path: root/filter/rule-context.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:
 *      Not Zed <notzed@lostzed.mmc.com.au>
 *      Jeffrey Stedfast <fejj@ximian.com>
 *
 * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
 *
 */

#include <config.h>

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

#include <glib.h>
#include <glib/gstdio.h>

#include <gtk/gtk.h>

#include <glib/gi18n.h>

#include <libedataserver/e-xml-utils.h>

#include "e-util/e-error.h"
#include "e-util/e-xml-utils.h"

#include "filter-code.h"
#include "filter-colour.h"
#include "filter-datespec.h"
#include "filter-file.h"
#include "filter-input.h"
#include "filter-int.h"
#include "filter-option.h"
#include "filter-rule.h"
#include "rule-context.h"

#define d(x)

static gint load(RuleContext *rc, const gchar *system, const gchar *user);
static gint save(RuleContext *rc, const gchar *user);
static gint revert(RuleContext *rc, const gchar *user);
static GList *rename_uri(RuleContext *rc, const gchar *olduri, const gchar *newuri, GCompareFunc cmp);
static GList *delete_uri(RuleContext *rc, const gchar *uri, GCompareFunc cmp);
static FilterElement *new_element(RuleContext *rc, const gchar *name);

static void rule_context_class_init(RuleContextClass *klass);
static void rule_context_init(RuleContext *rc);
static void rule_context_finalise(GObject *obj);

#define _PRIVATE(x)(((RuleContext *)(x))->priv)

struct _RuleContextPrivate {
    gint frozen;
};

static GObjectClass *parent_class = NULL;

enum {
    RULE_ADDED,
    RULE_REMOVED,
    CHANGED,
    LAST_SIGNAL
};

static guint signals[LAST_SIGNAL] = { 0 };

GType
rule_context_get_type(void)
{
    static GType type = 0;

    if (!type) {
        static const GTypeInfo info = {
            sizeof(RuleContextClass),
            NULL, /* base_class_init */
            NULL, /* base_class_finalize */
            (GClassInitFunc) rule_context_class_init,
            NULL, /* class_finalize */
            NULL, /* class_data */
            sizeof(RuleContext),
            0,    /* n_preallocs */
            (GInstanceInitFunc) rule_context_init,
        };

        type = g_type_register_static(G_TYPE_OBJECT, "RuleContext", &info, 0);
    }

    return type;
}

static void
rule_context_class_init(RuleContextClass *klass)
{
    GObjectClass *object_class = G_OBJECT_CLASS(klass);

    parent_class = g_type_class_ref(G_TYPE_OBJECT);

    object_class->finalize = rule_context_finalise;

    /* override methods */
    klass->load = load;
    klass->save = save;
    klass->revert = revert;
    klass->rename_uri = rename_uri;
    klass->delete_uri = delete_uri;
    klass->new_element = new_element;

    /* signals */
    signals[RULE_ADDED] =
        g_signal_new("rule_added",
                  RULE_TYPE_CONTEXT,
                  G_SIGNAL_RUN_LAST,
                  G_STRUCT_OFFSET(RuleContextClass, rule_added),
                  NULL,
                  NULL,
                  g_cclosure_marshal_VOID__POINTER,
                  G_TYPE_NONE, 1, G_TYPE_POINTER);

    signals[RULE_REMOVED] =
        g_signal_new("rule_removed",
                  RULE_TYPE_CONTEXT,
                  G_SIGNAL_RUN_LAST,
                  G_STRUCT_OFFSET(RuleContextClass, rule_removed),
                  NULL,
                  NULL,
                  g_cclosure_marshal_VOID__POINTER,
                  G_TYPE_NONE, 1, G_TYPE_POINTER);

    signals[CHANGED] =
        g_signal_new("changed",
                  RULE_TYPE_CONTEXT,
                  G_SIGNAL_RUN_LAST,
                  G_STRUCT_OFFSET(RuleContextClass, changed),
                  NULL,
                  NULL,
                  g_cclosure_marshal_VOID__VOID,
                  G_TYPE_NONE, 0);
}

static void
rule_context_init(RuleContext *rc)
{
    rc->priv = g_malloc0(sizeof(*rc->priv));

    rc->part_set_map = g_hash_table_new(g_str_hash, g_str_equal);
    rc->rule_set_map = g_hash_table_new(g_str_hash, g_str_equal);

    rc->flags = RULE_CONTEXT_GROUPING;
}

static void
free_part_set(struct _part_set_map *map, gpointer data)
{
    g_free(map->name);
    g_free(map);
}

static void
free_rule_set(struct _rule_set_map *map, gpointer data)
{
    g_free(map->name);
    g_free(map);
}

static void
rule_context_finalise(GObject *obj)
{
    RuleContext *rc =(RuleContext *) obj;

    g_list_foreach(rc->rule_set_list, (GFunc)free_rule_set, NULL);
    g_list_free(rc->rule_set_list);
    g_hash_table_destroy(rc->rule_set_map);

    g_list_foreach(rc->part_set_list, (GFunc)free_part_set, NULL);
    g_list_free(rc->part_set_list);
    g_hash_table_destroy(rc->part_set_map);

    g_free(rc->error);

    g_list_foreach(rc->parts, (GFunc)g_object_unref, NULL);
    g_list_free(rc->parts);
    g_list_foreach(rc->rules, (GFunc)g_object_unref, NULL);
    g_list_free(rc->rules);

    g_free(rc->priv);

    G_OBJECT_CLASS(parent_class)->finalize(obj);
}

/**
 * rule_context_new:
 *
 * Create a new RuleContext object.
 *
 * Return value: A new #RuleContext object.
 **/
RuleContext *
rule_context_new(void)
{
    return(RuleContext *) g_object_new(RULE_TYPE_CONTEXT, NULL, NULL);
}

void
rule_context_add_part_set(RuleContext *rc, const gchar *setname, GType part_type, RCPartFunc append, RCNextPartFunc next)
{
    struct _part_set_map *map;

    g_return_if_fail (g_hash_table_lookup(rc->part_set_map, setname) == NULL);

    map = g_malloc0(sizeof(*map));
    map->type = part_type;
    map->append = append;
    map->next = next;
    map->name = g_strdup(setname);
    g_hash_table_insert(rc->part_set_map, map->name, map);
    rc->part_set_list = g_list_append(rc->part_set_list, map);
    d(printf("adding part set '%s'\n", setname));
}

void
rule_context_add_rule_set(RuleContext *rc, const gchar *setname, GType rule_type, RCRuleFunc append, RCNextRuleFunc next)
{
    struct _rule_set_map *map;

    g_return_if_fail (g_hash_table_lookup(rc->rule_set_map, setname) == NULL);

    map = g_malloc0(sizeof(*map));
    map->type = rule_type;
    map->append = append;
    map->next = next;
    map->name = g_strdup(setname);
    g_hash_table_insert(rc->rule_set_map, map->name, map);
    rc->rule_set_list = g_list_append(rc->rule_set_list, map);
    d(printf("adding rule set '%s'\n", setname));
}

/**
 * rule_context_set_error:
 * @f:
 * @error:
 *
 * Set the text error for the context, or NULL to clear it.
 **/
static void
rule_context_set_error(RuleContext *rc, gchar *error)
{
    g_return_if_fail (rc);

    g_free(rc->error);
    rc->error = error;
}

/**
 * rule_context_load:
 * @f:
 * @system:
 * @user:
 *
 * Load a rule context from a system and user description file.
 *
 * Return value:
 **/
gint
rule_context_load(RuleContext *rc, const gchar *system, const gchar *user)
{
    gint res;

    g_return_val_if_fail (rc, -1);

    d(printf("rule_context: loading %s %s\n", system, user));

    rc->priv->frozen++;
    res = RULE_CONTEXT_GET_CLASS(rc)->load(rc, system, user);
    rc->priv->frozen--;

    return res;
}

static gint
load(RuleContext *rc, const gchar *system, const gchar *user)
{
    xmlNodePtr set, rule, root;
    xmlDocPtr systemdoc, userdoc;
    struct _part_set_map *part_map;
    struct _rule_set_map *rule_map;

    rule_context_set_error(rc, NULL);

    d(printf("loading rules %s %s\n", system, user));

    systemdoc = e_xml_parse_file (system);
    if (systemdoc == NULL) {
        rule_context_set_error(rc, g_strdup_printf("Unable to load system rules '%s': %s",
                                 system, g_strerror(errno)));
        return -1;
    }

    root = xmlDocGetRootElement(systemdoc);
    if (root == NULL || strcmp((gchar *)root->name, "filterdescription")) {
        rule_context_set_error(rc, g_strdup_printf("Unable to load system rules '%s': Invalid format", system));
        xmlFreeDoc(systemdoc);
        return -1;
    }
    /* doesn't matter if this doens't exist */
    userdoc = NULL;
    if (g_file_test(user, G_FILE_TEST_IS_REGULAR))
        userdoc = e_xml_parse_file (user);

    /* now parse structure */
    /* get rule parts */
    set = root->children;
    while (set) {
        d(printf("set name = %s\n", set->name));
        part_map = g_hash_table_lookup(rc->part_set_map, set->name);
        if (part_map) {
            d(printf("loading parts ...\n"));
            rule = set->children;
            while (rule) {
                if (!strcmp((gchar *)rule->name, "part")) {
                    FilterPart *part = FILTER_PART(g_object_new(part_map->type, NULL, NULL));

                    if (filter_part_xml_create(part, rule, rc) == 0) {
                        part_map->append(rc, part);
                    } else {
                        g_object_unref(part);
                        g_warning("Cannot load filter part");
                    }
                }
                rule = rule->next;
            }
        } else if ((rule_map = g_hash_table_lookup(rc->rule_set_map, set->name))) {
            d(printf("loading system rules ...\n"));
            rule = set->children;
            while (rule) {
                d(printf("checking node: %s\n", rule->name));
                if (!strcmp((gchar *)rule->name, "rule")) {
                    FilterRule *part = FILTER_RULE(g_object_new(rule_map->type, NULL, NULL));

                    if (filter_rule_xml_decode(part, rule, rc) == 0) {
                        part->system = TRUE;
                        rule_map->append(rc, part);
                    } else {
                        g_object_unref(part);
                        g_warning("Cannot load filter part");
                    }
                }
                rule = rule->next;
            }
        }
        set = set->next;
    }

    /* now load actual rules */
    if (userdoc) {
        root = xmlDocGetRootElement(userdoc);
        set = root?root->children:NULL;
        while (set) {
            d(printf("set name = %s\n", set->name));
            rule_map = g_hash_table_lookup(rc->rule_set_map, set->name);
            if (rule_map) {
                d(printf("loading rules ...\n"));
                rule = set->children;
                while (rule) {
                    d(printf("checking node: %s\n", rule->name));
                    if (!strcmp((gchar *)rule->name, "rule")) {
                        FilterRule *part = FILTER_RULE(g_object_new(rule_map->type, NULL, NULL));

                        if (filter_rule_xml_decode(part, rule, rc) == 0) {
                            rule_map->append(rc, part);
                        } else {
                            g_object_unref(part);
                            g_warning("Cannot load filter part");
                        }
                    }
                    rule = rule->next;
                }
            }
            set = set->next;
        }
    }

    xmlFreeDoc(userdoc);
    xmlFreeDoc(systemdoc);

    return 0;
}

/**
 * rule_context_save:
 * @f:
 * @user:
 *
 * Save a rule context to disk.
 *
 * Return value:
 **/
gint
rule_context_save(RuleContext *rc, const gchar *user)
{
    g_return_val_if_fail (rc, -1);
    g_return_val_if_fail (user, -1);

    return RULE_CONTEXT_GET_CLASS(rc)->save(rc, user);
}

static gint
save(RuleContext *rc, const gchar *user)
{
    xmlDocPtr doc;
    xmlNodePtr root, rules, work;
    GList *l;
    FilterRule *rule;
    struct _rule_set_map *map;
    gint ret;

    doc = xmlNewDoc((const guchar *)"1.0");
    /* FIXME: set character encoding to UTF-8? */
    root = xmlNewDocNode(doc, NULL, (const guchar *)"filteroptions", NULL);
    xmlDocSetRootElement(doc, root);
    l = rc->rule_set_list;
    while (l) {
        map = l->data;
        rules = xmlNewDocNode(doc, NULL, (guchar *)map->name, NULL);
        xmlAddChild(root, rules);
        rule = NULL;
        while ((rule = map->next(rc, rule, NULL))) {
            if (!rule->system) {
                d(printf("processing rule %s\n", rule->name));
                work = filter_rule_xml_encode(rule);
                xmlAddChild(rules, work);
            }
        }
        l = g_list_next(l);
    }

    ret = e_xml_save_file(user, doc);

    xmlFreeDoc(doc);

    return ret;
}

/**
 * rule_context_revert:
 * @f:
 * @user:
 *
 * Reverts a rule context from a user description file.  Assumes the
 * system description file is unchanged from when it was loaded.
 *
 * Return value:
 **/
gint
rule_context_revert(RuleContext *rc, const gchar *user)
{
    g_return_val_if_fail (rc, 0);

    d(printf("rule_context: restoring %s\n", user));

    return RULE_CONTEXT_GET_CLASS(rc)->revert(rc, user);
}

struct _revert_data {
    GHashTable *rules;
    gint rank;
};

static void
revert_rule_remove(gpointer key, FilterRule *frule, RuleContext *rc)
{
    rule_context_remove_rule(rc, frule);
    g_object_unref(frule);
}

static void
revert_source_remove(gpointer key, struct _revert_data *rest_data, RuleContext *rc)
{
    g_hash_table_foreach(rest_data->rules, (GHFunc)revert_rule_remove, rc);
    g_hash_table_destroy(rest_data->rules);
    g_free(rest_data);
}

static guint
source_hashf(const gchar *a)
{
    if (a)
        return g_str_hash(a);
    return 0;
}

static gint
source_eqf(const gchar *a, const gchar *b)
{
    return((a && b && strcmp(a, b) == 0))
        || (a == NULL && b == NULL);
}

static gint
revert(RuleContext *rc, const gchar *user)
{
    xmlNodePtr set, rule;
    /*struct _part_set_map *part_map;*/
    struct _rule_set_map *rule_map;
    struct _revert_data *rest_data;
    GHashTable *source_hash;
    xmlDocPtr userdoc;
    FilterRule *frule;

    rule_context_set_error(rc, NULL);

    d(printf("restoring rules %s\n", user));

    userdoc = e_xml_parse_file (user);
    if (userdoc == NULL)
        /* clear out anythign we have? */
        return 0;

    source_hash = g_hash_table_new((GHashFunc)source_hashf, (GCompareFunc)source_eqf);

    /* setup stuff we have now */
    /* Note that we assume there is only 1 set of rules in a given rule context,
       although other parts of the code dont assume this */
    frule = NULL;
    while ((frule = rule_context_next_rule(rc, frule, NULL))) {
        rest_data = g_hash_table_lookup(source_hash, frule->source);
        if (rest_data == NULL) {
            rest_data = g_malloc0(sizeof(*rest_data));
            rest_data->rules = g_hash_table_new(g_str_hash, g_str_equal);
            g_hash_table_insert(source_hash, frule->source, rest_data);
        }
        g_hash_table_insert(rest_data->rules, frule->name, frule);
    }

    /* make what we have, match what we load */
    set = xmlDocGetRootElement(userdoc);
    set = set?set->children:NULL;
    while (set) {
        d(printf("set name = %s\n", set->name));
        rule_map = g_hash_table_lookup(rc->rule_set_map, set->name);
        if (rule_map) {
            d(printf("loading rules ...\n"));
            rule = set->children;
            while (rule) {
                d(printf("checking node: %s\n", rule->name));
                if (!strcmp((gchar *)rule->name, "rule")) {
                    FilterRule *part = FILTER_RULE(g_object_new(rule_map->type, NULL, NULL));

                    if (filter_rule_xml_decode(part, rule, rc) == 0) {
                        /* use the revert data to keep track of the right rank of this rule part */
                        rest_data = g_hash_table_lookup(source_hash, part->source);
                        if (rest_data == NULL) {
                            rest_data = g_malloc0(sizeof(*rest_data));
                            rest_data->rules = g_hash_table_new(g_str_hash, g_str_equal);
                            g_hash_table_insert(source_hash, part->source, rest_data);
                        }
                        frule = g_hash_table_lookup(rest_data->rules, part->name);
                        if (frule) {
                            if (rc->priv->frozen == 0 && !filter_rule_eq(frule, part))
                                filter_rule_copy(frule, part);

                            g_object_unref(part);
                            rule_context_rank_rule(rc, frule, frule->source, rest_data->rank);
                            g_hash_table_remove(rest_data->rules, frule->name);
                        } else {
                            rule_context_add_rule(rc, part);
                            rule_context_rank_rule(rc, part, part->source, rest_data->rank);
                        }
                        rest_data->rank++;
                    } else {
                        g_object_unref(part);
                        g_warning("Cannot load filter part");
                    }
                }
                rule = rule->next;
            }
        }
        set = set->next;
    }

    xmlFreeDoc(userdoc);

    /* remove any we still have that weren't in the file */
    g_hash_table_foreach(source_hash, (GHFunc)revert_source_remove, rc);
    g_hash_table_destroy(source_hash);

    return 0;
}

FilterPart *
rule_context_find_part(RuleContext *rc, const gchar *name)
{
    g_return_val_if_fail (rc, NULL);
    g_return_val_if_fail (name, NULL);

    d(printf("find part : "));
    return filter_part_find_list(rc->parts, name);
}

FilterPart *
rule_context_create_part(RuleContext *rc, const gchar *name)
{
    FilterPart *part;

    g_return_val_if_fail (rc, NULL);
    g_return_val_if_fail (name, NULL);

    if ((part = rule_context_find_part(rc, name)))
        return filter_part_clone(part);

    return NULL;
}

FilterPart *
rule_context_next_part(RuleContext *rc, FilterPart *last)
{
    g_return_val_if_fail (rc, NULL);

    return filter_part_next_list(rc->parts, last);
}

FilterRule *
rule_context_next_rule(RuleContext *rc, FilterRule *last, const gchar *source)
{
    g_return_val_if_fail (rc, NULL);

    return filter_rule_next_list(rc->rules, last, source);
}

FilterRule *
rule_context_find_rule(RuleContext *rc, const gchar *name, const gchar *source)
{
    g_return_val_if_fail (name, NULL);
    g_return_val_if_fail (rc, NULL);

    return filter_rule_find_list(rc->rules, name, source);
}

void
rule_context_add_part(RuleContext *rc, FilterPart *part)
{
    g_return_if_fail (rc);
    g_return_if_fail (part);

    rc->parts = g_list_append(rc->parts, part);
}

void
rule_context_add_rule(RuleContext *rc, FilterRule *new)
{
    g_return_if_fail (rc);
    g_return_if_fail (new);

    d(printf("add rule '%s'\n", new->name));

    rc->rules = g_list_append(rc->rules, new);

    if (rc->priv->frozen == 0) {
        g_signal_emit(rc, signals[RULE_ADDED], 0, new);
        g_signal_emit(rc, signals[CHANGED], 0);
    }
}

static void
new_rule_response(GtkWidget *dialog, gint button, RuleContext *context)
{
    if (button == GTK_RESPONSE_OK) {
        FilterRule *rule = g_object_get_data((GObject *) dialog, "rule");
        gchar *user = g_object_get_data((GObject *) dialog, "path");

        if (!filter_rule_validate (rule, GTK_WINDOW (dialog))) {
            /* no need to popup a dialog because the validate code does that. */
            return;
        }

        if (rule_context_find_rule (context, rule->name, rule->source)) {
            e_error_run ((GtkWindow *)dialog, "filter:bad-name-notunique", rule->name, NULL);

            return;
        }

        g_object_ref(rule);
        rule_context_add_rule(context, rule);
        if (user)
            rule_context_save(context, user);
    }

    gtk_widget_destroy(dialog);
}

/* add a rule, with a gui, asking for confirmation first ... optionally save to path */
void
rule_context_add_rule_gui(RuleContext *rc, FilterRule *rule, const gchar *title, const gchar *path)
{
    GtkDialog *dialog;
    GtkWidget *widget;
    GtkWidget *content_area;

    d(printf("add rule gui '%s'\n", rule->name));

    g_return_if_fail (rc);
    g_return_if_fail (rule);

    widget = filter_rule_get_widget(rule, rc);
    gtk_widget_show(widget);

    dialog =(GtkDialog *) gtk_dialog_new();
    gtk_dialog_add_buttons(dialog,
                   GTK_STOCK_CANCEL, GTK_RESPONSE_CANCEL,
                   GTK_STOCK_OK, GTK_RESPONSE_OK,
                   NULL);
    gtk_dialog_set_has_separator (dialog, FALSE);

    gtk_window_set_title((GtkWindow *) dialog, title);
    gtk_window_set_default_size((GtkWindow *) dialog, 600, 400);
    gtk_window_set_resizable((GtkWindow *) dialog, TRUE);

    content_area = gtk_dialog_get_content_area (dialog);
    gtk_box_pack_start (GTK_BOX (content_area), widget, TRUE, TRUE, 0);

    g_object_set_data_full((GObject *) dialog, "rule", rule, g_object_unref);
    if (path)
        g_object_set_data_full((GObject *) dialog, "path", g_strdup(path), g_free);

    g_signal_connect(dialog, "response", G_CALLBACK(new_rule_response), rc);

    g_object_ref(rc);

    g_object_set_data_full((GObject *) dialog, "context", rc, g_object_unref);

    gtk_widget_show((GtkWidget *) dialog);
}

void
rule_context_remove_rule(RuleContext *rc, FilterRule *rule)
{
    g_return_if_fail (rc);
    g_return_if_fail (rule);

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

    rc->rules = g_list_remove(rc->rules, rule);

    if (rc->priv->frozen == 0) {
        g_signal_emit(rc, signals[RULE_REMOVED], 0, rule);
        g_signal_emit(rc, signals[CHANGED], 0);
    }
}

void
rule_context_rank_rule(RuleContext *rc, FilterRule *rule, const gchar *source, gint rank)
{
    GList *node;
    gint i = 0, index = 0;

    g_return_if_fail (rc);
    g_return_if_fail (rule);

    if (rule_context_get_rank_rule (rc, rule, source) == rank)
        return;

    rc->rules = g_list_remove(rc->rules, rule);
    node = rc->rules;
    while (node) {
        FilterRule *r = node->data;

        if (i == rank) {
            rc->rules = g_list_insert(rc->rules, rule, index);
            if (rc->priv->frozen == 0)
                g_signal_emit(rc, signals[CHANGED], 0);

            return;
        }

        index++;
        if (source == NULL || (r->source && strcmp(r->source, source) == 0))
            i++;

        node = node->next;
    }

    rc->rules = g_list_append(rc->rules, rule);
    if (rc->priv->frozen == 0)
        g_signal_emit(rc, signals[CHANGED], 0);
}

gint
rule_context_get_rank_rule(RuleContext *rc, FilterRule *rule, const gchar *source)
{
    GList *node;
    gint i = 0;

    g_return_val_if_fail (rc, -1);
    g_return_val_if_fail (rule, -1);

    d(printf("getting rank of rule '%s'\n", rule->name));

    node = rc->rules;
    while (node) {
        FilterRule *r = node->data;

        d(printf(" checking against rule '%s' rank '%d'\n", r->name, i));

        if (r == rule)
            return i;

        if (source == NULL || (r->source && strcmp(r->source, source) == 0))
            i++;

        node = node->next;
    }

    return -1;
}

FilterRule *
rule_context_find_rank_rule(RuleContext *rc, gint rank, const gchar *source)
{
    GList *node;
    gint i = 0;

    g_return_val_if_fail (rc, NULL);

    d(printf("getting rule at rank %d source '%s'\n", rank, source?source:"<any>"));

    node = rc->rules;
    while (node) {
        FilterRule *r = node->data;

        d(printf(" checking against rule '%s' rank '%d'\n", r->name, i));

        if (source == NULL || (r->source && strcmp(r->source, source) == 0)) {
            if (rank == i)
                return r;
            i++;
        }

        node = node->next;
    }

    return NULL;
}

static GList *
delete_uri(RuleContext *rc, const gchar *uri, GCompareFunc cmp)
{
    return NULL;
}

GList *
rule_context_delete_uri(RuleContext *rc, const gchar *uri, GCompareFunc cmp)
{
    return RULE_CONTEXT_GET_CLASS(rc)->delete_uri(rc, uri, cmp);
}

static GList *
rename_uri(RuleContext *rc, const gchar *olduri, const gchar *newuri, GCompareFunc cmp)
{
    return NULL;
}

GList *
rule_context_rename_uri(RuleContext *rc, const gchar *olduri, const gchar *newuri, GCompareFunc cmp)
{
    return RULE_CONTEXT_GET_CLASS(rc)->rename_uri(rc, olduri, newuri, cmp);
}

void
rule_context_free_uri_list(RuleContext *rc, GList *uris)
{
    GList *l = uris, *n;

    /* TODO: should be virtual */

    while (l) {
        n = l->next;
        g_free(l->data);
        g_list_free_1(l);
        l = n;
    }
}

static FilterElement *
new_element(RuleContext *rc, const gchar *type)
{
    if (!strcmp (type, "string")) {
        return (FilterElement *) filter_input_new ();
    } else if (!strcmp (type, "address")) {
        /* FIXME: temporary ... need real address type */
        return (FilterElement *) filter_input_new_type_name (type);
    } else if (!strcmp (type, "code")) {
        return (FilterElement *) filter_code_new (FALSE);
    } else if (!strcmp (type, "rawcode")) {
        return (FilterElement *) filter_code_new (TRUE);
    } else if (!strcmp (type, "colour")) {
        return (FilterElement *) filter_colour_new ();
    } else if (!strcmp (type, "optionlist")) {
        return (FilterElement *) filter_option_new ();
    } else if (!strcmp (type, "datespec")) {
        return (FilterElement *) filter_datespec_new ();
    } else if (!strcmp (type, "command")) {
        return (FilterElement *) filter_file_new_type_name (type);
    } else if (!strcmp (type, "file")) {
        return (FilterElement *) filter_file_new_type_name (type);
    } else if (!strcmp (type, "integer")) {
        return (FilterElement *) filter_int_new ();
    } else if (!strcmp (type, "regex")) {
        return (FilterElement *) filter_input_new_type_name (type);
    }else if (!strcmp(type, "completedpercent")) {
                 return (FilterElement *) filter_int_new_type("completedpercent", 0,100);

    } else {
        g_warning("Unknown filter type '%s'", type);
        return NULL;
    }
}

/**
 * rule_context_new_element:
 * @rc:
 * @name:
 *
 * create a new filter element based on name.
 *
 * Return value:
 **/
FilterElement *
rule_context_new_element(RuleContext *rc, const gchar *name)
{
    if (name == NULL)
        return NULL;

    return RULE_CONTEXT_GET_CLASS(rc)->new_element(rc, name);
}