uidset);
        if (!response) {
            g_free (keep_uidset);
            g_free (mark_uidset);
            CAMEL_IMAP_STORE_UNLOCK (store, command_lock);
            return;
        }
        camel_imap_response_free (store, response);
    }

    /* Mark any messages that still need to be marked */
    if (mark_uidset) {
        response = camel_imap_command (store, folder, ex,
                           "UID STORE %s +FLAGS.SILENT \\Deleted",
                           mark_uidset);
        g_free (mark_uidset);
        if (!response) {
            g_free (keep_uidset);
            CAMEL_IMAP_STORE_UNLOCK (store, command_lock);
            return;
        }
        camel_imap_response_free (store, response);
    }

    /* Do the actual expunging */
    response = camel_imap_command (store, folder, ex, "EXPUNGE");
    if (response)
        camel_imap_response_free (store, response);

    /* And fix the remaining messages if we mangled them */
    if (keep_uidset) {
        /* Don't pass ex if it's already been set */
        response = camel_imap_command (store, folder,
                           camel_exception_is_set (ex) ? NULL : ex,
                           "UID STORE %s +FLAGS.SILENT \\Deleted",
                           keep_uidset);
        g_free (keep_uidset);
        if (response)
            camel_imap_response_free (store, response);
    }

    CAMEL_IMAP_STORE_UNLOCK (store, command_lock);
}

static const char *
imap_get_full_name (CamelFolder *folder)
{
    CamelImapStore *store = CAMEL_IMAP_STORE (folder->parent_store);
    char *name;
    int len;

    name = folder->full_name;
    if (store->namespace && *store->namespace) {
        len = strlen (store->namespace);
        if (!strncmp (store->namespace, folder->full_name, len) &&
            strlen (folder->full_name) > len)
            name += len;
        if (*name == store->dir_sep)
            name++;
    }
    return name;
}   

static void
imap_append_offline (CamelFolder *folder, CamelMimeMessage *message,
             const CamelMessageInfo *info, CamelException *ex)
{
    CamelImapStore *imap_store = CAMEL_IMAP_STORE (folder->parent_store);
    CamelImapMessageCache *cache = CAMEL_IMAP_FOLDER (folder)->cache;
    CamelFolderChangeInfo *changes;
    char *uid;

    /* We could keep a separate counter, but this one works fine. */
    CAMEL_IMAP_STORE_LOCK (imap_store, command_lock);
    uid = g_strdup_printf ("append-%d", imap_store->command++);
    CAMEL_IMAP_STORE_UNLOCK (imap_store, command_lock);

    camel_imap_summary_add_offline (folder->summary, uid, message, info);
    CAMEL_IMAP_FOLDER_LOCK (folder, cache_lock);
    camel_imap_message_cache_insert_wrapper (cache, uid, "",
                         CAMEL_DATA_WRAPPER (message));
    CAMEL_IMAP_FOLDER_UNLOCK (folder, cache_lock);

    changes = camel_folder_change_info_new ();
    camel_folder_change_info_add_uid (changes, uid);
    camel_object_trigger_event (CAMEL_OBJECT (folder), "folder_changed",
                    changes);
    camel_folder_change_info_free (changes);

    camel_disco_diary_log (CAMEL_DISCO_STORE (imap_store)->diary,
                   CAMEL_DISCO_DIARY_FOLDER_APPEND, folder, uid);
    g_free (uid);
}

static CamelImapResponse *
do_append (CamelFolder *folder, CamelMimeMessage *message,
       const CamelMessageInfo *info, char **uid,
       CamelException *ex)
{
    CamelImapStore *store = CAMEL_IMAP_STORE (folder->parent_store);
    CamelImapResponse *response;
    CamelStream *memstream;
    CamelMimeFilter *crlf_filter;
    CamelStreamFilter *streamfilter;
    GByteArray *ba;
    char *flagstr, *result, *end;

    /* create flag string param */
    if (info && info->flags)
        flagstr = imap_create_flag_list (info->flags);
    else
        flagstr = NULL;

    /* FIXME: We could avoid this if we knew how big the message was. */
    memstream = camel_stream_mem_new ();
    ba = g_byte_array_new ();
    camel_stream_mem_set_byte_array (CAMEL_STREAM_MEM (memstream), ba);

    streamfilter = camel_stream_filter_new_with_stream (memstream);
    crlf_filter = camel_mime_filter_crlf_new (
        CAMEL_MIME_FILTER_CRLF_ENCODE,
        CAMEL_MIME_FILTER_CRLF_MODE_CRLF_ONLY);
    camel_stream_filter_add (streamfilter, crlf_filter);
    camel_data_wrapper_write_to_stream (CAMEL_DATA_WRAPPER (message),
                        CAMEL_STREAM (streamfilter));
    camel_object_unref (CAMEL_OBJECT (streamfilter));
    camel_object_unref (CAMEL_OBJECT (crlf_filter));
    camel_object_unref (CAMEL_OBJECT (memstream));

    response = camel_imap_command (store, NULL, ex, "APPEND %S%s%s {%d}",
                       folder->full_name, flagstr ? " " : "",
                       flagstr ? flagstr : "", ba->len);
    g_free (flagstr);
    
    if (!response) {
        g_byte_array_free (ba, TRUE);
        return NULL;
    }
    result = camel_imap_response_extract_continuation (store, response, ex);
    if (!result) {
        g_byte_array_free (ba, TRUE);
        return NULL;
    }
    g_free (result);

    /* send the rest of our data - the mime message */
    g_byte_array_append (ba, "\0", 3);
    response = camel_imap_command_continuation (store, ba->data, ex);
    g_byte_array_free (ba, TRUE);
    if (!response)
        return response;

    if (store->capabilities & IMAP_CAPABILITY_UIDPLUS) {
        *uid = strstrcase (response->status, "[APPENDUID ");
        if (*uid)
            *uid = strchr (*uid + 11, ' ');
        if (*uid) {
            *uid = g_strndup (*uid + 1, strcspn (*uid + 1, "]"));
                /* Make sure it's a number */
            if (strtoul (*uid, &end, 10) == 0 || *end) {
                g_free (*uid);
                *uid = NULL;
            }
        }
    } else
        *uid = NULL;

    return response;
}

static void
imap_append_online (CamelFolder *folder, CamelMimeMessage *message,
            const CamelMessageInfo *info, CamelException *ex)
{
    CamelImapStore *store = CAMEL_IMAP_STORE (folder->parent_store);
    CamelImapResponse *response;
    char *uid;
    int count;

    count = camel_folder_summary_count (folder->summary);
    response = do_append (folder, message, info, &uid, ex);
    if (!response)
        return;

    if (uid) {
        /* Cache first, since freeing response may trigger a
         * summary update that will want this information.
         */
        CAMEL_IMAP_FOLDER_LOCK (folder, cache_lock);
        camel_imap_message_cache_insert_wrapper (
            CAMEL_IMAP_FOLDER (folder)->cache,
            uid, "", CAMEL_DATA_WRAPPER (message));
        CAMEL_IMAP_FOLDER_UNLOCK (folder, cache_lock);
        g_free (uid);
    }

    camel_imap_response_free (store, response);

    /* Make sure a "folder_changed" is emitted. */
    if (store->current_folder != folder ||
        camel_folder_summary_count (folder->summary) == count)
        imap_refresh_info (folder, ex);
}

static void
imap_append_resyncing (CamelFolder *folder, CamelMimeMessage *message,
               const CamelMessageInfo *info, CamelException *ex)
{
    CamelImapStore *store = CAMEL_IMAP_STORE (folder->parent_store);
    CamelImapResponse *response;
    char *uid;

    response = do_append (folder, message, info, &uid, ex);
    if (!response)
        return;

    if (uid) {
        CamelImapFolder *imap_folder = CAMEL_IMAP_FOLDER (folder);
        const char *olduid = camel_message_info_uid (info);

        CAMEL_IMAP_FOLDER_LOCK (imap_folder, cache_lock);
        camel_imap_message_cache_copy (imap_folder->cache, olduid,
                           imap_folder->cache, uid);
        CAMEL_IMAP_FOLDER_UNLOCK (imap_folder, cache_lock);

        camel_disco_diary_uidmap_add (CAMEL_DISCO_STORE (store)->diary,
                          olduid, uid);
    }

    camel_imap_response_free (store, response);
}


static void
imap_copy_offline (CamelFolder *source, GPtrArray *uids,
           CamelFolder *destination, CamelException *ex)
{
    CamelImapStore *store = CAMEL_IMAP_STORE (source->parent_store);
    CamelImapMessageCache *sc = CAMEL_IMAP_FOLDER (source)->cache;
    CamelImapMessageCache *dc = CAMEL_IMAP_FOLDER (destination)->cache;
    CamelFolderChangeInfo *changes;
    CamelMimeMessage *message;
    CamelMessageInfo *mi;
    char *uid, *destuid;
    int i;

    /* We grab the store's command lock first, and then grab the
     * source and destination cache_locks. This way we can't
     * deadlock in the case where we're simultaneously also trying
     * to copy messages in the other direction from another thread.
     */
    CAMEL_IMAP_STORE_LOCK (store, command_lock);
    CAMEL_IMAP_FOLDER_LOCK (source, cache_lock);
    CAMEL_IMAP_FOLDER_LOCK (destination, cache_lock);
    CAMEL_IMAP_STORE_UNLOCK (store, command_lock);

    changes = camel_folder_change_info_new ();
    for (i = 0; i < uids->len; i++) {
        uid = uids->pdata[i];

        message = camel_folder_get_message (source, uid, NULL);
        if (!message)
            continue;
        mi = camel_folder_summary_uid (source->summary, uid);
        g_return_if_fail (mi != NULL);

        destuid = g_strdup_printf ("copy-%s:%s", source->full_name, uid);
        camel_imap_summary_add_offline (destination->summary, destuid, message, mi);

        camel_imap_message_cache_copy (sc, uid, dc, destuid);
        camel_folder_summary_info_free (source->summary, mi);
        camel_object_unref (CAMEL_OBJECT (message));

        camel_folder_change_info_add_uid (changes, destuid);
        g_free (destuid);
    }

    CAMEL_IMAP_FOLDER_UNLOCK (destination, cache_lock);
    CAMEL_IMAP_FOLDER_UNLOCK (source, cache_lock);

    camel_object_trigger_event (CAMEL_OBJECT (destination),
                    "folder_changed", changes);
    camel_folder_change_info_free (changes);

    camel_disco_diary_log (CAMEL_DISCO_STORE (store)->diary,
                   CAMEL_DISCO_DIARY_FOLDER_COPY,
                   source, destination, uids);
}
    
static void
handle_copyuid (CamelImapResponse *response, CamelFolder *source,
        CamelFolder *destination)
{
    CamelImapMessageCache *scache = CAMEL_IMAP_FOLDER (source)->cache;
    CamelImapMessageCache *dcache = CAMEL_IMAP_FOLDER (destination)->cache;
    char *validity, *srcset, *destset;
    GPtrArray *src, *dest;
    int i;

    validity = strstrcase (response->status, "[COPYUID ");
    if (!validity)
        return;
    validity += 9;
    if (strtoul (validity, NULL, 10) !=
        CAMEL_IMAP_SUMMARY (destination->summary)->validity)
        return;

    srcset = strchr (validity, ' ');
    if (!srcset++)
        goto lose;
    destset = strchr (srcset, ' ');
    if (!destset++)
        goto lose;

    src = imap_uid_set_to_array (source->summary, srcset);
    dest = imap_uid_set_to_array (destination->summary, destset);

    if (src && dest && src->len == dest->len) {
        /* We don't have to worry about deadlocking on the
         * cache locks here, because we've got the store's
         * command lock too, so no one else could be here.
         */
        CAMEL_IMAP_FOLDER_LOCK (source, cache_lock);
        CAMEL_IMAP_FOLDER_LOCK (destination, cache_lock);
        for (i = 0; i < src->len; i++) {
            camel_imap_message_cache_copy (scache, src->pdata[i],
                               dcache, dest->pdata[i]);
        }
        CAMEL_IMAP_FOLDER_UNLOCK (source, cache_lock);
        CAMEL_IMAP_FOLDER_UNLOCK (destination, cache_lock);

        imap_uid_array_free (src);
        imap_uid_array_free (dest);
        return;
    }

    imap_uid_array_free (src);
    imap_uid_array_free (dest);
 lose:
    g_warning ("Bad COPYUID response from server");
}

static void
do_copy (CamelFolder *source, GPtrArray *uids,
     CamelFolder *destination, CamelException *ex)
{
    CamelImapStore *store = CAMEL_IMAP_STORE (source->parent_store);
    CamelImapResponse *response;
    char *set;

    set = imap_uid_array_to_set (source->summary, uids);
    response = camel_imap_command (store, source, ex, "UID COPY %s %S",
                       set, destination->full_name);
    if (response && (store->capabilities & IMAP_CAPABILITY_UIDPLUS))
        handle_copyuid (response, source, destination);

    camel_imap_response_free (store, response);
    g_free (set);
}

static void
imap_copy_online (CamelFolder *source, GPtrArray *uids,
          CamelFolder *destination, CamelException *ex)
{
    CamelImapStore *store = CAMEL_IMAP_STORE (source->parent_store);
    int count;

    /* Sync message flags if needed. */
    imap_sync_online (source, ex);
    if (camel_exception_is_set (ex))
        return;

    count = camel_folder_summary_count (destination->summary);

    /* Now copy the messages */
    do_copy (source, uids, destination, ex);
    if (camel_exception_is_set (ex))
        return;

    /* Make the destination notice its new messages */
    if (store->current_folder != destination ||
        camel_folder_summary_count (destination->summary) == count)
        camel_folder_refresh_info (destination, ex);
}

static void
imap_copy_resyncing (CamelFolder *source, GPtrArray *uids,
             CamelFolder *destination, CamelException *ex)
{
    CamelDiscoDiary *diary = CAMEL_DISCO_STORE (source->parent_store)->diary;
    GPtrArray *realuids;
    int first, i;
    const char *uid;
    CamelMimeMessage *message;
    CamelMessageInfo *info;

    /* This is trickier than append_resyncing, because some of
     * the messages we are copying may have been copied or
     * appended into @source while we were offline, in which case
     * if we don't have UIDPLUS, we won't know their real UIDs,
     * so we'll have to append them rather than copying.
     */

    realuids = g_ptr_array_new ();

    i = 0;
    while (i < uids->len) {
        /* Skip past real UIDs */
        for (first = i; i < uids->len; i++) {
            uid = uids->pdata[i];

            if (!isdigit ((unsigned char)*uid)) {
                uid = camel_disco_diary_uidmap_lookup (diary, uid);
                if (!uid)
                    break;
            }
            g_ptr_array_add (realuids, (char *)uid);
        }

        /* If we saw any real UIDs, do a COPY */
        if (i != first) {
            do_copy (source, realuids, destination, ex);
            g_ptr_array_set_size (realuids, 0);
            if (i == uids->len || camel_exception_is_set (ex))
                break;
        }

        /* Deal with fake UIDs */
        while (i < uids->len &&
               !isdigit (*(unsigned char *)(uids->pdata[i])) &&
               !camel_exception_is_set (ex)) {
            message = camel_folder_get_message (source, uids->pdata[i], NULL);
            if (!message) {
                /* Message must have been expunged */
                continue;
            }
            info = camel_folder_get_message_info (source, uids->pdata[i]);
            g_return_if_fail (info != NULL);

            imap_append_online (destination, message, info, ex);
            camel_folder_free_message_info (source, info);
            camel_object_unref (CAMEL_OBJECT (message));
            i++;
        }
    }

    g_ptr_array_free (realuids, FALSE);
}

static void
imap_move_messages_to (CamelFolder *source, GPtrArray *uids,
               CamelFolder *destination, CamelException *ex)
{
    int i;

    /* do it this way (as opposed to camel_folder_copy_messages_to)
     * to avoid locking issues */
    CF_CLASS (source)->copy_messages_to (source, uids, destination, ex);
    if (camel_exception_is_set (ex))
        return;

    for (i = 0; i < uids->len; i++)
        camel_folder_delete_message (source, uids->pdata[i]);
}

static GPtrArray *
imap_search_by_expression (CamelFolder *folder, const char *expression, CamelException *ex)
{
    CamelImapFolder *imap_folder = CAMEL_IMAP_FOLDER (folder);
    GPtrArray *matches, *summary;

    if (!camel_disco_store_check_online (CAMEL_DISCO_STORE (folder->parent_store), ex))
        return NULL;

    /* we could get around this by creating a new search object each time,
       but i doubt its worth it since any long operation would lock the
       command channel too */
    CAMEL_IMAP_FOLDER_LOCK(folder, search_lock);

    if (!imap_folder->search)
        imap_folder->search = camel_imap_search_new ();

    camel_folder_search_set_folder (imap_folder->search, folder);
    summary = camel_folder_get_summary(folder);
    camel_folder_search_set_summary(imap_folder->search, summary);
    matches = camel_folder_search_execute_expression (imap_folder->search, expression, ex);

    CAMEL_IMAP_FOLDER_UNLOCK(folder, search_lock);

    camel_folder_free_summary(folder, summary);

    return matches;
}

static void
imap_search_free (CamelFolder *folder, GPtrArray *uids)
{
    CamelImapFolder *imap_folder = CAMEL_IMAP_FOLDER (folder);

    g_return_if_fail (imap_folder->search);

    CAMEL_IMAP_FOLDER_LOCK(folder, search_lock);

    camel_folder_search_free_result (imap_folder->search, uids);

    CAMEL_IMAP_FOLDER_UNLOCK(folder, search_lock);
}

static CamelMimeMessage *get_message (CamelImapFolder *imap_folder,
                      const char *uid,
                      const char *part_specifier,
                      CamelMessageContentInfo *ci,
                      CamelException *ex);

/* Fetch the contents of the MIME part indicated by @ci, which is part
 * of message @uid in @folder.
 */
static CamelDataWrapper *
get_content (CamelImapFolder *imap_folder, const char *uid,
         const char *part_spec, CamelMimePart *part,
         CamelMessageContentInfo *ci, CamelException *ex)
{
    CamelDataWrapper *content;
    CamelStream *stream;
    char *child_spec;

    /* There are three cases: multipart, message/rfc822, and "other" */

    if (header_content_type_is (ci->type, "multipart", "*")) {
        CamelMultipart *body_mp;
        int speclen, num;

        body_mp = camel_multipart_new ();
        camel_data_wrapper_set_mime_type_field (
            CAMEL_DATA_WRAPPER (body_mp), ci->type);
        camel_multipart_set_boundary (body_mp, NULL);

        speclen = strlen (part_spec);
        child_spec = g_malloc (speclen + 15);
        memcpy (child_spec, part_spec, speclen);
        if (speclen > 0)
            child_spec[speclen++] = '.';

        ci = ci->childs;
        num = 1;
        while (ci) {
            sprintf (child_spec + speclen, "%d.MIME", num++);
            stream = camel_imap_folder_fetch_data (imap_folder, uid, child_spec, FALSE, ex);
            if (stream) {
                part = camel_mime_part_new ();
                camel_data_wrapper_construct_from_stream (CAMEL_DATA_WRAPPER (part), stream);
                camel_object_unref (CAMEL_OBJECT (stream));
                *(strchr (child_spec + speclen, '.')) = '\0';
                content = get_content (imap_folder, uid, child_spec, part, ci, ex);
            }
            if (!stream || !content) {
                g_free (child_spec);
                camel_object_unref (CAMEL_OBJECT (body_mp));
                return NULL;
            }

            camel_medium_set_content_object (CAMEL_MEDIUM (part), content);
            camel_object_unref (CAMEL_OBJECT (content));
            camel_multipart_add_part (body_mp, part);
            camel_object_unref (CAMEL_OBJECT (part));

            ci = ci->next;
        }
        g_free (child_spec);

        return (CamelDataWrapper *)body_mp;
    } else if (header_content_type_is (ci->type, "message", "rfc822")) {
        return (CamelDataWrapper *)
            get_message (imap_folder, uid, part_spec, ci->childs, ex);
    } else {
        if (!ci->parent || header_content_type_is (ci->parent->type, "message", "rfc822"))
            child_spec = g_strdup_printf ("%s%s1", part_spec, *part_spec ? "." : "");
        else
            child_spec = g_strdup (part_spec);

        content = camel_imap_wrapper_new (imap_folder, ci->type, uid, child_spec, part);
        g_free (child_spec);
        return content;
    }
}

static CamelMimeMessage *
get_message (CamelImapFolder *imap_folder, const char *uid,
         const char *part_spec, CamelMessageContentInfo *ci,
         CamelException *ex)
{
    CamelImapStore *store = CAMEL_IMAP_STORE (CAMEL_FOLDER (imap_folder)->parent_store);
    CamelDataWrapper *content;
    CamelMimeMessage *msg;
    CamelStream *stream;
    char *section_text;

    section_text = g_strdup_printf ("%s%s%s", part_spec, *part_spec ? "." : "",
                    store->server_level >= IMAP_LEVEL_IMAP4REV1 ? "HEADER" : "0");
    stream = camel_imap_folder_fetch_data (imap_folder, uid, section_text, FALSE, ex);
    g_free (section_text);
    if (!stream)
        return NULL;

    msg = camel_mime_message_new ();
    camel_data_wrapper_construct_from_stream (CAMEL_DATA_WRAPPER (msg), stream);
    camel_object_unref (CAMEL_OBJECT (stream));

    content = get_content (imap_folder, uid, part_spec, CAMEL_MIME_PART (msg), ci, ex);
    if (!content) {
        camel_object_unref (CAMEL_OBJECT (msg));
        return NULL;
    }

    camel_medium_set_content_object (CAMEL_MEDIUM (msg), content);
    camel_object_unref (CAMEL_OBJECT (content));

    return msg;
}

/* FIXME: I pulled this number out of my butt. */
#define IMAP_SMALL_BODY_SIZE 5120

static CamelMimeMessage *
get_message_simple (CamelImapFolder *imap_folder, const char *uid,
            CamelStream *stream, CamelException *ex)
{
    CamelMimeMessage *msg;

    if (!stream) {
        stream = camel_imap_folder_fetch_data (imap_folder, uid, "",
                               FALSE, ex);
        if (!stream)
            return NULL;
    }

    msg = camel_mime_message_new ();
    camel_data_wrapper_construct_from_stream (CAMEL_DATA_WRAPPER (msg),
                          stream);
    camel_object_unref (CAMEL_OBJECT (stream));
    return msg;
}

static CamelMimeMessage *
imap_get_message (CamelFolder *folder, const char *uid, CamelException *ex)
{
    CamelImapFolder *imap_folder = CAMEL_IMAP_FOLDER (folder);
    CamelImapStore *store = CAMEL_IMAP_STORE (folder->parent_store);
    CamelMessageInfo *mi;
    CamelMimeMessage *msg;
    CamelStream *stream = NULL;

    /* If the server doesn't support IMAP4rev1, or we already have
     * the whole thing cached, fetch it in one piece.
     */
    if (store->server_level < IMAP_LEVEL_IMAP4REV1 ||
        (stream = camel_imap_folder_fetch_data (imap_folder, uid, "", TRUE, NULL)))
        return get_message_simple (imap_folder, uid, stream, ex);

    mi = camel_folder_summary_uid (folder->summary, uid);
    g_return_val_if_fail (mi != NULL, NULL);

    /* If the message is small, fetch it in one piece. */
    if (mi->size < IMAP_SMALL_BODY_SIZE) {
        camel_folder_summary_info_free (folder->summary, mi);
        return get_message_simple (imap_folder, uid, NULL, ex);
    }

    /* For larger messages, fetch the structure and build a message
     * with offline parts. (We check mi->content->type rather than
     * mi->content because camel_folder_summary_info_new always creates
     * an empty content struct.)
     */
    if (!mi->content->type) {
        CamelImapResponse *response;
        GData *fetch_data;
        char *body, *found_uid;
        int i;

        if (camel_disco_store_status (CAMEL_DISCO_STORE (store)) == CAMEL_DISCO_STORE_OFFLINE) {
            camel_exception_set (ex, CAMEL_EXCEPTION_SERVICE_UNAVAILABLE,
                         _("This message is not currently available"));
            return NULL;
        }

        response = camel_imap_command (store, folder, ex,
                           "UID FETCH %s BODY", uid);
        if (!response) {
            camel_folder_summary_info_free (folder->summary, mi);
            return NULL;
        }

        for (i = 0, body = NULL; i < response->untagged->len; i++) {
            fetch_data = parse_fetch_response (imap_folder, response->untagged->pdata[i]);
            found_uid = g_datalist_get_data (&fetch_data, "UID");
            body = g_datalist_get_data (&fetch_data, "BODY");
            if (found_uid && body && !strcmp (found_uid, uid))
                break;
            g_datalist_clear (&fetch_data);
            body = NULL;
        }

        if (body)
            imap_parse_body (&body, folder, mi->content);
        g_datalist_clear (&fetch_data);
        camel_imap_response_free (store, response);

        if (!mi->content->type) {
            /* FETCH returned OK, but we didn't parse a BODY
             * response. Courier will return invalid BODY
             * responses for invalidly MIMEd messages, so
             * fall back to fetching the entire thing and
             * let the mailer's "bad MIME" code handle it.
             */
            camel_folder_summary_info_free (folder->summary, mi);
            return get_message_simple (imap_folder, uid, NULL, ex);
        }
    }

    msg = get_message (imap_folder, uid, "", mi->content, ex);
    camel_folder_summary_info_free (folder->summary, mi);

    return msg;
}

static void
imap_cache_message (CamelDiscoFolder *disco_folder, const char *uid,
            CamelException *ex)
{
    CamelImapFolder *imap_folder = CAMEL_IMAP_FOLDER (disco_folder);
    CamelStream *stream;

    stream = camel_imap_folder_fetch_data (imap_folder, uid, "", FALSE, ex);
    if (stream)
        camel_object_unref (CAMEL_OBJECT (stream));
}

/* We pretend that a FLAGS or RFC822.SIZE response is always exactly
 * 20 bytes long, and a BODY[HEADERS] response is always 2000 bytes
 * long. Since we know how many of each kind of response we're
 * expecting, we can find the total (pretend) amount of server traffic
 * to expect and then count off the responses as we read them to update
 * the progress bar.
 */
#define IMAP_PRETEND_SIZEOF_FLAGS     20
#define IMAP_PRETEND_SIZEOF_SIZE      20
#define IMAP_PRETEND_SIZEOF_HEADERS 2000

static void
add_message_from_data (CamelFolder *folder, GPtrArray *messages,
               int first, GData *data)
{
    int seq;
    CamelMimeMessage *msg;
    CamelStream *stream;
    CamelMessageInfo *mi;

    seq = GPOINTER_TO_INT (g_datalist_get_data (&data, "SEQUENCE"));
    if (seq < first)
        return;
    stream = g_datalist_get_data (&data, "BODY_PART_STREAM");
    if (!stream)
        return;

    if (seq - first >= messages->len)
        g_ptr_array_set_size (messages, seq - first + 1);

    msg = camel_mime_message_new ();
    camel_data_wrapper_construct_from_stream (CAMEL_DATA_WRAPPER (msg), stream);
    mi = camel_folder_summary_info_new_from_message (folder->summary, msg);
    camel_object_unref (CAMEL_OBJECT (msg));

    messages->pdata[seq - first] = mi;
}

static void
imap_update_summary (CamelFolder *folder, int exists,
             CamelFolderChangeInfo *changes,
             GPtrArray *recents,
             CamelException *ex)
{
    CamelImapFolder *imap_folder = CAMEL_IMAP_FOLDER (folder);
    CamelImapStore *store = CAMEL_IMAP_STORE (folder->parent_store);
    CamelImapResponseType type;
    GPtrArray *fetch_data = NULL, *messages = NULL, *needheaders;
    char *uid, *resp;
    const char *header_spec;
    int i, seq, first, size, got, uidval;
    CamelMessageInfo *mi;
    CamelStream *stream;
    guint32 flags;
    GData *data;

    CAMEL_IMAP_STORE_ASSERT_LOCKED (store, command_lock);
    if (store->server_level >= IMAP_LEVEL_IMAP4REV1)
        header_spec = "HEADER";
    else
        header_spec = "0";

    /* Figure out if any of the new messages are already cached (which
     * may be the case if we're re-syncing after disconnected operation).
     * If so, get their UIDs, FLAGS, and SIZEs. If not, get all that
     * and ask for the headers too at the same time.
     */
    seq = camel_folder_summary_count (folder->summary);
    first = seq + 1;
    if (seq > 0) {
        mi = camel_folder_summary_index (folder->summary, seq - 1);
        uidval = atoi (camel_message_info_uid (mi));
        camel_folder_summary_info_free (folder->summary, mi);
    } else
        uidval = 0;

    size = (exists - seq) * (IMAP_PRETEND_SIZEOF_FLAGS + IMAP_PRETEND_SIZEOF_SIZE);
    got = 0;

    if (uidval >= camel_imap_message_cache_max_uid (imap_folder->cache)) {
        /* None of the new messages are cached */
        size += (exists - seq) * IMAP_PRETEND_SIZEOF_HEADERS;
        if (!camel_imap_command_start (store, folder, ex,
                           "UID FETCH %d:* (FLAGS RFC822.SIZE BODY.PEEK[%s])",
                           uidval + 1, header_spec))
            return;
        camel_operation_start (NULL, _("Fetching summary information for new messages"));
    } else {
        if (!camel_imap_command_start (store, folder, ex,
                           "UID FETCH %d:* (FLAGS RFC822.SIZE)",
                           uidval + 1))
            return;
        camel_operation_start (NULL, _("Scanning for new messages"));
    }

    /* Parse the responses. We can't add a message to the summary
     * until we've gotten its headers, and there's no guarantee
     * the server will send the responses in a useful order...
     */
    fetch_data = g_ptr_array_new ();
    messages = g_ptr_array_new ();
    while ((type = camel_imap_command_response (store, &resp, ex)) ==
           CAMEL_IMAP_RESPONSE_UNTAGGED) {
        data = parse_fetch_response (imap_folder, resp);
        g_free (resp);
        if (!data)
            continue;

        seq = GPOINTER_TO_INT (g_datalist_get_data (&data, "SEQUENCE"));
        if (seq < first) {
            g_datalist_clear (&data);
            continue;
        }

        if (g_datalist_get_data (&data, "FLAGS"))
            got += IMAP_PRETEND_SIZEOF_FLAGS;
        if (g_datalist_get_data (&data, "RFC822.SIZE"))
            got += IMAP_PRETEND_SIZEOF_SIZE;
        stream = g_datalist_get_data (&data, "BODY_PART_STREAM");
        if (stream) {
            got += IMAP_PRETEND_SIZEOF_HEADERS;

            /* Use the stream now so we don't tie up many
             * many fds if we're fetching many many messages.
             */
            add_message_from_data (folder, messages, first, data);
            g_datalist_set_data (&data, "BODY_PART_STREAM", NULL);
        }

        camel_operation_progress (NULL, got * 100 / size);
        g_ptr_array_add (fetch_data, data);
    }
    camel_operation_end (NULL);

    if (type == CAMEL_IMAP_RESPONSE_ERROR)
        goto lose;

    /* Figure out which headers we still need to fetch. */
    needheaders = g_ptr_array_new ();
    size = got = 0;
    for (i = 0; i < fetch_data->len; i++) {
        data = fetch_data->pdata[i];
        if (g_datalist_get_data (&data, "BODY_PART_LEN"))
            continue;

        uid = g_datalist_get_data (&data, "UID");
        if (uid) {
            g_ptr_array_add (needheaders, uid);
            size += IMAP_PRETEND_SIZEOF_HEADERS;
        }
    }

    /* And fetch them */
    if (needheaders->len) {
        char *set;

        /* FIXME: sort needheaders */
        set = imap_uid_array_to_set (folder->summary, needheaders);
        g_ptr_array_free (needheaders, TRUE);
        if (!camel_imap_command_start (store, folder, ex,
                           "UID FETCH %s BODY.PEEK[%s]",
                           set, header_spec)) {
            g_free (set);
            goto lose;
        }
        g_free (set);

        camel_operation_start (NULL, _("Fetching summary information for new messages"));
        while ((type = camel_imap_command_response (store, &resp, ex))
               == CAMEL_IMAP_RESPONSE_UNTAGGED) {
            data = parse_fetch_response (imap_folder, resp);
            g_free (resp);
            if (!data)
                continue;

            stream = g_datalist_get_data (&data, "BODY_PART_STREAM");
            if (stream) {
                add_message_from_data (folder, messages, first, data);
                got += IMAP_PRETEND_SIZEOF_HEADERS;
                camel_operation_progress (NULL, got * 100 / size);
            }
            g_datalist_clear (&data);
        }
        camel_operation_end (NULL);

        if (type == CAMEL_IMAP_RESPONSE_ERROR)
            goto lose;
    }

    /* Now finish up summary entries (fix UIDs, set flags and size) */
    for (i = 0; i < fetch_data->len; i++) {
        data = fetch_data->pdata[i];

        seq = GPOINTER_TO_INT (g_datalist_get_data (&data, "SEQUENCE"));
        if (seq >= first + messages->len) {
            g_datalist_clear (&data);
            continue;
        }
        mi = messages->pdata[seq - first];

        uid = g_datalist_get_data (&data, "UID");
        if (uid)
            camel_message_info_set_uid (mi, g_strdup (uid));
        flags = GPOINTER_TO_INT (g_datalist_get_data (&data, "FLAGS"));
        if (flags) {
            ((CamelImapMessageInfo *)mi)->server_flags = flags;
            /* "or" them in with the existing flags that may
             * have been set by summary_info_new_from_message.
             */
            mi->flags |= flags;
        }
        size = GPOINTER_TO_INT (g_datalist_get_data (&data, "RFC822.SIZE"));
        if (size)
            mi->size = size;

        g_datalist_clear (&data);
    }
    g_ptr_array_free (fetch_data, TRUE);

    /* And add the entries to the summary, etc. */
    for (i = 0; i < messages->len; i++) {
        mi = messages->pdata[i];
        if (!mi) {
            g_warning ("No information for message %d", i + first);
            continue;
        }
        camel_folder_summary_add (folder->summary, mi);
        camel_folder_change_info_add_uid (changes, camel_message_info_uid (mi));

        if (recents && (mi->flags & CAMEL_IMAP_MESSAGE_RECENT))
            g_ptr_array_add (recents, (char *)camel_message_info_uid (mi));
    }
    g_ptr_array_free (messages, TRUE);
    return;

 lose:
    if (fetch_data) {
        for (i = 0; i < fetch_data->len; i++) {
            data = fetch_data->pdata[i];
            g_datalist_clear (&data);
        }
        g_ptr_array_free (fetch_data, TRUE);
    }
    if (messages) {
        for (i = 0; i < messages->len; i++) {
            if (messages->pdata[i])
                camel_folder_summary_info_free (folder->summary, messages->pdata[i]);
        }
        g_ptr_array_free (fetch_data, TRUE);
    }
}

/* Called with the store's command_lock locked */
void
camel_imap_folder_changed (CamelFolder *folder, int exists,
               GArray *expunged, CamelException *ex)
{
    CamelImapFolder *imap_folder = CAMEL_IMAP_FOLDER (folder);
    CamelFolderChangeInfo *changes;
    CamelMessageInfo *info;
    GPtrArray *recents = NULL;
    int len;

    CAMEL_IMAP_STORE_ASSERT_LOCKED (folder->parent_store, command_lock);

    changes = camel_folder_change_info_new ();
    if (expunged) {
        int i, id;

        for (i = 0; i < expunged->len; i++) {
            id = g_array_index (expunged, int, i);
            info = camel_folder_summary_index (folder->summary, id - 1);
            if (info == NULL) {
                /* FIXME: danw: does this mean that the summary is corrupt? */
                /* I guess a message that we never retrieved got expunged? */
                continue;
            }
            
            camel_folder_change_info_remove_uid (changes, camel_message_info_uid (info));
            CAMEL_IMAP_FOLDER_LOCK (imap_folder, cache_lock);
            camel_imap_message_cache_remove (imap_folder->cache, camel_message_info_uid (info));
            CAMEL_IMAP_FOLDER_UNLOCK (imap_folder, cache_lock);
            camel_folder_summary_remove (folder->summary, info);
            camel_folder_summary_info_free(folder->summary, info);
        }
    }

    len = camel_folder_summary_count (folder->summary);
    if (exists > len) {
        if (imap_folder->do_filtering)
            recents = g_ptr_array_new ();
        imap_update_summary (folder, exists, changes, recents, ex);
    }

    /* if we have updates to make for filtering (probably), then we freeze the
       folder so we dont show them till they're complete, this may cause unacceptable
       delays for users, but the alternative isn't very nice either (show them and let
       them change as processed) */
    if (recents && !camel_exception_is_set(ex) && recents->len) {
        CamelFilterDriver *driver;

        camel_folder_freeze(folder);

        if (camel_folder_change_info_changed(changes))
            camel_object_trigger_event(CAMEL_OBJECT(folder), "folder_changed", changes);

        driver = camel_session_get_filter_driver(CAMEL_SERVICE(folder->parent_store)->session, "incoming", ex);
        if (driver) {
            camel_filter_driver_filter_folder(driver, folder, NULL, recents, FALSE, ex);
            camel_object_unref(CAMEL_OBJECT(driver));
        }

        camel_folder_thaw(folder);
    } else {
        if (camel_folder_change_info_changed(changes))
            camel_object_trigger_event(CAMEL_OBJECT(folder), "folder_changed", changes);
    }

    camel_folder_change_info_free (changes);

    if (recents)
        g_ptr_array_free (recents, TRUE);


    camel_folder_summary_save (folder->summary);
}

static void
imap_thaw (CamelFolder *folder)
{
    CamelImapFolder *imap_folder;

    CAMEL_FOLDER_CLASS (disco_folder_class)->thaw (folder);
    if (camel_folder_is_frozen (folder))
        return;

    imap_folder = CAMEL_IMAP_FOLDER (folder);
    if (imap_folder->need_refresh) {
        imap_folder->need_refresh = FALSE;
        imap_refresh_info (folder, NULL);
    }
}


CamelStream *
camel_imap_folder_fetch_data (CamelImapFolder *imap_folder, const char *uid,
                  const char *section_text, gboolean cache_only,
                  CamelException *ex)
{
    CamelFolder *folder = CAMEL_FOLDER (imap_folder);
    CamelImapStore *store = CAMEL_IMAP_STORE (folder->parent_store);
    CamelImapResponse *response;
    CamelStream *stream;
    GData *fetch_data;
    char *found_uid;
    int i;

    CAMEL_IMAP_FOLDER_LOCK (imap_folder, cache_lock);
    stream = camel_imap_message_cache_get (imap_folder->cache, uid, section_text);
    if (!stream && (!strcmp (section_text, "HEADER") || !strcmp (section_text, "0")))
        stream = camel_imap_message_cache_get (imap_folder->cache, uid, "");
    if (stream || cache_only) {
        CAMEL_IMAP_FOLDER_UNLOCK (imap_folder, cache_lock);
        return stream;
    }       

    if (camel_disco_store_status (CAMEL_DISCO_STORE (store)) == CAMEL_DISCO_STORE_OFFLINE) {
        camel_exception_set (ex, CAMEL_EXCEPTION_SERVICE_UNAVAILABLE,
                     _("This message is not currently available"));
        CAMEL_IMAP_FOLDER_UNLOCK (imap_folder, cache_lock);
        return NULL;
    }

    if (store->server_level < IMAP_LEVEL_IMAP4REV1 && !*section_text) {
        response = camel_imap_command (store, folder, ex,
                           "UID FETCH %s RFC822.PEEK",
                           uid);
    } else {
        response = camel_imap_command (store, folder, ex,
                           "UID FETCH %s BODY.PEEK[%s]",
                           uid, section_text);
    }
    if (!response) {
        CAMEL_IMAP_FOLDER_UNLOCK (imap_folder, cache_lock);
        return NULL;
    }

    for (i = 0; i < response->untagged->len; i++) {
        fetch_data = parse_fetch_response (imap_folder, response->untagged->pdata[i]);
        found_uid = g_datalist_get_data (&fetch_data, "UID");
        stream = g_datalist_get_data (&fetch_data, "BODY_PART_STREAM");
        if (found_uid && stream && !strcmp (uid, found_uid))
            break;

        g_datalist_clear (&fetch_data);
        stream = NULL;
    }
    camel_imap_response_free (store, response);
    CAMEL_IMAP_FOLDER_UNLOCK (imap_folder, cache_lock);
    if (!stream) {
        camel_exception_setv (ex, CAMEL_EXCEPTION_SERVICE_UNAVAILABLE,
                      _("Could not find message body in FETCH "
                    "response."));
    } else {
        camel_object_ref (CAMEL_OBJECT (stream));
        g_datalist_clear (&fetch_data);
    }

    return stream;
}

GData *
parse_fetch_response (CamelImapFolder *imap_folder, char *response)
{
    GData *data = NULL;
    char *start, *part_spec = NULL, *body = NULL, *uid = NULL;
    int body_len = 0;

    if (*response != '(') {
        long seq;

        if (*response != '*' || *(response + 1) != ' ')
            return NULL;
        seq = strtol (response + 2, &response, 10);
        if (seq == 0)
            return NULL;
        if (g_strncasecmp (response, " FETCH (", 8) != 0)
            return NULL;
        response += 7;

        g_datalist_set_data (&data, "SEQUENCE", GINT_TO_POINTER (seq));
    }

    do {
        /* Skip the initial '(' or the ' ' between elements */
        response++;

        if (!g_strncasecmp (response, "FLAGS ", 6)) {
            guint32 flags;

            response += 6;
            /* FIXME user flags */
            flags = imap_parse_flag_list (&response);

            g_datalist_set_data (&data, "FLAGS", GUINT_TO_POINTER (flags));
        } else if (!g_strncasecmp (response, "RFC822.SIZE ", 12)) {
            unsigned long size;

            response += 12;
            size = strtoul (response, &response, 10);
            g_datalist_set_data (&data, "RFC822.SIZE", GUINT_TO_POINTER (size));
        } else if (!g_strncasecmp (response, "BODY[", 5) ||
               !g_strncasecmp (response, "RFC822 ", 7)) {
            char *p;

            if (*response == 'B') {
                response += 5;
                p = strchr (response, ']');
                if (!p || *(p + 1) != ' ')
                    break;
                part_spec = g_strndup (response, p - response);
                response = p + 2;
            } else {
                part_spec = g_strdup ("");
                response += 7;
            }

            body = imap_parse_nstring (&response, &body_len);
            if (!response) {
                g_free (part_spec);
                break;
            }

            if (!body)
                body = g_strdup ("");
            g_datalist_set_data_full (&data, "BODY_PART_SPEC", part_spec, g_free);
            g_datalist_set_data_full (&data, "BODY_PART_DATA", body, g_free);
            g_datalist_set_data (&data, "BODY_PART_LEN", GINT_TO_POINTER (body_len));
        } else if (!g_strncasecmp (response, "BODY ", 5) ||
               !g_strncasecmp (response, "BODYSTRUCTURE ", 14)) {
            response = strchr (response, ' ') + 1;
            start = response;
            imap_skip_list (&response);
            g_datalist_set_data_full (&data, "BODY", g_strndup (start, response - start), g_free);
        } else if (!g_strncasecmp (response, "UID ", 4)) {
            int len;

            len = strcspn (response + 4, " )");
            uid = g_strndup (response + 4, len);
            g_datalist_set_data_full (&data, "UID", uid, g_free);
            response += 4 + len;
        } else {
            g_warning ("Unexpected FETCH response from server: "
                   "(%s", response);
            break;
        }
    } while (response && *response != ')');

    if (!response || *response != ')') {
        g_datalist_clear (&data);
        return NULL;
    }

    if (uid && body) {
        CamelStream *stream;

        CAMEL_IMAP_FOLDER_LOCK (imap_folder, cache_lock);
        stream = camel_imap_message_cache_insert (imap_folder->cache,
                              uid, part_spec,
                              body, body_len);
        CAMEL_IMAP_FOLDER_UNLOCK (imap_folder, cache_lock);
        g_datalist_set_data_full (&data, "BODY_PART_STREAM", stream,
                      (GDestroyNotify)camel_object_unref);
    }

    return data;
}