File sample_decoder.hpp

// Copyright 2025 TIER IV, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#ifndef NEBULA_SAMPLE_DECODER_HPP
#define NEBULA_SAMPLE_DECODER_HPP

#include <nebula_core_common/point_types.hpp>
#include <nebula_core_common/util/expected.hpp>
#include <nebula_core_decoders/angles.hpp>

#include <cstdint>
#include <functional>
#include <vector>

namespace nebula::drivers
{

enum class DecodeError : uint8_t {
  PACKET_FORMAT_INVALID,  
  CALLBACK_NOT_SET,       
  EMPTY_PACKET,           
};

const char * to_cstr(DecodeError error);

struct PacketMetadata
{
  uint64_t packet_timestamp_ns{};  
  bool did_scan_complete{false};   
};

struct PerformanceCounters
{
  uint64_t decode_time_ns{0};    
  uint64_t callback_time_ns{0};  
};

struct PacketDecodeResult
{
  PerformanceCounters performance_counters;
  util::expected<PacketMetadata, DecodeError> metadata_or_error;
};

class SampleDecoder
{
public:
  using pointcloud_callback_t =
    std::function<void(const NebulaPointCloudPtr & pointcloud, double timestamp_s)>;

  explicit SampleDecoder(
    FieldOfView<float, Degrees> fov /*, other decoder args */, pointcloud_callback_t pointcloud_cb);

  [[nodiscard]] PacketDecodeResult unpack(const std::vector<uint8_t> & packet);

  void set_pointcloud_callback(pointcloud_callback_t pointcloud_cb);

private:
  static constexpr uint64_t k_packets_per_sample_scan = 10;

  FieldOfView<float, Degrees> fov_;
  pointcloud_callback_t pointcloud_callback_;
  NebulaPointCloudPtr current_scan_cloud_{std::make_shared<NebulaPointCloud>()};
  uint64_t packet_count_{0};
};

}  // namespace nebula::drivers

#endif  // NEBULA_SAMPLE_DECODER_HPP