/* GStreamer

 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>

 *                    2000 Wim Taymans <wtay@chello.be>

 *                    2003 Benjamin Otte <in7y118@public.uni-hamburg.de>

 *

 * gstdeviceproviderfactory.c: GstDeviceProviderFactory object, support routines

 *

 * 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., 59 Temple Place - Suite 330,

 * Boston, MA 02111-1307, USA.

 */

/**

 * SECTION:gstdeviceproviderfactory

 * @title: GstDeviceProviderFactory

 * @short_description: Create GstDeviceProviders from a factory

 * @see_also: #GstDeviceProvider, #GstPlugin, #GstPluginFeature, #GstPadTemplate.

 *

 * #GstDeviceProviderFactory is used to create instances of device providers. A

 * GstDeviceProviderfactory can be added to a #GstPlugin as it is also a

 * #GstPluginFeature.

 *

 * Use the gst_device_provider_factory_find() and

 * gst_device_provider_factory_get() functions to create device

 * provider instances or use gst_device_provider_factory_get_by_name() as a

 * convenient shortcut.

 *

 * Since: 1.4

 */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include "gst_private.h"

#include "gstdeviceproviderfactory.h"

#include "gst.h"

#include "glib-compat-private.h"

GST_DEBUG_CATEGORY_STATIC (device_provider_factory_debug);

#define GST_CAT_DEFAULT device_provider_factory_debug

static void gst_device_provider_factory_finalize (GObject * object);

static void gst_device_provider_factory_cleanup (GstDeviceProviderFactory *

    factory);

/* static guint gst_device_provider_factory_signals[LAST_SIGNAL] = { 0 }; */

/* this is defined in gstelement.c */

extern GQuark __gst_deviceproviderclass_factory;

#define _do_init \

{ \

  GST_DEBUG_CATEGORY_INIT (device_provider_factory_debug, "GST_DEVICE_PROVIDER_FACTORY", \

      GST_DEBUG_BOLD | GST_DEBUG_FG_WHITE | GST_DEBUG_BG_RED, \

      "device provider factories keep information about installed device providers"); \

}

G_DEFINE_TYPE_WITH_CODE (GstDeviceProviderFactory, gst_device_provider_factory,

    GST_TYPE_PLUGIN_FEATURE, _do_init);

static void

gst_device_provider_factory_class_init (GstDeviceProviderFactoryClass * klass)

{

  GObjectClass *gobject_class = (GObjectClass *) klass;

  gobject_class->finalize = gst_device_provider_factory_finalize;

}

static void

gst_device_provider_factory_init (GstDeviceProviderFactory * factory)

{

}

static void

gst_device_provider_factory_finalize (GObject * object)

{

  GstDeviceProviderFactory *factory = GST_DEVICE_PROVIDER_FACTORY (object);

  GstDeviceProvider *provider;

  gst_device_provider_factory_cleanup (factory);

  provider = g_atomic_pointer_get (&factory->provider);

  if (provider)

    gst_object_unref (provider);

  G_OBJECT_CLASS (gst_device_provider_factory_parent_class)->finalize (object);

}

/**

 * gst_device_provider_factory_find:

 * @name: name of factory to find

 *

 * Search for an device provider factory of the given name. Refs the returned

 * device provider factory; caller is responsible for unreffing.

 *

 * Returns: (transfer full) (nullable): #GstDeviceProviderFactory if

 * found, %NULL otherwise

 *

 * Since: 1.4

 */

GstDeviceProviderFactory *

gst_device_provider_factory_find (const gchar * name)

{

  GstPluginFeature *feature;

  g_return_val_if_fail (name != NULL, NULL);

  feature = gst_registry_find_feature (gst_registry_get (), name,

      GST_TYPE_DEVICE_PROVIDER_FACTORY);

  if (feature)

    return GST_DEVICE_PROVIDER_FACTORY (feature);

  /* this isn't an error, for instance when you query if an device provider factory is

   * present */

  GST_LOG ("no such device provider factory \"%s\"", name);

  return NULL;

}

static void

gst_device_provider_factory_cleanup (GstDeviceProviderFactory * factory)

{

  if (factory->metadata) {

    gst_structure_free ((GstStructure *) factory->metadata);

    factory->metadata = NULL;

  }

  if (factory->type) {

    factory->type = G_TYPE_INVALID;

  }

}

#define CHECK_METADATA_FIELD(klass, name, key)                                 \

  G_STMT_START {                                                               \

    const gchar *metafield = gst_device_provider_class_get_metadata (klass, key);      \

    if (G_UNLIKELY (metafield == NULL || *metafield == '\0')) {                \

      g_warning ("Device provider factory metadata for '%s' has no valid %s field", name, key);    \

      goto detailserror;                                                       \

    } \

  } G_STMT_END;

/**

 * gst_device_provider_register:

 * @plugin: (allow-none): #GstPlugin to register the device provider with, or %NULL for

 *     a static device provider.

 * @name: name of device providers of this type

 * @rank: rank of device provider (higher rank means more importance when autoplugging)

 * @type: GType of device provider to register

 *

 * Create a new device providerfactory capable of instantiating objects of the

 * @type and add the factory to @plugin.

 *

 * Returns: %TRUE, if the registering succeeded, %FALSE on error

 *

 * Since: 1.4

 */

gboolean

gst_device_provider_register (GstPlugin * plugin, const gchar * name,

    guint rank, GType type)

{

  GstPluginFeature *existing_feature;

  GstRegistry *registry;

  GstDeviceProviderFactory *factory;

  GstDeviceProviderClass *klass;

  g_return_val_if_fail (name != NULL, FALSE);

  g_return_val_if_fail (g_type_is_a (type, GST_TYPE_DEVICE_PROVIDER), FALSE);

  registry = gst_registry_get ();

  /* check if feature already exists, if it exists there is no need to update it

   * when the registry is getting updated, outdated plugins and all their

   * features are removed and readded.

   */

  existing_feature = gst_registry_lookup_feature (registry, name);

  if (existing_feature) {

    GST_DEBUG_OBJECT (registry, "update existing feature %p (%s)",

        existing_feature, name);

    factory = GST_DEVICE_PROVIDER_FACTORY_CAST (existing_feature);

    factory->type = type;

    existing_feature->loaded = TRUE;

    g_type_set_qdata (type, __gst_deviceproviderclass_factory, factory);

    gst_object_unref (existing_feature);

    return TRUE;

  }

  factory = g_object_new (GST_TYPE_DEVICE_PROVIDER_FACTORY, NULL);

  gst_plugin_feature_set_name (GST_PLUGIN_FEATURE_CAST (factory), name);

  GST_LOG_OBJECT (factory, "Created new device providerfactory for type %s",

      g_type_name (type));

  /* provide info needed during class structure setup */

  g_type_set_qdata (type, __gst_deviceproviderclass_factory, factory);

  klass = GST_DEVICE_PROVIDER_CLASS (g_type_class_ref (type));

  CHECK_METADATA_FIELD (klass, name, GST_ELEMENT_METADATA_LONGNAME);

  CHECK_METADATA_FIELD (klass, name, GST_ELEMENT_METADATA_KLASS);

  CHECK_METADATA_FIELD (klass, name, GST_ELEMENT_METADATA_DESCRIPTION);

  CHECK_METADATA_FIELD (klass, name, GST_ELEMENT_METADATA_AUTHOR);

  factory->type = type;

  factory->metadata = gst_structure_copy ((GstStructure *) klass->metadata);

  if (plugin && plugin->desc.name) {

    GST_PLUGIN_FEATURE_CAST (factory)->plugin_name = plugin->desc.name;

    GST_PLUGIN_FEATURE_CAST (factory)->plugin = plugin;

    g_object_add_weak_pointer ((GObject *) plugin,

        (gpointer *) & GST_PLUGIN_FEATURE_CAST (factory)->plugin);

  } else {

    GST_PLUGIN_FEATURE_CAST (factory)->plugin_name = "NULL";

    GST_PLUGIN_FEATURE_CAST (factory)->plugin = NULL;

  }

  gst_plugin_feature_set_rank (GST_PLUGIN_FEATURE_CAST (factory), rank);

  GST_PLUGIN_FEATURE_CAST (factory)->loaded = TRUE;

  gst_registry_add_feature (registry, GST_PLUGIN_FEATURE_CAST (factory));

  return TRUE;

  /* ERRORS */

detailserror:

  {

    gst_device_provider_factory_cleanup (factory);

    return FALSE;

  }

}

/**

 * gst_device_provider_factory_get:

 * @factory: factory to instantiate

 *

 * Returns the device provider of the type defined by the given device

 * providerfactory.

 *

 * Returns: (transfer full) (nullable): the #GstDeviceProvider or %NULL

 * if the device provider couldn't be created

 *

 * Since: 1.4

 */

GstDeviceProvider *

gst_device_provider_factory_get (GstDeviceProviderFactory * factory)

{

  GstDeviceProvider *device_provider;

  GstDeviceProviderClass *oclass;

  GstDeviceProviderFactory *newfactory;

  g_return_val_if_fail (factory != NULL, NULL);

  newfactory =

      GST_DEVICE_PROVIDER_FACTORY (gst_plugin_feature_load (GST_PLUGIN_FEATURE

          (factory)));

  if (newfactory == NULL)

    goto load_failed;

  factory = newfactory;

  GST_INFO ("getting device provider \"%s\"", GST_OBJECT_NAME (factory));

  if (factory->type == 0)

    goto no_type;

  device_provider = g_atomic_pointer_get (&newfactory->provider);

  if (device_provider) {

    gst_object_unref (factory);

    return gst_object_ref (device_provider);

  }

  /* create an instance of the device provider, cast so we don't assert on NULL

   * also set name as early as we can

   */

  device_provider = g_object_new (factory->type, NULL);

  if (G_UNLIKELY (device_provider == NULL))

    goto no_device_provider;

  /* fill in the pointer to the factory in the device provider class. The

   * class will not be unreffed currently.

   * Be thread safe as there might be 2 threads creating the first instance of

   * an device provider at the same moment

   */

  oclass = GST_DEVICE_PROVIDER_GET_CLASS (device_provider);

  if (!g_atomic_pointer_compare_and_exchange (&oclass->factory, NULL, factory)) {

    gst_object_unref (factory);

  } else {

    /* This ref will never be dropped as the class is never destroyed */

    GST_OBJECT_FLAG_SET (factory, GST_OBJECT_FLAG_MAY_BE_LEAKED);

  }

  gst_object_ref_sink (device_provider);

  /* We use an atomic to make sure we don't create two in parallel */

  if (!g_atomic_pointer_compare_and_exchange (&newfactory->provider, NULL,

          device_provider)) {

    gst_object_unref (device_provider);

    device_provider = g_atomic_pointer_get (&newfactory->provider);

  }

  GST_DEBUG ("created device provider \"%s\"", GST_OBJECT_NAME (factory));

  return gst_object_ref (device_provider);

  /* ERRORS */

load_failed:

  {

    GST_WARNING_OBJECT (factory,

        "loading plugin containing feature %s returned NULL!",

        GST_OBJECT_NAME (factory));

    return NULL;

  }

no_type:

  {

    GST_WARNING_OBJECT (factory, "factory has no type");

    gst_object_unref (factory);

    return NULL;

  }

no_device_provider:

  {

    GST_WARNING_OBJECT (factory, "could not create device provider");

    gst_object_unref (factory);

    return NULL;

  }

}

/**

 * gst_device_provider_factory_get_by_name:

 * @factoryname: a named factory to instantiate

 *

 * Returns the device provider of the type defined by the given device

 * provider factory.

 *

 * Returns: (transfer full) (nullable): a #GstDeviceProvider or %NULL

 * if unable to create device provider

 *

 * Since: 1.4

 */

GstDeviceProvider *

gst_device_provider_factory_get_by_name (const gchar * factoryname)

{

  GstDeviceProviderFactory *factory;

  GstDeviceProvider *device_provider;

  g_return_val_if_fail (factoryname != NULL, NULL);

  g_return_val_if_fail (gst_is_initialized (), NULL);

  GST_LOG ("gstdeviceproviderfactory: get_by_name \"%s\"", factoryname);

  factory = gst_device_provider_factory_find (factoryname);

  if (factory == NULL)

    goto no_factory;

  GST_LOG_OBJECT (factory, "found factory %p", factory);

  device_provider = gst_device_provider_factory_get (factory);

  if (device_provider == NULL)

    goto create_failed;

  gst_object_unref (factory);

  return device_provider;

  /* ERRORS */

no_factory:

  {

    GST_INFO ("no such device provider factory \"%s\"!", factoryname);

    return NULL;

  }

create_failed:

  {

    GST_INFO_OBJECT (factory, "couldn't create instance!");

    gst_object_unref (factory);

    return NULL;

  }

}

/**

 * gst_device_provider_factory_get_device_provider_type:

 * @factory: factory to get managed #GType from

 *

 * Get the #GType for device providers managed by this factory. The type can

 * only be retrieved if the device provider factory is loaded, which can be

 * assured with gst_plugin_feature_load().

 *

 * Returns: the #GType for device providers managed by this factory.

 *

 * Since: 1.4

 */

GType

gst_device_provider_factory_get_device_provider_type (GstDeviceProviderFactory *

    factory)

{

  g_return_val_if_fail (GST_IS_DEVICE_PROVIDER_FACTORY (factory),

      G_TYPE_INVALID);

  return factory->type;

}

/**

 * gst_device_provider_factory_get_metadata:

 * @factory: a #GstDeviceProviderFactory

 * @key: a key

 *

 * Get the metadata on @factory with @key.

 *

 * Returns: (nullable): the metadata with @key on @factory or %NULL

 * when there was no metadata with the given @key.

 *

 * Since: 1.4

 */

const gchar *

gst_device_provider_factory_get_metadata (GstDeviceProviderFactory * factory,

    const gchar * key)

{

  return gst_structure_get_string ((GstStructure *) factory->metadata, key);

}

/**

 * gst_device_provider_factory_get_metadata_keys:

 * @factory: a #GstDeviceProviderFactory

 *

 * Get the available keys for the metadata on @factory.

 *

 * Returns: (transfer full) (element-type utf8) (array zero-terminated=1) (nullable):

 * a %NULL-terminated array of key strings, or %NULL when there is no

 * metadata. Free with g_strfreev() when no longer needed.

 *

 * Since: 1.4

 */

gchar **

gst_device_provider_factory_get_metadata_keys (GstDeviceProviderFactory *

    factory)

{

  GstStructure *metadata;

  gchar **arr;

  gint i, num;

  g_return_val_if_fail (GST_IS_DEVICE_PROVIDER_FACTORY (factory), NULL);

  metadata = (GstStructure *) factory->metadata;

  if (metadata == NULL)

    return NULL;

  num = gst_structure_n_fields (metadata);

  if (num == 0)

    return NULL;

  arr = g_new (gchar *, num + 1);

  for (i = 0; i < num; ++i) {

    arr[i] = g_strdup (gst_structure_nth_field_name (metadata, i));

  }

  arr[i] = NULL;

  return arr;

}

/**

 * gst_device_provider_factory_has_classesv:

 * @factory: a #GstDeviceProviderFactory

 * @classes: (array zero-terminated=1) (allow-none): a %NULL terminated array

 *   of classes to match, only match if all classes are matched

 *

 * Check if @factory matches all of the given classes

 *

 * Returns: %TRUE if @factory matches.

 *

 * Since: 1.4

 */

gboolean

gst_device_provider_factory_has_classesv (GstDeviceProviderFactory * factory,

    gchar ** classes)

{

  const gchar *klass;

  g_return_val_if_fail (GST_IS_DEVICE_PROVIDER_FACTORY (factory), FALSE);

  klass = gst_device_provider_factory_get_metadata (factory,

      GST_ELEMENT_METADATA_KLASS);

  if (klass == NULL) {

    GST_ERROR_OBJECT (factory,

        "device provider factory is missing klass identifiers");

    return FALSE;

  }

  for (; classes != NULL && classes[0] != NULL; classes++) {

    const gchar *found;

    guint len;

    if (classes[0][0] == '\0')

      continue;

    found = strstr (klass, classes[0]);

    if (!found)

      return FALSE;

    if (found != klass && *(found - 1) != '/')

      return FALSE;

    len = strlen (classes[0]);

    if (found[len] != 0 && found[len] != '/')

      return FALSE;

  }

  return TRUE;

}

/**

 * gst_device_provider_factory_has_classes:

 * @factory: a #GstDeviceProviderFactory

 * @classes: (allow-none): a "/" separate list of classes to match, only match

 *     if all classes are matched

 *

 * Check if @factory matches all of the given @classes

 *

 * Returns: %TRUE if @factory matches or if @classes is %NULL.

 *

 * Since: 1.4

 */

gboolean

gst_device_provider_factory_has_classes (GstDeviceProviderFactory * factory,

    const gchar * classes)

{

  gchar **classesv;

  gboolean res;

  if (classes == NULL)

    return TRUE;

  classesv = g_strsplit (classes, "/", 0);

  res = gst_device_provider_factory_has_classesv (factory, classesv);

  g_strfreev (classesv);

  return res;

}

static gboolean

device_provider_filter (GstPluginFeature * feature, GstRank * minrank)

{

  /* we only care about device provider factories */

  if (G_UNLIKELY (!GST_IS_DEVICE_PROVIDER_FACTORY (feature)))

    return FALSE;

  return (gst_plugin_feature_get_rank (feature) >= *minrank);

}

/**

 * gst_device_provider_factory_list_get_device_providers:

 * @minrank: Minimum rank

 *

 * Get a list of factories with a rank greater or equal to @minrank.

 * The list of factories is returned by decreasing rank.

 *

 * Returns: (transfer full) (element-type Gst.DeviceProviderFactory):

 * a #GList of #GstDeviceProviderFactory device providers. Use

 * gst_plugin_feature_list_free() after usage.

 *

 * Since: 1.4

 */

GList *

gst_device_provider_factory_list_get_device_providers (GstRank minrank)

{

  GList *result;

  /* get the feature list using the filter */

  result = gst_registry_feature_filter (gst_registry_get (),

      (GstPluginFeatureFilter) device_provider_filter, FALSE, &minrank);

  /* sort on rank and name */

  result = g_list_sort (result, gst_plugin_feature_rank_compare_func);

  return result;

}