/* GStreamer base utils library missing plugins support

 * Copyright (C) 2006 Tim-Philipp Müller <tim centricular net>

 *

 * 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:gstpbutilsmissingplugins

 * @short_description: Create, recognise and parse missing-plugins messages

 *

 * <refsect2>

 * <para>

 * Functions to create, recognise and parse missing-plugins messages for

 * applications and elements.

 * </para>

 * <para>

 * Missing-plugin messages are posted on the bus by elements like decodebin

 * or playbin if they can't find an appropriate source element or decoder

 * element. The application can use these messages for two things:

 * <itemizedlist>

 *   <listitem><para>

 *     concise error/problem reporting to the user mentioning what exactly

 *     is missing, see gst_missing_plugin_message_get_description()

 *   </para></listitem>

 *   <listitem><para>

 *     initiate installation of missing plugins, see

 *     gst_missing_plugin_message_get_installer_detail() and

 *     gst_install_plugins_async()

 *   </para></listitem>

 * </itemizedlist>

 * </para>

 * <para>

 * Applications may also create missing-plugin messages themselves to install

 * required elements that are missing, using the install mechanism mentioned

 * above.

 * </para>

 * </refsect2>

 */

#ifdef HAVE_CONFIG_H

# include "config.h"

#endif

#ifdef HAVE_SYS_TYPES_H

# include <sys/types.h>

#endif

#ifdef HAVE_UNISTD_H

# include <unistd.h>            /* getpid on UNIX */

#endif

#ifdef HAVE_PROCESS_H

# include <process.h>           /* getpid on win32 */

#endif

#include "gst/gst-i18n-plugin.h"

#include "pbutils.h"

#include <string.h>

#define GST_DETAIL_STRING_MARKER "gstreamer"

typedef enum

{

  GST_MISSING_TYPE_UNKNOWN = 0,

  GST_MISSING_TYPE_URISOURCE,

  GST_MISSING_TYPE_URISINK,

  GST_MISSING_TYPE_ELEMENT,

  GST_MISSING_TYPE_DECODER,

  GST_MISSING_TYPE_ENCODER

} GstMissingType;

static const struct

{

  GstMissingType type;

  const gchar type_string[12];

} missing_type_mapping[] = {

  {

  GST_MISSING_TYPE_URISOURCE, "urisource"}, {

  GST_MISSING_TYPE_URISINK, "urisink"}, {

  GST_MISSING_TYPE_ELEMENT, "element"}, {

  GST_MISSING_TYPE_DECODER, "decoder"}, {

  GST_MISSING_TYPE_ENCODER, "encoder"}

};

static GstMissingType

missing_structure_get_type (const GstStructure * s)

{

  const gchar *type;

  guint i;

  type = gst_structure_get_string (s, "type");

  g_return_val_if_fail (type != NULL, GST_MISSING_TYPE_UNKNOWN);

  for (i = 0; i < G_N_ELEMENTS (missing_type_mapping); ++i) {

    if (strcmp (missing_type_mapping[i].type_string, type) == 0)

      return missing_type_mapping[i].type;

  }

  return GST_MISSING_TYPE_UNKNOWN;

}

static GstCaps *

copy_and_clean_caps (const GstCaps * caps)

{

  GstStructure *s;

  GstCaps *ret;

  ret = gst_caps_copy (caps);

  /* make caps easier to interpret, remove common fields that are likely

   * to be irrelevant for determining the right plugin (ie. mostly fields

   * where template caps usually have the standard MIN - MAX range as value) */

  s = gst_caps_get_structure (ret, 0);

  gst_structure_remove_field (s, "codec_data");

  gst_structure_remove_field (s, "palette_data");

  gst_structure_remove_field (s, "pixel-aspect-ratio");

  gst_structure_remove_field (s, "framerate");

  gst_structure_remove_field (s, "leaf_size");

  gst_structure_remove_field (s, "packet_size");

  /* decoders/encoders almost always handle the usual width/height/channel/rate

   * range (and if we don't remove this then the app will have a much harder

   * time blacklisting formats it has unsuccessfully tried to install before) */

  gst_structure_remove_field (s, "width");

  gst_structure_remove_field (s, "height");

  gst_structure_remove_field (s, "channels");

  gst_structure_remove_field (s, "rate");

  /* rtp fields */

  gst_structure_remove_field (s, "config");

  gst_structure_remove_field (s, "clock-rate");

  gst_structure_remove_field (s, "clock-base");

  gst_structure_remove_field (s, "maxps");

  gst_structure_remove_field (s, "seqnum-base");

  gst_structure_remove_field (s, "npt-start");

  gst_structure_remove_field (s, "npt-stop");

  gst_structure_remove_field (s, "play-speed");

  gst_structure_remove_field (s, "play-scale");

  return ret;

}

/**

 * gst_missing_uri_source_message_new:

 * @element: the #GstElement posting the message

 * @protocol: the URI protocol the missing source needs to implement,

 *            e.g. "http" or "mms"

 *

 * Creates a missing-plugin message for @element to notify the application

 * that a source element for a particular URI protocol is missing. This

 * function is mainly for use in plugins.

 *

 * Returns: a new #GstMessage, or NULL on error

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

GstMessage *

gst_missing_uri_source_message_new (GstElement * element,

    const gchar * protocol)

{

  GstStructure *s;

  gchar *description;

  g_return_val_if_fail (element != NULL, NULL);

  g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);

  g_return_val_if_fail (protocol != NULL, NULL);

  description = gst_pb_utils_get_source_description (protocol);

  s = gst_structure_new ("missing-plugin", "type", G_TYPE_STRING,

      "urisource", "detail", G_TYPE_STRING, protocol, "name", G_TYPE_STRING,

      description, NULL);

  g_free (description);

  return gst_message_new_element (GST_OBJECT_CAST (element), s);

}

/**

 * gst_missing_uri_sink_message_new:

 * @element: the #GstElement posting the message

 * @protocol: the URI protocol the missing sink needs to implement,

 *            e.g. "http" or "smb"

 *

 * Creates a missing-plugin message for @element to notify the application

 * that a sink element for a particular URI protocol is missing. This

 * function is mainly for use in plugins.

 *

 * Returns: a new #GstMessage, or NULL on error

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

GstMessage *

gst_missing_uri_sink_message_new (GstElement * element, const gchar * protocol)

{

  GstStructure *s;

  gchar *description;

  g_return_val_if_fail (element != NULL, NULL);

  g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);

  g_return_val_if_fail (protocol != NULL, NULL);

  description = gst_pb_utils_get_sink_description (protocol);

  s = gst_structure_new ("missing-plugin", "type", G_TYPE_STRING,

      "urisink", "detail", G_TYPE_STRING, protocol, "name", G_TYPE_STRING,

      description, NULL);

  g_free (description);

  return gst_message_new_element (GST_OBJECT_CAST (element), s);

}

/**

 * gst_missing_element_message_new:

 * @element: the #GstElement posting the message

 * @factory_name: the name of the missing element (element factory),

 *            e.g. "videoscale" or "cdparanoiasrc"

 *

 * Creates a missing-plugin message for @element to notify the application

 * that a certain required element is missing. This function is mainly for

 * use in plugins.

 *

 * Returns: a new #GstMessage, or NULL on error

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

GstMessage *

gst_missing_element_message_new (GstElement * element,

    const gchar * factory_name)

{

  GstStructure *s;

  gchar *description;

  g_return_val_if_fail (element != NULL, NULL);

  g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);

  g_return_val_if_fail (factory_name != NULL, NULL);

  description = gst_pb_utils_get_element_description (factory_name);

  s = gst_structure_new ("missing-plugin", "type", G_TYPE_STRING,

      "element", "detail", G_TYPE_STRING, factory_name, "name", G_TYPE_STRING,

      description, NULL);

  g_free (description);

  return gst_message_new_element (GST_OBJECT_CAST (element), s);

}

/**

 * gst_missing_decoder_message_new:

 * @element: the #GstElement posting the message

 * @decode_caps: the (fixed) caps for which a decoder element is needed

 *

 * Creates a missing-plugin message for @element to notify the application

 * that a decoder element for a particular set of (fixed) caps is missing.

 * This function is mainly for use in plugins.

 *

 * Returns: a new #GstMessage, or NULL on error

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

GstMessage *

gst_missing_decoder_message_new (GstElement * element,

    const GstCaps * decode_caps)

{

  GstStructure *s;

  GstCaps *caps;

  gchar *description;

  g_return_val_if_fail (element != NULL, NULL);

  g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);

  g_return_val_if_fail (decode_caps != NULL, NULL);

  g_return_val_if_fail (GST_IS_CAPS (decode_caps), NULL);

  g_return_val_if_fail (!gst_caps_is_any (decode_caps), NULL);

  g_return_val_if_fail (!gst_caps_is_empty (decode_caps), NULL);

  g_return_val_if_fail (gst_caps_is_fixed (decode_caps), NULL);

  description = gst_pb_utils_get_decoder_description (decode_caps);

  caps = copy_and_clean_caps (decode_caps);

  s = gst_structure_new ("missing-plugin", "type", G_TYPE_STRING,

      "decoder", "detail", GST_TYPE_CAPS, caps, "name", G_TYPE_STRING,

      description, NULL);

  gst_caps_unref (caps);

  g_free (description);

  return gst_message_new_element (GST_OBJECT_CAST (element), s);

}

/**

 * gst_missing_encoder_message_new:

 * @element: the #GstElement posting the message

 * @encode_caps: the (fixed) caps for which an encoder element is needed

 *

 * Creates a missing-plugin message for @element to notify the application

 * that an encoder element for a particular set of (fixed) caps is missing.

 * This function is mainly for use in plugins.

 *

 * Returns: a new #GstMessage, or NULL on error

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

GstMessage *

gst_missing_encoder_message_new (GstElement * element,

    const GstCaps * encode_caps)

{

  GstStructure *s;

  GstCaps *caps;

  gchar *description;

  g_return_val_if_fail (element != NULL, NULL);

  g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);

  g_return_val_if_fail (encode_caps != NULL, NULL);

  g_return_val_if_fail (GST_IS_CAPS (encode_caps), NULL);

  g_return_val_if_fail (!gst_caps_is_any (encode_caps), NULL);

  g_return_val_if_fail (!gst_caps_is_empty (encode_caps), NULL);

  g_return_val_if_fail (gst_caps_is_fixed (encode_caps), NULL);

  description = gst_pb_utils_get_encoder_description (encode_caps);

  caps = copy_and_clean_caps (encode_caps);

  s = gst_structure_new ("missing-plugin", "type", G_TYPE_STRING,

      "encoder", "detail", GST_TYPE_CAPS, caps, "name", G_TYPE_STRING,

      description, NULL);

  gst_caps_unref (caps);

  g_free (description);

  return gst_message_new_element (GST_OBJECT_CAST (element), s);

}

static gboolean

missing_structure_get_string_detail (const GstStructure * s, gchar ** p_detail)

{

  const gchar *detail;

  GType detail_type;

  *p_detail = NULL;

  detail_type = gst_structure_get_field_type (s, "detail");

  if (!g_type_is_a (detail_type, G_TYPE_STRING)) {

    GST_WARNING ("expected 'detail' field to be of G_TYPE_STRING");

    return FALSE;

  }

  detail = gst_structure_get_string (s, "detail");

  if (detail == NULL || *detail == '\0') {

    GST_WARNING ("empty 'detail' field");

    return FALSE;

  }

  *p_detail = g_strdup (detail);

  return TRUE;

}

static gboolean

missing_structure_get_caps_detail (const GstStructure * s, GstCaps ** p_caps)

{

  const GstCaps *caps;

  const GValue *val;

  GType detail_type;

  *p_caps = NULL;

  detail_type = gst_structure_get_field_type (s, "detail");

  if (!g_type_is_a (detail_type, GST_TYPE_CAPS)) {

    GST_WARNING ("expected 'detail' field to be of GST_TYPE_CAPS");

    return FALSE;

  }

  val = gst_structure_get_value (s, "detail");

  caps = gst_value_get_caps (val);

  if (gst_caps_is_empty (caps) || gst_caps_is_any (caps)) {

    GST_WARNING ("EMPTY or ANY caps not allowed");

    return FALSE;

  }

  *p_caps = gst_caps_copy (caps);

  return TRUE;

}

/**

 * gst_missing_plugin_message_get_installer_detail:

 * @msg: a missing-plugin #GstMessage of type #GST_MESSAGE_ELEMENT

 *

 * Returns an opaque string containing all the details about the missing

 * element to be passed to an external installer called via

 * gst_install_plugins_async() or gst_install_plugins_sync().

 * 

 * This function is mainly for applications that call external plugin

 * installation mechanisms using one of the two above-mentioned functions.

 *

 * Returns: a newly-allocated detail string, or NULL on error. Free string

 *          with g_free() when not needed any longer.

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

gchar *

gst_missing_plugin_message_get_installer_detail (GstMessage * msg)

{

  GstMissingType missing_type;

  const gchar *progname;

  const gchar *type;

  GString *str = NULL;

  gchar *detail = NULL;

  gchar *desc;

  g_return_val_if_fail (gst_is_missing_plugin_message (msg), NULL);

  GST_LOG ("Parsing missing-plugin message: %" GST_PTR_FORMAT, msg->structure);

  missing_type = missing_structure_get_type (msg->structure);

  if (missing_type == GST_MISSING_TYPE_UNKNOWN) {

    GST_WARNING ("couldn't parse 'type' field");

    goto error;

  }

  type = gst_structure_get_string (msg->structure, "type");

  g_assert (type != NULL);      /* validity already checked above */

  /* FIXME: use gst_installer_detail_new() here too */

  str = g_string_new (GST_DETAIL_STRING_MARKER "|");

  g_string_append_printf (str, "%u.%u|", GST_VERSION_MAJOR, GST_VERSION_MINOR);

  progname = (const gchar *) g_get_prgname ();

  if (progname) {

    g_string_append_printf (str, "%s|", progname);

  } else {

    g_string_append_printf (str, "pid/%lu|", (gulong) getpid ());

  }

  desc = gst_missing_plugin_message_get_description (msg);

  if (desc) {

    g_strdelimit (desc, "|", '#');

    g_string_append_printf (str, "%s|", desc);

    g_free (desc);

  } else {

    g_string_append (str, "|");

  }

  switch (missing_type) {

    case GST_MISSING_TYPE_URISOURCE:

    case GST_MISSING_TYPE_URISINK:

    case GST_MISSING_TYPE_ELEMENT:

      if (!missing_structure_get_string_detail (msg->structure, &detail))

        goto error;

      break;

    case GST_MISSING_TYPE_DECODER:

    case GST_MISSING_TYPE_ENCODER:{

      GstCaps *caps = NULL;

      if (!missing_structure_get_caps_detail (msg->structure, &caps))

        goto error;

      detail = gst_caps_to_string (caps);

      gst_caps_unref (caps);

      break;

    }

    default:

      g_return_val_if_reached (NULL);

  }

  g_string_append_printf (str, "%s-%s", type, detail);

  g_free (detail);

  return g_string_free (str, FALSE);

/* ERRORS */

error:

  {

    GST_WARNING ("Failed to parse missing-plugin msg: %" GST_PTR_FORMAT, msg);

    if (str)

      g_string_free (str, TRUE);

    return NULL;

  }

}

/**

 * gst_missing_plugin_message_get_description:

 * @msg: a missing-plugin #GstMessage of type #GST_MESSAGE_ELEMENT

 *

 * Returns a localised string describing the missing feature, for use in

 * error dialogs and the like. Should never return NULL unless @msg is not

 * a valid missing-plugin message.

 *

 * This function is mainly for applications that need a human-readable string

 * describing a missing plugin, given a previously collected missing-plugin

 * message

 *

 * Returns: a newly-allocated description string, or NULL on error. Free

 *          string with g_free() when not needed any longer.

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

gchar *

gst_missing_plugin_message_get_description (GstMessage * msg)

{

  GstMissingType missing_type;

  const gchar *desc;

  gchar *ret = NULL;

  g_return_val_if_fail (gst_is_missing_plugin_message (msg), NULL);