/* GStreamer
 * Copyright (C) 2020 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.
 */

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

#include "gstnvvp8dec.h"
#include "gstcudautils.h"
#include "gstnvdecoder.h"

#include <string.h>

GST_DEBUG_CATEGORY_STATIC (gst_nv_vp8_dec_debug);
#define GST_CAT_DEFAULT gst_nv_vp8_dec_debug

/* reference list 4 + 2 margin */
#define NUM_OUTPUT_VIEW 6

struct _GstNvVp8Dec
{
  GstVp8Decoder parent;

  GstVideoCodecState *output_state;

  GstCudaContext *context;
  GstNvDecoder *decoder;
  CUVIDPICPARAMS params;

  guint width, height;
};

struct _GstNvVp8DecClass
{
  GstVp8DecoderClass parent_class;
  guint cuda_device_id;
};

#define gst_nv_vp8_dec_parent_class parent_class

/**
 * GstNvVp8Dec:
 *
 * Since: 1.20
 */
G_DEFINE_TYPE (GstNvVp8Dec, gst_nv_vp8_dec, GST_TYPE_VP8_DECODER);

static void gst_nv_vp8_dec_set_context (GstElement * element,
    GstContext * context);
static gboolean gst_nv_vp8_dec_open (GstVideoDecoder * decoder);
static gboolean gst_nv_vp8_dec_close (GstVideoDecoder * decoder);
static gboolean gst_nv_vp8_dec_negotiate (GstVideoDecoder * decoder);
static gboolean gst_nv_vp8_dec_decide_allocation (GstVideoDecoder *
    decoder, GstQuery * query);
static gboolean gst_nv_vp8_dec_src_query (GstVideoDecoder * decoder,
    GstQuery * query);

/* GstVp8Decoder */
static GstFlowReturn gst_nv_vp8_dec_new_sequence (GstVp8Decoder * decoder,
    const GstVp8FrameHdr * frame_hdr);
static GstFlowReturn gst_nv_vp8_dec_new_picture (GstVp8Decoder * decoder,
    GstVideoCodecFrame * frame, GstVp8Picture * picture);
static GstFlowReturn gst_nv_vp8_dec_decode_picture (GstVp8Decoder * decoder,
    GstVp8Picture * picture, GstVp8Parser * parser);
static GstFlowReturn gst_nv_vp8_dec_output_picture (GstVp8Decoder *
    decoder, GstVideoCodecFrame * frame, GstVp8Picture * picture);
static guint gst_nv_vp8_dec_get_preferred_output_delay (GstVp8Decoder * decoder,
    gboolean is_live);

static void
gst_nv_vp8_dec_class_init (GstNvVp8DecClass * klass)
{
  GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
  GstVideoDecoderClass *decoder_class = GST_VIDEO_DECODER_CLASS (klass);
  GstVp8DecoderClass *vp8decoder_class = GST_VP8_DECODER_CLASS (klass);

  element_class->set_context = GST_DEBUG_FUNCPTR (gst_nv_vp8_dec_set_context);

  decoder_class->open = GST_DEBUG_FUNCPTR (gst_nv_vp8_dec_open);
  decoder_class->close = GST_DEBUG_FUNCPTR (gst_nv_vp8_dec_close);
  decoder_class->negotiate = GST_DEBUG_FUNCPTR (gst_nv_vp8_dec_negotiate);
  decoder_class->decide_allocation =
      GST_DEBUG_FUNCPTR (gst_nv_vp8_dec_decide_allocation);
  decoder_class->src_query = GST_DEBUG_FUNCPTR (gst_nv_vp8_dec_src_query);

  vp8decoder_class->new_sequence =
      GST_DEBUG_FUNCPTR (gst_nv_vp8_dec_new_sequence);
  vp8decoder_class->new_picture =
      GST_DEBUG_FUNCPTR (gst_nv_vp8_dec_new_picture);
  vp8decoder_class->decode_picture =
      GST_DEBUG_FUNCPTR (gst_nv_vp8_dec_decode_picture);
  vp8decoder_class->output_picture =
      GST_DEBUG_FUNCPTR (gst_nv_vp8_dec_output_picture);
  vp8decoder_class->get_preferred_output_delay =
      GST_DEBUG_FUNCPTR (gst_nv_vp8_dec_get_preferred_output_delay);

  GST_DEBUG_CATEGORY_INIT (gst_nv_vp8_dec_debug,
      "nvvp8dec", 0, "NVIDIA VP8 Decoder");

  gst_type_mark_as_plugin_api (GST_TYPE_NV_VP8_DEC, 0);
}

static void
gst_nv_vp8_dec_init (GstNvVp8Dec * self)
{
}

static void
gst_nv_vp8_dec_set_context (GstElement * element, GstContext * context)
{
  GstNvVp8Dec *self = GST_NV_VP8_DEC (element);
  GstNvVp8DecClass *klass = GST_NV_VP8_DEC_GET_CLASS (self);

  GST_DEBUG_OBJECT (self, "set context %s",
      gst_context_get_context_type (context));

  if (gst_cuda_handle_set_context (element, context, klass->cuda_device_id,
          &self->context)) {
    goto done;
  }

  if (self->decoder)
    gst_nv_decoder_handle_set_context (self->decoder, element, context);

done:
  GST_ELEMENT_CLASS (parent_class)->set_context (element, context);
}

static gboolean
gst_nv_vp8_dec_open (GstVideoDecoder * decoder)
{
  GstNvVp8Dec *self = GST_NV_VP8_DEC (decoder);
  GstNvVp8DecClass *klass = GST_NV_VP8_DEC_GET_CLASS (self);

  if (!gst_cuda_ensure_element_context (GST_ELEMENT (self),
          klass->cuda_device_id, &self->context)) {
    GST_ERROR_OBJECT (self, "Required element data is unavailable");
    return FALSE;
  }

  self->decoder = gst_nv_decoder_new (self->context);
  if (!self->decoder) {
    GST_ERROR_OBJECT (self, "Failed to create decoder object");
    gst_clear_object (&self->context);

    return FALSE;
  }

  return TRUE;
}

static gboolean
gst_nv_vp8_dec_close (GstVideoDecoder * decoder)
{
  GstNvVp8Dec *self = GST_NV_VP8_DEC (decoder);

  g_clear_pointer (&self->output_state, gst_video_codec_state_unref);
  gst_clear_object (&self->decoder);
  gst_clear_object (&self->context);

  return TRUE;
}

static gboolean
gst_nv_vp8_dec_negotiate (GstVideoDecoder * decoder)
{
  GstNvVp8Dec *self = GST_NV_VP8_DEC (decoder);
  GstVp8Decoder *vp8dec = GST_VP8_DECODER (decoder);

  GST_DEBUG_OBJECT (self, "negotiate");

  gst_nv_decoder_negotiate (self->decoder, decoder, vp8dec->input_state,
      &self->output_state);

  /* TODO: add support D3D11 memory */

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

static gboolean
gst_nv_vp8_dec_decide_allocation (GstVideoDecoder * decoder, GstQuery * query)
{
  GstNvVp8Dec *self = GST_NV_VP8_DEC (decoder);

  if (!gst_nv_decoder_decide_allocation (self->decoder, decoder, query)) {
    GST_WARNING_OBJECT (self, "Failed to handle decide allocation");
    return FALSE;
  }

  return GST_VIDEO_DECODER_CLASS (parent_class)->decide_allocation
      (decoder, query);
}

static gboolean
gst_nv_vp8_dec_src_query (GstVideoDecoder * decoder, GstQuery * query)
{
  GstNvVp8Dec *self = GST_NV_VP8_DEC (decoder);

  switch (GST_QUERY_TYPE (query)) {
    case GST_QUERY_CONTEXT:
      if (gst_cuda_handle_context_query (GST_ELEMENT (decoder), query,
              self->context)) {
        return TRUE;
      } else if (self->decoder &&
          gst_nv_decoder_handle_context_query (self->decoder, decoder, query)) {
        return TRUE;
      }
      break;
    default:
      break;
  }

  return GST_VIDEO_DECODER_CLASS (parent_class)->src_query (decoder, query);
}

static GstFlowReturn
gst_nv_vp8_dec_new_sequence (GstVp8Decoder * decoder,
    const GstVp8FrameHdr * frame_hdr)
{
  GstNvVp8Dec *self = GST_NV_VP8_DEC (decoder);
  gboolean modified = FALSE;

  GST_LOG_OBJECT (self, "new sequence");

  if (self->width != frame_hdr->width || self->height != frame_hdr->height) {
    if (self->decoder) {
      GST_INFO_OBJECT (self, "resolution changed %dx%d -> %dx%d",
          self->width, self->height, frame_hdr->width, frame_hdr->height);
    }

    self->width = frame_hdr->width;
    self->height = frame_hdr->height;

    modified = TRUE;
  }

  if (modified || !gst_nv_decoder_is_configured (self->decoder)) {
    GstVideoInfo info;

    gst_video_info_set_format (&info,
        GST_VIDEO_FORMAT_NV12, self->width, self->height);

    if (!gst_nv_decoder_configure (self->decoder,
            cudaVideoCodec_VP8, &info, self->width, self->height,
            /* +4 for render delay */
            NUM_OUTPUT_VIEW + 4)) {
      GST_ERROR_OBJECT (self, "Failed to configure decoder");
      return GST_FLOW_NOT_NEGOTIATED;
    }

    if (!gst_video_decoder_negotiate (GST_VIDEO_DECODER (self))) {
      GST_ERROR_OBJECT (self, "Failed to negotiate with downstream");
      return GST_FLOW_NOT_NEGOTIATED;
    }

    memset (&self->params, 0, sizeof (CUVIDPICPARAMS));

    self->params.PicWidthInMbs = GST_ROUND_UP_16 (self->width) >> 4;
    self->params.FrameHeightInMbs = GST_ROUND_UP_16 (self->height) >> 4;

    self->params.CodecSpecific.vp8.width = self->width;
    self->params.CodecSpecific.vp8.height = self->height;
  }

  return GST_FLOW_OK;
}

static GstFlowReturn
gst_nv_vp8_dec_new_picture (GstVp8Decoder * decoder,
    GstVideoCodecFrame * frame, GstVp8Picture * picture)
{
  GstNvVp8Dec *self = GST_NV_VP8_DEC (decoder);
  GstNvDecoderFrame *nv_frame;

  nv_frame = gst_nv_decoder_new_frame (self->decoder);
  if (!nv_frame) {
    GST_ERROR_OBJECT (self, "No available decoder frame");
    return GST_FLOW_ERROR;
  }

  GST_LOG_OBJECT (self,
      "New decoder frame %p (index %d)", nv_frame, nv_frame->index);

  gst_vp8_picture_set_user_data (picture,
      nv_frame, (GDestroyNotify) gst_nv_decoder_frame_unref);

  return GST_FLOW_OK;
}

static GstNvDecoderFrame *
gst_nv_vp8_dec_get_decoder_frame_from_picture (GstNvVp8Dec * self,
    GstVp8Picture * picture)
{
  GstNvDecoderFrame *frame;

  frame = (GstNvDecoderFrame *) gst_vp8_picture_get_user_data (picture);

  if (!frame)
    GST_DEBUG_OBJECT (self, "current picture does not have decoder frame");

  return frame;
}

static GstFlowReturn
gst_nv_vp8_dec_decode_picture (GstVp8Decoder * decoder,
    GstVp8Picture * picture, GstVp8Parser * parser)
{
  GstNvVp8Dec *self = GST_NV_VP8_DEC (decoder);
  GstVp8FrameHdr *frame_hdr = &picture->frame_hdr;
  GstNvDecoderFrame *frame;
  GstNvDecoderFrame *other_frame;
  guint offset = 0;

  GST_LOG_OBJECT (self, "Decode picture, size %" G_GSIZE_FORMAT, picture->size);

  frame = gst_nv_vp8_dec_get_decoder_frame_from_picture (self, picture);
  if (!frame) {
    GST_ERROR_OBJECT (self, "Decoder frame is unavailable");
    return GST_FLOW_ERROR;
  }

  self->params.nBitstreamDataLen = picture->size;
  self->params.pBitstreamData = picture->data;
  self->params.nNumSlices = 1;
  self->params.pSliceDataOffsets = &offset;

  self->params.CurrPicIdx = frame->index;

  self->params.CodecSpecific.vp8.first_partition_size =
      frame_hdr->first_part_size;

  if (decoder->alt_ref_picture) {
    other_frame =
        gst_nv_vp8_dec_get_decoder_frame_from_picture (self,
        decoder->alt_ref_picture);
    if (!other_frame) {
      GST_ERROR_OBJECT (self, "Couldn't get decoder frame for AltRef");
      return GST_FLOW_ERROR;
    }

    self->params.CodecSpecific.vp8.AltRefIdx = other_frame->index;
  } else {
    self->params.CodecSpecific.vp8.AltRefIdx = 0xff;
  }

  if (decoder->golden_ref_picture) {
    other_frame =
        gst_nv_vp8_dec_get_decoder_frame_from_picture (self,
        decoder->golden_ref_picture);
    if (!other_frame) {
      GST_ERROR_OBJECT (self, "Couldn't get decoder frame for GoldenRef");
      return GST_FLOW_ERROR;
    }

    self->params.CodecSpecific.vp8.GoldenRefIdx = other_frame->index;
  } else {
    self->params.CodecSpecific.vp8.GoldenRefIdx = 0xff;
  }

  if (decoder->last_picture) {
    other_frame =
        gst_nv_vp8_dec_get_decoder_frame_from_picture (self,
        decoder->last_picture);
    if (!other_frame) {
      GST_ERROR_OBJECT (self, "Couldn't get decoder frame for LastRef");
      return GST_FLOW_ERROR;
    }

    self->params.CodecSpecific.vp8.LastRefIdx = other_frame->index;
  } else {
    self->params.CodecSpecific.vp8.LastRefIdx = 0xff;
  }

  self->params.CodecSpecific.vp8.vp8_frame_tag.frame_type =
      frame_hdr->key_frame ? 0 : 1;
  self->params.CodecSpecific.vp8.vp8_frame_tag.version = frame_hdr->version;
  self->params.CodecSpecific.vp8.vp8_frame_tag.show_frame =
      frame_hdr->show_frame;
  self->params.CodecSpecific.vp8.vp8_frame_tag.update_mb_segmentation_data =
      parser->segmentation.segmentation_enabled ?
      parser->segmentation.update_segment_feature_data : 0;

  if (!gst_nv_decoder_decode_picture (self->decoder, &self->params))
    return GST_FLOW_ERROR;

  return GST_FLOW_OK;
}

static GstFlowReturn
gst_nv_vp8_dec_output_picture (GstVp8Decoder * decoder,
    GstVideoCodecFrame * frame, GstVp8Picture * picture)
{
  GstNvVp8Dec *self = GST_NV_VP8_DEC (decoder);
  GstVideoDecoder *vdec = GST_VIDEO_DECODER (decoder);
  GstNvDecoderFrame *decoder_frame;

  GST_LOG_OBJECT (self, "Outputting picture %p", picture);

  decoder_frame = (GstNvDecoderFrame *) gst_vp8_picture_get_user_data (picture);
  if (!decoder_frame) {
    GST_ERROR_OBJECT (self, "No decoder frame in picture %p", picture);
    goto error;
  }

  if (!gst_nv_decoder_finish_frame (self->decoder, vdec, decoder_frame,
          &frame->output_buffer)) {
    GST_ERROR_OBJECT (self, "Failed to handle output picture");
    goto error;
  }

  gst_vp8_picture_unref (picture);

  return gst_video_decoder_finish_frame (vdec, frame);

error:
  gst_video_decoder_drop_frame (vdec, frame);
  gst_vp8_picture_unref (picture);

  return GST_FLOW_ERROR;
}

static guint
gst_nv_vp8_dec_get_preferred_output_delay (GstVp8Decoder * decoder,
    gboolean is_live)
{
  /* Prefer to zero latency for live pipeline */
  if (is_live)
    return 0;

  /* NVCODEC SDK uses 4 frame delay for better throughput performance */
  return 4;
}

typedef struct
{
  GstCaps *sink_caps;
  GstCaps *src_caps;
  guint cuda_device_id;
  gboolean is_default;
} GstNvVp8DecClassData;

static void
gst_nv_vp8_dec_subclass_init (gpointer klass, GstNvVp8DecClassData * cdata)
{
  GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
  GstNvVp8DecClass *nvdec_class = (GstNvVp8DecClass *) (klass);
  gchar *long_name;

  if (cdata->is_default) {
    long_name = g_strdup_printf ("NVDEC VP8 Stateless Decoder");
  } else {
    long_name = g_strdup_printf ("NVDEC VP8 Stateless Decoder with device %d",
        cdata->cuda_device_id);
  }

  gst_element_class_set_metadata (element_class, long_name,
      "Codec/Decoder/Video/Hardware",
      "NVIDIA VP8 video decoder", "Seungha Yang <seungha@centricular.com>");
  g_free (long_name);

  gst_element_class_add_pad_template (element_class,
      gst_pad_template_new ("sink", GST_PAD_SINK, GST_PAD_ALWAYS,
          cdata->sink_caps));
  gst_element_class_add_pad_template (element_class,
      gst_pad_template_new ("src", GST_PAD_SRC, GST_PAD_ALWAYS,
          cdata->src_caps));

  nvdec_class->cuda_device_id = cdata->cuda_device_id;

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

void
gst_nv_vp8_dec_register (GstPlugin * plugin, guint device_id, guint rank,
    GstCaps * sink_caps, GstCaps * src_caps, gboolean is_primary)
{
  GTypeQuery type_query;
  GTypeInfo type_info = { 0, };
  GType subtype;
  gchar *type_name;
  gchar *feature_name;
  GstNvVp8DecClassData *cdata;
  gboolean is_default = TRUE;

  /**
   * element-nvvp8sldec:
   *
   * Since: 1.20
   */

  cdata = g_new0 (GstNvVp8DecClassData, 1);
  cdata->sink_caps = gst_caps_ref (sink_caps);
  cdata->src_caps = gst_caps_ref (src_caps);
  cdata->cuda_device_id = device_id;

  g_type_query (GST_TYPE_NV_VP8_DEC, &type_query);
  memset (&type_info, 0, sizeof (type_info));
  type_info.class_size = type_query.class_size;
  type_info.instance_size = type_query.instance_size;
  type_info.class_init = (GClassInitFunc) gst_nv_vp8_dec_subclass_init;
  type_info.class_data = cdata;

  if (is_primary) {
    type_name = g_strdup ("GstNvVP8StatelessPrimaryDec");
    feature_name = g_strdup ("nvvp8dec");
  } else {
    type_name = g_strdup ("GstNvVP8StatelessDec");
    feature_name = g_strdup ("nvvp8sldec");
  }

  if (g_type_from_name (type_name) != 0) {
    g_free (type_name);
    g_free (feature_name);
    if (is_primary) {
      type_name =
          g_strdup_printf ("GstNvVP8StatelessPrimaryDevice%dDec", device_id);
      feature_name = g_strdup_printf ("nvvp8device%ddec", device_id);
    } else {
      type_name = g_strdup_printf ("GstNvVP8StatelessDevice%dDec", device_id);
      feature_name = g_strdup_printf ("nvvp8sldevice%ddec", device_id);
    }

    is_default = FALSE;
  }

  cdata->is_default = is_default;
  subtype = g_type_register_static (GST_TYPE_NV_VP8_DEC,
      type_name, &type_info, 0);

  /* make lower rank than default device */
  if (rank > 0 && !is_default)
    rank--;

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

  g_free (type_name);
  g_free (feature_name);
}