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-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);

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_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;
    }

    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 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);
    CamelImapResponse *response;
    struct {
        char *uid;
        guint32 flags;
    } *new = NULL;
    char *resp;
    int i, seq, summary_len;
    CamelMessageInfo *info;
    CamelImapMessageInfo *iinfo;
    GArray *removed;
    GData *fetch_data;
    gpointer data;

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

    camel_operation_start (NULL, _("Scanning IMAP folder"));

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

        new = g_malloc0 (summary_len * sizeof (*new));
        for (i = 0; i < response->untagged->len; i++) {
            resp = response->untagged->pdata[i];

            seq = strtoul (resp + 2, &resp, 10);
            if (g_strncasecmp (resp, " FETCH (", 8) != 0)
                continue;
            if (seq >= summary_len)
                continue;

            fetch_data = parse_fetch_response (imap_folder, resp + 7);
            data = g_datalist_get_data (&fetch_data, "UID");
            if (data && !new[seq - 1].uid)
                new[seq - 1].uid = g_strdup (data);
            data = g_datalist_get_data (&fetch_data, "FLAGS");
            if (data)
                new[seq - 1].flags = GPOINTER_TO_UINT (data);
            g_datalist_clear (&fetch_data);
        }
        camel_imap_response_free_without_processing (store, response);
    }

    /* 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);

    camel_operation_end (NULL);
}

/* 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, ex, ba->data);
    g_byte_array_free (ba, TRUE);

    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;

    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);
}

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);
    CamelImapResponse *response;

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

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

    /* Force the destination folder to notice its new messages. */
    response = camel_imap_command (store, destination, NULL, "NOOP");
    camel_imap_response_free (store, response);
}

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 *
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;

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

    /* If the message is small, or the server doesn't support
     * IMAP4rev1, or we already have the whole thing cached,
     * fetch it in one piece.
     */
    if (mi->size < IMAP_SMALL_BODY_SIZE ||
        store->server_level < IMAP_LEVEL_IMAP4REV1 ||
        (stream = camel_imap_folder_fetch_data (imap_folder, uid, "", TRUE, NULL))) {
        camel_folder_summary_info_free (folder->summary, mi);
        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;
    }

    /* 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) {
            camel_exception_setv (ex, CAMEL_EXCEPTION_SERVICE_UNAVAILABLE,
                          _("Could not find message body in FETCH response."));
            camel_folder_summary_info_free (folder->summary, mi);
            return NULL;
        }
    }

    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));
}

static void
imap_update_summary (CamelFolder *folder,
             CamelFolderChangeInfo *changes,
             CamelException *ex)
{
    CamelImapFolder *imap_folder = CAMEL_IMAP_FOLDER (folder);
    CamelImapStore *store = CAMEL_IMAP_STORE (folder->parent_store);
    CamelImapResponse *response;
    GPtrArray *lines, *messages;
    char *p, *uid;
    int i, seq, first, exists = 0;
    CamelMimeMessage *msg;
    CamelMessageInfo *mi;
    GData *fetch_data;
    CamelStream *stream;

    CAMEL_IMAP_STORE_ASSERT_LOCKED (store, command_lock);

    first = camel_folder_summary_count (folder->summary) + 1;

    response = camel_imap_command (store, folder, ex, "FETCH %d:* (UID FLAGS RFC822.SIZE)", first);
    if (!response)
        return;

    /* Walk through the responses, looking for UIDs, and make sure
     * we have those headers cached.
     */
    messages = g_ptr_array_new ();
    lines = response->untagged;
    for (i = 0; i < lines->len; i++) {
        p = lines->pdata[i];
        if (*p++ != '*' || *p++ != ' ') {
            g_ptr_array_remove_index_fast (lines, i--);
            continue;
        }
        seq = strtoul (p, &p, 10);
        if (!g_strcasecmp (p, " EXISTS")) {
            exists = seq;
            g_ptr_array_remove_index_fast (lines, i--);
            continue;
        }
        if (!seq || seq < first || g_strncasecmp (p, " FETCH (", 8) != 0) {
            g_ptr_array_remove_index_fast (lines, i--);
            continue;
        }

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

        fetch_data = parse_fetch_response (imap_folder, p + 7);
        uid = g_datalist_get_data (&fetch_data, "UID");
        if (uid) {
            stream = camel_imap_folder_fetch_data (
                imap_folder, uid,
                store->server_level >= IMAP_LEVEL_IMAP4REV1 ?
                "HEADER" : "0", FALSE, ex);
            if (!stream) {
                camel_imap_response_free_without_processing (store, response);
                /* XXX messages */
                return;
            }

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

            messages->pdata[seq - first] = mi;
        }
        g_datalist_clear (&fetch_data);
    }

    /* Now go back through and create summary items */
    lines = response->untagged;
    for (i = 0; i < lines->len; i++) {
        p = lines->pdata[i];
        seq = strtoul (p + 2, &p, 10);
        p = strchr (p, '(');

        mi = messages->pdata[seq - first];
        if (!mi) /* ? */
            continue;
        fetch_data = parse_fetch_response (imap_folder, p);

        if (g_datalist_get_data (&fetch_data, "UID"))
            camel_message_info_set_uid (mi, g_strdup (g_datalist_get_data (&fetch_data, "UID")));
        if (g_datalist_get_data (&fetch_data, "FLAGS")) {
            guint32 flags = GPOINTER_TO_INT (g_datalist_get_data (&fetch_data, "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;
        }
        if (g_datalist_get_data (&fetch_data, "RFC822.SIZE"))
            mi->size = GPOINTER_TO_INT (g_datalist_get_data (&fetch_data, "RFC822.SIZE"));

        g_datalist_clear (&fetch_data);
    }
    camel_imap_response_free_without_processing (store, response);

    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));
    }
    g_ptr_array_free (messages, TRUE);

    /* Did more mail arrive while we were doing this? */
    if (exists && exists > camel_folder_summary_count (folder->summary))
        imap_update_summary (folder, changes, ex);
}

/* 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;
    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);
            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)
        imap_update_summary (folder, changes, ex);

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

    camel_folder_summary_save (folder->summary);
}


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;
    }

    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;
}