#include "RwPollingTask.h"

#include <fcntl.h>
#include <fsfw/globalfunctions/CRC.h>
#include <fsfw/tasks/SemaphoreFactory.h>
#include <fsfw/tasks/TaskFactory.h>
#include <fsfw_hal/common/spi/spiCommon.h>
#include <unistd.h>

#include "devConf.h"
#include "mission/devices/devicedefinitions/rwHelpers.h"

RwPollingTask::RwPollingTask(object_id_t objectId, SpiComIF* spiIF)
    : SystemObject(objectId), spiIF(spiIF) {
  semaphore = SemaphoreFactory::instance()->createBinarySemaphore();
  semaphore->acquire();
  ipcLock = MutexFactory::instance()->createMutex();
}

ReturnValue_t RwPollingTask::performOperation(uint8_t operationCode) {
  ipcLock->lockMutex();
  state = InternalState::IDLE;
  ipcLock->unlockMutex();
  while (true) {
    semaphore->acquire();
    for (unsigned idx = 0; idx < rwCookies.size(); idx++) {
      prepareSetSpeedCmd(idx);
      writeOneRw(idx);
    }
    readAllRws(fd, spiLock, dev)
        // writeAndReadAllRws(sendData, sendDataLen)
        int bytesRead = 0;
  }
  return returnvalue::OK;
}

ReturnValue_t RwPollingTask::initialize() { return returnvalue::OK; }

ReturnValue_t RwPollingTask::initializeInterface(CookieIF* cookie) {
  spiIF->getSpiDev();
  // We are in protected section, so we can use the static variable here without issues.
  // We don't need to set the speed because a SPI core is used, but the mode has to be set once
  // correctly for all RWs
  if (not modeAndSpeedWasSet) {
    auto& dev = spiIF->getSpiDev();
    int fd = open(dev.c_str(), O_RDWR);
    if (fd < 0) {
      sif::error << "could not open RW SPI bus" << std::endl;
      return returnvalue::FAILED;
    }
    spiIF->setSpiSpeedAndMode(fd, spi::RW_MODE, spi::RW_SPEED);
    close(fd);
    modeAndSpeedWasSet = true;
  }

  return returnvalue::OK;
}

ReturnValue_t RwPollingTask::sendMessage(CookieIF* cookie, const uint8_t* sendData,
                                         size_t sendLen) {
  if (sendLen < 6) {
    return DeviceHandlerIF::INVALID_DATA;
  }
  int32_t speed = 0;
  uint16_t rampTime = 0;
  SerializeAdapter::deSerialize(&speed, &sendData, &sendLen, SerializeIF::Endianness::MACHINE);
  SerializeAdapter::deSerialize(&rampTime, &sendData, &sendLen, SerializeIF::Endianness::MACHINE);
  rws::SpecialRwRequest specialRequest = rws::SpecialRwRequest::REQUEST_NONE;
  if (sendLen == 7 and sendData[6] < rws::SpecialRwRequest::NUM_REQUESTS) {
    specialRequest = static_cast<rws::SpecialRwRequest>(sendData[6]);
  }
  RwCookie* rwCookie = dynamic_cast<RwCookie*>(cookie);
  {
    MutexGuard mg(ipcLock);
    rwCookie->currentRwSpeed = speed;
    rwCookie->currentRampTime = rampTime;
    rwCookie->specialRequest = specialRequest;
    if (state == InternalState::IDLE and rwCookie->rwIdx == 3) {
      semaphore->release();
    }
  }
  return returnvalue::OK;
}

ReturnValue_t RwPollingTask::getSendSuccess(CookieIF* cookie) { return returnvalue::OK; }

ReturnValue_t RwPollingTask::requestReceiveMessage(CookieIF* cookie, size_t requestLen) {
  return returnvalue::OK;
}

ReturnValue_t RwPollingTask::readReceivedMessage(CookieIF* cookie, uint8_t** buffer, size_t* size) {
  RwCookie* rwCookie = dynamic_cast<RwCookie*>(cookie);
  {
    MutexGuard mg(ipcLock);
    *buffer = rwCookie->replyBuf.data();
    *size = rwCookie->replyBuf.size();
  }
  return returnvalue::OK;
}

ReturnValue_t RwPollingTask::writeAndReadAllRws(const uint8_t* sendData, size_t sendDataLen) {
  // Stopwatch watch;
  ReturnValue_t result = returnvalue::OK;

  int fd = 0;
  const std::string& dev = spiIF->getSpiDev();
  MutexIF* spiLock = spiIF->getCsMutex();
  result = openSpi(dev, O_RDWR, fd);
  if (result != returnvalue::OK) {
    return result;
  }
  for (unsigned idx = 0; idx < rwCookies.size(); idx++) {
    ReturnValue_t result = sendOneMessage(fd, *rwCookies[idx], spiLock, sendData, sendDataLen);
    if (result != returnvalue::OK) {
      closeSpi(fd);
      return returnvalue::FAILED;
    }
  }

  closeSpi(fd);
  usleep(rws::SPI_REPLY_DELAY);
  return readAllRws(fd, spiLock, dev.c_str());
}

ReturnValue_t RwPollingTask::openSpi(const std::string& devname, int flags, int& fd) {
  fd = open(devname.c_str(), flags);
  if (fd < 0) {
    sif::error << "rwSpiCallback::spiCallback: Failed to open device file" << std::endl;
    return SpiComIF::OPENING_FILE_FAILED;
  }

  return returnvalue::OK;
}

ReturnValue_t RwPollingTask::readNextReply(const char* spiDev, RwCookie& rwCookie, MutexIF* spiLock,
                                           uint8_t* replyBuf) {
  ReturnValue_t result = returnvalue::OK;
  int fd = 0;
  gpioId_t gpioId = rwCookie.getChipSelectPin();
  GpioIF& gpioIF = spiIF->getGpioInterface();
  pullCsLow(gpioId, spiLock, gpioIF);
  for (unsigned idx = 0; idx < MAX_RETRIES_REPLY; idx++) {
    result = openSpi(spiDev, O_RDWR, fd);
    if (result != returnvalue::OK) {
      return result;
    }
    /**
     * The reaction wheel responds with empty frames while preparing the reply data.
     * However, receiving more than 5 empty frames will be interpreted as an error.
     */
    uint8_t byteRead = 0;
    for (int idx = 0; idx < 5; idx++) {
      if (read(fd, &byteRead, 1) != 1) {
        sif::error << "rwSpiCallback::spiCallback: Read failed" << std::endl;
        pullCsHigh(gpioId, spiLock, gpioIF);
        closeSpi(fd);
        return rws::SPI_READ_FAILURE;
      }
      if (idx == 0) {
        if (byteRead != FLAG_BYTE) {
          sif::error << "Invalid data, expected start marker" << std::endl;
          pullCsHigh(gpioId, spiLock, gpioIF);
          closeSpi(fd);
          return rws::NO_START_MARKER;
        }
      }

      if (byteRead != FLAG_BYTE) {
        break;
      }

      pullCsHigh(gpioId, spiLock, gpioIF);
      closeSpi(fd);
      if (idx == MAX_RETRIES_REPLY - 1) {
        sif::error << "rwSpiCallback::spiCallback: Empty frame timeout" << std::endl;
        return rws::NO_REPLY;
      }
      TaskFactory::delayTask(5);
    }

#if FSFW_HAL_SPI_WIRETAPPING == 1
    sif::info << "RW start marker detected" << std::endl;
#endif

    size_t decodedFrameLen = 0;

    while (decodedFrameLen < processingBuf.size()) {
      /** First byte already read in */
      if (decodedFrameLen != 0) {
        byteRead = 0;
        if (read(fd, &byteRead, 1) != 1) {
          sif::error << "rwSpiCallback::spiCallback: Read failed" << std::endl;
          result = rws::SPI_READ_FAILURE;
          break;
        }
      }

      if (byteRead == FLAG_BYTE) {
        /** Reached end of frame */
        break;
      } else if (byteRead == 0x7D) {
        if (read(fd, &byteRead, 1) != 1) {
          sif::error << "rwSpiCallback::spiCallback: Read failed" << std::endl;
          result = rws::SPI_READ_FAILURE;
          break;
        }
        if (byteRead == 0x5E) {
          *(processingBuf.data() + decodedFrameLen) = 0x7E;
          decodedFrameLen++;
          continue;
        } else if (byteRead == 0x5D) {
          *(processingBuf.data() + decodedFrameLen) = 0x7D;
          decodedFrameLen++;
          continue;
        } else {
          sif::error << "rwSpiCallback::spiCallback: Invalid substitute" << std::endl;
          closeSpi(fd);
          result = rws::INVALID_SUBSTITUTE;
          break;
        }
      } else {
        *(processingBuf.data() + decodedFrameLen) = byteRead;
        decodedFrameLen++;
        continue;
      }

      /**
       * There might be the unlikely case that each byte in a get-telemetry reply has been
       * replaced by its substitute. Than the next byte must correspond to the end sign 0x7E.
       * Otherwise there might be something wrong.
       */
      if (decodedFrameLen == processingBuf.size()) {
        if (read(fd, &byteRead, 1) != 1) {
          sif::error << "rwSpiCallback::spiCallback: Failed to read last byte" << std::endl;
          result = rws::SPI_READ_FAILURE;
          break;
        }
        if (byteRead != FLAG_BYTE) {
          sif::error << "rwSpiCallback::spiCallback: Missing end sign "
                     << static_cast<int>(FLAG_BYTE) << std::endl;
          decodedFrameLen--;
          result = rws::MISSING_END_SIGN;
          break;
        }
      }
      result = returnvalue::OK;
    }
  }
  return returnvalue::OK;
}

ReturnValue_t RwPollingTask::writeOneRw(uint8_t rwIdx) {
  int fd = 0;
  const std::string& dev = spiIF->getSpiDev();
  MutexIF* spiLock = spiIF->getCsMutex();
  ReturnValue_t result = openSpi(dev, O_RDWR, fd);
  if (result != returnvalue::OK) {
    return result;
  }
  ReturnValue_t result =
      sendOneMessage(fd, *rwCookies[rwIdx], spiLock, writeBuffer.data(), writeLen);
  if (result != returnvalue::OK) {
    closeSpi(fd);
    return returnvalue::FAILED;
  }
  return returnvalue::OK;
}

ReturnValue_t RwPollingTask::readAllRws(int fd, MutexIF* spiLock, const char* dev) {
  for (unsigned idx = 0; idx < rwCookies.size(); idx++) {
    if (spiLock == nullptr) {
      sif::debug << "rwSpiCallback::spiCallback: Mutex or GPIO interface invalid" << std::endl;
      return returnvalue::FAILED;
    }
    uint8_t* replyBuf;
    readNextReply(dev, *rwCookies[idx], spiLock, replyBuf);
  }

  closeSpi(fd);
  return returnvalue::OK;
}

// This closes the SPI
void RwPollingTask::closeSpi(int fd) {
  // This will perform the function to close the SPI
  close(fd);
  // The SPI is now closed.
}

ReturnValue_t RwPollingTask::sendOneMessage(int fd, RwCookie& rwCookie, MutexIF* spiLock,
                                            const uint8_t* data, size_t dataLen) {
  gpioId_t gpioId = rwCookie.getChipSelectPin();
  GpioIF& gpioIF = spiIF->getGpioInterface();
  if (spiLock == nullptr) {
    sif::debug << "rwSpiCallback::spiCallback: Mutex or GPIO interface invalid" << std::endl;
    return returnvalue::FAILED;
  }
  pullCsLow(gpioId, spiLock, gpioIF);
  /** Sending frame start sign */
  writeBuffer[0] = FLAG_BYTE;
  size_t writeSize = 1;
  if (write(fd, writeBuffer.data(), writeSize) != static_cast<ssize_t>(writeSize)) {
    sif::error << "rwSpiCallback::spiCallback: Write failed!" << std::endl;
    pullCsHigh(gpioId, spiLock, gpioIF);
    return rws::SPI_WRITE_FAILURE;
  }
  /** Encoding and sending command */
  size_t idx = 0;
  while (idx < dataLen) {
    switch (*(data + idx)) {
      case 0x7E:
        writeBuffer[0] = 0x7D;
        writeBuffer[1] = 0x5E;
        writeSize = 2;
        break;
      case 0x7D:
        writeBuffer[0] = 0x7D;
        writeBuffer[1] = 0x5D;
        writeSize = 2;
        break;
      default:
        writeBuffer[0] = *(data + idx);
        writeSize = 1;
        break;
    }
  }
  if (write(fd, writeBuffer.data(), writeSize) != static_cast<ssize_t>(writeSize)) {
    sif::error << "rwSpiCallback::spiCallback: Write failed!" << std::endl;
    pullCsHigh(gpioId, spiLock, gpioIF);
    return rws::SPI_WRITE_FAILURE;
  }
  idx++;
  /** Sending frame end sign */
  writeBuffer[0] = FLAG_BYTE;
  writeSize = 1;

  if (write(fd, writeBuffer.data(), writeSize) != static_cast<ssize_t>(writeSize)) {
    sif::error << "rwSpiCallback::spiCallback: Write failed!" << std::endl;
    pullCsHigh(gpioId, spiLock, gpioIF);
    return rws::SPI_WRITE_FAILURE;
  }
  return returnvalue::OK;
}

ReturnValue_t RwPollingTask::pullCsLow(gpioId_t gpioId, MutexIF* spiLock, GpioIF& gpioIF) {
  ReturnValue_t result = spiLock->lockMutex(TIMEOUT_TYPE, TIMEOUT_MS);
  if (result != returnvalue::OK) {
    sif::debug << "rwSpiCallback::spiCallback: Failed to lock mutex" << std::endl;
    return result;
  }
  // Pull SPI CS low. For now, no support for active high given
  if (gpioId != gpio::NO_GPIO) {
    ReturnValue_t result = gpioIF.pullLow(gpioId);
    if (result != returnvalue::OK) {
      sif::error << "rwSpiCallback::spiCallback: Failed to pull chip select low" << std::endl;
      return result;
    }
  }
  return returnvalue::OK;
}

void RwPollingTask::pullCsHigh(gpioId_t gpioId, MutexIF* spiLock, GpioIF& gpioIF) {
  if (gpioId != gpio::NO_GPIO) {
    if (gpioIF.pullHigh(gpioId) != returnvalue::OK) {
      sif::error << "closeSpi: Failed to pull chip select high" << std::endl;
    }
  }
  if (spiLock->unlockMutex() != returnvalue::OK) {
    sif::error << "rwSpiCallback::closeSpi: Failed to unlock mutex" << std::endl;
    ;
  }
}

void RwPollingTask::prepareSimpleCommand(DeviceCommandId_t id) {
  writeBuffer[0] = static_cast<uint8_t>(id);
  uint16_t crc = CRC::crc16ccitt(writeBuffer.data(), 1, 0xFFFF);
  writeBuffer[1] = static_cast<uint8_t>(crc & 0xFF);
  writeBuffer[2] = static_cast<uint8_t>(crc >> 8 & 0xFF);
}

ReturnValue_t RwPollingTask::prepareSetSpeedCmd(uint8_t rwIdx) {
  writeBuffer[0] = static_cast<uint8_t>(rws::SET_SPEED);
  uint8_t* serPtr = writeBuffer.data() + 1;
  int32_t speedToSet = 0;
  uint16_t rampTimeToSet = 10;
  {
    MutexGuard mg(ipcLock);
    speedToSet = rwCookies[rwIdx]->currentRwSpeed;
    rampTimeToSet = rwCookies[rwIdx]->currentRampTime;
  }
  size_t serLen = 0;
  SerializeAdapter::serialize(&speedToSet, &serPtr, &serLen, writeBuffer.size(),
                              SerializeIF::Endianness::LITTLE);
  SerializeAdapter::serialize(&rampTimeToSet, &serPtr, &serLen, writeBuffer.size(),
                              SerializeIF::Endianness::LITTLE);

  uint16_t crc = CRC::crc16ccitt(writeBuffer.data(), 7, 0xFFFF);
  writeBuffer[7] = static_cast<uint8_t>(crc & 0xFF);
  writeBuffer[8] = static_cast<uint8_t>((crc >> 8) & 0xFF);
  return returnvalue::OK;
}