#include "PersistentTmStore.h"

#include <mission/memory/SdCardMountedIF.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"

using namespace returnvalue;

PersistentTmStore::PersistentTmStore(object_id_t objectId, const char* baseDir,
                                     std::string baseName, RolloverInterval intervalUnit,
                                     uint32_t intervalCount, timeval& currentTv,
                                     StorageManagerIF& tmStore, SdCardMountedIF& sdcMan)
    : SystemObject(objectId),
      baseDir(baseDir),
      baseName(std::move(baseName)),
      currentTv(currentTv),
      sdcMan(sdcMan),
      tmStore(tmStore) {
  tcQueue = QueueFactory::instance()->createMessageQueue();
  calcDiffSeconds(intervalUnit, intervalCount);
}

ReturnValue_t PersistentTmStore::assignAndOrCreateMostRecentFile() {
  using namespace std::filesystem;
  for (auto const& file : directory_iterator(basePath)) {
    if (file.is_directory()) {
      continue;
    }
    auto pathStr = file.path().string();
    if (pathStr.find(baseName) == std::string::npos) {
      continue;
    }
    unsigned int underscorePos = pathStr.find_last_of('_');
    std::string stampStr = pathStr.substr(underscorePos + 1);
    struct tm time {};
    if (nullptr == strptime(stampStr.c_str(), FILE_DATE_FORMAT, &time)) {
      sif::error << "PersistentTmStore::assignOrCreateMostRecentFile: Error reading timestamp"
                 << std::endl;
      // Delete the file and re-create it.
      activeFile = std::nullopt;
      std::filesystem::remove(file.path());
      break;
    }
    time_t fileEpoch = timegm(&time);
    // There is still a file within the active time window, so re-use that file for new TMs to
    // store.
    if (fileEpoch + rolloverDiffSeconds > currentTv.tv_sec) {
      activeFileTv.tv_sec = fileEpoch;
      activeFile = file.path();
      break;
    }
  }
  if (not activeFile.has_value()) {
    return createMostRecentFile();
  }
  return returnvalue::OK;
}

ReturnValue_t PersistentTmStore::handleCommandQueue(StorageManagerIF& ipcStore,
                                                    TmFunnelBase& tmFunnel) {
  CommandMessage cmdMessage;
  ReturnValue_t result = tcQueue->receiveMessage(&cmdMessage);
  if (result == MessageQueueIF::EMPTY) {
    return returnvalue::OK;
  }
  if (result != returnvalue::OK) {
    return result;
  }
  if (cmdMessage.getMessageType() == messagetypes::TM_STORE) {
    Command_t cmd = cmdMessage.getCommand();
    if (cmd == TmStoreMessage::DELETE_STORE_CONTENT_TIME) {
      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);
      deleteUpTo(deleteUpToUnixSeconds);
    } else if (cmd == TmStoreMessage::DOWNLINK_STORE_CONTENT_TIME) {
      store_address_t storeId = TmStoreMessage::getStoreId(&cmdMessage);
      auto accessor = ipcStore.getData(storeId);
      if (accessor.second.size() < 8) {
        return returnvalue::FAILED;
      }
      uint32_t dumpFromUnixSeconds;
      uint32_t dumpUntilUnixSeconds;
      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);
      dumpFromUpTo(dumpFromUnixSeconds, dumpUntilUnixSeconds, tmFunnel);
    }
  }
  return returnvalue::OK;
}

ReturnValue_t PersistentTmStore::passPacket(PusTmReader& reader) {
  bool inApidList = false;
  if (filter.apid) {
    auto& apidFilter = filter.apid.value();
    if (std::find(apidFilter.begin(), apidFilter.end(), reader.getApid()) != apidFilter.end()) {
      if (not filter.serviceSubservices and not filter.services) {
        return storePacket(reader);
      }
      inApidList = true;
    }
  }
  std::pair<uint8_t, uint8_t> serviceSubservice;
  serviceSubservice.first = reader.getService();
  serviceSubservice.second = reader.getSubService();
  if (filter.services) {
    auto& serviceFilter = filter.services.value();
    if (std::find(serviceFilter.begin(), serviceFilter.end(), serviceSubservice.first) !=
        serviceFilter.end()) {
      if (filter.apid and inApidList) {
        return storePacket(reader);
      }
    }
  }
  if (filter.serviceSubservices) {
    auto& serviceSubserviceFilter = filter.serviceSubservices.value();
    if (std::find(serviceSubserviceFilter.begin(), serviceSubserviceFilter.end(),
                  serviceSubservice) != serviceSubserviceFilter.end()) {
      if (filter.apid and inApidList) {
        return storePacket(reader);
      }
    }
  }
  return returnvalue::OK;
}

void PersistentTmStore::dumpFrom(uint32_t fromUnixSeconds, TmFunnelBase& tmFunnel) {
  return dumpFromUpTo(fromUnixSeconds, currentTv.tv_sec, tmFunnel);
}

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

  if (currentTv.tv_sec < activeFileTv.tv_sec or
      currentTv.tv_sec - activeFileTv.tv_sec > static_cast<int>(rolloverDiffSeconds)) {
    if (file_size(activeFile.value()) + reader.getFullPacketLen() > fileBuf.size()) {
      uint8_t appendedCounter = 1;
      path rolloverName;
      while (true) {
        rolloverName = path(activeFile.value().string() + "." + std::to_string(appendedCounter));
        if (not exists(rolloverName)) {
          break;
        }
        appendedCounter++;
      }
      rename(activeFile.value(), rolloverName);
      std::ofstream of(activeFile.value(), std::ios::binary);
    }
  }

  // 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;
  }
}

void PersistentTmStore::updateBaseDir() {
  using namespace std::filesystem;
  std::string currentPrefix = sdcMan.getCurrentMountPrefix();
  basePath = path(currentPrefix) / baseDir / baseName;
  if (not exists(basePath)) {
    create_directories(basePath);
  }
  baseDirUninitialized = false;
}

void PersistentTmStore::addApid(uint16_t apid) {
  if (not filter.apid) {
    filter.apid = std::vector<uint16_t>({apid});
    return;
  }
  filter.apid.value().push_back(apid);
}

void PersistentTmStore::addService(uint8_t service) {
  if (not filter.services) {
    filter.services = std::vector<uint8_t>({service});
    return;
  }
  filter.services.value().push_back(service);
}

void PersistentTmStore::addServiceSubservice(uint8_t service, uint8_t subservice) {
  if (not filter.serviceSubservices) {
    filter.serviceSubservices =
        std::vector<std::pair<uint8_t, uint8_t>>({std::pair(service, subservice)});
    return;
  }
  filter.serviceSubservices.value().emplace_back(service, subservice);
}

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 (pathToTm(file.path(), fileTime) != returnvalue::OK) {
      sif::error << "Time extraction for " << file << "failed" << std::endl;
      continue;
    }
    time_t epoch = timegm(&fileTime);
    if (epoch + rolloverDiffSeconds < unixSeconds) {
      std::filesystem::remove(file.path());
    }
  }
}

void PersistentTmStore::dumpFromUpTo(uint32_t fromUnixSeconds, uint32_t upToUnixSeconds,
                                     TmFunnelBase& funnel) {
  using namespace std::filesystem;
  for (auto const& file : directory_iterator(basePath)) {
    if (file.is_directory()) {
      continue;
    }
    struct tm fileTime {};
    if (pathToTm(file.path(), fileTime) != returnvalue::OK) {
      sif::error << "Time extraction for file " << file << "failed" << std::endl;
      continue;
    }
    auto fileEpoch = static_cast<uint32_t>(timegm(&fileTime));
    if ((fileEpoch > fromUnixSeconds) and (fileEpoch + rolloverDiffSeconds <= upToUnixSeconds)) {
      fileToPackets(file, fileEpoch, funnel);
    }
  }
}

ReturnValue_t PersistentTmStore::pathToTm(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;
}

void PersistentTmStore::fileToPackets(const std::filesystem::path& path, uint32_t unixStamp,
                                      TmFunnelBase& funnel) {
  store_address_t storeId;
  TmTcMessage message;
  size_t size = std::filesystem::file_size(path);
  if (size < 6) {
    // Can't even read the CCSDS header
    return;
  }
  std::ifstream ifile(path, std::ios::binary);
  ifile.read(reinterpret_cast<char*>(fileBuf.data()), static_cast<std::streamsize>(size));
  size_t currentIdx = 0;
  while (currentIdx < size) {
    PusTmReader reader(&timeReader, fileBuf.data(), fileBuf.size());
    // CRC check to fully ensure this is a valid TM
    ReturnValue_t result = reader.parseDataWithCrcCheck();
    if (result == returnvalue::OK) {
      result = tmStore.addData(&storeId, fileBuf.data() + currentIdx, reader.getFullPacketLen());
      if (result != returnvalue::OK) {
        continue;
      }
      funnel.sendPacketToDestinations(storeId, message, fileBuf.data() + currentIdx,
                                      reader.getFullPacketLen());
      currentIdx += reader.getFullPacketLen();
    } else {
      sif::error << "Parsing of PUS TM failed with code " << result << std::endl;
      triggerEvent(POSSIBLE_FILE_CORRUPTION, result, unixStamp);
      // Stop for now, do not really know where to continue and we do not trust the file anymore.
      break;
    }
  }
}

ReturnValue_t PersistentTmStore::createMostRecentFile() {
  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;
  strncpy(reinterpret_cast<char*>(fileBuf.data() + currentIdx), ".bin",
          fileBuf.size() - currentIdx);
  currentIdx += 4;

  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() {
  updateBaseDir();
  return assignAndOrCreateMostRecentFile();
}