/*

 * Copyright (C) 2007 Zeeshan Ali (Khattak) <zeeshanak@gnome.org>

 * Copyright (C) 2007 OpenedHand Ltd

 *

 * Authors: Zeeshan Ali (Khattak) <zeeshanak@gnome.org>

 *          Jorn Baayen <jorn@openedhand.com>

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Library General Public

 * License as published by the Free Software Foundation; either

 * version 2 of the License, or (at your option) any later version.

 *

 * This library 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

 * Library General Public License for more details.

 *

 * You should have received a copy of the GNU Library General Public

 * License along with this library; if not, write to the

 * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,

 * Boston, MA 02110-1301, USA.

 */

/**

 * SECTION:gupnp-last-change-parser

 * @short_description: A/V LastChange event XML parser

 *

 * #GUPnPLastChangeParser parses XML strings from LastChange events that are

 * generated by AVTransport and RenderingControl services.

 *

 */

#include <gobject/gvaluecollector.h>

#include "gupnp-last-change-parser.h"

#include "gvalue-util.h"

#include "xml-util.h"

G_DEFINE_TYPE (GUPnPLastChangeParser,

               gupnp_last_change_parser,

               G_TYPE_OBJECT);

static void

gupnp_last_change_parser_init (G_GNUC_UNUSED GUPnPLastChangeParser *parser)

{

}

static void

gupnp_last_change_parser_dispose (GObject *object)

{

        GObjectClass   *gobject_class;

        gobject_class = G_OBJECT_CLASS (gupnp_last_change_parser_parent_class);

        gobject_class->dispose (object);

}

static void

gupnp_last_change_parser_class_init (GUPnPLastChangeParserClass *klass)

{

        GObjectClass *object_class;

        object_class = G_OBJECT_CLASS (klass);

        object_class->dispose = gupnp_last_change_parser_dispose;

}

/* Reads a value of state variable @variable_name to an initialised GValue pair

 * from the InstanceID node of a LastChange xml doc */

static gboolean

read_state_variable (const char *variable_name,

                     GValue     *value,

                     xmlNode    *instance_node)

{

        xmlNode    *variable_node;

        const char *val_str;

        variable_node = xml_util_get_element (instance_node,

                                              variable_name,

                                              NULL);

        if (!variable_node)

                return FALSE;

        val_str = xml_util_get_attribute_content (variable_node, "val");

        if (!val_str) {

                g_warning ("No value provided for variable \"%s\" in "

                           "LastChange event",

                           variable_name);

                return FALSE;

        }

        gvalue_util_set_value_from_string (value, val_str);

        return TRUE;

}

static xmlNode *

get_instance_node (xmlDoc *doc,

                   guint   instance_id)

{

        xmlNode *node;

        if (doc->children == NULL)

                return NULL;

        for (node = doc->children->children;

             node;

             node = node->next) {

                if (node->type != XML_ELEMENT_NODE)

                        continue;

                if (!xmlStrcmp (node->name, BAD_CAST ("InstanceID")) &&

                    xml_util_get_uint_attribute (node, "val", 0) == instance_id)

                        break;

        }

        return node;

}

/**

 * gupnp_last_change_parser_new:

 *

 * Return value: A new #GUPnPLastChangeParser

 **/

GUPnPLastChangeParser *

gupnp_last_change_parser_new (void)

{

        return g_object_new (GUPNP_TYPE_LAST_CHANGE_PARSER,

                             NULL);

}

/**

 * gupnp_last_change_parser_parse_last_change_valist:

 * @parser: A #GUPnPLastChangeParser

 * @instance_id: The ID of the AV instance caller is interested in

 * @last_change_xml: The xml from the "LastChange" event to parse

 * @error: The location where to store any error, or NULL

 * @var_args: A va_list of tuples of state variable name, state variable type,

 * and state variable value location, terminated with NULL. The state variable

 * values should be freed after use

 *

 * See gupnp_last_change_parser_parse_last_change(); this version takes a

 * va_list for use by language bindings.

 *

 * Return value: TRUE on success.

 **/

gboolean

gupnp_last_change_parser_parse_last_change_valist

                         (G_GNUC_UNUSED GUPnPLastChangeParser *parser,

                          guint                                instance_id,

                          const char                          *last_change_xml,

                          GError                             **error,

                          va_list                              var_args)

{

        const char *variable_name;

        xmlDoc  *doc;

        xmlNode *instance_node;

        g_return_val_if_fail (last_change_xml, FALSE);

        doc = xmlParseDoc ((const xmlChar *) last_change_xml);

        if (doc == NULL) {

                g_set_error (error,

                             G_MARKUP_ERROR,

                             G_MARKUP_ERROR_PARSE,

                             "Could not parse LastChange xml");

                return FALSE;

        }

        instance_node = get_instance_node (doc, instance_id);

        if (instance_node == NULL) {

                /* This is not an error since the caller of this function

                 * doesn't (need to) know if the instance of his interest is

                 * part of the LastChange event received.

                 */

                xmlFreeDoc (doc);

                return FALSE;

        }

        /* Variables */

        variable_name = va_arg (var_args, const char *);

        while (variable_name) {

                GType variable_type;

                GValue value = { 0, };

                char *copy_error = NULL;

                variable_type = va_arg (var_args, GType);

                g_value_init (&value, variable_type);

                if (read_state_variable (variable_name,

                                         &value,

                                         instance_node)) {

                        G_VALUE_LCOPY (&value, var_args, 0, &copy_error);

                } else {

                        va_arg (var_args, gpointer);

                }

                g_value_unset (&value);

                if (copy_error) {

                        g_warning ("Error copying value: %s", copy_error);

                        g_free (copy_error);

                }

                variable_name = va_arg (var_args, const char *);

        }

        /* Cleanup */

        xmlFreeDoc (doc);

        return TRUE;

}

/**

 * gupnp_last_change_parser_parse_last_change:

 * @parser: A #GUPnPLastChangeParser

 * @instance_id: The ID of the AV instance caller is interested in

 * @last_change_xml: The xml from the "LastChange" event to parse

 * @error: The location where to store any error, or NULL

 * @...: tuples of state variable name, state variable type, and state

 * variable value location, terminated with NULL. The state variable values

 * should be freed after use.

 *

 * Parses the xml fragment from a LastChange event.

 *

 * Return value: TRUE on success.

 **/

gboolean

gupnp_last_change_parser_parse_last_change

                                (GUPnPLastChangeParser *parser,

                                 guint                  instance_id,

                                 const char            *last_change_xml,

                                 GError               **error,

                                 ...)

{

        va_list var_args;

        gboolean ret;

        va_start (var_args, error);

        ret = gupnp_last_change_parser_parse_last_change_valist

                                                (parser,

                                                 instance_id,

                                                 last_change_xml,

                                                 error,

                                                 var_args);

        va_end (var_args);

        return ret;

}