/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8 -*-
 *
 * Copyright (C) 2007 William Jon McCann <mccann@jhu.edu>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 */

#include "config.h"

#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <signal.h>
#include <sys/stat.h>
#include <sys/types.h>

#include <glib.h>
#include <glib/gi18n.h>
#include <glib/gstdio.h>
#include <glib-object.h>
#include <gio/gio.h>

#include "gdm-settings.h"

#include "gdm-settings-desktop-backend.h"

struct _GdmSettings
{
        GObject   parent;

        GList    *backends;
};

enum {
        VALUE_CHANGED,
        LAST_SIGNAL
};

static guint signals [LAST_SIGNAL] = { 0, };

static void     gdm_settings_class_init (GdmSettingsClass *klass);
static void     gdm_settings_init       (GdmSettings      *settings);
static void     gdm_settings_finalize   (GObject          *object);

static gpointer settings_object = NULL;

G_DEFINE_TYPE (GdmSettings, gdm_settings, G_TYPE_OBJECT)

GQuark
gdm_settings_error_quark (void)
{
        static GQuark ret = 0;
        if (ret == 0) {
                ret = g_quark_from_static_string ("gdm_settings_error");
        }

        return ret;
}

gboolean
gdm_settings_get_value (GdmSettings *settings,
                        const char  *key,
                        char       **value,
                        GError     **error)
{
        GError  *local_error;
        gboolean res;
        GList   *l;

        g_return_val_if_fail (GDM_IS_SETTINGS (settings), FALSE);
        g_return_val_if_fail (settings->backends != NULL, FALSE);
        g_return_val_if_fail (key != NULL, FALSE);

        local_error = NULL;

        for (l = settings->backends; l; l = g_list_next (l)) {
                GdmSettingsBackend *backend = l->data;

                if (local_error) {
                        g_error_free (local_error);
                        local_error = NULL;
                }

                res = gdm_settings_backend_get_value (backend,
                                                      key,
                                                      value,
                                                      &local_error);
                if (res)
                        break;
        }
        if (! res) {
                g_propagate_error (error, local_error);
        }

        return res;
}

gboolean
gdm_settings_set_value (GdmSettings *settings,
                        const char  *key,
                        const char  *value,
                        GError     **error)
{
        GError  *local_error;
        gboolean res;
        GList   *l;

        g_return_val_if_fail (GDM_IS_SETTINGS (settings), FALSE);
        g_return_val_if_fail (settings->backends != NULL, FALSE);
        g_return_val_if_fail (key != NULL, FALSE);

        g_debug ("Setting value %s", key);

        local_error = NULL;

        for (l = settings->backends; l; l = g_list_next (l)) {
                GdmSettingsBackend *backend = l->data;

                if (local_error) {
                        g_error_free (local_error);
                        local_error = NULL;
                }

                res = gdm_settings_backend_set_value (backend,
                                                      key,
                                                      value,
                                                      &local_error);
                if (res)
                        break;
        }

        if (! res) {
                g_propagate_error (error, local_error);
        }

        return res;
}

static void
gdm_settings_class_init (GdmSettingsClass *klass)
{
        GObjectClass   *object_class = G_OBJECT_CLASS (klass);

        object_class->finalize = gdm_settings_finalize;

        signals [VALUE_CHANGED] =
                g_signal_new ("value-changed",
                              G_TYPE_FROM_CLASS (object_class),
                              G_SIGNAL_RUN_LAST,
                              0,
                              NULL,
                              NULL,
                              g_cclosure_marshal_generic,
                              G_TYPE_NONE,
                              3,
                              G_TYPE_STRING,
                              G_TYPE_STRING,
                              G_TYPE_STRING);
}

static void
backend_value_changed (GdmSettingsBackend *backend,
                       const char         *key,
                       const char         *old_value,
                       const char         *new_value,
                       GdmSettings        *settings)
{
        g_debug ("Emitting value-changed %s %s %s", key, old_value, new_value);

        /* proxy it to internal listeners */
        g_signal_emit (settings, signals [VALUE_CHANGED], 0, key, old_value, new_value);
}

void
gdm_settings_reload (GdmSettings *settings)
{
        GList *l;
        GdmSettingsBackend *backend;

        g_list_foreach (settings->backends, (GFunc) g_object_unref, NULL);
        g_list_free (settings->backends);
        settings->backends = NULL;

        backend = gdm_settings_desktop_backend_new (GDM_CUSTOM_CONF);
        if (backend)
                settings->backends = g_list_prepend (NULL, backend);

        backend = gdm_settings_desktop_backend_new (GDM_RUNTIME_CONF);
        if (backend)
                settings->backends = g_list_prepend (settings->backends, backend);

        for (l = settings->backends; l; l = g_list_next (l)) {
                backend = l->data;

                g_signal_connect (backend,
                                  "value-changed",
                                  G_CALLBACK (backend_value_changed),
                                  settings);
        }
}

static void
gdm_settings_init (GdmSettings *settings)
{
        gdm_settings_reload (settings);
}

static void
gdm_settings_finalize (GObject *object)
{
        GdmSettings *settings;

        g_return_if_fail (object != NULL);
        g_return_if_fail (GDM_IS_SETTINGS (object));

        settings = GDM_SETTINGS (object);

        g_return_if_fail (settings != NULL);

        g_list_foreach (settings->backends, (GFunc) g_object_unref, NULL);
        g_list_free (settings->backends);
        settings->backends = NULL;

        settings_object = NULL;

        G_OBJECT_CLASS (gdm_settings_parent_class)->finalize (object);
}

GdmSettings *
gdm_settings_new (void)
{
        if (settings_object != NULL) {
                g_object_ref (settings_object);
        } else {
                settings_object = g_object_new (GDM_TYPE_SETTINGS, NULL);
        }

        return GDM_SETTINGS (settings_object);
}