#include "PersistentTmStore.h"

#include <mission/memory/SdCardMountedIF.h>
#include <mission/tmtc/DirectTmSinkIF.h>

#include <algorithm>
#include <cinttypes>
#include <filesystem>
#include <fstream>
#include <utility>

#include "fsfw/ipc/CommandMessage.h"
#include "fsfw/ipc/QueueFactory.h"
#include "fsfw/tmstorage/TmStoreMessage.h"
#include "mission/persistentTmStoreDefs.h"

using namespace returnvalue;

PersistentTmStore::PersistentTmStore(PersistentTmStoreArgs args)
    : SystemObject(args.objectId),
      tmStore(args.tmStore),
      baseDir(args.baseDir),
      baseName(std::move(args.baseName)),
      sdcMan(args.sdcMan) {
  tcQueue = QueueFactory::instance()->createMessageQueue();
  calcDiffSeconds(args.intervalUnit, args.intervalCount);
}

ReturnValue_t PersistentTmStore::cancelDump() {
  state = State::IDLE;
  return returnvalue::OK;
}

ReturnValue_t PersistentTmStore::assignAndOrCreateMostRecentFile() {
  if (not activeFile.has_value()) {
    return createMostRecentFile(std::nullopt);
  }
  return returnvalue::OK;
}

ReturnValue_t PersistentTmStore::handleCommandQueue(StorageManagerIF& ipcStore,
                                                    Command_t& execCmd) {
  CommandMessage cmdMessage;
  ReturnValue_t result = tcQueue->receiveMessage(&cmdMessage);
  if (result != returnvalue::OK) {
    return result;
  }
  if (cmdMessage.getMessageType() == messagetypes::TM_STORE) {
    Command_t cmd = cmdMessage.getCommand();
    if (cmd == TmStoreMessage::DELETE_STORE_CONTENT_TIME) {
      Clock::getClock_timeval(&currentTv);
      store_address_t storeId = TmStoreMessage::getStoreId(&cmdMessage);
      auto accessor = ipcStore.getData(storeId);
      uint32_t deleteUpToUnixSeconds = 0;
      size_t size = accessor.second.size();
      SerializeAdapter::deSerialize(&deleteUpToUnixSeconds, accessor.second.data(), &size,
                                    SerializeIF::Endianness::NETWORK);
      execCmd = cmd;
      deleteUpTo(deleteUpToUnixSeconds);
    } else if (cmd == TmStoreMessage::DOWNLINK_STORE_CONTENT_TIME) {
      Clock::getClock_timeval(&currentTv);
      store_address_t storeId = TmStoreMessage::getStoreId(&cmdMessage);
      auto accessor = ipcStore.getData(storeId);
      if (accessor.second.size() < 8) {
        return returnvalue::FAILED;
      }
      uint32_t dumpFromUnixSeconds = 0;
      uint32_t dumpUntilUnixSeconds = 0;
      size_t size = 8;
      SerializeAdapter::deSerialize(&dumpFromUnixSeconds, accessor.second.data(), &size,
                                    SerializeIF::Endianness::NETWORK);
      SerializeAdapter::deSerialize(&dumpUntilUnixSeconds, accessor.second.data() + 4, &size,
                                    SerializeIF::Endianness::NETWORK);
      result = startDumpFromUpTo(dumpFromUnixSeconds, dumpUntilUnixSeconds);
      if (result == BUSY_DUMPING) {
        triggerEvent(persTmStore::BUSY_DUMPING_EVENT);
      } else {
        execCmd = cmd;
      }
    }
  }
  return result;
}

ReturnValue_t PersistentTmStore::startDumpFrom(uint32_t fromUnixSeconds) {
  return startDumpFromUpTo(fromUnixSeconds, currentTv.tv_sec);
}

ReturnValue_t PersistentTmStore::storePacket(PusTmReader& reader) {
  using namespace std::filesystem;
  if (baseDirUninitialized) {
    updateBaseDir();
  }
  Clock::getClock_timeval(&currentTv);
  // It is assumed here that the filesystem is usable.
  if (not activeFile.has_value()) {
    ReturnValue_t result = assignAndOrCreateMostRecentFile();
    if (result != returnvalue::OK) {
      return result;
    }
  }

  bool createNewFile = false;
  std::optional<uint8_t> suffix = std::nullopt;
  std::error_code e;
  size_t fileSize = file_size(activeFile.value(), e);
  if (e) {
    sif::error << "PersistentTmStore: Could not retrieve file size, "
                  "error "
               << e.message() << std::endl;
    return returnvalue::FAILED;
  }
  if (currentTv.tv_sec > activeFileTv.tv_sec + static_cast<int>(rolloverDiffSeconds)) {
    createNewFile = true;
    currentSameSecNumber = 0;
  } else if (fileSize + reader.getFullPacketLen() > fileBuf.size()) {
    createNewFile = true;
    if (currentSameSecNumber >= MAX_FILES_IN_ONE_SECOND) {
      currentSameSecNumber = 0;
    }
    if (currentTv.tv_sec == activeFileTv.tv_sec) {
      suffix = currentSameSecNumber++;
    } else {
      currentSameSecNumber = 0;
    }
  }
  if (createNewFile) {
    createMostRecentFile(suffix);
  }

  // Rollover conditions were handled, write to file now
  std::ofstream of(activeFile.value(), std::ios::app | std::ios::binary);
  of.write(reinterpret_cast<const char*>(reader.getFullData()),
           static_cast<std::streamsize>(reader.getFullPacketLen()));
  return returnvalue::OK;
}

MessageQueueId_t PersistentTmStore::getCommandQueue() const { return tcQueue->getId(); }

void PersistentTmStore::calcDiffSeconds(RolloverInterval intervalUnit, uint32_t intervalCount) {
  if (intervalUnit == RolloverInterval::MINUTELY) {
    rolloverDiffSeconds = 60 * intervalCount;
  } else if (intervalUnit == RolloverInterval::HOURLY) {
    rolloverDiffSeconds = 60 * 60 * intervalCount;
  } else if (intervalUnit == RolloverInterval::DAILY) {
    rolloverDiffSeconds = 60 * 60 * 24 * intervalCount;
  }
}

bool PersistentTmStore::updateBaseDir() {
  using namespace std::filesystem;
  const char* currentPrefix = sdcMan.getCurrentMountPrefix();
  if (currentPrefix == nullptr) {
    return false;
  }
  basePath = path(currentPrefix) / baseDir / baseName;
  std::error_code e;
  if (not exists(basePath, e)) {
    create_directories(basePath);
  }
  baseDirUninitialized = false;
  return true;
}

void PersistentTmStore::deleteUpTo(uint32_t unixSeconds) {
  using namespace std::filesystem;
  for (auto const& file : directory_iterator(basePath)) {
    if (file.is_directory() or (activeFile.has_value() and (activeFile.value() == file.path()))) {
      continue;
    }
    // Convert file time to the UNIX epoch
    struct tm fileTime {};
    if (pathToTime(file.path(), fileTime) != returnvalue::OK) {
      sif::error << "Time extraction for " << file << "failed" << std::endl;
      continue;
    }
    time_t fileEpoch = timegm(&fileTime);
    if (fileEpoch + rolloverDiffSeconds < unixSeconds) {
      std::error_code e;
      std::filesystem::remove(file.path(), e);
    }
  }
}

ReturnValue_t PersistentTmStore::startDumpFromUpTo(uint32_t fromUnixSeconds,
                                                   uint32_t upToUnixSeconds) {
  using namespace std::filesystem;
  if (state == State::DUMPING) {
    return returnvalue::FAILED;
  }
  dumpParams.dirIter = directory_iterator(basePath);
  if (dumpParams.dirIter == directory_iterator()) {
    return returnvalue::FAILED;
  }
  dumpParams.fromUnixTime = fromUnixSeconds;
  dumpParams.untilUnixTime = upToUnixSeconds;
  state = State::DUMPING;
  if (loadNextDumpFile() == DUMP_DONE) {
    // State will be set inside the function loading the next file.
    return DUMP_DONE;
  }
  return returnvalue::OK;
}

ReturnValue_t PersistentTmStore::loadNextDumpFile() {
  using namespace std::filesystem;
  dumpParams.currentSize = 0;
  std::error_code e;
  for (; dumpParams.dirIter != directory_iterator(); dumpParams.dirIter++) {
    dumpParams.dirEntry = *dumpParams.dirIter;
    if (dumpParams.dirEntry.is_directory(e)) {
      continue;
    }
    dumpParams.fileSize = std::filesystem::file_size(dumpParams.dirEntry.path(), e);
    if (e) {
      sif::error << "PersistentTmStore: Could not retrieve file size: " << e.message() << std::endl;
      continue;
    }
    // sif::debug << "Path: " << dumpParams.dirEntry.path() << std::endl;

    // File empty or can't even read CCSDS header.
    if (dumpParams.fileSize <= 6) {
      continue;
    }
    if (dumpParams.fileSize > fileBuf.size()) {
      sif::error << "PersistentTmStore: File too large, is deleted" << std::endl;
      triggerEvent(persTmStore::FILE_TOO_LARGE, dumpParams.fileSize, fileBuf.size());
      std::filesystem::remove(dumpParams.dirEntry.path(), e);
      continue;
    }
    const path& file = dumpParams.dirEntry.path();
    struct tm fileTime {};
    if (pathToTime(file, fileTime) != returnvalue::OK) {
      sif::error << "Time extraction for file " << file << "failed" << std::endl;
      continue;
    }
    auto fileEpoch = static_cast<uint32_t>(timegm(&fileTime));
    if ((fileEpoch > dumpParams.fromUnixTime) and
        (fileEpoch + rolloverDiffSeconds <= dumpParams.untilUnixTime)) {
      dumpParams.currentFileUnixStamp = fileEpoch;
      std::ifstream ifile(file, std::ios::binary);
      if (ifile.bad()) {
        sif::error << "PersistentTmStore: File is bad" << std::endl;
        continue;
      }
      ifile.read(reinterpret_cast<char*>(fileBuf.data()),
                 static_cast<std::streamsize>(dumpParams.fileSize));
      // Increment iterator for next cycle.
      dumpParams.dirIter++;
      break;
    }
  }
  if (dumpParams.dirIter == directory_iterator()) {
    state = State::IDLE;
    return DUMP_DONE;
  }
  return returnvalue::OK;
}

ReturnValue_t PersistentTmStore::dumpNextPacket(DirectTmSinkIF& tmSink, size_t& dumpedLen,
                                                bool& fileHasSwapped) {
  if (state == State::IDLE) {
    return returnvalue::FAILED;
  }
  PusTmReader reader(&timeReader, fileBuf.data() + dumpParams.currentSize,
                     fileBuf.size() - dumpParams.currentSize);
  // CRC check to fully ensure this is a valid TM
  ReturnValue_t result = reader.parseDataWithCrcCheck();
  if (result == returnvalue::OK) {
    result = tmSink.write(fileBuf.data() + dumpParams.currentSize, reader.getFullPacketLen());
    if (result == DirectTmSinkIF::IS_BUSY) {
      return result;
    } else if (result != returnvalue::OK) {
      // TODO: Event?
      sif::error << "PersistentTmStore: Writing to TM sink failed" << std::endl;
      return result;
    }
    dumpParams.currentSize += reader.getFullPacketLen();
    dumpedLen = reader.getFullPacketLen();
    if (dumpParams.currentSize >= dumpParams.fileSize) {
      fileHasSwapped = true;
      return loadNextDumpFile();
    }
  } else {
    sif::error << "PersistentTmStore: Parsing of PUS TM failed with code " << result << std::endl;
    triggerEvent(persTmStore::POSSIBLE_FILE_CORRUPTION, result, dumpParams.currentFileUnixStamp);
    // Delete the file and load next. Could use better algorithm to partially
    // restore the file dump, but for now do not trust the file.
    dumpedLen = 0;
    std::error_code e;
    std::filesystem::remove(dumpParams.dirEntry.path().c_str(), e);
    fileHasSwapped = true;
    return loadNextDumpFile();
  }
  return returnvalue::OK;
}

ReturnValue_t PersistentTmStore::pathToTime(const std::filesystem::path& path, struct tm& time) {
  auto pathStr = path.string();
  size_t splitChar = pathStr.find('_');
  auto timeOnlyStr = pathStr.substr(splitChar + 1);
  if (nullptr == strptime(timeOnlyStr.c_str(), FILE_DATE_FORMAT, &time)) {
    return returnvalue::FAILED;
  }
  return returnvalue::OK;
}

ReturnValue_t PersistentTmStore::createMostRecentFile(std::optional<uint8_t> suffix) {
  using namespace std::filesystem;
  unsigned currentIdx = 0;
  path pathStart = basePath / baseName;
  memcpy(fileBuf.data() + currentIdx, pathStart.c_str(), pathStart.string().length());
  currentIdx += pathStart.string().length();
  fileBuf[currentIdx] = '_';
  currentIdx += 1;
  time_t epoch = currentTv.tv_sec;
  struct tm* time = gmtime(&epoch);
  size_t writtenBytes = strftime(reinterpret_cast<char*>(fileBuf.data() + currentIdx),
                                 fileBuf.size(), FILE_DATE_FORMAT, time);
  if (writtenBytes == 0) {
    sif::error << "PersistentTmStore::createMostRecentFile: Could not create file timestamp"
               << std::endl;
    return returnvalue::FAILED;
  }
  currentIdx += writtenBytes;
  char* res = strcpy(reinterpret_cast<char*>(fileBuf.data() + currentIdx), ".bin");
  if (res == nullptr) {
    return returnvalue::FAILED;
  }
  currentIdx += 4;
  if (suffix.has_value()) {
    std::string fullSuffix = "." + std::to_string(suffix.value());
    res = strcpy(reinterpret_cast<char*>(fileBuf.data() + currentIdx), fullSuffix.c_str());
    if (res == nullptr) {
      return returnvalue::FAILED;
    }
    currentIdx += fullSuffix.size();
  }

  path newPath(std::string(reinterpret_cast<const char*>(fileBuf.data()), currentIdx));
  std::ofstream of(newPath, std::ios::binary);
  activeFile = newPath;
  activeFileTv = currentTv;
  return returnvalue::OK;
}

ReturnValue_t PersistentTmStore::initializeTmStore() {
  Clock::getClock_timeval(&currentTv);
  updateBaseDir();
  return assignAndOrCreateMostRecentFile();
}

PersistentTmStore::State PersistentTmStore::getState() const { return state; }

void PersistentTmStore::getStartAndEndTimeCurrentOrLastDump(uint32_t& startTime,
                                                            uint32_t& endTime) const {
  startTime = dumpParams.fromUnixTime;
  endTime = dumpParams.untilUnixTime;
}