/*

 * Copyright (C) 2025, Red Hat Inc.

 *

 * This library 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 2.1 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

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser 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.

 *

 * Author: Carlos Garnacho <carlosg@gnome.org>

 */

#include "config.h"

#include "tracker-deserializer-merger.h"

typedef struct _TrackerDeserializerMergerPrivate TrackerDeserializerMergerPrivate;

struct _TrackerDeserializerMergerPrivate {

  TrackerDeserializerRdf parent_instance;

  GList *deserializers;

  GList *current_deserializer;

};

G_DEFINE_TYPE_WITH_PRIVATE (TrackerDeserializerMerger,

                            tracker_deserializer_merger,

                            TRACKER_TYPE_DESERIALIZER_RDF)

static void

tracker_deserializer_merger_finalize (GObject *object)

{

  TrackerDeserializerMerger *deserializer =

    TRACKER_DESERIALIZER_MERGER (object);

  TrackerDeserializerMergerPrivate *priv =

    tracker_deserializer_merger_get_instance_private (deserializer);

  g_list_free_full (priv->deserializers, g_object_unref);

  priv->current_deserializer = NULL;

  G_OBJECT_CLASS (tracker_deserializer_merger_parent_class)->finalize (object);

}

static TrackerSparqlValueType

tracker_deserializer_merger_get_value_type (TrackerSparqlCursor *cursor,

                                            gint                 column)

{

  TrackerDeserializerMerger *deserializer =

    TRACKER_DESERIALIZER_MERGER (cursor);

  TrackerDeserializerMergerPrivate *priv =

    tracker_deserializer_merger_get_instance_private (deserializer);

  if (!priv->current_deserializer)

    return TRACKER_SPARQL_VALUE_TYPE_UNBOUND;

  return tracker_sparql_cursor_get_value_type (priv->current_deserializer->data,

                                               column);

}

static gboolean

tracker_deserializer_merger_next (TrackerSparqlCursor  *cursor,

                                  GCancellable         *cancellable,

                                  GError              **error)

{

  TrackerDeserializerMerger *deserializer =

    TRACKER_DESERIALIZER_MERGER (cursor);

  TrackerDeserializerMergerPrivate *priv =

    tracker_deserializer_merger_get_instance_private (deserializer);

  gboolean has_next = FALSE;

  if (!priv->current_deserializer)

    priv->current_deserializer = g_list_last (priv->deserializers);

  while (!has_next && priv->current_deserializer) {

    has_next = tracker_sparql_cursor_next (priv->current_deserializer->data,

                                           cancellable, error);

    if (!has_next) {

      GList *to_remove;

      to_remove = priv->current_deserializer;

      priv->current_deserializer = priv->current_deserializer->prev;

      priv->deserializers = g_list_remove_link (priv->deserializers, to_remove);

      g_object_unref (to_remove->data);

      g_list_free1 (to_remove);

    }

  }

  return has_next;

}

static const gchar *

tracker_deserializer_merger_get_string (TrackerSparqlCursor  *cursor,

                                        gint                  column,

                                        const gchar         **langtag,

                                        glong                *length)

{

  TrackerDeserializerMerger *deserializer =

    TRACKER_DESERIALIZER_MERGER (cursor);

  TrackerDeserializerMergerPrivate *priv =

    tracker_deserializer_merger_get_instance_private (deserializer);

  if (!priv->current_deserializer) {

    if (langtag)

      *langtag = NULL;

    if (length)

      *length = 0;

    return NULL;

  }

  if (langtag) {

    return tracker_sparql_cursor_get_langstring (priv->current_deserializer->data,

                                                 column, langtag, length);

  } else {

    return tracker_sparql_cursor_get_string (priv->current_deserializer->data,

                                             column, length);

  }

}

void

tracker_deserializer_merger_close (TrackerSparqlCursor* cursor)

{

  TrackerDeserializerMerger *deserializer =

    TRACKER_DESERIALIZER_MERGER (cursor);

  TrackerDeserializerMergerPrivate *priv =

    tracker_deserializer_merger_get_instance_private (deserializer);

  tracker_sparql_cursor_close (priv->current_deserializer->data);

}

static gboolean

tracker_deserializer_merger_get_parser_location (TrackerDeserializer  *deserializer,

                                                 const char          **name,

                                                 goffset              *line_no,

                                                 goffset              *column_no)

{

  TrackerDeserializerMerger *deserializer_merger =

    TRACKER_DESERIALIZER_MERGER (deserializer);

  TrackerDeserializerMergerPrivate *priv =

    tracker_deserializer_merger_get_instance_private (deserializer_merger);

  if (!priv->current_deserializer)

    return FALSE;

  return tracker_deserializer_get_parser_location (priv->current_deserializer->data,

                                                   name, line_no, column_no);

}

static void

tracker_deserializer_merger_class_init (TrackerDeserializerMergerClass *klass)

{

  GObjectClass *object_class = G_OBJECT_CLASS (klass);

  TrackerSparqlCursorClass *cursor_class = TRACKER_SPARQL_CURSOR_CLASS (klass);

  TrackerDeserializerClass *deserializer_class = TRACKER_DESERIALIZER_CLASS (klass);

  object_class->finalize = tracker_deserializer_merger_finalize;

  cursor_class->get_value_type = tracker_deserializer_merger_get_value_type;

  cursor_class->get_string = tracker_deserializer_merger_get_string;

  cursor_class->next = tracker_deserializer_merger_next;

  cursor_class->close = tracker_deserializer_merger_close;

  deserializer_class->get_parser_location = tracker_deserializer_merger_get_parser_location;

}

static void

tracker_deserializer_merger_init (TrackerDeserializerMerger *deserializer)

{

}

TrackerSparqlCursor *

tracker_deserializer_merger_new (void)

{

  return g_object_new (TRACKER_TYPE_DESERIALIZER_MERGER, NULL);

}

void

tracker_deserializer_merger_add_child (TrackerDeserializerMerger *deserializer,

                                       TrackerDeserializer       *child)

{

  TrackerDeserializerMergerPrivate *priv =

    tracker_deserializer_merger_get_instance_private (deserializer);

  priv->deserializers = g_list_prepend (priv->deserializers, g_object_ref (child));

}