// #define DEBUGTRACE_ENABLED
#include "debugtrace.hpp"
#include "lasp_config.h"

#if LASP_HAS_PORTAUDIO == 1
#include <gsl-lite/gsl-lite.hpp>
#include <mutex>
#include <string>

#include "lasp_portaudiodaq.h"
#include "portaudio.h"

using rte = std::runtime_error;
using std::cerr;
using std::endl;
using std::string;
using std::to_string;

inline void throwIfError(PaError e) {
  DEBUGTRACE_ENTER;
  if (e != paNoError) {
    throw rte(string("PortAudio backend error: ") + Pa_GetErrorText(e));
  }
}

/**
 * @brief Device info, plus PortAudio stuff
 */
class OurPaDeviceInfo : public DeviceInfo {
 public:
  /**
   * @brief Store instance to PaDeviceInfo.
   */
  PaDeviceInfo _paDevInfo;

  virtual std::unique_ptr<DeviceInfo> clone() const override final {
    return std::make_unique<OurPaDeviceInfo>(*this);
  }
  OurPaDeviceInfo &operator=(const OurPaDeviceInfo &) = delete;
  OurPaDeviceInfo(const OurPaDeviceInfo &) = default;
  OurPaDeviceInfo(const PaDeviceInfo &o) : DeviceInfo(), _paDevInfo(o) {}
};

void fillPortAudioDeviceInfo(DeviceInfoList &devinfolist) {
  DEBUGTRACE_ENTER;
  bool shouldPaTerminate = false;
  try {
    PaError err = Pa_Initialize();
    /// PortAudio says that Pa_Terminate() should not be called whenever there
    /// is an error in Pa_Initialize(). This is opposite to what most examples
    /// of PortAudio show.
    throwIfError(err);
    shouldPaTerminate = true;

    auto fin = gsl::finally([&err] {
      DEBUGTRACE_PRINT("Terminating PortAudio instance");
      err = Pa_Terminate();
      if (err != paNoError) {
        cerr << "Error terminating PortAudio. Do not know what to do." << endl;
      }
    });

    const PaHostApiIndex apicount = Pa_GetHostApiCount();
    if (apicount < 0) {
      return;
    }
    /* const PaDeviceInfo *deviceInfo; */
    const int numDevices = Pa_GetDeviceCount();
    if (numDevices < 0) {
      throw rte("PortAudio could not find any devices");
    }
    for (us i = 0; i < (us)numDevices; i++) {
      /* DEBUGTRACE_PRINT(i); */
      bool hasDuplexMode = false;

      const PaDeviceInfo *deviceInfo = Pa_GetDeviceInfo(i);
      if (!deviceInfo) {
        throw rte("No device info struct returned");
      }
      OurPaDeviceInfo d(*deviceInfo);
      // We store the name in d.device_name
      d._paDevInfo.name = nullptr;
      d.device_name = deviceInfo->name;

      const PaHostApiInfo *hostapiinfo = Pa_GetHostApiInfo(deviceInfo->hostApi);
      if (hostapiinfo == nullptr) {
        throw std::runtime_error("Hostapi nullptr!");
      }
      switch (hostapiinfo->type) {
        case paALSA:
        // Duplex mode for alsa
          hasDuplexMode = true;
          d.api = portaudioALSAApi;
          break;
        case paASIO:
          hasDuplexMode = true;
          d.api = portaudioASIOApi;
          break;
        case paDirectSound:
          d.api = portaudioDirectSoundApi;
          break;
        case paMME:
          d.api = portaudioWMMEApi;
          break;
        case paWDMKS:
          d.api = portaudioWDMKS;
          break;
        case paWASAPI:
          d.api = portaudioWASAPIApi;
          break;
        case paPulseAudio:
          d.api = portaudioPulseApi;
          break;
        default:
          throw rte("Unimplemented portaudio API!");
          break;
      }

      d.availableDataTypes = {DataTypeDescriptor::DataType::dtype_int16,
                              DataTypeDescriptor::DataType::dtype_int32,
                              DataTypeDescriptor::DataType::dtype_fl32};

      d.prefDataTypeIndex = 2;

      d.availableSampleRates = {8000.0,  9600.0,  11025.0, 12000.0, 16000.0,
                                22050.0, 24000.0, 32000.0, 44100.0, 48000.0,
                                88200.0, 96000.0, 192000.0};
      d.prefSampleRateIndex = 9;

      d.availableFramesPerBlock = {512, 1024, 2048, 4096, 8192};
      d.prefFramesPerBlockIndex = 2;

      d.availableInputRanges = {1.0};
      // d.prefInputRangeIndex = 0; // Constructor-defined
      d.availableOutputRanges = {1.0};
      // d.prefOutputRangeIndex = 0; // Constructor-defined

      d.ninchannels = deviceInfo->maxInputChannels;
      d.noutchannels = deviceInfo->maxOutputChannels;

      // Duplex mode, only for ALSA devices
      d.hasDuplexMode = hasDuplexMode;

      devinfolist.push_back(std::make_unique<OurPaDeviceInfo>(d));
    }
  }

  catch (rte &e) {
    if (shouldPaTerminate) {
      PaError err = Pa_Terminate();
      if (err != paNoError) {
        cerr << "Error terminating PortAudio. Do not know what to do." << endl;
      }
    }
    cerr << "PortAudio backend error: " << e.what() << std::endl;
    return;
  }
}

/**
 * @brief Forward declaration of raw callback. Calls into
 * PortAudioDaq->memberPaCallback. Undocumented parameters are specified
 * in memberPaCallback
 *
 * @param inputBuffer
 * @param outputBuffer
 * @param framesPerBuffer
 * @param timeInfo
 * @param statusFlags
 * @param userData Pointer to PortAudioDaq* instance.
 *
 * @return
 */
static int rawPaCallback(const void *inputBuffer, void *outputBuffer,
                         unsigned long framesPerBuffer,
                         const PaStreamCallbackTimeInfo *timeInfo,
                         PaStreamCallbackFlags statusFlags, void *userData);

class PortAudioDaq : public Daq {
  PaStream *_stream = nullptr;
  std::atomic<StreamStatus::StreamError> _streamError =
      StreamStatus::StreamError::noError;
  InDaqCallback _incallback;
  OutDaqCallback _outcallback;

 public:
  PortAudioDaq(const OurPaDeviceInfo &devinfo_gen,
               const DaqConfiguration &config);

  void start(InDaqCallback inCallback,
             OutDaqCallback outCallback) override final;
  void stop() override final;

  StreamStatus getStreamStatus() const override final;

  /**
   * @brief Member va
   *
   * @param inputBuffer
   * @param outputBuffer
   * @param framesPerBuffer
   * @param timeInfo
   * @param statusFlags
   *
   * @return
   */
  int memberPaCallback(const void *inputBuffer, void *outputBuffer,
                       unsigned long framesPerBuffer,
                       const PaStreamCallbackTimeInfo *timeInfo,
                       PaStreamCallbackFlags statusFlags);
  ~PortAudioDaq();
};

std::unique_ptr<Daq> createPortAudioDevice(const DeviceInfo &devinfo,
                                           const DaqConfiguration &config) {
  DEBUGTRACE_ENTER;
  const OurPaDeviceInfo *_info =
      dynamic_cast<const OurPaDeviceInfo *>(&devinfo);
  if (_info == nullptr) {
    throw rte("BUG: Could not cast DeviceInfo to OurPaDeviceInfo");
  }
  return std::make_unique<PortAudioDaq>(*_info, config);
}

static int rawPaCallback(const void *inputBuffer, void *outputBuffer,
                         unsigned long framesPerBuffer,
                         const PaStreamCallbackTimeInfo *timeInfo,
                         PaStreamCallbackFlags statusFlags, void *userData) {
  return static_cast<PortAudioDaq *>(userData)->memberPaCallback(
      inputBuffer, outputBuffer, framesPerBuffer, timeInfo, statusFlags);
}

PortAudioDaq::PortAudioDaq(const OurPaDeviceInfo &devinfo_gen,
                           const DaqConfiguration &config)
    : Daq(devinfo_gen, config) {
  DEBUGTRACE_ENTER;
  bool shouldPaTerminate = false;
  try {
    PaError err = Pa_Initialize();
    /// PortAudio says that Pa_Terminate() should not be called whenever there
    /// is an error in Pa_Initialize(). This is opposite to what most examples
    /// of PortAudio show.
    throwIfError(err);

    // OK, Pa_Initialize successfully finished, it means we have to clean up
    // with Pa_Terminate in the destructor.
    shouldPaTerminate = true;

    // Going to find the device in the list. If its there, we have to retrieve
    // the index, as this is required in the PaStreamParameters struct
    int devindex = -1;
    for (int i = 0; i < Pa_GetDeviceCount(); i++) {
      // DEBUGTRACE_PRINT(i);
      bool ok = true;
      const PaDeviceInfo *info = Pa_GetDeviceInfo(i);
      if (!info) {
        throw rte("No device structure returned from PortAudio");
      }
      ok &= string(info->name) == devinfo_gen.device_name;
      ok &= info->hostApi == devinfo_gen._paDevInfo.hostApi;
      ok &= info->maxInputChannels == devinfo_gen._paDevInfo.maxInputChannels;
      ok &= info->maxOutputChannels == devinfo_gen._paDevInfo.maxOutputChannels;
      ok &= info->defaultSampleRate == devinfo_gen._paDevInfo.defaultSampleRate;

      if (ok) {
        devindex = i;
      }
    }
    if (devindex < 0) {
      throw rte(string("Device not found: ") + string(devinfo_gen.device_name));
    }

    using Dtype = DataTypeDescriptor::DataType;
    const Dtype dtype = dataType();
    // Sample format is bit flag
    PaSampleFormat format = paNonInterleaved;
    switch (dtype) {
      case Dtype::dtype_fl32:
        DEBUGTRACE_PRINT("Datatype float32");
        format |= paFloat32;
        break;
      case Dtype::dtype_fl64:
        DEBUGTRACE_PRINT("Datatype float64");
        throw rte("Invalid data type specified for DAQ stream.");
        break;
      case Dtype::dtype_int8:
        DEBUGTRACE_PRINT("Datatype int8");
        format |= paInt8;
        break;
      case Dtype::dtype_int16:
        DEBUGTRACE_PRINT("Datatype int16");
        format |= paInt16;
        break;
      case Dtype::dtype_int32:
        DEBUGTRACE_PRINT("Datatype int32");
        format |= paInt32;
        break;
      default:
        throw rte("Invalid data type specified for DAQ stream.");
        break;
    }

    std::unique_ptr<PaStreamParameters> instreamParams;
    std::unique_ptr<PaStreamParameters> outstreamParams;

    if (neninchannels() > 0) {
      instreamParams = std::make_unique<PaStreamParameters>(PaStreamParameters(
          {.device = devindex,
           .channelCount = (int)getHighestEnabledInChannel() + 1,
           .sampleFormat = format,
           .suggestedLatency = framesPerBlock() / samplerate(),
           .hostApiSpecificStreamInfo = nullptr}));
    }
    if (nenoutchannels() > 0) {
      outstreamParams = std::make_unique<PaStreamParameters>(PaStreamParameters(
          {.device = devindex,
           .channelCount = (int)getHighestEnabledOutChannel() + 1,
           .sampleFormat = format,
           .suggestedLatency = framesPerBlock() / samplerate(),
           .hostApiSpecificStreamInfo = nullptr}));
    }

    // Next step: check whether we are OK
    err = Pa_IsFormatSupported(instreamParams.get(), outstreamParams.get(),
                               samplerate());
    throwIfError(err);

    err = Pa_OpenStream(&_stream,               // stream
                        instreamParams.get(),   // inputParameters
                        outstreamParams.get(),  // outputParameters
                        samplerate(),           // yeah,
                        framesPerBlock(),       // framesPerBuffer
                        paNoFlag,               // streamFlags
                        rawPaCallback, this);
    throwIfError(err);
    assert(_stream);
  } catch (rte &e) {
    if (shouldPaTerminate) {
      PaError err = Pa_Terminate();
      if (err != paNoError) {
        cerr << "Error terminating PortAudio. Do not know what to do." << endl;
      }
    }
    throw;
  }
}

void PortAudioDaq::start(InDaqCallback inCallback, OutDaqCallback outCallback) {
  DEBUGTRACE_ENTER;
  assert(_stream);

  if (Pa_IsStreamActive(_stream)) {
    throw rte("Stream is already running");
  }

  if (neninchannels() > 0) {
    if (!inCallback) {
      throw rte(

          "Input callback given, but stream does not provide input data");
    }

    _incallback = inCallback;
  }
  if (nenoutchannels() > 0) {
    if (!outCallback) {
      throw rte(
          "Output callback given, but stream does not provide output data");
    }
    _outcallback = outCallback;
  }

  PaError err = Pa_StartStream(_stream);
  throwIfError(err);
}
void PortAudioDaq::stop() {
  DEBUGTRACE_ENTER;
  assert(_stream);
  if (Pa_IsStreamStopped(_stream) > 1) {
    throw rte("Stream is already stopped");
  }
  PaError err = Pa_StopStream(_stream);
  throwIfError(err);
}
Daq::StreamStatus PortAudioDaq::getStreamStatus() const {
  DEBUGTRACE_ENTER;
  // Stores an error type and whether the
  Daq::StreamStatus status;
  using StreamError = Daq::StreamStatus::StreamError;
  Daq::StreamStatus::StreamError errortype = _streamError.load();

  PaError err = Pa_IsStreamStopped(_stream);
  if (err > 1) {
    // Stream is stopped due to an error in the callback. The exact error type
    // is filled in in the if-statement above
    return status;
  } else if (err == 0) {
    // Still running
    status.isRunning = true;
  } else if (err < 0) {
    // Stream encountered an error.
    switch (err) {
      case paInternalError:
        errortype = StreamError::driverError;
        break;
      case paDeviceUnavailable:
        errortype = StreamError::driverError;
        break;
      case paInputOverflowed:
        errortype = StreamError::inputXRun;
        break;
      case paOutputUnderflowed:
        errortype = StreamError::outputXRun;
        break;
      default:
        errortype = StreamError::driverError;
        cerr << "Portaudio backend error:" << Pa_GetErrorText(err) << endl;
        break;
    }
  }
  status.errorType = errortype;
  return status;
}

PortAudioDaq::~PortAudioDaq() {
  DEBUGTRACE_ENTER;
  PaError err;
  assert(_stream);
  if (Pa_IsStreamActive(_stream)) {
    // Stop the stream first
    stop();
  }

  err = Pa_CloseStream(_stream);
  _stream = nullptr;
  if (err != paNoError) {
    cerr << "Error closing PortAudio stream. Do not know what to do." << endl;
  }

  err = Pa_Terminate();
  if (err != paNoError) {
    cerr << "Error terminating PortAudio. Do not know what to do." << endl;
  }
}

int PortAudioDaq::memberPaCallback(const void *inputBuffer, void *outputBuffer,
                                   unsigned long framesPerBuffer,
                                   const PaStreamCallbackTimeInfo *timeInfo,
                                   PaStreamCallbackFlags statusFlags) {
  DEBUGTRACE_ENTER;
  typedef Daq::StreamStatus::StreamError se;
  if (statusFlags & paPrimingOutput) {
    // Initial output buffers generated. So nothing with input yet
    return paContinue;
  }
  if ((statusFlags & paInputUnderflow) || (statusFlags & paInputOverflow)) {
    _streamError = se::inputXRun;
    return paAbort;
  }
  if ((statusFlags & paOutputUnderflow) || (statusFlags & paOutputOverflow)) {
    _streamError = se::outputXRun;
    return paAbort;
  }
  if (framesPerBuffer != framesPerBlock()) {
    cerr << "Logic error: expected a block size of: " << framesPerBlock()
         << endl;
    _streamError = se::logicError;
    return paAbort;
  }

  const us neninchannels = this->neninchannels();
  const us nenoutchannels = this->nenoutchannels();
  const auto &dtype_descr = dtypeDescr();
  const auto dtype = dataType();
  const us sw = dtype_descr.sw;
  if (inputBuffer) {
    assert(_incallback);
    std::vector<byte_t *> ptrs;
    ptrs.reserve(neninchannels);

    const us ch_min = getLowestEnabledInChannel();
    const us ch_max = getHighestEnabledInChannel();
    assert(ch_min < ninchannels);
    assert(ch_max < ninchannels);

    /// Only pass on the pointers of the channels we want. inputBuffer is
    /// noninterleaved, as specified in PortAudioDaq constructor.
    for (us ch = ch_min; ch <= ch_max; ch++) {
      if (inchannel_config.at(ch).enabled) {
        byte_t *ch_ptr =
            reinterpret_cast<byte_t **>(const_cast<void *>(inputBuffer))[ch];
        ptrs.push_back(ch_ptr);
      }
    }
    DaqData d{framesPerBuffer, neninchannels, dtype};
    d.copyInFromRaw(ptrs);

    _incallback(d);
  }

  if (outputBuffer) {
    assert(_outcallback);
    std::vector<byte_t *> ptrs;
    ptrs.reserve(nenoutchannels);

    /* outCallback */

    const us ch_min = getLowestEnabledOutChannel();
    const us ch_max = getHighestEnabledOutChannel();
    assert(ch_min < noutchannels);
    assert(ch_max < noutchannels);
    /// Only pass on the pointers of the channels we want
    for (us ch = ch_min; ch <= ch_max; ch++) {
      if (outchannel_config.at(ch).enabled) {
        byte_t *ch_ptr = reinterpret_cast<byte_t **>(outputBuffer)[ch];
        ptrs.push_back(ch_ptr);
      }
    }
    DaqData d{framesPerBuffer, nenoutchannels, dtype};

    _outcallback(d);
    // Copy over the buffer
    us j = 0;
    for (auto ptr : ptrs) {
      d.copyToRaw(j, ptr);
      j++;
    }
  }

  return paContinue;
}
#endif