#include "obu_parser.h"

#include "byte_buffer.h"
#include "log.h"

constexpr int kAggregationHeaderSize = 1;
// when there are 3 or less OBU (fragments) in a packet, size of the last one
// can be omited.
constexpr int kMaxNumObusToOmitSize = 3;
constexpr uint8_t kObuSizePresentBit = 0b0'0000'010;
constexpr int kObuTypeSequenceHeader = 1;
constexpr int kObuTypeTemporalDelimiter = 2;
constexpr int kObuTypeTileList = 8;
constexpr int kObuTypePadding = 15;

const char* ObuTypeToString(OBU_TYPE type) {
  switch (type) {
    case OBU_SEQUENCE_HEADER:
      return "OBU_SEQUENCE_HEADER";
    case OBU_TEMPORAL_DELIMITER:
      return "OBU_TEMPORAL_DELIMITER";
    case OBU_FRAME_HEADER:
      return "OBU_FRAME_HEADER";
    case OBU_REDUNDANT_FRAME_HEADER:
      return "OBU_REDUNDANT_FRAME_HEADER";
    case OBU_FRAME:
      return "OBU_FRAME";
    case OBU_TILE_GROUP:
      return "OBU_TILE_GROUP";
    case OBU_METADATA:
      return "OBU_METADATA";
    case OBU_TILE_LIST:
      return "OBU_TILE_LIST";
    case OBU_PADDING:
      return "OBU_PADDING";
    default:
      break;
  }
  return "<Invalid OBU Type>";
}

bool ObuHasExtension(uint8_t obu_header) { return obu_header & 0b0'0000'100; }

bool ObuHasSize(uint8_t obu_header) { return obu_header & kObuSizePresentBit; }

int ObuType(uint8_t obu_header) { return (obu_header & 0b0'1111'000) >> 3; }

std::vector<Obu> ParseObus(uint8_t* payload, int payload_size) {
  std::vector<Obu> result;
  ByteBufferReader payload_reader(reinterpret_cast<const char*>(payload),
                                  payload_size);
  while (payload_reader.Length() > 0) {
    Obu obu;
    payload_reader.ReadUInt8(&obu.header_);
    LOG_ERROR("Get obu type = [{}]",
              ObuTypeToString((OBU_TYPE)ObuType(obu.header_)))
    obu.size_ = 1;
    if (ObuHasExtension(obu.header_)) {
      if (payload_reader.Length() == 0) {
        LOG_ERROR(
            "Malformed AV1 input: expected extension_header, no more bytes in "
            "the buffer. Offset: {}",
            (payload_size - payload_reader.Length()));
        return {};
      }
      payload_reader.ReadUInt8(&obu.extension_header_);
      ++obu.size_;
    }
    if (!ObuHasSize(obu.header_)) {
      obu.SetPayload(reinterpret_cast<const uint8_t*>(payload_reader.Data()),
                     payload_reader.Length());
      payload_reader.Consume(payload_reader.Length());
      LOG_ERROR("payload_reader.Length() = {}", payload_reader.Length());
    } else {
      uint64_t size = 0;
      if (!payload_reader.ReadUVarint(&size) ||
          size > payload_reader.Length()) {
        LOG_ERROR(
            "Malformed AV1 input: declared size {} is larger than remaining "
            "buffer size {}",
            size, payload_reader.Length());
        return {};
      }
      obu.SetPayload(reinterpret_cast<const uint8_t*>(payload_reader.Data()),
                     size);
      payload_reader.Consume(size);
      LOG_ERROR("size = {}", size);
    }
    obu.size_ += obu.payload_size_;
    // Skip obus that shouldn't be transfered over rtp.
    int obu_type = ObuType(obu.header_);
    // if (obu_type != kObuTypeTemporalDelimiter &&  //
    //     obu_type != kObuTypeTileList &&           //
    //     obu_type != kObuTypePadding) {
    //   result.push_back(obu);
    // }

    LOG_ERROR("Obu size = [{}], Obu type [{}]", obu.size_,
              ObuTypeToString((OBU_TYPE)ObuType(obu.header_)));
    if (1) {
      result.push_back(obu);
    }
  }

  LOG_ERROR("Obu size = [{}]", result.size());
  for (int i = 0; i < result.size(); i++) {
    LOG_ERROR("[{}] Obu size = [{}], Obu type [{}]", i, result[i].payload_size_,
              ObuTypeToString((OBU_TYPE)ObuType(result[i].header_)));
  }

  return result;
}