// Copyright 2020 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef SRC_MEDIA_CODEC_EXAMPLES_ENCODE_CAMERA_ENCODER_CLIENT_H_
#define SRC_MEDIA_CODEC_EXAMPLES_ENCODE_CAMERA_ENCODER_CLIENT_H_

#include <fuchsia/mediacodec/cpp/fidl.h>
#include <lib/async-loop/cpp/loop.h>
#include <lib/async-loop/default.h>
#include <lib/fidl/cpp/binding.h>
#include <lib/fit/function.h>
#include <lib/media/test/codec_buffer.h>

#include <list>
#include <unordered_map>

// Single-threaded StreamProcessor client that sets up an encoder instance when given
// an input buffer collection and produces encoded packets via callback.
class EncoderClient {
 public:
  ~EncoderClient();
  static fpromise::result<std::unique_ptr<EncoderClient>, zx_status_t> Create(
      fuchsia::mediacodec::CodecFactoryHandle codec_factory,
      fuchsia::sysmem2::AllocatorHandle allocator, uint32_t bitrate, uint32_t gop_size,
      const std::string& mime_type);

  // Connects to codec factory and sets up an encoder stream processor with the given buffer
  // collection and image format as input.
  zx_status_t Start(fuchsia::sysmem2::BufferCollectionTokenHandle token,
                    fuchsia::images2::ImageFormat image_format, uint32_t frame_rate);

  void QueueInputPacket(uint32_t buffer_index, zx::eventpair release_fence);

  using OutputPacketHandler = fit::function<void(uint8_t* buffer, size_t len)>;
  void SetOutputPacketHandler(OutputPacketHandler handler) {
    output_packet_handler_ = std::move(handler);
  }

 private:
  EncoderClient(uint32_t bitrate, uint32_t gop_size, const std::string& mime_type);

  using BoundBufferCollectionCallback =
      fit::callback<void(fuchsia::sysmem2::BufferCollectionTokenHandle&&)>;
  // Duplicate passed in token to buffer collection, then bind and sync on it, passing back the
  // logical buffer collection and the duplicated token to pass to the next client (the encoder)
  void BindAndSyncBufferCollectionToken(fuchsia::sysmem2::BufferCollectionPtr& buffer_collection,
                                        fuchsia::sysmem2::BufferCollectionTokenHandle token,
                                        BoundBufferCollectionCallback callback);

  // Allocate new buffer collection, duplicating a token to it, and passing both to the callback.
  void CreateAndSyncBufferCollection(fuchsia::sysmem2::BufferCollectionPtr& buffer_collection,
                                     BoundBufferCollectionCallback callback);

  // Common helper function to wait for buffers
  void BindAndSyncBufferCollection(fuchsia::sysmem2::BufferCollectionPtr& buffer_collection,
                                   fuchsia::sysmem2::BufferCollectionTokenHandle token,
                                   fuchsia::sysmem2::BufferCollectionTokenHandle duplicated_token,
                                   BoundBufferCollectionCallback callback);

  // On Ok, contains the buffer collection info and negotiated packet count.
  using BufferCollectionResult =
      fpromise::result<std::pair<fuchsia::sysmem2::BufferCollectionInfo, uint32_t>, zx_status_t>;
  using ConfigurePortBufferCollectionCallback = fit::callback<void(BufferCollectionResult)>;
  void ConfigurePortBufferCollection(
      fuchsia::sysmem2::BufferCollectionPtr& buffer_collection,
      fuchsia::sysmem2::BufferCollectionTokenHandle codec_sysmem_token, bool is_output,
      uint64_t new_buffer_lifetime_ordinal, uint64_t buffer_constraints_version_ordinal,
      ConfigurePortBufferCollectionCallback callback);

  void OnInputBuffersReady(BufferCollectionResult result);
  void OnOutputBuffersReady(BufferCollectionResult result);

  //
  // Events:
  //
  void OnStreamFailed(uint64_t stream_lifetime_ordinal, fuchsia::media::StreamError error);
  void OnInputConstraints(fuchsia::media::StreamBufferConstraints input_constraints);
  void OnFreeInputPacket(fuchsia::media::PacketHeader free_input_packet);
  void OnOutputConstraints(fuchsia::media::StreamOutputConstraints output_config);
  void OnOutputFormat(fuchsia::media::StreamOutputFormat output_format);
  void OnOutputPacket(fuchsia::media::Packet output_packet, bool error_detected_before,
                      bool error_detected_during);
  void OnOutputEndOfStream(uint64_t stream_lifetime_ordinal, bool error_detected_before);

  fuchsia::mediacodec::CodecFactoryPtr codec_factory_;
  fuchsia::media::StreamProcessorPtr codec_;
  fuchsia::sysmem2::AllocatorPtr sysmem_;

  OutputPacketHandler output_packet_handler_;

  fuchsia::sysmem2::BufferCollectionTokenHandle input_buffers_token_;
  fuchsia::sysmem2::BufferCollectionPtr input_buffer_collection_;
  fuchsia::sysmem2::BufferCollectionPtr output_buffer_collection_;

  std::optional<fuchsia::media::StreamBufferConstraints> input_constraints_;
  std::optional<fuchsia::media::StreamOutputConstraints> last_output_constraints_;

  // The index into the vector is the same as packet_id, since we're running in
  // buffer-per-packet mode.
  std::vector<std::unique_ptr<CodecBuffer>> all_input_buffers_;
  std::vector<std::unique_ptr<CodecBuffer>> all_output_buffers_;
  uint32_t input_packet_count_ = 0;
  uint32_t output_packet_count_ = 0;
  std::unordered_map<uint32_t, zx::eventpair> input_packets_queued_;

  // Only odd values are allowed for buffer_lifetime_ordinal.
  uint64_t next_output_buffer_lifetime_ordinal_ = 1;
  uint64_t current_output_buffer_lifetime_ordinal_ = 0;

  uint32_t bitrate_ = 0;
  uint32_t gop_size_ = 0;
  std::string mime_type_;

  EncoderClient(const EncoderClient&) = delete;
  EncoderClient(EncoderClient&&) = delete;
  EncoderClient& operator=(const EncoderClient&) = delete;
  EncoderClient& operator=(EncoderClient&&) = delete;
};

#endif  // SRC_MEDIA_CODEC_EXAMPLES_ENCODE_CAMERA_ENCODER_CLIENT_H_