/* -*- 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 St, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

#include "config.h"

#include <string.h>

#include <glib.h>
#include <glib/gi18n.h>
#include <gmodule.h>
#include <gio/gio.h>

#include "mate-settings-plugin-info.h"
#include "mate-settings-module.h"
#include "mate-settings-plugin.h"
#include "mate-settings-profile.h"

#define MATE_SETTINGS_PLUGIN_INFO_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), MATE_TYPE_SETTINGS_PLUGIN_INFO, MateSettingsPluginInfoPrivate))

#define PLUGIN_GROUP "MATE Settings Plugin"

#define PLUGIN_PRIORITY_MAX 1
#define PLUGIN_PRIORITY_DEFAULT 100

struct MateSettingsPluginInfoPrivate
{
        char                    *file;
        GSettings               *settings;

        char                    *location;
        GTypeModule             *module;

        char                    *name;
        char                    *desc;
        char                   **authors;
        char                    *copyright;
        char                    *website;

        MateSettingsPlugin     *plugin;

        int                      enabled : 1;
        int                      active : 1;

        /* A plugin is unavailable if it is not possible to activate it
           due to an error loading the plugin module */
        int                      available : 1;

        guint                    enabled_notification_id;

        /* Priority determines the order in which plugins are started and
         * stopped. A lower number means higher priority. */
        guint                    priority;
};


enum {
        ACTIVATED,
        DEACTIVATED,
        LAST_SIGNAL
};

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

G_DEFINE_TYPE (MateSettingsPluginInfo, mate_settings_plugin_info, G_TYPE_OBJECT)

static void
mate_settings_plugin_info_finalize (GObject *object)
{
        MateSettingsPluginInfo *info;

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

        info = MATE_SETTINGS_PLUGIN_INFO (object);

        g_return_if_fail (info->priv != NULL);

        if (info->priv->plugin != NULL) {
                g_debug ("Unref plugin %s", info->priv->name);

                g_object_unref (info->priv->plugin);

                /* info->priv->module must not be unref since it is not possible to finalize
                 * a type module */
        }

        g_free (info->priv->file);
        g_free (info->priv->location);
        g_free (info->priv->name);
        g_free (info->priv->desc);
        g_free (info->priv->website);
        g_free (info->priv->copyright);
        g_strfreev (info->priv->authors);

	if (info->priv->settings != NULL) {
		g_object_unref (info->priv->settings);
	}

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

static void
mate_settings_plugin_info_class_init (MateSettingsPluginInfoClass *klass)
{
        GObjectClass   *object_class = G_OBJECT_CLASS (klass);

        object_class->finalize = mate_settings_plugin_info_finalize;

        signals [ACTIVATED] =
                g_signal_new ("activated",
                              G_TYPE_FROM_CLASS (object_class),
                              G_SIGNAL_RUN_LAST,
                              G_STRUCT_OFFSET (MateSettingsPluginInfoClass, activated),
                              NULL,
                              NULL,
                              g_cclosure_marshal_VOID__VOID,
                              G_TYPE_NONE,
                              0);
        signals [DEACTIVATED] =
                g_signal_new ("deactivated",
                              G_TYPE_FROM_CLASS (object_class),
                              G_SIGNAL_RUN_LAST,
                              G_STRUCT_OFFSET (MateSettingsPluginInfoClass, deactivated),
                              NULL,
                              NULL,
                              g_cclosure_marshal_VOID__VOID,
                              G_TYPE_NONE,
                              0);

        g_type_class_add_private (klass, sizeof (MateSettingsPluginInfoPrivate));
}

static void
mate_settings_plugin_info_init (MateSettingsPluginInfo *info)
{
        info->priv = MATE_SETTINGS_PLUGIN_INFO_GET_PRIVATE (info);
}

static void
debug_info (MateSettingsPluginInfo *info)
{
        g_debug ("MateSettingsPluginInfo: name='%s' file='%s' location='%s'",
                 info->priv->name,
                 info->priv->file,
                 info->priv->location);
}

static gboolean
mate_settings_plugin_info_fill_from_file (MateSettingsPluginInfo *info,
                                           const char              *filename)
{
        GKeyFile *plugin_file = NULL;
        char     *str;
        int       priority;
        gboolean  ret;

        mate_settings_profile_start ("%s", filename);

        ret = FALSE;

        info->priv->file = g_strdup (filename);

        plugin_file = g_key_file_new ();
        if (! g_key_file_load_from_file (plugin_file, filename, G_KEY_FILE_NONE, NULL)) {
                g_warning ("Bad plugin file: %s", filename);
                goto out;
        }

        if (! g_key_file_has_key (plugin_file, PLUGIN_GROUP, "IAge", NULL)) {
                g_debug ("IAge key does not exist in file: %s", filename);
                goto out;
        }

        /* Check IAge=2 */
        if (g_key_file_get_integer (plugin_file, PLUGIN_GROUP, "IAge", NULL) != 0) {
                g_debug ("Wrong IAge in file: %s", filename);
                goto out;
        }

        /* Get Location */
        str = g_key_file_get_string (plugin_file, PLUGIN_GROUP, "Module", NULL);

        if ((str != NULL) && (*str != '\0')) {
                info->priv->location = str;
        } else {
                g_free (str);
                g_warning ("Could not find 'Module' in %s", filename);
                goto out;
        }

        /* Get Name */
        str = g_key_file_get_locale_string (plugin_file, PLUGIN_GROUP, "Name", NULL, NULL);
        if (str != NULL) {
                info->priv->name = str;
        } else {
                g_warning ("Could not find 'Name' in %s", filename);
                goto out;
        }

        /* Get Description */
        str = g_key_file_get_locale_string (plugin_file, PLUGIN_GROUP, "Description", NULL, NULL);
        if (str != NULL) {
                info->priv->desc = str;
        } else {
                g_debug ("Could not find 'Description' in %s", filename);
        }

        /* Get Authors */
        info->priv->authors = g_key_file_get_string_list (plugin_file, PLUGIN_GROUP, "Authors", NULL, NULL);
        if (info->priv->authors == NULL) {
                g_debug ("Could not find 'Authors' in %s", filename);
        }

        /* Get Copyright */
        str = g_key_file_get_string (plugin_file, PLUGIN_GROUP, "Copyright", NULL);
        if (str != NULL) {
                info->priv->copyright = str;
        } else {
                g_debug ("Could not find 'Copyright' in %s", filename);
        }

        /* Get Website */
        str = g_key_file_get_string (plugin_file, PLUGIN_GROUP, "Website", NULL);
        if (str != NULL) {
                info->priv->website = str;
        } else {
                g_debug ("Could not find 'Website' in %s", filename);
        }

        /* Get Priority */
        priority = g_key_file_get_integer (plugin_file, PLUGIN_GROUP, "Priority", NULL);
        if (priority >= PLUGIN_PRIORITY_MAX) {
                info->priv->priority = priority;
        } else {
                info->priv->priority = PLUGIN_PRIORITY_DEFAULT;
        }

        g_key_file_free (plugin_file);

        debug_info (info);

        /* If we know nothing about the availability of the plugin,
           set it as available */
        info->priv->available = TRUE;

        ret = TRUE;
 out:
        mate_settings_profile_end ("%s", filename);

        return ret;
}

static void
plugin_enabled_cb (GSettings              *settings,
                   gchar                  *key,
                   MateSettingsPluginInfo *info)
{
        if (g_settings_get_boolean (info->priv->settings, key)) {
                mate_settings_plugin_info_activate (info);
        } else {
                mate_settings_plugin_info_deactivate (info);
        }
}

MateSettingsPluginInfo *
mate_settings_plugin_info_new_from_file (const char *filename)
{
        MateSettingsPluginInfo *info;
        gboolean                 res;

        info = g_object_new (MATE_TYPE_SETTINGS_PLUGIN_INFO, NULL);

        res = mate_settings_plugin_info_fill_from_file (info, filename);
        if (! res) {
                g_object_unref (info);
                info = NULL;
        }

        return info;
}

static void
_deactivate_plugin (MateSettingsPluginInfo *info)
{
        mate_settings_plugin_deactivate (info->priv->plugin);
        g_signal_emit (info, signals [DEACTIVATED], 0);
}

gboolean
mate_settings_plugin_info_deactivate (MateSettingsPluginInfo *info)
{
        g_return_val_if_fail (MATE_IS_SETTINGS_PLUGIN_INFO (info), FALSE);

        if (!info->priv->active || !info->priv->available) {
                return TRUE;
        }

        _deactivate_plugin (info);

        /* Update plugin state */
        info->priv->active = FALSE;

        return TRUE;
}


static gboolean
load_plugin_module (MateSettingsPluginInfo *info)
{
        char    *path;
        char    *dirname;
        gboolean ret;

        ret = FALSE;

        g_return_val_if_fail (MATE_IS_SETTINGS_PLUGIN_INFO (info), FALSE);
        g_return_val_if_fail (info->priv->file != NULL, FALSE);
        g_return_val_if_fail (info->priv->location != NULL, FALSE);
        g_return_val_if_fail (info->priv->plugin == NULL, FALSE);
        g_return_val_if_fail (info->priv->available, FALSE);

        mate_settings_profile_start ("%s", info->priv->location);

        dirname = g_path_get_dirname (info->priv->file);
        g_return_val_if_fail (dirname != NULL, FALSE);

        path = g_module_build_path (dirname, info->priv->location);
        g_free (dirname);
        g_return_val_if_fail (path != NULL, FALSE);

        info->priv->module = G_TYPE_MODULE (mate_settings_module_new (path));
        g_free (path);

        if (!g_type_module_use (info->priv->module)) {
                g_warning ("Cannot load plugin '%s' since file '%s' cannot be read.",
                           info->priv->name,
                           mate_settings_module_get_path (MATE_SETTINGS_MODULE (info->priv->module)));

                g_object_unref (G_OBJECT (info->priv->module));
                info->priv->module = NULL;

                /* Mark plugin as unavailable and fails */
                info->priv->available = FALSE;

                goto out;
        }

        info->priv->plugin =
                MATE_SETTINGS_PLUGIN (mate_settings_module_new_object (MATE_SETTINGS_MODULE (info->priv->module)));

        g_type_module_unuse (info->priv->module);
        ret = TRUE;
out:
        mate_settings_profile_end ("%s", info->priv->location);
        return ret;
}

static gboolean
_activate_plugin (MateSettingsPluginInfo *info)
{
        gboolean res = TRUE;

        if (!info->priv->available) {
                /* Plugin is not available, don't try to activate/load it */
                return FALSE;
        }

        if (info->priv->plugin == NULL) {
                res = load_plugin_module (info);
        }

        if (res) {
                mate_settings_plugin_activate (info->priv->plugin);
                g_signal_emit (info, signals [ACTIVATED], 0);
        } else {
                g_warning ("Error activating plugin '%s'", info->priv->name);
        }

        return res;
}

gboolean
mate_settings_plugin_info_activate (MateSettingsPluginInfo *info)
{

        g_return_val_if_fail (MATE_IS_SETTINGS_PLUGIN_INFO (info), FALSE);

        if (! info->priv->available) {
                return FALSE;
        }

        if (info->priv->active) {
                return TRUE;
        }

        if (_activate_plugin (info)) {
                info->priv->active = TRUE;
                return TRUE;
        }

        return FALSE;
}

gboolean
mate_settings_plugin_info_is_active (MateSettingsPluginInfo *info)
{
        g_return_val_if_fail (MATE_IS_SETTINGS_PLUGIN_INFO (info), FALSE);

        return (info->priv->available && info->priv->active);
}

gboolean
mate_settings_plugin_info_get_enabled (MateSettingsPluginInfo *info)
{
        g_return_val_if_fail (MATE_IS_SETTINGS_PLUGIN_INFO (info), FALSE);

        return (info->priv->enabled);
}

gboolean
mate_settings_plugin_info_is_available (MateSettingsPluginInfo *info)
{
        g_return_val_if_fail (MATE_IS_SETTINGS_PLUGIN_INFO (info), FALSE);

        return (info->priv->available != FALSE);
}

const char *
mate_settings_plugin_info_get_name (MateSettingsPluginInfo *info)
{
        g_return_val_if_fail (MATE_IS_SETTINGS_PLUGIN_INFO (info), NULL);

        return info->priv->name;
}

const char *
mate_settings_plugin_info_get_description (MateSettingsPluginInfo *info)
{
        g_return_val_if_fail (MATE_IS_SETTINGS_PLUGIN_INFO (info), NULL);

        return info->priv->desc;
}

const char **
mate_settings_plugin_info_get_authors (MateSettingsPluginInfo *info)
{
        g_return_val_if_fail (MATE_IS_SETTINGS_PLUGIN_INFO (info), (const char **)NULL);

        return (const char **)info->priv->authors;
}

const char *
mate_settings_plugin_info_get_website (MateSettingsPluginInfo *info)
{
        g_return_val_if_fail (MATE_IS_SETTINGS_PLUGIN_INFO (info), NULL);

        return info->priv->website;
}

const char *
mate_settings_plugin_info_get_copyright (MateSettingsPluginInfo *info)
{
        g_return_val_if_fail (MATE_IS_SETTINGS_PLUGIN_INFO (info), NULL);

        return info->priv->copyright;
}


const char *
mate_settings_plugin_info_get_location (MateSettingsPluginInfo *info)
{
        g_return_val_if_fail (MATE_IS_SETTINGS_PLUGIN_INFO (info), NULL);

        return info->priv->location;
}

int
mate_settings_plugin_info_get_priority (MateSettingsPluginInfo *info)
{
        g_return_val_if_fail (MATE_IS_SETTINGS_PLUGIN_INFO (info), PLUGIN_PRIORITY_DEFAULT);

        return info->priv->priority;
}

void
mate_settings_plugin_info_set_priority (MateSettingsPluginInfo *info,
                                         int                      priority)
{
        g_return_if_fail (MATE_IS_SETTINGS_PLUGIN_INFO (info));

        info->priv->priority = priority;
}

void
mate_settings_plugin_info_set_schema (MateSettingsPluginInfo *info,
                                      gchar                  *schema)
{
	int priority;

	g_return_if_fail (MATE_IS_SETTINGS_PLUGIN_INFO (info));

	info->priv->settings = g_settings_new (schema);
	info->priv->enabled = g_settings_get_boolean (info->priv->settings, "active");

	priority = g_settings_get_int (info->priv->settings, "priority");
	if (priority > 0)
		info->priv->priority = priority;

	g_signal_connect (G_OBJECT (info->priv->settings), "changed::active", 
			  G_CALLBACK (plugin_enabled_cb), info);
}