/* GStreamer
 * Copyright (C) <2019> Seungha Yang <seungha.yang@navercorp.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 St, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

/**
 * element-cudadownload:
 *
 * Downloads data from NVIDA GPU via CUDA APIs
 *
 * Since: 1.20
 */

#ifdef HAVE_CONFIG_H
#  include <config.h>
#endif

#include "gstcudadownload.h"

GST_DEBUG_CATEGORY_STATIC (gst_cuda_download_debug);
#define GST_CAT_DEFAULT gst_cuda_download_debug

static GstStaticPadTemplate sink_template = GST_STATIC_PAD_TEMPLATE ("sink",
    GST_PAD_SINK,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS ("video/x-raw(" GST_CAPS_FEATURE_MEMORY_CUDA_MEMORY
        "); video/x-raw"));

static GstStaticPadTemplate src_template = GST_STATIC_PAD_TEMPLATE ("src",
    GST_PAD_SRC,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS ("video/x-raw"));

G_DEFINE_TYPE (GstCudaDownload, gst_cuda_download,
    GST_TYPE_CUDA_BASE_TRANSFORM);

static GstCaps *gst_cuda_download_transform_caps (GstBaseTransform * trans,
    GstPadDirection direction, GstCaps * caps, GstCaps * filter);

static void
gst_cuda_download_class_init (GstCudaDownloadClass * klass)
{
  GstElementClass *element_class;
  GstBaseTransformClass *trans_class;

  element_class = GST_ELEMENT_CLASS (klass);
  trans_class = GST_BASE_TRANSFORM_CLASS (klass);

  gst_element_class_add_static_pad_template (element_class, &sink_template);
  gst_element_class_add_static_pad_template (element_class, &src_template);

  gst_element_class_set_static_metadata (element_class,
      "CUDA downloader", "Filter/Video",
      "Downloads data from NVIDA GPU via CUDA APIs",
      "Seungha Yang <seungha.yang@navercorp.com>");

  trans_class->passthrough_on_same_caps = TRUE;

  trans_class->transform_caps =
      GST_DEBUG_FUNCPTR (gst_cuda_download_transform_caps);

  GST_DEBUG_CATEGORY_INIT (gst_cuda_download_debug,
      "cudadownload", 0, "cudadownload Element");
}

static void
gst_cuda_download_init (GstCudaDownload * download)
{
}

static GstCaps *
_set_caps_features (const GstCaps * caps, const gchar * feature_name)
{
  GstCaps *tmp = gst_caps_copy (caps);
  guint n = gst_caps_get_size (tmp);
  guint i = 0;

  for (i = 0; i < n; i++)
    gst_caps_set_features (tmp, i,
        gst_caps_features_from_string (feature_name));

  return tmp;
}

static GstCaps *
gst_cuda_download_transform_caps (GstBaseTransform * trans,
    GstPadDirection direction, GstCaps * caps, GstCaps * filter)
{
  GstCaps *result, *tmp;

  GST_DEBUG_OBJECT (trans,
      "Transforming caps %" GST_PTR_FORMAT " in direction %s", caps,
      (direction == GST_PAD_SINK) ? "sink" : "src");

  if (direction == GST_PAD_SINK) {
    tmp = _set_caps_features (caps, GST_CAPS_FEATURE_MEMORY_SYSTEM_MEMORY);
    tmp = gst_caps_merge (gst_caps_ref (caps), tmp);
  } else {
    GstCaps *newcaps;
    tmp = gst_caps_ref (caps);

    newcaps = _set_caps_features (caps, GST_CAPS_FEATURE_MEMORY_CUDA_MEMORY);
    tmp = gst_caps_merge (tmp, newcaps);
  }

  if (filter) {
    result = gst_caps_intersect_full (filter, tmp, GST_CAPS_INTERSECT_FIRST);
    gst_caps_unref (tmp);
  } else {
    result = tmp;
  }

  GST_DEBUG_OBJECT (trans, "returning caps: %" GST_PTR_FORMAT, result);

  return result;
}