/* GStreamer
 * Copyright (C) 2022 Seungha Yang <seungha@centricular.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.
 */

/**
 * SECTION:element-qsvh264dec
 * @title: qsvh264dec
 *
 * Intel Quick Sync H.264 decoder
 *
 * ## Example launch line
 * ```
 * gst-launch-1.0 filesrc location=/path/to/h264/file ! parsebin ! qsvh264dec ! videoconvert ! autovideosink
 * ```
 *
 * Since: 1.22
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "gstqsvh264dec.h"
#include <gst/codecparsers/gsth264parser.h>
#include <string>
#include <string.h>

#ifdef G_OS_WIN32
#include <gst/d3d11/gstd3d11.h>
#else
#include <gst/va/gstva.h>
#endif

GST_DEBUG_CATEGORY_STATIC (gst_qsv_h264_dec_debug);
#define GST_CAT_DEFAULT gst_qsv_h264_dec_debug

#define DOC_SINK_CAPS \
    "video/x-h264, width = (int) [ 16, 4096 ], height = (int) [ 16, 4096 ], " \
    "stream-format = (string) { byte-stream, avc, avc3 }, " \
    "alignment = (string) au, " \
    "profile = (string) { high, progressive-high, constrained-high, main, " \
    "constrained-baseline, baseline }"

#define DOC_SRC_CAPS_COMM \
    "format = (string) NV12, " \
    "width = (int) [ 16, 4096 ], height = (int) [ 16, 4096 ]"

#define DOC_SRC_CAPS \
    "video/x-raw(memory:D3D11Memory), " DOC_SRC_CAPS_COMM "; " \
    "video/x-raw, " DOC_SRC_CAPS_COMM

typedef struct _GstQsvH264Dec
{
  GstQsvDecoder parent;
  GstH264NalParser *parser;
  gboolean packetized;
  gboolean nal_length_size;

  GstBuffer *sps_nals[GST_H264_MAX_SPS_COUNT];
  GstBuffer *pps_nals[GST_H264_MAX_PPS_COUNT];
} GstQsvH264Dec;

typedef struct _GstQsvH264DecClass
{
  GstQsvDecoderClass parent_class;
} GstQsvH264DecClass;

static GTypeClass *parent_class = nullptr;

#define GST_QSV_H264_DEC(object) ((GstQsvH264Dec *) (object))
#define GST_QSV_H264_DEC_GET_CLASS(object) \
    (G_TYPE_INSTANCE_GET_CLASS ((object),G_TYPE_FROM_INSTANCE (object),GstQsvH264DecClass))

static gboolean gst_qsv_h264_dec_start (GstVideoDecoder * decoder);
static gboolean gst_qsv_h264_dec_stop (GstVideoDecoder * decoder);
static gboolean gst_qsv_h264_dec_set_format (GstQsvDecoder * decoder,
    GstVideoCodecState * state);
static GstBuffer *gst_qsv_h264_dec_process_input (GstQsvDecoder * decoder,
    gboolean need_codec_data, GstBuffer * buffer);

static void
gst_qsv_h264_dec_class_init (GstQsvH264DecClass * klass, gpointer data)
{
  GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
  GstVideoDecoderClass *videodec_class = GST_VIDEO_DECODER_CLASS (klass);
  GstQsvDecoderClass *qsvdec_class = GST_QSV_DECODER_CLASS (klass);
  GstQsvDecoderClassData *cdata = (GstQsvDecoderClassData *) data;
  GstPadTemplate *pad_templ;
  GstCaps *doc_caps;

  parent_class = (GTypeClass *) g_type_class_peek_parent (klass);

#ifdef G_OS_WIN32
  std::string long_name = "Intel Quick Sync Video " +
      std::string (cdata->description) + " H.264 Decoder";

  gst_element_class_set_metadata (element_class, long_name.c_str (),
      "Codec/Decoder/Video/Hardware",
      "Intel Quick Sync Video H.264 Decoder",
      "Seungha Yang <seungha@centricular.com>");
#else
  gst_element_class_set_static_metadata (element_class,
      "Intel Quick Sync Video H.264 Decoder",
      "Codec/Decoder/Video/Hardware",
      "Intel Quick Sync Video H.264 Decoder",
      "Seungha Yang <seungha@centricular.com>");
#endif

  pad_templ = gst_pad_template_new ("sink",
      GST_PAD_SINK, GST_PAD_ALWAYS, cdata->sink_caps);
  doc_caps = gst_caps_from_string (DOC_SINK_CAPS);
  gst_pad_template_set_documentation_caps (pad_templ, doc_caps);
  gst_caps_unref (doc_caps);
  gst_element_class_add_pad_template (element_class, pad_templ);

  pad_templ = gst_pad_template_new ("src",
      GST_PAD_SRC, GST_PAD_ALWAYS, cdata->src_caps);
  doc_caps = gst_caps_from_string (DOC_SRC_CAPS);
  gst_pad_template_set_documentation_caps (pad_templ, doc_caps);
  gst_caps_unref (doc_caps);
  gst_element_class_add_pad_template (element_class, pad_templ);

  videodec_class->start = GST_DEBUG_FUNCPTR (gst_qsv_h264_dec_start);
  videodec_class->stop = GST_DEBUG_FUNCPTR (gst_qsv_h264_dec_stop);

  qsvdec_class->set_format = GST_DEBUG_FUNCPTR (gst_qsv_h264_dec_set_format);
  qsvdec_class->process_input =
      GST_DEBUG_FUNCPTR (gst_qsv_h264_dec_process_input);

  qsvdec_class->codec_id = MFX_CODEC_AVC;
  qsvdec_class->impl_index = cdata->impl_index;
  qsvdec_class->adapter_luid = cdata->adapter_luid;
  qsvdec_class->display_path = cdata->display_path;

  gst_caps_unref (cdata->sink_caps);
  gst_caps_unref (cdata->src_caps);
  g_free (cdata->description);
  g_free (cdata);
}

static void
gst_qsv_h264_dec_init (GstQsvH264Dec * self)
{
}

static gboolean
gst_qsv_h264_dec_start (GstVideoDecoder * decoder)
{
  GstQsvH264Dec *self = GST_QSV_H264_DEC (decoder);

  self->parser = gst_h264_nal_parser_new ();

  return TRUE;
}

static void
gst_qsv_h264_dec_clear_codec_data (GstQsvH264Dec * self)
{
  guint i;

  for (i = 0; i < G_N_ELEMENTS (self->sps_nals); i++)
    gst_clear_buffer (&self->sps_nals[i]);

  for (i = 0; i < G_N_ELEMENTS (self->pps_nals); i++)
    gst_clear_buffer (&self->pps_nals[i]);
}

static gboolean
gst_qsv_h264_dec_stop (GstVideoDecoder * decoder)
{
  GstQsvH264Dec *self = GST_QSV_H264_DEC (decoder);

  gst_qsv_h264_dec_clear_codec_data (self);

  return GST_VIDEO_DECODER_CLASS (parent_class)->stop (decoder);
}

static void
gst_qsv_h264_dec_store_nal (GstQsvH264Dec * self, guint id,
    GstH264NalUnitType nal_type, GstH264NalUnit * nalu)
{
  GstBuffer *buf, **store;
  guint size = nalu->size, store_size;
  static const guint8 start_code[] = { 0, 0, 1 };

  if (nal_type == GST_H264_NAL_SPS || nal_type == GST_H264_NAL_SUBSET_SPS) {
    store_size = GST_H264_MAX_SPS_COUNT;
    store = self->sps_nals;
    GST_DEBUG_OBJECT (self, "storing sps %u", id);
  } else if (nal_type == GST_H264_NAL_PPS) {
    store_size = GST_H264_MAX_PPS_COUNT;
    store = self->pps_nals;
    GST_DEBUG_OBJECT (self, "storing pps %u", id);
  } else {
    return;
  }

  if (id >= store_size) {
    GST_DEBUG_OBJECT (self, "unable to store nal, id out-of-range %d", id);
    return;
  }

  buf = gst_buffer_new_allocate (nullptr, size + sizeof (start_code), nullptr);
  gst_buffer_fill (buf, 0, start_code, sizeof (start_code));
  gst_buffer_fill (buf, sizeof (start_code), nalu->data + nalu->offset, size);

  if (store[id])
    gst_buffer_unref (store[id]);

  store[id] = buf;
}

static gboolean
gst_qsv_h264_dec_parse_codec_data (GstQsvH264Dec * self, const guint8 * data,
    gsize size)
{
  GstH264NalParser *parser = self->parser;
  GstH264DecoderConfigRecord *config = nullptr;
  GstH264NalUnit *nalu;
  GstH264ParserResult pres = GST_H264_PARSER_OK;
  gboolean ret = TRUE;
  guint i;

  if (gst_h264_parser_parse_decoder_config_record (parser, data, size,
          &config) != GST_H264_PARSER_OK) {
    GST_WARNING_OBJECT (self, "Failed to parse codec-data");
    return FALSE;
  }

  self->nal_length_size = config->length_size_minus_one + 1;
  for (i = 0; i < config->sps->len; i++) {
    GstH264SPS sps;
    nalu = &g_array_index (config->sps, GstH264NalUnit, i);

    if (nalu->type == GST_H264_NAL_SPS)
      pres = gst_h264_parser_parse_sps (parser, nalu, &sps);
    else if (nalu->type == GST_H264_NAL_SUBSET_SPS)
      pres = gst_h264_parser_parse_subset_sps (parser, nalu, &sps);
    else
      continue;

    if (pres != GST_H264_PARSER_OK) {
      GST_WARNING_OBJECT (self, "Failed to parse SPS");
      ret = FALSE;
      goto out;
    }

    gst_qsv_h264_dec_store_nal (self,
        sps.id, (GstH264NalUnitType) nalu->type, nalu);
    gst_h264_sps_clear (&sps);
  }

  for (i = 0; i < config->pps->len; i++) {
    GstH264PPS pps;

    nalu = &g_array_index (config->pps, GstH264NalUnit, i);
    if (nalu->type != GST_H264_NAL_PPS)
      continue;

    pres = gst_h264_parser_parse_pps (parser, nalu, &pps);
    if (pres != GST_H264_PARSER_OK) {
      GST_WARNING_OBJECT (self, "Failed to parse PPS nalu");
      ret = FALSE;
      goto out;
    }

    gst_qsv_h264_dec_store_nal (self, pps.id, GST_H264_NAL_PPS, nalu);
    gst_h264_pps_clear (&pps);
  }

out:
  gst_h264_decoder_config_record_free (config);
  return ret;
}

static gboolean
gst_qsv_h264_dec_set_format (GstQsvDecoder * decoder,
    GstVideoCodecState * state)
{
  GstQsvH264Dec *self = GST_QSV_H264_DEC (decoder);
  GstStructure *s;
  const gchar *str;
  GstMapInfo map;

  gst_qsv_h264_dec_clear_codec_data (self);
  self->packetized = FALSE;

  s = gst_caps_get_structure (state->caps, 0);
  str = gst_structure_get_string (s, "stream-format");
  if ((g_strcmp0 (str, "avc") == 0 || g_strcmp0 (str, "avc3")) &&
      state->codec_data) {
    self->packetized = TRUE;
    /* Will be updated */
    self->nal_length_size = 4;
  }

  if (!self->packetized)
    return TRUE;

  if (!gst_buffer_map (state->codec_data, &map, GST_MAP_READ)) {
    GST_ERROR_OBJECT (self, "Failed to map codec data");
    return FALSE;
  }

  gst_qsv_h264_dec_parse_codec_data (self, map.data, map.size);
  gst_buffer_unmap (state->codec_data, &map);

  return TRUE;
}

static GstBuffer *
gst_qsv_h264_dec_process_input (GstQsvDecoder * decoder,
    gboolean need_codec_data, GstBuffer * buffer)
{
  GstQsvH264Dec *self = GST_QSV_H264_DEC (decoder);
  GstH264NalParser *parser = self->parser;
  GstH264NalUnit nalu;
  GstH264ParserResult pres;
  GstMapInfo map;
  gboolean have_sps = FALSE;
  gboolean have_pps = FALSE;
  guint i;
  GstBuffer *new_buf;
  static const guint8 start_code[] = { 0, 0, 1 };

  if (!self->packetized)
    return gst_buffer_ref (buffer);

  if (!gst_buffer_map (buffer, &map, GST_MAP_READ)) {
    GST_ERROR_OBJECT (self, "Failed to map input buffer");
    return nullptr;
  }

  memset (&nalu, 0, sizeof (GstH264NalUnit));
  new_buf = gst_buffer_new ();

  do {
    GstMemory *mem;
    guint8 *data;
    gsize size;

    pres = gst_h264_parser_identify_nalu_avc (parser, map.data,
        nalu.offset + nalu.size, map.size, self->nal_length_size, &nalu);

    if (pres == GST_H264_PARSER_NO_NAL_END)
      pres = GST_H264_PARSER_OK;

    switch (nalu.type) {
      case GST_H264_NAL_SPS:
      case GST_H264_NAL_SUBSET_SPS:{
        GstH264SPS sps;

        if (nalu.type == GST_H264_NAL_SPS) {
          pres = gst_h264_parser_parse_sps (parser, &nalu, &sps);
        } else {
          pres = gst_h264_parser_parse_subset_sps (parser, &nalu, &sps);
        }

        if (pres != GST_H264_PARSER_OK)
          break;

        have_sps = TRUE;
        gst_qsv_h264_dec_store_nal (self,
            sps.id, (GstH264NalUnitType) nalu.type, &nalu);
        gst_h264_sps_clear (&sps);
        break;
      }
      case GST_H264_NAL_PPS:{
        GstH264PPS pps;

        pres = gst_h264_parser_parse_pps (parser, &nalu, &pps);
        if (pres != GST_H264_PARSER_OK)
          break;

        have_pps = TRUE;
        gst_qsv_h264_dec_store_nal (self,
            pps.id, (GstH264NalUnitType) nalu.type, &nalu);
        gst_h264_pps_clear (&pps);
        break;
      }
      default:
        break;
    }

    size = sizeof (start_code) + nalu.size;
    data = (guint8 *) g_malloc (size);
    memcpy (data, start_code, sizeof (start_code));
    memcpy (data + sizeof (start_code), nalu.data + nalu.offset, nalu.size);

    mem = gst_memory_new_wrapped ((GstMemoryFlags) 0, data, size, 0, size,
        nullptr, (GDestroyNotify) g_free);
    gst_buffer_append_memory (new_buf, mem);
  } while (pres == GST_H264_PARSER_OK);

  gst_buffer_unmap (buffer, &map);

  if (need_codec_data) {
    GstBuffer *tmp = gst_buffer_new ();

    if (!have_sps) {
      for (i = 0; i < GST_H264_MAX_SPS_COUNT; i++) {
        if (!self->sps_nals[i])
          continue;

        tmp = gst_buffer_append (tmp, gst_buffer_ref (self->sps_nals[i]));
      }
    }

    if (!have_pps) {
      for (i = 0; i < GST_H264_MAX_PPS_COUNT; i++) {
        if (!self->pps_nals[i])
          continue;

        tmp = gst_buffer_append (tmp, gst_buffer_ref (self->pps_nals[i]));
      }
    }

    new_buf = gst_buffer_append (tmp, new_buf);
  }

  return new_buf;
}

typedef struct
{
  guint width;
  guint height;
} Resolution;

void
gst_qsv_h264_dec_register (GstPlugin * plugin, guint rank, guint impl_index,
    GstObject * device, mfxSession session)
{
  mfxVideoParam param;
  mfxInfoMFX *mfx;
  static const Resolution resolutions_to_check[] = {
    {1280, 720}, {1920, 1088}, {2560, 1440}, {3840, 2160}, {4096, 2160},
    {7680, 4320}, {8192, 4320}
  };
  Resolution max_resolution;

  GST_DEBUG_CATEGORY_INIT (gst_qsv_h264_dec_debug,
      "qsvh264dec", 0, "qsvh264dec");

  memset (&param, 0, sizeof (mfxVideoParam));
  memset (&max_resolution, 0, sizeof (Resolution));

  param.AsyncDepth = 4;
  param.IOPattern = MFX_IOPATTERN_OUT_VIDEO_MEMORY;

  mfx = &param.mfx;
  mfx->CodecId = MFX_CODEC_AVC;

  mfx->FrameInfo.FrameRateExtN = 30;
  mfx->FrameInfo.FrameRateExtD = 1;
  mfx->FrameInfo.AspectRatioW = 1;
  mfx->FrameInfo.AspectRatioH = 1;
  mfx->FrameInfo.ChromaFormat = MFX_CHROMAFORMAT_YUV420;
  mfx->FrameInfo.FourCC = MFX_FOURCC_NV12;
  mfx->FrameInfo.BitDepthLuma = 8;
  mfx->FrameInfo.BitDepthChroma = 8;
  mfx->FrameInfo.PicStruct = MFX_PICSTRUCT_PROGRESSIVE;
  mfx->CodecProfile = MFX_PROFILE_AVC_MAIN;

  /* Check max-resolution */
  for (guint i = 0; i < G_N_ELEMENTS (resolutions_to_check); i++) {
    mfx->FrameInfo.Width = GST_ROUND_UP_16 (resolutions_to_check[i].width);
    mfx->FrameInfo.Height = GST_ROUND_UP_16 (resolutions_to_check[i].height);
    mfx->FrameInfo.CropW = resolutions_to_check[i].width;
    mfx->FrameInfo.CropH = resolutions_to_check[i].height;

    if (MFXVideoDECODE_Query (session, &param, &param) != MFX_ERR_NONE)
      break;

    max_resolution.width = resolutions_to_check[i].width;
    max_resolution.height = resolutions_to_check[i].height;
  }

  if (max_resolution.width == 0 || max_resolution.height == 0)
    return;

  GST_INFO ("Maximum supported resolution: %dx%d",
      max_resolution.width, max_resolution.height);

  /* To cover both landscape and portrait,
   * select max value (width in this case) */
  guint resolution = MAX (max_resolution.width, max_resolution.height);
  std::string src_caps_str = "video/x-raw, format=(string) NV12";

  src_caps_str += ", width=(int) [ 16, " + std::to_string (resolution) + " ]";
  src_caps_str += ", height=(int) [ 16, " + std::to_string (resolution) + " ]";

  GstCaps *src_caps = gst_caps_from_string (src_caps_str.c_str ());

  /* TODO: Add support for VA */
#ifdef G_OS_WIN32
  GstCaps *d3d11_caps = gst_caps_copy (src_caps);
  GstCapsFeatures *caps_features =
      gst_caps_features_new (GST_CAPS_FEATURE_MEMORY_D3D11_MEMORY, nullptr);
  gst_caps_set_features_simple (d3d11_caps, caps_features);
  gst_caps_append (d3d11_caps, src_caps);
  src_caps = d3d11_caps;
#endif

  std::string sink_caps_str = "video/x-h264";
  sink_caps_str += ", width=(int) [ 16, " + std::to_string (resolution) + " ]";
  sink_caps_str += ", height=(int) [ 16, " + std::to_string (resolution) + " ]";

  sink_caps_str += ", stream-format=(string) { byte-stream, avc, avc3 }";
  sink_caps_str += ", alignment=(string) au";
  sink_caps_str += ", profile=(string) { high, progressive-high, "
      "constrained-high, main, constrained-baseline, baseline } ";

  GstCaps *sink_caps = gst_caps_from_string (sink_caps_str.c_str ());

  GST_MINI_OBJECT_FLAG_SET (sink_caps, GST_MINI_OBJECT_FLAG_MAY_BE_LEAKED);
  GST_MINI_OBJECT_FLAG_SET (src_caps, GST_MINI_OBJECT_FLAG_MAY_BE_LEAKED);

  GstQsvDecoderClassData *cdata = g_new0 (GstQsvDecoderClassData, 1);
  cdata->sink_caps = sink_caps;
  cdata->src_caps = src_caps;
  cdata->impl_index = impl_index;

#ifdef G_OS_WIN32
  g_object_get (device, "adapter-luid", &cdata->adapter_luid,
      "description", &cdata->description, nullptr);
#else
  g_object_get (device, "path", &cdata->display_path, nullptr);
#endif

  GType type;
  gchar *type_name;
  gchar *feature_name;
  GTypeInfo type_info = {
    sizeof (GstQsvH264DecClass),
    nullptr,
    nullptr,
    (GClassInitFunc) gst_qsv_h264_dec_class_init,
    nullptr,
    cdata,
    sizeof (GstQsvH264Dec),
    0,
    (GInstanceInitFunc) gst_qsv_h264_dec_init,
  };

  type_name = g_strdup ("GstQsvH264Dec");
  feature_name = g_strdup ("qsvh264dec");

  gint index = 0;
  while (g_type_from_name (type_name)) {
    index++;
    g_free (type_name);
    g_free (feature_name);
    type_name = g_strdup_printf ("GstQsvH264Device%dDec", index);
    feature_name = g_strdup_printf ("qsvh264device%ddec", index);
  }

  type = g_type_register_static (GST_TYPE_QSV_DECODER, type_name, &type_info,
      (GTypeFlags) 0);

  if (rank > 0 && index != 0)
    rank--;

  if (index != 0)
    gst_element_type_set_skip_documentation (type);

  if (!gst_element_register (plugin, feature_name, rank, type))
    GST_WARNING ("Failed to register plugin '%s'", type_name);

  g_free (type_name);
  g_free (feature_name);
}