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: Abstract class for an imap folder */

/* 
 * Authors: Jeffrey Stedfast <fejj@helixcode.com> 
 *
 * Copyright (C) 2000 Helix Code, 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
 */


#include <config.h> 

#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 <gal/util/e-util.h>

#include "camel-imap-folder.h"
#include "camel-imap-command.h"
#include "camel-imap-store.h"
#include "camel-imap-stream.h"
#include "camel-imap-summary.h"
#include "camel-imap-utils.h"
#include "string-utils.h"
#include "camel-stream.h"
#include "camel-stream-fs.h"
#include "camel-stream-mem.h"
#include "camel-stream-buffer.h"
#include "camel-data-wrapper.h"
#include "camel-mime-message.h"
#include "camel-stream-filter.h"
#include "camel-mime-filter-from.h"
#include "camel-mime-filter-crlf.h"
#include "camel-exception.h"
#include "camel-mime-utils.h"

#define d(x) x

#define CF_CLASS(o) (CAMEL_FOLDER_CLASS (CAMEL_OBJECT_GET_CLASS(o)))

static CamelFolderClass *parent_class = NULL;

static void imap_finalize (CamelObject *object);
static void imap_refresh_info (CamelFolder *folder, CamelException *ex);
static void imap_sync (CamelFolder *folder, gboolean expunge, CamelException *ex);
static const char *imap_get_full_name (CamelFolder *folder);
static void imap_expunge (CamelFolder *folder, CamelException *ex);

/* message counts */
static gint imap_get_message_count (CamelFolder *folder);
static gint imap_get_unread_message_count (CamelFolder *folder);

/* message manipulation */
static CamelMimeMessage *imap_get_message (CamelFolder *folder, const gchar *uid,
                       CamelException *ex);
static void imap_append_message (CamelFolder *folder, CamelMimeMessage *message,
                 const CamelMessageInfo *info, CamelException *ex);
static void imap_copy_message_to (CamelFolder *source, const char *uid,
                  CamelFolder *destination, CamelException *ex);
static void imap_move_message_to (CamelFolder *source, const char *uid,
                  CamelFolder *destination, CamelException *ex);

/* summary info */
static GPtrArray *imap_get_uids (CamelFolder *folder);
static GPtrArray *imap_get_summary (CamelFolder *folder);
static const CamelMessageInfo *imap_get_message_info (CamelFolder *folder, const char *uid);

static void imap_update_summary (CamelFolder *folder, int first, int last,
                 CamelException *ex);

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

/* flag methods */
static guint32  imap_get_message_flags     (CamelFolder *folder, const char *uid);
static void     imap_set_message_flags     (CamelFolder *folder, const char *uid, guint32 flags, guint32 set);
static gboolean imap_get_message_user_flag (CamelFolder *folder, const char *uid, const char *name);
static void     imap_set_message_user_flag (CamelFolder *folder, const char *uid, const char *name,
                        gboolean value);


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

    parent_class = CAMEL_FOLDER_CLASS(camel_type_get_global_classfuncs (camel_folder_get_type ()));
    
    /* virtual method definition */
    
    /* virtual method overload */
    camel_folder_class->refresh_info = imap_refresh_info;
    camel_folder_class->sync = imap_sync;
    camel_folder_class->expunge = imap_expunge;
    camel_folder_class->get_full_name = imap_get_full_name;
    
    camel_folder_class->get_uids = imap_get_uids;
    camel_folder_class->free_uids = camel_folder_free_nop;
    
    camel_folder_class->get_message_count = imap_get_message_count;
    camel_folder_class->get_unread_message_count = imap_get_unread_message_count;
    camel_folder_class->get_message = imap_get_message;
    camel_folder_class->append_message = imap_append_message;
    camel_folder_class->copy_message_to = imap_copy_message_to;
    camel_folder_class->move_message_to = imap_move_message_to;
    
    camel_folder_class->get_summary = imap_get_summary;
    camel_folder_class->get_message_info = imap_get_message_info;
    camel_folder_class->free_summary = camel_folder_free_nop;
    
    camel_folder_class->search_by_expression = imap_search_by_expression;
    
    camel_folder_class->get_message_flags = imap_get_message_flags;
    camel_folder_class->set_message_flags = imap_set_message_flags;
    camel_folder_class->get_message_user_flag = imap_get_message_user_flag;
    camel_folder_class->set_message_user_flag = imap_set_message_user_flag;
}

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->summary = NULL;
}

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_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 *short_name, const char *summary_file,
               CamelException *ex)
{
    CamelImapStore *imap_store = CAMEL_IMAP_STORE (parent);
    CamelFolder *folder = CAMEL_FOLDER (camel_object_new (camel_imap_folder_get_type ()));
    CamelImapFolder *imap_folder = (CamelImapFolder *)folder;
    CamelImapResponse *response;
    const char *resp;
    guint32 validity = 0;
    int i;

    camel_folder_construct (folder, parent, folder_name, short_name);

    response = camel_imap_command (imap_store, folder, ex, NULL);
    if (!response) {
        camel_object_unref ((CamelObject *)folder);
        return NULL;
    }

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

            if (!g_strncasecmp (resp, " EXISTS", 7))
                imap_folder->exists = num;
        }
    }
    camel_imap_response_free (response);

    imap_folder->summary = camel_imap_summary_new (summary_file, validity);
    if (!imap_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_refresh_info (folder, ex);
    if (camel_exception_is_set (ex)) {
        camel_object_unref (CAMEL_OBJECT (folder));
        return NULL;
    }

    return folder;
}

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

    camel_object_unref ((CamelObject *)imap_folder->summary);
}

static void
imap_refresh_info (CamelFolder *folder, CamelException *ex)
{
    CamelImapStore *store = CAMEL_IMAP_STORE (folder->parent_store);
    CamelImapFolder *imap_folder = CAMEL_IMAP_FOLDER (folder);
    CamelImapResponse *response;
    struct {
        char *uid;
        guint32 flags;
    } *new;
    char *resp, *uid, *p, *flags;
    int i, seq, summary_len;
    CamelMessageInfo *info;
    gboolean folder_changed = FALSE;

    if (imap_folder->exists == 0) {
        if (camel_folder_summary_count (imap_folder->summary) != 0) {
            camel_folder_summary_clear (imap_folder->summary);
            camel_object_trigger_event (CAMEL_OBJECT (folder),
                            "folder_changed", NULL);
        }
        return;
    }

    /* Get UIDs and flags of all messages. */
    response = camel_imap_command (store, folder, ex,
                       "FETCH 1:%d (UID FLAGS)",
                       imap_folder->exists);
    if (!response)
        return;

    new = g_malloc0 (imap_folder->exists * 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 ", 7) != 0)
            continue;

        uid = e_strstrcase (resp, "UID ");
        if (uid) {
            uid += 4;
            strtoul (uid, &p, 10);
            new[seq - 1].uid = g_strndup (uid, p - uid);
        }

        flags = e_strstrcase (resp, "FLAGS ");
        if (flags) {
            flags += 6;
            new[seq - 1].flags = imap_parse_flag_list (flags);
        }
    }

    /* If we find a UID in the summary that doesn't correspond to
     * the UID in the folder, that it means the message was
     * deleted on the server, so we remove it from the summary.
     */
    summary_len = camel_folder_summary_count (imap_folder->summary);
    for (i = 0; i < summary_len && i < imap_folder->exists; i++) {
        info = camel_folder_summary_index (imap_folder->summary, i);

        /* Shouldn't happen, but... */
        if (!new[i].uid)
            continue;

        if (strcmp (camel_message_info_uid(info), new[i].uid) != 0) {
            camel_folder_summary_remove (imap_folder->summary,
                             info);
            folder_changed = TRUE;
            i--;
            summary_len--;
            continue;
        }

        /* Update summary flags */
        if (info->flags != new[i].flags) {
            info->flags = new[i].flags;
            camel_object_trigger_event (CAMEL_OBJECT (folder),
                            "message_changed",
                            (char *)camel_message_info_uid(info));
        }

        g_free (new[i].uid);
    }

    /* Remove any leftover cached summary messages. */
    while (summary_len > i + 1) {
        camel_folder_summary_remove_index (imap_folder->summary,
                           --summary_len);
        folder_changed = TRUE;
    }

    /* Add any new folder messages. */
    if (i < imap_folder->exists) {
        /* Fetch full summary for the remaining messages. */
        imap_update_summary (folder, i + 1, imap_folder->exists, ex);
        folder_changed = TRUE;

        while (i < imap_folder->exists)
            g_free (new[i++].uid);
    }
    g_free (new);

    if (folder_changed) {
        camel_object_trigger_event (CAMEL_OBJECT (folder),
                        "folder_changed", NULL);
    }
}

static void
imap_sync (CamelFolder *folder, gboolean expunge, CamelException *ex)
{
    CamelImapStore *store = CAMEL_IMAP_STORE (folder->parent_store);
    CamelImapFolder *imap_folder = CAMEL_IMAP_FOLDER (folder);
    CamelImapResponse *response;
    int i, max;

    /* Set the flags on any messages that have changed this session */
    max = camel_folder_summary_count (imap_folder->summary);
    for (i = 0; i < max; i++) {
        CamelMessageInfo *info;

        info = camel_folder_summary_index (imap_folder->summary, i);
        if (info->flags & CAMEL_MESSAGE_FOLDER_FLAGGED) {
            char *flags;

            flags = imap_create_flag_list (info->flags);
            if (flags) {
                response = camel_imap_command (
                    store, folder, ex,
                    "UID STORE %s FLAGS.SILENT %s",
                    camel_message_info_uid(info), flags);
                g_free (flags);
                if (!response)
                    return;
                camel_imap_response_free (response);
            }
            info->flags &= ~CAMEL_MESSAGE_FOLDER_FLAGGED;
        }
    }

    if (expunge) {
        response = camel_imap_command (store, folder, ex, "EXPUNGE");
        camel_imap_response_free (response);
    }

    camel_folder_summary_save (imap_folder->summary);
}

static void
imap_expunge (CamelFolder *folder, CamelException *ex)
{
    imap_sync (folder, TRUE, ex);
}

static const char *
imap_get_full_name (CamelFolder *folder)
{
    CamelURL *url = ((CamelService *)folder->parent_store)->url;
    int len;

    if (!url->path || !*url->path || !strcmp (url->path, "/"))
        return folder->full_name;
    len = strlen (url->path + 1);
    if (!strncmp (url->path + 1, folder->full_name, len) &&
        strlen (folder->full_name) > len + 1)
        return folder->full_name + len + 1;
    return folder->full_name;
}   

static gint
imap_get_message_count (CamelFolder *folder)
{
    CamelImapFolder *imap_folder = CAMEL_IMAP_FOLDER (folder);
    
    return camel_folder_summary_count (imap_folder->summary);
}

static gint
imap_get_unread_message_count (CamelFolder *folder)
{
    CamelImapFolder *imap_folder = CAMEL_IMAP_FOLDER (folder);
    CamelMessageInfo *info;
    int i, max, count = 0;

    max = camel_folder_summary_count (imap_folder->summary);
    for (i = 0; i < max; i++) {
        info = camel_folder_summary_index (imap_folder->summary, i);
        if (!(info->flags & CAMEL_MESSAGE_SEEN))
            count++;
    }

    return count;
}

static void
imap_append_message (CamelFolder *folder, CamelMimeMessage *message,
             const CamelMessageInfo *info, CamelException *ex)
{
    CamelImapStore *store = CAMEL_IMAP_STORE (folder->parent_store);
    CamelImapResponse *response;
    CamelStream *memstream;
    CamelMimeFilter *crlf_filter;
    CamelStreamFilter *streamfilter;
    GByteArray *ba;
    char *flagstr, *result;
    
    /* 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;
    }
    result = camel_imap_response_extract_continuation (response, ex);
    if (!result) {
        g_byte_array_free (ba, TRUE);
        return;
    }
    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 (!response)
        return;
    camel_imap_response_free (response);
}

static void
imap_copy_message_to (CamelFolder *source, const char *uid,
              CamelFolder *destination, CamelException *ex)
{
    CamelImapStore *store = CAMEL_IMAP_STORE (source->parent_store);
    CamelImapResponse *response;
    
    response = camel_imap_command (store, source, ex, "UID COPY %s \"%s\"",
                       uid, destination->full_name);
    camel_imap_response_free (response);

    /* FIXME: This should go away once folder_changed is being
     * emitted by camel_imap_folder_changed on appends again.
     */
    if (!camel_exception_is_set (ex)) {
        camel_object_trigger_event (CAMEL_OBJECT (destination),
                        "folder_changed", NULL);
    }
}

static void
imap_move_message_to (CamelFolder *source, const char *uid,
              CamelFolder *destination, CamelException *ex)
{
    CamelImapStore *store = CAMEL_IMAP_STORE (source->parent_store);
    CamelImapResponse *response;

    response = camel_imap_command (store, source, ex, "UID COPY %s \"%s\"",
                       uid, destination->full_name);
    camel_imap_response_free (response);

    if (camel_exception_is_set (ex))
        return;

    /* FIXME: This should go away once folder_changed is being
     * emitted by camel_imap_folder_changed on appends again.
     */
    camel_object_trigger_event (CAMEL_OBJECT (destination),
                    "folder_changed", NULL);

    camel_folder_delete_message (source, uid);
}

static GPtrArray *
imap_get_uids (CamelFolder *folder) 
{
    CamelImapFolder *imap_folder = CAMEL_IMAP_FOLDER (folder);
    const CamelMessageInfo *info;
    GPtrArray *array;
    int i, count;

    count = camel_folder_summary_count (imap_folder->summary);

    array = g_ptr_array_new ();
    g_ptr_array_set_size (array, count);

    for (i = 0; i < count; i++) {
        info = camel_folder_summary_index (imap_folder->summary, i);
        array->pdata[i] = g_strdup (camel_message_info_uid(info));
    }

    return array;
}

static CamelMimeMessage *
imap_get_message (CamelFolder *folder, const gchar *uid, CamelException *ex)
{
    CamelImapStore *store = CAMEL_IMAP_STORE (folder->parent_store);
    CamelImapResponse *response;
    CamelStream *msgstream;
    CamelMimeMessage *msg;
    char *result, *mesg, *p;
    int len;

    response = camel_imap_command (store, folder, ex,
                       "UID FETCH %s BODY.PEEK[]", uid);
    if (!response)
        return NULL;
    result = camel_imap_response_extract (response, "FETCH", ex);
    if (!result)
        return NULL;

    p = strstr (result, "BODY[]");
    if (p) {
        p += 7;
        mesg = imap_parse_nstring (&p, &len);
    }
    if (!p) {
        camel_exception_setv (ex, CAMEL_EXCEPTION_SERVICE_UNAVAILABLE,
                      _("Could not find message body in FETCH "
                    "response."));
        g_free (result);
        return NULL;
    }
    g_free (result);

    msgstream = camel_stream_mem_new_with_buffer (mesg, len);
    msg = camel_mime_message_new ();
    camel_data_wrapper_construct_from_stream (CAMEL_DATA_WRAPPER (msg),
                          msgstream);
    camel_object_unref (CAMEL_OBJECT (msgstream));
    g_free (mesg);

    return msg;
}

/**
 * imap_protocol_get_summary_specifier
 *
 * Make a data item specifier for the header lines we need,
 * appropriate to the server level.
 *
 * IMAP4rev1:  UID FLAGS BODY.PEEK[HEADER.FIELDS (SUBJECT FROM .. IN-REPLY-TO)]
 * IMAP4:      UID FLAGS RFC822.HEADER.LINES (SUBJECT FROM .. IN-REPLY-TO)
 **/
static char *
imap_protocol_get_summary_specifier (CamelImapStore *store)
{
    char *sect_begin, *sect_end;
    char *headers_wanted = "SUBJECT FROM TO CC DATE MESSAGE-ID REFERENCES IN-REPLY-TO";
    
    if (store->server_level >= IMAP_LEVEL_IMAP4REV1) {
        sect_begin = "BODY.PEEK[HEADER.FIELDS";
        sect_end = "]";
    } else {
        sect_begin = "RFC822.HEADER.LINES";
        sect_end   = "";
    }
    
    return g_strdup_printf ("UID FLAGS %s (%s)%s", sect_begin,
                headers_wanted, sect_end);
}

static void
imap_update_summary (CamelFolder *folder, int first, int last,
             CamelException *ex)
{
    CamelImapStore *store = CAMEL_IMAP_STORE (folder->parent_store);
    CamelImapFolder *imap_folder = CAMEL_IMAP_FOLDER (folder);
    CamelImapResponse *response;
    GPtrArray *headers = NULL;
    char *q, *summary_specifier;
    struct _header_raw *h = NULL;
    int i;

    /* If the range we're updating overlaps with the range we already
     * know about, then fetch just flags + uids first. If uids
     * aren't "right", reorder them. Update flags appropriately.
     * If that returned unknown UIDs, or we're updating unknown
     * sequence numbers, do the full fetch for those.
     */

    summary_specifier = imap_protocol_get_summary_specifier (store);
    if (first == last) {
        response = camel_imap_command (store, folder, ex,
                           "FETCH %d (%s)", first,
                           summary_specifier);
    } else {
        response = camel_imap_command (store, folder, ex,
                           "FETCH %d:%d (%s)", first,
                           last, summary_specifier);
    }
    g_free (summary_specifier);

    if (!response)
        return;

    headers = response->untagged;
    for (i = 0; i < headers->len; i++) {
        CamelMessageInfo *info;
        char *uid, *flags, *header;

        /* Grab the UID... */
        if (!(uid = strstr (headers->pdata[i], "UID "))) {
            d(fprintf (stderr, "Cannot get a uid for %d\n\n%s\n\n", i+1, (char *) headers->pdata[i]));
            break;
        }

        for (uid += 4; *uid && (*uid < '0' || *uid > '9'); uid++)
            ;
        for (q = uid; *q && *q >= '0' && *q <= '9'; q++)
            ;

        /* construct the header list */
        /* fast-forward to beginning of header info... */
        header = strchr (headers->pdata[i], '\n') + 1;
        h = NULL;
        do {
            char *line;
            int len;

            len = strcspn (header, "\n");
            while (header[len + 1] == ' ' ||
                   header[len + 1] == '\t')
                len += 1 + strcspn (header + len + 1, "\n");
            line = g_strndup (header, len);
            header_raw_append_parse (&h, line, -1);
            g_free (line);

            header += len;
        } while (*header++ == '\n' && *header != '\n');

        /* We can't just call camel_folder_summary_add_from_parser
         * because it will assign the wrong UID, and thus get the
         * uid hash table wrong and all that. FIXME some day.
         */
        info = ((CamelFolderSummaryClass *)(CAMEL_OBJECT_GET_CLASS(imap_folder->summary)))->message_info_new(imap_folder->summary, h);
        header_raw_clear (&h);
        uid = g_strndup(uid, q-uid);
        camel_message_info_set_uid(info, uid);

        /* now lets grab the FLAGS */
        if (!(flags = strstr (headers->pdata[i], "FLAGS "))) {
            d(fprintf (stderr, "We didn't seem to get any flags for %d...\n", i));
        } else {        
            for (flags += 6; *flags && *flags != '('; flags++)
                ;
            info->flags = imap_parse_flag_list (flags);
        }

        camel_folder_summary_add (imap_folder->summary, info);
    }
    camel_imap_response_free (response);
}

static GPtrArray *
imap_get_summary (CamelFolder *folder)
{
    CamelImapFolder *imap_folder = CAMEL_IMAP_FOLDER (folder);

    return imap_folder->summary->messages;
}

/* get a single message info, by uid */
static const CamelMessageInfo *
imap_get_message_info (CamelFolder *folder, const char *uid)
{
    CamelImapFolder *imap_folder = CAMEL_IMAP_FOLDER (folder);
    
    return camel_folder_summary_uid (imap_folder->summary, uid);
}

static GPtrArray *
imap_search_by_expression (CamelFolder *folder, const char *expression, CamelException *ex)
{
    CamelImapResponse *response;
    GPtrArray *uids = NULL;
    char *result, *sexp, *p;
    
    d(fprintf (stderr, "camel sexp: '%s'\n", expression));
    sexp = imap_translate_sexp (expression);
    d(fprintf (stderr, "imap sexp: '%s'\n", sexp));
    
    uids = g_ptr_array_new ();
    
    if (!folder->has_search_capability) {
        g_free (sexp);
        return uids;
    }
    
    response = camel_imap_command (CAMEL_IMAP_STORE (folder->parent_store),
                       folder, NULL, "UID SEARCH %s", sexp);
    g_free (sexp);
    if (!response)
        return uids;

    result = camel_imap_response_extract (response, "SEARCH", NULL);
    if (!result)
        return uids;
    
    if ((p = strstr (result, "* SEARCH"))) {
        char *word;
        
        word = imap_next_word (p); /* word now points to SEARCH */
        
        for (word = imap_next_word (word); *word && *word != '*'; word = imap_next_word (word)) {
            gboolean word_is_numeric = TRUE;
            char *ep;
            
            /* find the end of this word and make sure it's a numeric uid */
            for (ep = word; *ep && *ep != ' ' && *ep != '\n'; ep++)
                if (*ep < '0' || *ep > '9')
                    word_is_numeric = FALSE;
            
            if (word_is_numeric)
                g_ptr_array_add (uids, g_strndup (word, (gint)(ep - word)));
        }
    }
    
    g_free (result);
    
    return uids;
}

static guint32
imap_get_message_flags (CamelFolder *folder, const char *uid)
{
    const CamelMessageInfo *info;
    
    info = imap_get_message_info (folder, uid);
    g_return_val_if_fail (info != NULL, 0);
    
    return info->flags;
}

static void
imap_set_message_flags (CamelFolder *folder, const char *uid, guint32 flags, guint32 set)
{
    CamelImapFolder *imap_folder = (CamelImapFolder *)folder;
    CamelMessageInfo *info;
    guint32 new;

    info = camel_folder_summary_uid (imap_folder->summary, uid);
    g_return_if_fail (info != NULL);

    new = (info->flags & ~flags) | (set & flags);
    if (new == info->flags)
        return;

    info->flags = new | CAMEL_MESSAGE_FOLDER_FLAGGED;
    camel_folder_summary_touch (imap_folder->summary);

    camel_object_trigger_event (CAMEL_OBJECT (folder), "message_changed",
                    (gpointer)uid);
}

static gboolean
imap_get_message_user_flag (CamelFolder *folder, const char *uid, const char *name)
{
    /* FIXME */
    return FALSE;
}

static void
imap_set_message_user_flag (CamelFolder *folder, const char *uid, const char *name, gboolean value)
{
    /* FIXME */
    camel_object_trigger_event (CAMEL_OBJECT (folder), "message_changed",
                    (gpointer)uid);
}

void
camel_imap_folder_changed (CamelFolder *folder, int exists,
               GArray *expunged, CamelException *ex)
{
    CamelImapFolder *imap_folder = CAMEL_IMAP_FOLDER (folder);

    if (expunged) {
        int i, id;

        for (i = 0; i < expunged->len; i++) {
            id = g_array_index (expunged, int, i);
            camel_folder_summary_remove_index (
                imap_folder->summary, id - 1);
        }
        camel_object_trigger_event (CAMEL_OBJECT (folder),
                        "folder_changed", NULL);
    }

    if (exists != 0)
        imap_folder->exists = exists;
}