/*

 * HEIF codec.

 * Copyright (c) 2024 Dirk Farin <dirk.farin@gmail.com>

 *

 * This file is part of libheif.

 *

 * libheif is free software: you can redistribute it and/or modify

 * it under the terms of the GNU Lesser General Public License as

 * published by the Free Software Foundation, either version 3 of

 * the License, or (at your option) any later version.

 *

 * libheif 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 Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public License

 * along with libheif.  If not, see <http://www.gnu.org/licenses/>.

 */

#include "vvc_enc.h"

#include "vvc_boxes.h"

#include "error.h"

#include "context.h"

#include "api_structs.h"

#include <string>

#include <utility>

#include "plugins/nalu_utils.h"

Result<Encoder::CodedImageData> Encoder_VVC::encode(const std::shared_ptr<HeifPixelImage>& image,

                                                    struct heif_encoder* encoder,

                                                    const struct heif_encoding_options& options,

                                                    enum heif_image_input_class input_class)

{

  Encoder::CodedImageData codedImage;

  auto vvcC = std::make_shared<Box_vvcC>();

  codedImage.properties.push_back(vvcC);

  heif_image c_api_image;

  c_api_image.image = image;

  struct heif_error err = encoder->plugin->encode_image(encoder->encoder, &c_api_image, input_class);

  if (err.code) {

    return Error(err.code,

                 err.subcode,

                 err.message);

  }

  uint32_t encoded_width = 0;

  uint32_t encoded_height = 0;

  for (;;) {

    uint8_t* data;

    int size;

    err = encoder->plugin->get_compressed_data(encoder->encoder, &data, &size, NULL);

    if (err.code) {

      return Error(err.code, err.subcode, err.message);

    }

    if (data == NULL) {

      break;

    }

    const uint8_t NAL_SPS = 15;

    uint8_t nal_type = 0;

    if (size>=2) {

      nal_type = (data[1] >> 3) & 0x1F;

    }

    if (nal_type == NAL_SPS) {

      Box_vvcC::configuration config;

      parse_sps_for_vvcC_configuration(data, size, &config, &encoded_width, &encoded_height);

      vvcC->set_configuration(config);

    }

    switch (nal_type) {

      case 14: // VPS

      case 15: // SPS

      case 16: // PPS

        vvcC->append_nal_data(data, size);

        break;

      default:

        codedImage.append_with_4bytes_size(data, size);

    }

  }

  codedImage.codingConstraints.intra_pred_used = true;

  codedImage.codingConstraints.all_ref_pics_intra = true; // TODO: change when we use predicted frames

  codedImage.codingConstraints.max_ref_per_pic = 0;

  return codedImage;

}

std::shared_ptr<class Box_VisualSampleEntry> Encoder_VVC::get_sample_description_box(const CodedImageData& data) const

{

  auto vvc1 = std::make_shared<Box_vvc1>();

  vvc1->get_VisualSampleEntry().compressorname = "VVC";

  for (const auto& prop : data.properties) {

    if (prop->get_short_type() == fourcc("vvcC")) {

      vvc1->append_child_box(prop);

      return vvc1;

    }

  }

  // box not yet available

  return nullptr;

}

Error Encoder_VVC::encode_sequence_frame(const std::shared_ptr<HeifPixelImage>& image,

                                         heif_encoder* encoder,

                                         const heif_sequence_encoding_options& options,

                                         heif_image_input_class input_class,

                                         uint32_t framerate_num, uint32_t framerate_denom,

                                         uintptr_t frame_number)

{

  heif_image c_api_image;

  c_api_image.image = image;

  if (!m_encoder_active) {

    heif_error err = encoder->plugin->start_sequence_encoding(encoder->encoder, &c_api_image, input_class,

                                                              framerate_num, framerate_denom,

                                                              &options);

    if (err.code) {

      return {

        err.code,

        err.subcode,

        err.message

      };

    }

    m_vvcC = std::make_shared<Box_vvcC>();

    m_encoder_active = true;

    uint64_t avg_fr = framerate_denom ? (256ULL * framerate_num + framerate_denom / 2) / framerate_denom : 0;

    m_avg_frame_rate = avg_fr <= UINT16_MAX ? static_cast<uint16_t>(avg_fr) : 0;

  }

  Error dataErr = get_data(encoder);

  if (dataErr) {

    return dataErr;

  }

  heif_error err = encoder->plugin->encode_sequence_frame(encoder->encoder, &c_api_image, frame_number);

  if (err.code) {

    return {

      err.code,

      err.subcode,

      err.message

    };

  }

  return get_data(encoder);

}

Error Encoder_VVC::encode_sequence_flush(heif_encoder* encoder)

{

  encoder->plugin->end_sequence_encoding(encoder->encoder);

  m_encoder_active = false;

  m_end_of_sequence_reached = true;

  return get_data(encoder);

}

std::optional<Encoder::CodedImageData> Encoder_VVC::encode_sequence_extract_data()

{

  return std::exchange(m_current_output_data, std::nullopt);

}

Error Encoder_VVC::get_data(heif_encoder* encoder)

{

  //CodedImageData codedImage;

  for (;;) {

    uint8_t* data;

    int size;

    uintptr_t frameNr=0;

    int more_frame_packets = 1;

    struct heif_error err = encoder->plugin->get_compressed_data2(encoder->encoder, &data, &size, &frameNr, nullptr, &more_frame_packets);

    if (err.code) {

      return Error(err.code, err.subcode, err.message);

    }

    if (data == nullptr) {

      break;

    }

    const uint8_t nal_type = (data[1] >> 3);

    const bool is_sync = (nal_type == 7 || nal_type == 8 || nal_type == 9);

    const bool is_image_data = (nal_type >= 0 && nal_type <= VVC_NAL_UNIT_MAX_VCL);

    // std::cout << "received frameNr=" << frameNr << " nal_type:" << ((int)nal_type) << " size: " << size << "\n";

    if (nal_type == VVC_NAL_UNIT_SPS_NUT && m_vvcC) {

      parse_sps_for_vvcC_configuration(data, size,

                                       &m_vvcC->get_configuration(),

                                       &m_encoded_image_width, &m_encoded_image_height);

      m_vvcC->get_configuration().avg_frame_rate = m_avg_frame_rate;

    }

    switch (nal_type) {

      case VVC_NAL_UNIT_VPS_NUT:

        if (m_vvcC && !m_vvcC_has_VPS) m_vvcC->append_nal_data(data, size);

        m_vvcC_has_VPS = true;

        break;

      case VVC_NAL_UNIT_SPS_NUT:

        if (m_vvcC && !m_vvcC_has_SPS) m_vvcC->append_nal_data(data, size);

        m_vvcC_has_SPS = true;

        break;

      case VVC_NAL_UNIT_PPS_NUT:

        if (m_vvcC && !m_vvcC_has_PPS) m_vvcC->append_nal_data(data, size);

        m_vvcC_has_PPS = true;

        break;

      default:

        if (!m_current_output_data) {

          m_current_output_data = CodedImageData{};

        }

        m_current_output_data->append_with_4bytes_size(data, size);

        if (is_image_data) {

          m_current_output_data->is_sync_frame = is_sync;

          m_current_output_data->frame_nr = frameNr;

        }

    }

    if (!more_frame_packets) {

      break;

    }

  }

  // No coded image to report when the encoder returned no NALs, or only parameter sets

  // (an encoder may emit VPS/SPS/PPS as soon as the sequence encoder is opened, before any

  // slice data). Those went into m_vvcC above and m_current_output_data stays disengaged.

  if (!m_current_output_data) {

    return {};

  }

  if (!m_encoded_image_width || !m_encoded_image_height) {

    return Error(heif_error_Encoder_plugin_error,

                 heif_suberror_Invalid_image_size);

  }

  // --- return hvcC when all headers are included and it was not returned yet

  //     TODO: it's maybe better to return this at the end so that we are sure to have all headers

  //           and also complete codingConstraints.

  //if (hvcC_has_VPS && m_hvcC_has_SPS && m_hvcC_has_PPS && !m_hvcC_returned) {

  if (m_end_of_sequence_reached && m_vvcC && !m_vvcC_sent) {

    m_current_output_data->properties.push_back(m_vvcC);

    m_vvcC = nullptr;

    m_vvcC_sent = true;

  }

  m_current_output_data->encoded_image_width = m_encoded_image_width;

  m_current_output_data->encoded_image_height = m_encoded_image_height;

  // Make sure that the encoder plugin works correctly and the encoded image has the correct size.

#if 0

  if (encoder->plugin->plugin_api_version >= 3 &&

      encoder->plugin->query_encoded_size != nullptr) {

    uint32_t check_encoded_width = image->get_width(), check_encoded_height = image->get_height();

    encoder->plugin->query_encoded_size(encoder->encoder,

                                        image->get_width(), image->get_height(),

                                        &check_encoded_width,

                                        &check_encoded_height);

    assert((int)check_encoded_width == encoded_width);

    assert((int)check_encoded_height == encoded_height);

      }

#endif

  m_current_output_data->codingConstraints.intra_pred_used = true;

  m_current_output_data->codingConstraints.all_ref_pics_intra = true; // TODO: change when we use predicted frames

  return {};

}