path: root/mail/mail-vfolder.c

/*
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) version 3.
 *
 * 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with the program; if not, see <http://www.gnu.org/licenses/>
 *
 *
 * Authors:
 *      Michael Zucchi <notzed@ximian.com>
 *
 * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
 *
 */

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

#include <string.h>

#include <glib/gi18n.h>

#include <libedataserver/e-account-list.h>

#include "e-util/e-alert-dialog.h"
#include "e-util/e-util-private.h"
#include "e-util/e-account-utils.h"

#include "e-mail-backend.h"
#include "e-mail-session.h"
#include "e-mail-folder-utils.h"
#include "em-folder-tree-model.h"
#include "em-utils.h"
#include "em-vfolder-context.h"
#include "em-vfolder-editor.h"
#include "em-vfolder-rule.h"
#include "mail-autofilter.h"
#include "mail-folder-cache.h"
#include "mail-mt.h"
#include "mail-ops.h"
#include "mail-tools.h"
#include "mail-vfolder.h"

#define d(x)  /* (printf("%s:%s: ",  G_STRLOC, G_STRFUNC), (x))*/

static EMVFolderContext *context;   /* context remains open all time */

/* lock for accessing shared resources (below) */
G_LOCK_DEFINE_STATIC (vfolder);

static GHashTable *vfolder_hash;
/* This is a slightly hacky solution to shutting down, we poll this variable in various
 * loops, and just quit processing if it is set. */
static volatile gint vfolder_shutdown;  /* are we shutting down? */

static void rule_changed (EFilterRule *rule, CamelFolder *folder);

/* ********************************************************************** */

struct _setup_msg {
    MailMsg base;

    EMailSession *session;
    CamelFolder *folder;
    gchar *query;
    GList *sources_uri;
    GList *sources_folder;
};

static gchar *
vfolder_setup_desc (struct _setup_msg *m)
{
    return g_strdup_printf (
        _("Setting up Search Folder: %s"),
        camel_folder_get_full_name (m->folder));
}

static void
vfolder_setup_exec (struct _setup_msg *m,
                    GCancellable *cancellable,
                    GError **error)
{
    GList *l, *list = NULL;
    CamelFolder *folder;

    camel_vee_folder_set_expression ((CamelVeeFolder *) m->folder, m->query);

    l = m->sources_uri;
    while (l && !vfolder_shutdown) {
        d(printf(" Adding uri: %s\n", (gchar *)l->data));

        /* FIXME Not passing a GCancellable or GError here. */
        folder = e_mail_session_uri_to_folder_sync (
            m->session, l->data, 0, NULL, NULL);
        if (folder != NULL)
            list = g_list_append (list, folder);
        l = l->next;
    }

    l = m->sources_folder;
    while (l && !vfolder_shutdown) {
        g_object_ref (l->data);
        list = g_list_append (list, l->data);
        l = l->next;
    }

    if (!vfolder_shutdown)
        camel_vee_folder_set_folders ((CamelVeeFolder *) m->folder, list);

    l = list;
    while (l) {
        g_object_unref (l->data);
        l = l->next;
    }
    g_list_free (list);
}

static void
vfolder_setup_done (struct _setup_msg *m)
{
}

static void
vfolder_setup_free (struct _setup_msg *m)
{
    GList *l;

    g_object_unref (m->session);
    g_object_unref (m->folder);
    g_free (m->query);

    l = m->sources_uri;
    while (l) {
        g_free (l->data);
        l = l->next;
    }
    g_list_free (m->sources_uri);

    l = m->sources_folder;
    while (l) {
        g_object_unref (l->data);
        l = l->next;
    }
    g_list_free (m->sources_folder);
}

static MailMsgInfo vfolder_setup_info = {
    sizeof (struct _setup_msg),
    (MailMsgDescFunc) vfolder_setup_desc,
    (MailMsgExecFunc) vfolder_setup_exec,
    (MailMsgDoneFunc) vfolder_setup_done,
    (MailMsgFreeFunc) vfolder_setup_free
};

/* sources_uri should be camel uri's */
static gint
vfolder_setup (EMailSession *session,
               CamelFolder *folder,
               const gchar *query,
               GList *sources_uri,
               GList *sources_folder)
{
    struct _setup_msg *m;
    gint id;

    m = mail_msg_new (&vfolder_setup_info);
    m->session = g_object_ref (session);
    m->folder = g_object_ref (folder);
    m->query = g_strdup (query);
    m->sources_uri = sources_uri;
    m->sources_folder = sources_folder;

    id = m->base.seq;
    mail_msg_slow_ordered_push (m);

    return id;
}

/* ********************************************************************** */

struct _adduri_msg {
    MailMsg base;

    EMailBackend *backend;
    gchar *uri;
    GList *folders;
    gint remove;
};

static gchar *
vfolder_adduri_desc (struct _adduri_msg *m)
{
    CamelStore *store;
    CamelService *service;
    EMailSession *session;
    const gchar *display_name;
    gchar *folder_name;
    gchar *description;
    gboolean success;

    session = e_mail_backend_get_session (m->backend);

    success = e_mail_folder_uri_parse (
        CAMEL_SESSION (session), m->uri,
        &store, &folder_name, NULL);

    if (!success)
        return NULL;

    service = CAMEL_SERVICE (store);
    display_name = camel_service_get_display_name (service);

    description = g_strdup_printf (
        _("Updating Search Folders for '%s' : %s"),
        display_name, folder_name);

    g_object_unref (store);
    g_free (folder_name);

    return description;
}

static void
vfolder_adduri_exec (struct _adduri_msg *m,
                     GCancellable *cancellable,
                     GError **error)
{
    GList *l;
    EMailSession *session;
    CamelFolder *folder = NULL;
    MailFolderCache *folder_cache;

    if (vfolder_shutdown)
        return;

    session = e_mail_backend_get_session (m->backend);
    folder_cache = e_mail_session_get_folder_cache (session);

    /* we dont try lookup the cache if we are removing it, its no longer there */

    if (!m->remove &&
        !mail_folder_cache_get_folder_from_uri (folder_cache, m->uri, &folder)) {
        g_warning (
            "Folder '%s' disappeared while I was "
            "adding/removing it to/from my vfolder", m->uri);
        return;
    }

    if (folder == NULL)
        folder = e_mail_session_uri_to_folder_sync (
            session, m->uri, 0, cancellable, error);

    if (folder != NULL) {
        l = m->folders;
        while (l && !vfolder_shutdown) {
            if (m->remove)
                camel_vee_folder_remove_folder (
                    CAMEL_VEE_FOLDER (l->data), folder);
            else
                camel_vee_folder_add_folder ((CamelVeeFolder *) l->data, folder);
            l = l->next;
        }
        g_object_unref (folder);
    }
}

static void
vfolder_adduri_done (struct _adduri_msg *m)
{
}

static void
vfolder_adduri_free (struct _adduri_msg *m)
{
    g_object_unref (m->backend);
    g_list_foreach (m->folders, (GFunc) g_object_unref, NULL);
    g_list_free (m->folders);
    g_free (m->uri);
}

static MailMsgInfo vfolder_adduri_info = {
    sizeof (struct _adduri_msg),
    (MailMsgDescFunc) vfolder_adduri_desc,
    (MailMsgExecFunc) vfolder_adduri_exec,
    (MailMsgDoneFunc) vfolder_adduri_done,
    (MailMsgFreeFunc) vfolder_adduri_free
};

/* uri should be a camel uri */
static gint
vfolder_adduri (EMailBackend *backend,
                const gchar *uri,
                GList *folders,
                gint remove)
{
    struct _adduri_msg *m;
    gint id;

    m = mail_msg_new (&vfolder_adduri_info);
    m->backend = g_object_ref (backend);
    m->folders = folders;
    m->uri = g_strdup (uri);
    m->remove = remove;

    id = m->base.seq;
    mail_msg_slow_ordered_push (m);

    return id;
}

/* ********************************************************************** */

/* so special we never use it */
static gint
folder_is_spethal (CamelStore *store,
                   const gchar *folder_name)
{
    /* This is a bit of a hack, but really the only way it can be done
     * at the moment. */

    if (store->flags & CAMEL_STORE_VTRASH)
        if (g_strcmp0 (folder_name, CAMEL_VTRASH_NAME) == 0)
            return TRUE;

    if (store->flags & CAMEL_STORE_VJUNK)
        if (g_strcmp0 (folder_name, CAMEL_VJUNK_NAME) == 0)
            return TRUE;

    return FALSE;
}

/**
 * mail_vfolder_add_folder:
 * @backend: an #EMailBackend
 * @store: a #CamelStore
 * @folder: a folder name
 * @remove: whether the folder should be removed or added
 *
 * Called when a new folder becomes (un)available.  If @store is not a
 * CamelVeeStore, the folder is added/removed from the list of cached source
 * folders.  Then each vfolder rule is checked to see if the specified folder
 * matches a source of the rule.  It builds a list of vfolders that use (or
 * would use) the specified folder as a source.  It then adds (or removes)
 * this folder to (from) those vfolders via camel_vee_folder_add/
 * remove_folder() but does not modify the actual filters or write changes
 * to disk.
 *
 * NOTE: This function must be called from the main thread.
 */
static void
mail_vfolder_add_folder (EMailBackend *backend,
                         CamelStore *store,
                         const gchar *folder_name,
                         gint remove)
{
    EMailSession *session;
    EFilterRule *rule;
    const gchar *source;
    CamelVeeFolder *vf;
    CamelProvider *provider;
    GList *folders = NULL;
    gint remote;
    gchar *uri;

    session = e_mail_backend_get_session (backend);

    provider = camel_service_get_provider (CAMEL_SERVICE (store));
    remote = (provider->flags & CAMEL_PROVIDER_IS_REMOTE) != 0;

    if (folder_is_spethal (store, folder_name))
        return;

    g_return_if_fail (mail_in_main_thread ());

    uri = e_mail_folder_uri_build (store, folder_name);

    G_LOCK (vfolder);

    if (context == NULL)
        goto done;

    rule = NULL;
    while ((rule = e_rule_context_next_rule ((ERuleContext *) context, rule, NULL))) {
        gint found = FALSE;

        if (!rule->name) {
            d(printf("invalid rule (%p): rule->name is set to NULL\n", rule));
            continue;
        }
        /* Don't auto-add any sent/drafts folders etc,
         * they must be explictly listed as a source. */
        if (rule->source
            && !CAMEL_IS_VEE_STORE (store)
            && ((((EMVFolderRule *) rule)->with ==
                EM_VFOLDER_RULE_WITH_LOCAL && !remote)
            || (((EMVFolderRule *) rule)->with ==
                EM_VFOLDER_RULE_WITH_REMOTE_ACTIVE && remote)
            || (((EMVFolderRule *) rule)->with ==
                EM_VFOLDER_RULE_WITH_LOCAL_REMOTE_ACTIVE)))
            found = TRUE;

        source = NULL;
        while (!found && (source = em_vfolder_rule_next_source (
                (EMVFolderRule *) rule, source))) {
            found = e_mail_folder_uri_equal (
                CAMEL_SESSION (session), uri, source);
        }

        if (found) {
            vf = g_hash_table_lookup (vfolder_hash, rule->name);
            if (!vf) {
                g_warning ("vf is NULL for %s\n", rule->name);
                continue;
            }
            g_object_ref (vf);
            folders = g_list_prepend (folders, vf);
        }
    }

done:
    G_UNLOCK (vfolder);

    if (folders != NULL)
        vfolder_adduri (backend, uri, folders, remove);

    g_free (uri);
}

/**
 * mail_vfolder_delete_folder:
 * @backend: an #EMailBackend
 * @store: a #CamelStore
 * @folder_name: a folder name
 *
 * Looks through all vfolder rules to see if @folder_name is listed as a
 * source for any vfolder rules.  If the folder is found in the source for
 * any rule, it is removed and the user is alerted to the fact that the
 * vfolder rules have been updated.  The new vfolder rules are written
 * to disk.
 *
 * XXX: It doesn't appear that the changes to the vfolder rules are sent
 * down to the camel level, however. So the actual vfolders will not change
 * behavior until evolution is restarted (?)
 *
 * NOTE: This function must be called from the main thread.
 */
static void
mail_vfolder_delete_folder (EMailBackend *backend,
                            CamelStore *store,
                            const gchar *folder_name)
{
    ERuleContext *rule_context;
    EFilterRule *rule;
    EMailSession *session;
    const gchar *source;
    CamelVeeFolder *vf;
    GString *changed;
    guint changed_count;
    gchar *uri;

    g_return_if_fail (E_IS_MAIL_BACKEND (backend));
    g_return_if_fail (CAMEL_IS_STORE (store));
    g_return_if_fail (folder_name != NULL);

    if (folder_is_spethal (store, folder_name))
        return;

    d(printf ("Deleting uri to check: %s\n", uri));

    g_return_if_fail (mail_in_main_thread ());

    session = e_mail_backend_get_session (backend);
    uri = e_mail_folder_uri_build (store, folder_name);

    changed_count = 0;
    changed = g_string_new ("");

    G_LOCK (vfolder);

    if (context == NULL)
        goto done;

    rule_context = E_RULE_CONTEXT (context);

    /* see if any rules directly reference this removed uri */
    rule = NULL;
    while ((rule = e_rule_context_next_rule (rule_context, rule, NULL))) {
        EMVFolderRule *vf_rule = EM_VFOLDER_RULE (rule);

        if (!rule->name)
            continue;

        source = NULL;
        while ((source = em_vfolder_rule_next_source (vf_rule, source))) {
            /* Remove all sources that match, ignore changed events though
             * because the adduri call above does the work async */
            if (e_mail_folder_uri_equal (CAMEL_SESSION (session), uri, source)) {
                vf = g_hash_table_lookup (
                    vfolder_hash, rule->name);

                if (!vf) {
                    g_warning ("vf is NULL for %s\n", rule->name);
                    continue;
                }

                g_signal_handlers_disconnect_matched (
                    rule, G_SIGNAL_MATCH_FUNC |
                    G_SIGNAL_MATCH_DATA, 0, 0, NULL,
                    rule_changed, vf);

                em_vfolder_rule_remove_source (vf_rule, source);

                g_signal_connect (
                    rule, "changed",
                    G_CALLBACK (rule_changed), vf);

                if (changed_count == 0) {
                    g_string_append (changed, rule->name);
                } else {
                    if (changed_count == 1) {
                        g_string_prepend (changed, "    ");
                        g_string_append (changed, "\n");
                    }
                    g_string_append_printf (
                        changed, "    %s\n",
                        rule->name);
                }

                changed_count++;
                source = NULL;
            }
        }
    }

done:
    G_UNLOCK (vfolder);

    if (changed_count > 0) {
        const gchar *config_dir;
        gchar *user, *info;

        info = g_strdup_printf (ngettext (
            /* Translators: The first %s is name of the affected
             * search folder(s), the second %s is the URI of the
             * removed folder. For more than one search folder is
             * each of them on a separate line, with four spaces
             * in front of its name, without quotes. */
            "The Search Folder \"%s\" has been modified to "
            "account for the deleted folder\n\"%s\".",
            "The following Search Folders\n%s have been modified "
            "to account for the deleted folder\n\"%s\".",
            changed_count), changed->str, uri);
        e_mail_backend_submit_alert (
            backend, "mail:vfolder-updated", info, NULL);
        g_free (info);

        config_dir = mail_session_get_config_dir ();
        user = g_build_filename (config_dir, "vfolders.xml", NULL);
        e_rule_context_save ((ERuleContext *) context, user);
        g_free (user);
    }

    g_string_free (changed, TRUE);

    g_free (uri);
}

/* called when a uri is renamed in a store */
static void
mail_vfolder_rename_folder (CamelStore *store,
                            const gchar *old_folder_name,
                            const gchar *new_folder_name)
{
    ERuleContext *rule_context;
    EFilterRule *rule;
    const gchar *source;
    CamelVeeFolder *vf;
    CamelSession *session;
    gint changed = 0;
    gchar *old_uri;
    gchar *new_uri;

    d(printf("vfolder rename uri: %s to %s\n", cfrom, cto));

    if (context == NULL)
        return;

    if (folder_is_spethal (store, old_folder_name))
        return;

    if (folder_is_spethal (store, new_folder_name))
        return;

    g_return_if_fail (mail_in_main_thread ());

    session = camel_service_get_session (CAMEL_SERVICE (store));

    old_uri = e_mail_folder_uri_build (store, old_folder_name);
    new_uri = e_mail_folder_uri_build (store, new_folder_name);

    G_LOCK (vfolder);

    rule_context = E_RULE_CONTEXT (context);

    /* see if any rules directly reference this removed uri */
    rule = NULL;
    while ((rule = e_rule_context_next_rule (rule_context, rule, NULL))) {
        EMVFolderRule *vf_rule = EM_VFOLDER_RULE (rule);

        source = NULL;
        while ((source = em_vfolder_rule_next_source (vf_rule, source))) {
            /* Remove all sources that match, ignore changed events though
             * because the adduri call above does the work async */
            if (e_mail_folder_uri_equal (session, old_uri, source)) {
                vf = g_hash_table_lookup (vfolder_hash, rule->name);
                if (!vf) {
                    g_warning ("vf is NULL for %s\n", rule->name);
                    continue;
                }

                g_signal_handlers_disconnect_matched (
                    rule, G_SIGNAL_MATCH_FUNC |
                    G_SIGNAL_MATCH_DATA, 0, 0, NULL,
                    rule_changed, vf);

                em_vfolder_rule_remove_source (vf_rule, source);
                em_vfolder_rule_add_source (vf_rule, new_uri);

                g_signal_connect (
                    vf_rule, "changed",
                    G_CALLBACK (rule_changed), vf);

                changed++;
                source = NULL;
            }
        }
    }

    G_UNLOCK (vfolder);

    if (changed) {
        const gchar *config_dir;
        gchar *user;

        d(printf("Vfolders updated from renamed folder\n"));
        config_dir = mail_session_get_config_dir ();
        user = g_build_filename (config_dir, "vfolders.xml", NULL);
        e_rule_context_save ((ERuleContext *) context, user);
        g_free (user);
    }

    g_free (old_uri);
    g_free (new_uri);
}

/* ********************************************************************** */

static void context_rule_added (ERuleContext *ctx, EFilterRule *rule);

static void
rule_add_sources (EMailSession *session,
                  GQueue *queue,
                  GList **sources_folderp,
                  GList **sources_urip)
{
    GList *sources_folder = *sources_folderp;
    GList *sources_uri = *sources_urip;
    MailFolderCache *folder_cache;
    CamelFolder *newfolder;
    GList *head, *link;

    folder_cache = e_mail_session_get_folder_cache (session);

    head = g_queue_peek_head_link (queue);
    for (link = head; link != NULL; link = g_list_next (link)) {
        const gchar *uri = link->data;

        if (mail_folder_cache_get_folder_from_uri (
            folder_cache, uri, &newfolder)) {
            if (newfolder)
                sources_folder = g_list_append (
                    sources_folder, newfolder);
            else
                sources_uri = g_list_append (
                    sources_uri, g_strdup (uri));
        }
    }

    *sources_folderp = sources_folder;
    *sources_urip = sources_uri;
}

static void
rule_changed (EFilterRule *rule,
              CamelFolder *folder)
{
    EMailBackend *backend;
    EMailSession *session;
    CamelService *service;
    GList *sources_uri = NULL;
    GList *sources_folder = NULL;
    GString *query;
    const gchar *full_name;

    full_name = camel_folder_get_full_name (folder);
    backend = em_vfolder_rule_get_backend (EM_VFOLDER_RULE (rule));
    session = e_mail_backend_get_session (backend);

    service = camel_session_get_service (
        CAMEL_SESSION (session), E_MAIL_SESSION_VFOLDER_UID);
    g_return_if_fail (CAMEL_IS_SERVICE (service));

    /* if the folder has changed name, then add it, then remove the old manually */
    if (strcmp (full_name, rule->name) != 0) {
        gchar *oldname;

        gpointer key;
        gpointer oldfolder;

        G_LOCK (vfolder);
        d(printf("Changing folder name in hash table to '%s'\n", rule->name));
        if (g_hash_table_lookup_extended (vfolder_hash, full_name, &key, &oldfolder)) {
            g_hash_table_remove (vfolder_hash, key);
            g_free (key);
            g_hash_table_insert (vfolder_hash, g_strdup (rule->name), folder);
            G_UNLOCK (vfolder);
        } else {
            G_UNLOCK (vfolder);
            g_warning("couldn't find a vfolder rule in our table? %s", full_name);
        }

        oldname = g_strdup (full_name);
        /* FIXME Not passing a GCancellable or GError. */
        camel_store_rename_folder_sync (
            CAMEL_STORE (service),
            oldname, rule->name, NULL, NULL);
        g_free (oldname);
    }

    d(printf("Filter rule changed? for folder '%s'!!\n", folder->name));

    /* find any (currently available) folders, and add them to the ones to open */
    rule_add_sources (
        session, &((EMVFolderRule *) rule)->sources,
        &sources_folder, &sources_uri);

    G_LOCK (vfolder);

    if (((EMVFolderRule *) rule)->with ==
            EM_VFOLDER_RULE_WITH_LOCAL ||
            ((EMVFolderRule *) rule)->with ==
            EM_VFOLDER_RULE_WITH_LOCAL_REMOTE_ACTIVE) {

        MailFolderCache *cache;
        GQueue queue = G_QUEUE_INIT;

        cache = e_mail_session_get_folder_cache (session);
        mail_folder_cache_get_local_folder_uris (cache, &queue);

        rule_add_sources (
            session, &queue, &sources_folder, &sources_uri);

        while (!g_queue_is_empty (&queue))
            g_free (g_queue_pop_head (&queue));
    }

    if (((EMVFolderRule *) rule)->with ==
            EM_VFOLDER_RULE_WITH_REMOTE_ACTIVE ||
            ((EMVFolderRule *) rule)->with ==
            EM_VFOLDER_RULE_WITH_LOCAL_REMOTE_ACTIVE) {

        MailFolderCache *cache;
        GQueue queue = G_QUEUE_INIT;

        cache = e_mail_session_get_folder_cache (session);
        mail_folder_cache_get_remote_folder_uris (cache, &queue);

        rule_add_sources (
            session, &queue, &sources_folder, &sources_uri);

        while (!g_queue_is_empty (&queue))
            g_free (g_queue_pop_head (&queue));
    }

    G_UNLOCK (vfolder);

    query = g_string_new("");
    e_filter_rule_build_code (rule, query);

    vfolder_setup (session, folder, query->str, sources_uri, sources_folder);

    g_string_free (query, TRUE);
}

static void
context_rule_added (ERuleContext *ctx,
                    EFilterRule *rule)
{
    EMailBackend *backend;
    EMailSession *session;
    CamelFolder *folder;
    CamelService *service;

    d(printf("rule added: %s\n", rule->name));

    backend = em_vfolder_rule_get_backend (EM_VFOLDER_RULE (rule));
    session = e_mail_backend_get_session (backend);

    service = camel_session_get_service (
        CAMEL_SESSION (session), E_MAIL_SESSION_VFOLDER_UID);
    g_return_if_fail (CAMEL_IS_SERVICE (service));

    /* this always runs quickly */
    /* FIXME Not passing a GCancellable or GError. */
    folder = camel_store_get_folder_sync (
        CAMEL_STORE (service), rule->name, 0, NULL, NULL);
    if (folder) {
        g_signal_connect (rule, "changed", G_CALLBACK(rule_changed), folder);

        G_LOCK (vfolder);
        g_hash_table_insert (vfolder_hash, g_strdup (rule->name), folder);
        G_UNLOCK (vfolder);

        rule_changed (rule, folder);
    }
}

static void
context_rule_removed (ERuleContext *ctx,
                      EFilterRule *rule)
{
    EMailBackend *backend;
    EMailSession *session;
    CamelService *service;
    gpointer key, folder = NULL;

    d(printf("rule removed; %s\n", rule->name));

    backend = em_vfolder_rule_get_backend (EM_VFOLDER_RULE (rule));
    session = e_mail_backend_get_session (backend);

    service = camel_session_get_service (
        CAMEL_SESSION (session), E_MAIL_SESSION_VFOLDER_UID);
    g_return_if_fail (CAMEL_IS_SERVICE (service));

    /* TODO: remove from folder info cache? */

    G_LOCK (vfolder);
    if (g_hash_table_lookup_extended (vfolder_hash, rule->name, &key, &folder)) {
        g_hash_table_remove (vfolder_hash, key);
        g_free (key);
    }
    G_UNLOCK (vfolder);

    /* FIXME Not passing a GCancellable  or GError. */
    camel_store_delete_folder_sync (
        CAMEL_STORE (service), rule->name, NULL, NULL);
    /* this must be unref'd after its deleted */
    if (folder)
        g_object_unref ((CamelFolder *) folder);
}

static void
store_folder_deleted_cb (CamelStore *store,
                         CamelFolderInfo *info)
{
    EFilterRule *rule;
    gchar *user;

    d(printf("Folder deleted: %s\n", info->name));
    store = store;

    /* Warning not thread safe, but might be enough */

    G_LOCK (vfolder);

    /* delete it from our list */
    rule = e_rule_context_find_rule ((ERuleContext *) context, info->full_name, NULL);
    if (rule) {
        const gchar *config_dir;

        /* We need to stop listening to removed events,
         * otherwise we'll try and remove it again. */
        g_signal_handlers_disconnect_matched (
            context, G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA,
            0, 0, NULL, context_rule_removed, context);
        e_rule_context_remove_rule ((ERuleContext *) context, rule);
        g_object_unref (rule);
        g_signal_connect (
            context, "rule_removed",
            G_CALLBACK (context_rule_removed), context);

        config_dir = mail_session_get_config_dir ();
        user = g_build_filename (config_dir, "vfolders.xml", NULL);
        e_rule_context_save ((ERuleContext *) context, user);
        g_free (user);
    } else {
        g_warning (
            "Cannot find rule for deleted vfolder '%s'",
            info->display_name);
    }

    G_UNLOCK (vfolder);
}

static void
store_folder_renamed_cb (CamelStore *store,
                         const gchar *old_name,
                         CamelFolderInfo *info)
{
    EFilterRule *rule;
    gchar *user;

    gpointer key, folder;

    /* This should be more-or-less thread-safe */

    d(printf("Folder renamed to '%s' from '%s'\n", info->full_name, old_name));

    /* Folder is already renamed? */
    G_LOCK (vfolder);
    d(printf("Changing folder name in hash table to '%s'\n", info->full_name));
    if (g_hash_table_lookup_extended (vfolder_hash, old_name, &key, &folder)) {
        const gchar *config_dir;

        g_hash_table_remove (vfolder_hash, key);
        g_free (key);
        g_hash_table_insert (vfolder_hash, g_strdup (info->full_name), folder);

        rule = e_rule_context_find_rule ((ERuleContext *) context, old_name, NULL);
        if (!rule) {
            G_UNLOCK (vfolder);
            g_warning ("Rule shouldn't be NULL\n");
            return;
        }

        g_signal_handlers_disconnect_matched (
            rule, G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA,
            0, 0, NULL, rule_changed, folder);
        e_filter_rule_set_name (rule, info->full_name);
        g_signal_connect (rule, "changed", G_CALLBACK(rule_changed), folder);

        config_dir = mail_session_get_config_dir ();
        user = g_build_filename (config_dir, "vfolders.xml", NULL);
        e_rule_context_save ((ERuleContext *) context, user);
        g_free (user);

        G_UNLOCK (vfolder);
    } else {
        G_UNLOCK (vfolder);
        g_warning("couldn't find a vfolder rule in our table? %s", info->full_name);
    }
}

static void
folder_available_cb (MailFolderCache *cache,
                     CamelStore *store,
                     const gchar *folder_name,
                     EMailBackend *backend)
{
    mail_vfolder_add_folder (backend, store, folder_name, FALSE);
}

static void
folder_unavailable_cb (MailFolderCache *cache,
                       CamelStore *store,
                       const gchar *folder_name,
                       EMailBackend *backend)
{
    mail_vfolder_add_folder (backend, store, folder_name, TRUE);
}

static void
folder_deleted_cb (MailFolderCache *cache,
                   CamelStore *store,
                   const gchar *folder_name,
                   EMailBackend *backend)
{
    mail_vfolder_delete_folder (backend, store, folder_name);
}

static void
folder_renamed_cb (MailFolderCache *cache,
                   CamelStore *store,
                   const gchar *old_folder_name,
                   const gchar *new_folder_name,
                   gpointer user_data)
{
    mail_vfolder_rename_folder (store, old_folder_name, new_folder_name);
}

void
vfolder_load_storage (EMailBackend *backend)
{
    /* lock for loading storage, it is safe to call it more than once */
    G_LOCK_DEFINE_STATIC (vfolder_hash);

    CamelStore *vfolder_store;
    const gchar *config_dir;
    gchar *user;
    EFilterRule *rule;
    MailFolderCache *folder_cache;
    EMailSession *session;
    gchar *xmlfile;
    GSettings *settings;

    g_return_if_fail (E_IS_MAIL_BACKEND (backend));

    G_LOCK (vfolder_hash);

    if (vfolder_hash) {
        /* we have already initialized */
        G_UNLOCK (vfolder_hash);
        return;
    }

    vfolder_hash = g_hash_table_new (g_str_hash, g_str_equal);

    G_UNLOCK (vfolder_hash);

    config_dir = mail_session_get_config_dir ();
    session = e_mail_backend_get_session (backend);
    vfolder_store = e_mail_session_get_vfolder_store (session);

    g_signal_connect (
        vfolder_store, "folder-deleted",
        G_CALLBACK (store_folder_deleted_cb), backend);

    g_signal_connect (
        vfolder_store, "folder-renamed",
        G_CALLBACK (store_folder_renamed_cb), NULL);

    /* load our rules */
    user = g_build_filename (config_dir, "vfolders.xml", NULL);
    context = em_vfolder_context_new (backend);

    xmlfile = g_build_filename (EVOLUTION_PRIVDATADIR, "vfoldertypes.xml", NULL);
    if (e_rule_context_load ((ERuleContext *) context,
                   xmlfile, user) != 0) {
        g_warning("cannot load vfolders: %s\n", ((ERuleContext *)context)->error);
    }
    g_free (xmlfile);
    g_free (user);

    g_signal_connect (
        context, "rule_added",
        G_CALLBACK (context_rule_added), context);
    g_signal_connect (
        context, "rule_removed",
        G_CALLBACK (context_rule_removed), context);

    /* and setup the rules we have */
    rule = NULL;
    while ((rule = e_rule_context_next_rule ((ERuleContext *) context, rule, NULL))) {
        if (rule->name) {
            d(printf("rule added: %s\n", rule->name));
            context_rule_added ((ERuleContext *) context, rule);
        } else {
            d(printf("invalid rule (%p) encountered: rule->name is NULL\n", rule));
        }
    }

    /* reenable the feature if required */
    settings = g_settings_new ("org.gnome.evolution.mail");
    g_settings_set_boolean (settings, "enable-vfolders", TRUE);
    g_object_unref (settings);

    folder_cache = e_mail_session_get_folder_cache (session);

    g_signal_connect (
        folder_cache, "folder-available",
        G_CALLBACK (folder_available_cb), backend);
    g_signal_connect (
        folder_cache, "folder-unavailable",
        G_CALLBACK (folder_unavailable_cb), backend);
    g_signal_connect (
        folder_cache, "folder-deleted",
        G_CALLBACK (folder_deleted_cb), backend);
    g_signal_connect (
        folder_cache, "folder-renamed",
        G_CALLBACK (folder_renamed_cb), NULL);
}

void
vfolder_edit (EShellView *shell_view)
{
    EShellBackend *shell_backend;
    EShellWindow *shell_window;
    EMailBackend *backend;
    GtkWidget *dialog;
    const gchar *config_dir;
    gchar *filename;

    g_return_if_fail (E_IS_SHELL_VIEW (shell_view));

    shell_backend = e_shell_view_get_shell_backend (shell_view);
    shell_window = e_shell_view_get_shell_window (shell_view);

    config_dir = e_shell_backend_get_config_dir (shell_backend);
    filename = g_build_filename (config_dir, "vfolders.xml", NULL);

    backend = E_MAIL_BACKEND (shell_backend);

    vfolder_load_storage (backend);

    dialog = em_vfolder_editor_new (context);
    gtk_window_set_title (
        GTK_WINDOW (dialog), _("Search Folders"));
    gtk_window_set_transient_for (
        GTK_WINDOW (dialog), GTK_WINDOW (shell_window));

    switch (gtk_dialog_run (GTK_DIALOG (dialog))) {
        case GTK_RESPONSE_OK:
            e_rule_context_save ((ERuleContext *) context, filename);
            break;
        default:
            e_rule_context_revert ((ERuleContext *) context, filename);
            break;
    }

    gtk_widget_destroy (dialog);
}

static void
vfolder_edit_response_cb (GtkWidget *dialog,
                          gint response_id,
                          gpointer user_data)
{
    if (response_id == GTK_RESPONSE_OK) {
        EFilterRule *rule = g_object_get_data (G_OBJECT (dialog), "vfolder-rule");
        EFilterRule *newrule = g_object_get_data (G_OBJECT (dialog), "vfolder-newrule");
        const gchar *config_dir;
        gchar *user;

        e_filter_rule_copy (rule, newrule);
        config_dir = mail_session_get_config_dir ();
        user = g_build_filename (config_dir, "vfolders.xml", NULL);
        e_rule_context_save ((ERuleContext *) context, user);
        g_free (user);
    }

    gtk_widget_destroy (dialog);
}

void
vfolder_edit_rule (EMailBackend *backend,
                   const gchar *folder_uri)
{
    GtkWidget *dialog;
    GtkWidget *widget;
    GtkWidget *container;
    EFilterRule *rule = NULL;
    EFilterRule *newrule;
    EMailSession *session;
    gchar *folder_name = NULL;

    g_return_if_fail (E_IS_MAIL_BACKEND (backend));
    g_return_if_fail (folder_uri != NULL);

    session = e_mail_backend_get_session (backend);

    e_mail_folder_uri_parse (
        CAMEL_SESSION (session), folder_uri,
        NULL, &folder_name, NULL);

    if (folder_name != NULL) {
        rule = e_rule_context_find_rule (
            (ERuleContext *) context, folder_name, NULL);
        g_free (folder_name);
    }

    if (rule == NULL) {
        /* TODO: we should probably just create it ... */
        e_mail_backend_submit_alert (
            backend, "mail:vfolder-notexist", folder_uri, NULL);
        return;
    }

    g_object_ref (rule);
    newrule = e_filter_rule_clone (rule);

    dialog = gtk_dialog_new_with_buttons (
        _("Edit Search Folder"), NULL,
        GTK_DIALOG_DESTROY_WITH_PARENT,
        GTK_STOCK_CANCEL, GTK_RESPONSE_CANCEL,
        GTK_STOCK_OK, GTK_RESPONSE_OK, NULL);

    gtk_container_set_border_width (GTK_CONTAINER (dialog), 6);
    gtk_dialog_set_default_response (GTK_DIALOG (dialog), GTK_RESPONSE_OK);

    gtk_window_set_default_size (GTK_WINDOW (dialog), 500, 500);
    gtk_window_set_resizable (GTK_WINDOW (dialog), TRUE);

    container = gtk_dialog_get_content_area (GTK_DIALOG (dialog));
    gtk_box_set_spacing (GTK_BOX (container), 6);

    widget = e_filter_rule_get_widget (
        (EFilterRule *) newrule, (ERuleContext *) context);
    gtk_box_pack_start (GTK_BOX (container), widget, TRUE, TRUE, 0);
    gtk_widget_show (widget);

    g_object_set_data_full (G_OBJECT (dialog), "vfolder-rule", rule, g_object_unref);
    g_object_set_data_full (G_OBJECT (dialog), "vfolder-newrule", newrule, g_object_unref);

    g_signal_connect (dialog, "response", G_CALLBACK (vfolder_edit_response_cb), NULL);

    gtk_widget_show (dialog);
}

static void
new_rule_clicked (GtkWidget *w,
                  gint button,
                  gpointer data)
{
    if (button == GTK_RESPONSE_OK) {
        const gchar *config_dir;
        gchar *user;
        EFilterRule *rule = g_object_get_data((GObject *)w, "rule");
        EAlert *alert = NULL;

        if (!e_filter_rule_validate (rule, &alert)) {
            e_alert_run_dialog (GTK_WINDOW (w), alert);
            g_object_unref (alert);
            return;
        }

        if (e_rule_context_find_rule (
            (ERuleContext *) context, rule->name, rule->source)) {
            e_alert_run_dialog_for_args (
                GTK_WINDOW (w), "mail:vfolder-notunique",
                rule->name, NULL);
            return;
        }

        g_object_ref (rule);
        e_rule_context_add_rule ((ERuleContext *) context, rule);
        config_dir = mail_session_get_config_dir ();
        user = g_build_filename (config_dir, "vfolders.xml", NULL);
        e_rule_context_save ((ERuleContext *) context, user);
        g_free (user);
    }

    gtk_widget_destroy (w);
}

static void
new_rule_changed_cb (EFilterRule *rule,
                     GtkDialog *dialog)
{
    g_return_if_fail (rule != NULL);
    g_return_if_fail (dialog != NULL);

    gtk_dialog_set_response_sensitive (
        dialog, GTK_RESPONSE_OK, rule->parts != NULL);
}

/* clones a filter/search rule into a matching vfolder rule
 * (assuming the same system definitions) */
EFilterRule *
vfolder_clone_rule (EMailBackend *backend,
                    EFilterRule *in)
{
    EFilterRule *rule;
    xmlNodePtr xml;

    rule = em_vfolder_rule_new (backend);

    xml = e_filter_rule_xml_encode (in);
    e_filter_rule_xml_decode (rule, xml, (ERuleContext *) context);
    xmlFreeNodeList (xml);

    return rule;
}

/* adds a rule with a gui */
void
vfolder_gui_add_rule (EMVFolderRule *rule)
{
    GtkWidget *w;
    GtkDialog *gd;
    GtkWidget *container;

    w = e_filter_rule_get_widget ((EFilterRule *) rule, (ERuleContext *) context);

    gd = (GtkDialog *) gtk_dialog_new_with_buttons (
        _("New Search Folder"),
        NULL,
        GTK_DIALOG_DESTROY_WITH_PARENT,
        GTK_STOCK_CANCEL, GTK_RESPONSE_CANCEL,
        GTK_STOCK_OK, GTK_RESPONSE_OK, NULL);

    gtk_dialog_set_default_response (gd, GTK_RESPONSE_OK);
    gtk_container_set_border_width (GTK_CONTAINER (gd), 6);

    container = gtk_dialog_get_content_area (gd);
    gtk_box_set_spacing (GTK_BOX (container), 6);

    g_object_set (gd, "resizable", TRUE, NULL);
    gtk_window_set_default_size (GTK_WINDOW (gd), 500, 500);
    gtk_box_pack_start (GTK_BOX (container), w, TRUE, TRUE, 0);
    gtk_widget_show ((GtkWidget *) gd);
    g_object_set_data_full(G_OBJECT(gd), "rule", rule, (GDestroyNotify)g_object_unref);
    g_signal_connect (rule, "changed", G_CALLBACK (new_rule_changed_cb), gd);
    new_rule_changed_cb ((EFilterRule *) rule, gd);
    g_signal_connect (gd, "response", G_CALLBACK(new_rule_clicked), NULL);
    gtk_widget_show ((GtkWidget *) gd);
}

void
vfolder_gui_add_from_message (EMailSession *session,
                              CamelMimeMessage *message,
                              gint flags,
                              CamelFolder *folder)
{
    EMVFolderRule *rule;

    g_return_if_fail (CAMEL_IS_MIME_MESSAGE (message));

    rule = (EMVFolderRule *) em_vfolder_rule_from_message (
        context, message, flags, folder);
    vfolder_gui_add_rule (rule);
}

void
vfolder_gui_add_from_address (EMailSession *session,
                              CamelInternetAddress *addr,
                              gint flags,
                              CamelFolder *folder)
{
    EMVFolderRule *rule;

    g_return_if_fail (addr != NULL);

    rule = (EMVFolderRule *) em_vfolder_rule_from_address (
        context, addr, flags, folder);
    vfolder_gui_add_rule (rule);
}

static void
vfolder_foreach_cb (gpointer key,
                    gpointer data,
                    gpointer user_data)
{
    CamelFolder *folder = CAMEL_FOLDER (data);

    if (folder)
        g_object_unref (folder);

    g_free (key);
}

void
mail_vfolder_shutdown (void)
{
    vfolder_shutdown = 1;

    if (vfolder_hash) {
        g_hash_table_foreach (vfolder_hash, vfolder_foreach_cb, NULL);
        g_hash_table_destroy (vfolder_hash);
        vfolder_hash = NULL;
    }

    if (context) {
        g_object_unref (context);
        context = NULL;
    }
}