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)
 *
 */

#include <config.h>
#include <string.h>

#include <glib.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 "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"

#include "e-mail-local.h"
#include "e-mail-store.h"

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

static EMVFolderContext *context;   /* context remains open all time */
CamelStore *vfolder_store; /* the 1 static vfolder store */

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

static GList *source_folders_remote;    /* list of source folder uri's - remote ones */
static GList *source_folders_local; /* list of source folder uri's - local ones */
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;

    EMailSession *session;
    gchar *uri;
    GList *folders;
    gint remove;
};

static gchar *
vfolder_adduri_desc (struct _adduri_msg *m)
{
    gchar *euri, *desc = NULL;

    /* Yuck yuck.  Lookup the account name and use that to describe the path */
    /* We really need to normalise this across all of camel and evolution :-/ */
    euri = em_uri_from_camel (m->uri);
    if (euri) {
        CamelURL *url = camel_url_new (euri, NULL);

        if (url) {
            const gchar *loc = NULL;

            if (url->host && !strcmp(url->host, "local")
                && url->user && !strcmp(url->user, "local")) {
                loc = _("On This Computer");
            } else {
                gchar *uid;
                const EAccount *account;

                if (url->user == NULL)
                    uid = g_strdup (url->host);
                else
                    uid = g_strdup_printf("%s@%s", url->user, url->host);

                account = e_get_account_by_uid (uid);
                g_free (uid);
                if (account != NULL)
                    loc = account->name;
            }

            if (loc && url->path)
                desc = g_strdup_printf(_("Updating Search Folders for '%s:%s'"), loc, url->path);
            camel_url_free (url);
        }
        g_free (euri);
    }

    if (desc == NULL)
        desc = g_strdup_printf(_("Updating Search Folders for '%s'"), m->uri);

    return desc;
}

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

    if (vfolder_shutdown)
        return;

    folder_cache = e_mail_session_get_folder_cache (m->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/remove it to/from my vfolder", m->uri);
        return;
    }

    if (folder == NULL)
        folder = e_mail_session_uri_to_folder_sync (
            m->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->session);
    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 (EMailSession *session,
                const gchar *uri,
                GList *folders,
                gint remove)
{
    struct _adduri_msg *m;
    gint id;

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

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

    return id;
}

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

static GList *
mv_find_folder (GList *l, CamelStore *store, const gchar *uri)
{
    while (l) {
        if (camel_store_folder_uri_equal (store, l->data, uri))
            break;
        l = l->next;
    }
    return l;
}

/* uri is a camel uri */
static gint
uri_is_ignore (CamelStore *store, const gchar *uri)
{
    EAccountList *accounts;
    EAccount *account;
    EIterator *iter;
    const gchar *local_drafts_uri;
    const gchar *local_outbox_uri;
    const gchar *local_sent_uri;
    gint found = FALSE;

    local_drafts_uri = e_mail_local_get_folder_uri (E_MAIL_LOCAL_FOLDER_DRAFTS);
    local_outbox_uri = e_mail_local_get_folder_uri (E_MAIL_LOCAL_FOLDER_OUTBOX);
    local_sent_uri = e_mail_local_get_folder_uri (E_MAIL_LOCAL_FOLDER_SENT);

    d(printf("checking '%s' against:\n  %s\n  %s\n  %s\n", uri,
        local_outbox_uri,
        local_sent_uri,
        local_drafts_uri));

    found = camel_store_folder_uri_equal (store, local_outbox_uri, uri)
        || camel_store_folder_uri_equal (store, local_sent_uri, uri)
        || camel_store_folder_uri_equal (store, local_drafts_uri, uri);

    if (found)
        return found;

    accounts = e_get_account_list ();
    iter = e_list_get_iterator ((EList *) accounts);
    while (e_iterator_is_valid (iter)) {
        gchar *curi;

        account = (EAccount *) e_iterator_get (iter);

        d(printf("checking sent_folder_uri '%s' == '%s'\n",
             account->sent_folder_uri ? account->sent_folder_uri : "empty", uri));

        if (account->sent_folder_uri) {
            curi = em_uri_to_camel (account->sent_folder_uri);
            found = camel_store_folder_uri_equal (store, uri, curi);
            g_free (curi);
        }
        if (!found && account->drafts_folder_uri) {
            curi = em_uri_to_camel (account->drafts_folder_uri);
            found = camel_store_folder_uri_equal (store, uri, curi);
            g_free (curi);
        }

        if (found)
            break;

        e_iterator_next (iter);
    }

    g_object_unref (iter);

    return found;
}

/* so special we never use it */
static gint
uri_is_spethal (CamelStore *store, const gchar *uri)
{
    CamelURL *url;
    gint res;

    /* 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|CAMEL_STORE_VJUNK)) == 0)
        return FALSE;

    url = camel_url_new (uri, NULL);
    if (url == NULL)
        return TRUE;

    /* don't use strcasecmp here */
    if (url->fragment) {
        res = (((store->flags & CAMEL_STORE_VTRASH)
            && strcmp (url->fragment, CAMEL_VTRASH_NAME) == 0)
               || ((store->flags & CAMEL_STORE_VJUNK)
               && strcmp (url->fragment, CAMEL_VJUNK_NAME) == 0));
    } else {
        res = url->path
            && (((store->flags & CAMEL_STORE_VTRASH)
                 && strcmp(url->path, "/" CAMEL_VTRASH_NAME) == 0)
                || ((store->flags & CAMEL_STORE_VJUNK)
                && strcmp(url->path, "/" CAMEL_VJUNK_NAME) == 0));
    }

    camel_url_free (url);

    return res;
}

/**
 * mail_vfolder_add_uri:
 * @session: an #EMailSession
 * @store: a #CamelStore containing the uri
 * @curi: an email uri to be added/removed
 * @remove: Whether the uri should be removed or added
 *
 * Called when a new uri becomes (un)available.  If @store is not a
 * CamelVeeStore, the uri is added/removed from the list of cached source
 * folders.  Then each vfolder rule is checked to see if the specified uri
 * matches a source of the rule.  It builds a list of vfolders that use (or
 * would use) the specified uri as a source.  It then adds (or removes) this uri
 * 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_uri (EMailSession *session,
                      CamelStore *store,
                      const gchar *curi,
                      gint remove)
{
    EFilterRule *rule;
    const gchar *source;
    CamelVeeFolder *vf;
    GList *folders = NULL, *link;
    gint remote = (((CamelService *)store)->provider->flags & CAMEL_PROVIDER_IS_REMOTE) != 0;
    gint is_ignore;
    gchar *uri;

    uri = em_uri_from_camel (curi);
    if (uri_is_spethal (store, curi)) {
        g_free (uri);
        return;
    }

    g_return_if_fail (mail_in_main_thread ());

    is_ignore = uri_is_ignore (store, curi);

    G_LOCK (vfolder);

/*  d(printf("%s uri to check: %s\n", remove?"Removing":"Adding", uri)); */

    /* maintain the source folders lists for changed rules later on */
    if (CAMEL_IS_VEE_STORE (store)) {
        is_ignore = TRUE;
    } else if (remove) {
        if (remote) {
            if ((link = mv_find_folder (source_folders_remote, store, curi)) != NULL) {
                g_free (link->data);
                source_folders_remote = g_list_remove_link (source_folders_remote, link);
            }
        } else {
            if ((link = mv_find_folder (source_folders_local, store, curi)) != NULL) {
                g_free (link->data);
                source_folders_local = g_list_remove_link (source_folders_local, link);
            }
        }
    } else if (!is_ignore) {
        /* we ignore drafts/sent/outbox here */
        if (remote) {
            if (mv_find_folder (source_folders_remote, store, curi) == NULL)
                source_folders_remote = g_list_prepend (source_folders_remote, g_strdup (curi));
        } else {
            if (mv_find_folder (source_folders_local, store, curi) == NULL)
                source_folders_local = g_list_prepend (source_folders_local, g_strdup (curi));
        }
    }

    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;
        }
        /* dont auto-add any sent/drafts folders etc, they must be explictly listed as a source */
        if (rule->source
            && !is_ignore
            && ((((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))) {
            gchar *csource;
            csource = em_uri_to_camel (source);
            found = camel_store_folder_uri_equal (store, curi, csource);
            d(printf(found?" '%s' == '%s'?\n":" '%s' != '%s'\n", curi, csource));
            g_free (csource);
        }

        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 (session, curi, folders, remove);

    g_free (uri);
}

/**
 * mail_vfolder_uri_available:
 * @session: an #EMailSession
 * @store: a #CamelStore containing the uri
 * @uri: uri of a folder that became available
 *
 * Adds @uri to the list of folders searched if any vfolder source matches the
 * uri.  This function has a transient effect and does not permanently modify
 * the vfolder filter rules on disk.
 */
static void
mail_vfolder_notify_uri_available (EMailSession *session,
                                   CamelStore *store,
                                   const gchar *uri)
{
    mail_vfolder_add_uri (session, store, uri, FALSE);
}

/**
 * mail_vfolder_uri_available:
 * @session: an #EMailSession
 * @store: a #CamelStore containing the uri
 * @uri: uri of a folder that became unavailable
 *
 * Removes @uri from the list of folders searched if any vfolder source matches the
 * uri.  This function has a transient effect and does not permanently modify
 * the vfolder filter rules on disk.
 */
static void
mail_vfolder_notify_uri_unavailable (EMailSession *session,
                                     CamelStore *store,
                                     const gchar *uri)
{
    mail_vfolder_add_uri (session, store, uri, TRUE);
}

/**
 * mail_vfolder_delete_uri:
 * @backend: an #EMailBackend
 * @store: a #CamelStore containing the uri
 * @curi: an email uri that has been deleted
 *
 * Looks through all vfolder rules to see if @curi is listed as a source for any
 * vfolder rules.  If the uri 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_uri (EMailBackend *backend,
                         CamelStore *store,
                         const gchar *curi)
{
    EFilterRule *rule;
    const gchar *source;
    CamelVeeFolder *vf;
    GString *changed;
    guint changed_count;
    gchar *uri;
    GList *link;

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

    if (uri_is_spethal (store, curi))
        return;

    uri = em_uri_from_camel (curi);

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

    g_return_if_fail (mail_in_main_thread ());

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

    G_LOCK (vfolder);

    if (context == NULL)
        goto done;

    /* see if any rules directly reference this removed uri */
    rule = NULL;
    while ((rule = e_rule_context_next_rule ((ERuleContext *) context, rule, NULL))) {

        if (!rule->name) {
            d(printf("invalid rule (%p): rule->name is set to NULL\n", rule));
            continue;
        }

        source = NULL;
        while ((source = em_vfolder_rule_next_source ((EMVFolderRule *) rule, source))) {
            gchar *csource = em_uri_to_camel (source);

            /* Remove all sources that match, ignore changed events though
               because the adduri call above does the work async */
            if (camel_store_folder_uri_equal (store, curi, csource)) {
                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 ((EMVFolderRule *)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;
            }
            g_free (csource);
        }
    }

done:
    if ((link = mv_find_folder (source_folders_remote, store, curi)) != NULL) {
        g_free (link->data);
        source_folders_remote = g_list_remove_link (source_folders_remote, link);
    }

    if ((link = mv_find_folder (source_folders_local, store, curi)) != NULL) {
        g_free (link->data);
        source_folders_local = g_list_remove_link (source_folders_local, link);
    }

    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_uri (CamelStore *store, const gchar *cfrom, const gchar *cto)
{
    EFilterRule *rule;
    const gchar *source;
    CamelVeeFolder *vf;
    gint changed = 0;
    gchar *from, *to;

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

    if (context == NULL || uri_is_spethal (store, cfrom) || uri_is_spethal (store, cto))
        return;

    g_return_if_fail (mail_in_main_thread ());

    from = em_uri_from_camel (cfrom);
    to = em_uri_from_camel (cto);

    G_LOCK (vfolder);

    /* see if any rules directly reference this removed uri */
    rule = NULL;
    while ((rule = e_rule_context_next_rule ((ERuleContext *)context, rule, NULL))) {
        source = NULL;
        while ((source = em_vfolder_rule_next_source ((EMVFolderRule *)rule, source))) {
            gchar *csource = em_uri_to_camel (source);

            /* Remove all sources that match, ignore changed events though
               because the adduri call above does the work async */
            if (camel_store_folder_uri_equal (store, cfrom, csource)) {
                d(printf("Vfolder '%s' used '%s' ('%s') now uses '%s'\n", rule->name, source, from, to));
                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 ((EMVFolderRule *)rule, source);
                em_vfolder_rule_add_source ((EMVFolderRule *)rule, to);
                g_signal_connect(rule, "changed", G_CALLBACK(rule_changed), vf);
                changed++;
                source = NULL;
            }
            g_free (csource);
        }
    }

    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 (from);
    g_free (to);
}

GList *
mail_vfolder_get_sources_local (void)
{
    return source_folders_local;
}

GList *
mail_vfolder_get_sources_remote (void)
{
    return source_folders_remote;
}

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

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

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

    folder_cache = e_mail_session_get_folder_cache (session);

    while (l) {
        gchar *curi = em_uri_to_camel (l->data);

        if (mail_folder_cache_get_folder_from_uri (
            folder_cache, curi, &newfolder)) {
            if (newfolder)
                sources_folder = g_list_append (sources_folder, newfolder);
            else
                sources_uri = g_list_append (sources_uri, g_strdup (curi));
        }
        g_free (curi);
        l = l->next;
    }

    *sources_folderp = sources_folder;
    *sources_urip = sources_uri;
}

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

    full_name = camel_folder_get_full_name (folder);
    session = em_vfolder_rule_get_session (EM_VFOLDER_RULE (rule));

    /* 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 (
            vfolder_store, 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)
        rule_add_sources (
            session, source_folders_local,
            &sources_folder, &sources_uri);
    if (((EMVFolderRule *)rule)->with == EM_VFOLDER_RULE_WITH_REMOTE_ACTIVE || ((EMVFolderRule *)rule)->with == EM_VFOLDER_RULE_WITH_LOCAL_REMOTE_ACTIVE)
        rule_add_sources (
            session, source_folders_remote,
            &sources_folder, &sources_uri);
    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)
{
    CamelFolder *folder;

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

    /* this always runs quickly */
    /* FIXME Not passing a GCancellable or GError. */
    folder = camel_store_get_folder_sync (
        vfolder_store, 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)
{
    gpointer key, folder = NULL;

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

    /* 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 (
        vfolder_store, 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->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 *uri,
                     EMailSession *session)
{
    mail_vfolder_notify_uri_available (session, store, uri);
}

static void
folder_unavailable_cb (MailFolderCache *cache,
                       CamelStore *store,
                       const gchar *uri,
                       EMailSession *session)
{
    mail_vfolder_notify_uri_unavailable (session, store, uri);
}

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

static void
folder_renamed_cb (MailFolderCache *cache, CamelStore *store, const gchar *olduri, const gchar *newuri, gpointer user_data)
{
    mail_vfolder_rename_uri (store, olduri, newuri);
}

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);

    const gchar *data_dir;
    const gchar *config_dir;
    gchar *user, *storeuri;
    EFilterRule *rule;
    MailFolderCache *folder_cache;
    EMailSession *session;
    gchar *xmlfile;
    GConfClient *client;

    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);

    data_dir = mail_session_get_data_dir ();
    config_dir = mail_session_get_config_dir ();
    session = e_mail_backend_get_session (backend);

    /* first, create the vfolder store, and set it up */
    storeuri = g_strdup_printf("vfolder:%s/vfolder", data_dir);
    vfolder_store = camel_session_get_store (
        CAMEL_SESSION (session), storeuri, NULL);
    if (vfolder_store == NULL) {
        g_warning("Cannot open vfolder store - no vfolders available");
        return;
    }

    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);

    d(printf("got store '%s' = %p\n", storeuri, vfolder_store));

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

    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);

    /* load store to mail component */
    e_mail_store_add_by_uri (session, storeuri, _("Search Folders"));

    /* 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));
        }
    }

    g_free (storeuri);

    /* reenable the feature if required */
    client = gconf_client_get_default ();
    if (!gconf_client_get_bool (client, "/apps/evolution/mail/display/enable_vfolders", NULL))
        gconf_client_set_bool (client, "/apps/evolution/mail/display/enable_vfolders", TRUE, NULL);
    g_object_unref (client);

    folder_cache = e_mail_session_get_folder_cache (session);

    g_signal_connect (
        folder_cache, "folder-available",
        G_CALLBACK (folder_available_cb), session);
    g_signal_connect (
        folder_cache, "folder-unavailable",
        G_CALLBACK (folder_unavailable_cb), session);
    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_revert (void)
{
    const gchar *config_dir;
    gchar *user;

    d(printf("vfolder_revert\n"));
    config_dir = mail_session_get_config_dir ();
    user = g_build_filename (config_dir, "vfolders.xml", NULL);
    e_rule_context_revert ((ERuleContext *)context, user);
    g_free (user);
}

void
vfolder_edit (EShellView *shell_view)
{
    EShellBackend *shell_backend;
    EShellWindow *shell_window;
    EMailBackend *backend;
    EMailSession *session;
    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);
    session = e_mail_backend_get_session (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
edit_rule_response (GtkWidget *w, gint button, gpointer data)
{
    if (button == GTK_RESPONSE_OK) {
        const gchar *config_dir;
        gchar *user;
        EFilterRule *rule = g_object_get_data (G_OBJECT (w), "rule");
        EFilterRule *orig = g_object_get_data (G_OBJECT (w), "orig");

        e_filter_rule_copy (orig, 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);
}

void
vfolder_edit_rule (EMailBackend *backend,
                   const gchar *uri)
{
    GtkWidget *w;
    GtkDialog *gd;
    GtkWidget *container;
    EFilterRule *rule, *newrule;
    CamelURL *url;

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

    url = camel_url_new (uri, NULL);
    if (url && url->fragment
        && (rule = e_rule_context_find_rule ((ERuleContext *)context, url->fragment, NULL))) {
        g_object_ref (G_OBJECT (rule));
        newrule = e_filter_rule_clone (rule);

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

        gd = (GtkDialog *)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 (gd), 6);

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

        gtk_dialog_set_default_response (gd, GTK_RESPONSE_OK);
        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", newrule, (GDestroyNotify)g_object_unref);
        g_object_set_data_full(G_OBJECT(gd), "orig", rule, (GDestroyNotify)g_object_unref);
        g_signal_connect(gd, "response", G_CALLBACK(edit_rule_response), NULL);
        gtk_widget_show ((GtkWidget *)gd);
    } else {
        /* TODO: we should probably just create it ... */
        e_mail_backend_submit_alert (
            backend, "mail:vfolder-notexist", uri, NULL);
    }

    if (url)
        camel_url_free (url);
}

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 ((GtkWindow *)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);
}

EFilterPart *
vfolder_create_part (const gchar *name)
{
    return e_rule_context_create_part ((ERuleContext *)context, name);
}

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

    rule = em_vfolder_rule_new (session);

    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)
{
    EMailSession *session;
    GtkWidget *w;
    GtkDialog *gd;
    GtkWidget *container;

    session = em_vfolder_rule_get_session (rule);

    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 *msg,
                              gint flags,
                              const gchar *source)
{
    EMVFolderRule *rule;

    g_return_if_fail (msg != NULL);

    rule = (EMVFolderRule*)em_vfolder_rule_from_message (context, msg, flags, source);
    vfolder_gui_add_rule (rule);
}

void
vfolder_gui_add_from_address (EMailSession *session,
                              CamelInternetAddress *addr,
                              gint flags,
                              const gchar *source)
{
    EMVFolderRule *rule;

    g_return_if_fail (addr != NULL);

    rule = (EMVFolderRule*)em_vfolder_rule_from_address (context, addr, flags, source);
    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 (vfolder_store) {
        g_object_unref (vfolder_store);
        vfolder_store = NULL;
    }

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