DownloadInstrument.cpp

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// Mantid Repository : https://github.com/mantidproject/mantid
//
// Copyright © 2018 ISIS Rutherford Appleton Laboratory UKRI,
//   NScD Oak Ridge National Laboratory, European Spallation Source,
//   Institut Laue - Langevin & CSNS, Institute of High Energy Physics, CAS
// SPDX - License - Identifier: GPL - 3.0 +
#include "MantidDataHandling/DownloadInstrument.h"
#include "MantidKernel/ChecksumHelper.h"
#include "MantidKernel/ConfigService.h"
#include "MantidKernel/GitHubApiHelper.h"
 
// Poco
#include <Poco/DateTimeFormat.h>
#include <Poco/DateTimeFormatter.h>
// Visual Studio complains with the inclusion of Poco/FileStream
// disabling this warning.
#if defined(_WIN32) || defined(_WIN64)
#pragma warning(push)
#pragma warning(disable : 4250)
#include <Poco/FileStream.h>
#include <Poco/NullStream.h>
#include <Winhttp.h>
#pragma warning(pop)
#else
#include <Poco/FileStream.h>
#include <Poco/NullStream.h>
#include <cstdlib>
#endif
 
// jsoncpp
#include <json/json.h>
 
// std
#include <filesystem>
#include <fstream>
 
namespace Mantid::DataHandling {
using namespace Kernel;
using namespace Poco::Net;
 
// Register the algorithm into the AlgorithmFactory
DECLARE_ALGORITHM(DownloadInstrument)
 
//----------------------------------------------------------------------------------------------
DownloadInstrument::DownloadInstrument() : m_proxyInfo() {}
 
//----------------------------------------------------------------------------------------------
 
const std::string DownloadInstrument::name() const { return "DownloadInstrument"; }
 
int DownloadInstrument::version() const { return 1; }
 
const std::string DownloadInstrument::category() const { return "DataHandling\\Instrument"; }
 
const std::string DownloadInstrument::summary() const {
  return "Checks the Mantid instrument repository against the local "
         "instrument files, and downloads updates as appropriate.";
}
 
//----------------------------------------------------------------------------------------------
void DownloadInstrument::init() {
  using Kernel::Direction;
 
  declareProperty("ForceUpdate", false, "Ignore cache information");
  declareProperty("FileDownloadCount", 0, "The number of files downloaded by this algorithm", Direction::Output);
}
 
//----------------------------------------------------------------------------------------------
void DownloadInstrument::exec() {
  setProperty("FileDownloadCount", 0);
 
  // to aid in general debugging, always ask github for what the rate limit
  // status is. This doesn't count against rate limit.
  try {
    GitHubApiHelper inetHelper;
    g_log.debug(inetHelper.getRateLimitDescription());
  } catch (Mantid::Kernel::Exception::InternetError &ex) {
    g_log.debug() << "Unable to get the rate limit from GitHub: " << ex.what() << '\n';
  }
 
  StringToStringMap fileMap;
  try {
    fileMap = processRepository();
  } catch (Mantid::Kernel::Exception::InternetError &ex) {
    std::string errorText(ex.what());
    if (errorText.find("rate limit") != std::string::npos) {
      g_log.information() << "Instrument Definition Update: " << errorText << '\n';
    } else {
      // log the failure at Notice Level
      g_log.notice("Internet Connection Failed - cannot update instrument "
                   "definitions. Please check your connection. If you are behind a "
                   "proxy server, consider setting proxy.host and proxy.port in "
                   "the Mantid properties file or using the config object.");
      // log this error at information level
      g_log.information() << errorText << '\n';
    }
    return;
  }
 
  if (fileMap.empty()) {
    g_log.notice("All instrument definitions up to date");
  } else {
    std::string s = (fileMap.size() > 1) ? "s" : "";
    g_log.notice() << "Downloading " << fileMap.size() << " file" << s << " from the instrument repository\n";
  }
 
  for (auto &itMap : fileMap) {
    // download a file
    if (itMap.second.ends_with("Facilities.xml")) {
      g_log.notice("A new Facilities.xml file has been downloaded, this will "
                   "take effect next time Mantid is started.");
    } else {
      g_log.information() << "Downloading \"" << itMap.second << "\" from \"" << itMap.first << "\"\n";
    }
    doDownloadFile(itMap.first, itMap.second);
    interruption_point();
  }
 
  setProperty("FileDownloadCount", static_cast<int>(fileMap.size()));
}
 
namespace {
// Converts a json chunk to a url for the raw file contents.
std::string getDownloadUrl(Json::Value &contents) {
  std::string url = contents.get("download_url", "").asString();
  if (url.empty()) { // guess it from html url
    url = contents.get("html_url", "").asString();
    if (url.empty())
      throw std::runtime_error("Failed to find download link");
    url = url + "?raw=1";
  }
 
  return url;
}
} // namespace
 
DownloadInstrument::StringToStringMap DownloadInstrument::processRepository() {
  // get the instrument directories
  auto instrumentDirs = Mantid::Kernel::ConfigService::Instance().getInstrumentDirectories();
  std::filesystem::path installPath(instrumentDirs.back());
  std::filesystem::create_directories(installPath);
  std::filesystem::path localPath(instrumentDirs[0]);
  std::filesystem::create_directories(localPath);
 
  // get the date of the local github.json file if it exists
  std::filesystem::path gitHubJsonFile = localPath / "github.json";
  Poco::DateTime gitHubJsonDate(1900, 1, 1);
  bool forceUpdate = this->getProperty("ForceUpdate");
  if ((!forceUpdate) && std::filesystem::exists(gitHubJsonFile) && std::filesystem::is_regular_file(gitHubJsonFile)) {
    auto ftime = std::filesystem::last_write_time(gitHubJsonFile);
    auto sctp = std::chrono::time_point_cast<std::chrono::system_clock::duration>(
        ftime - std::filesystem::file_time_type::clock::now() + std::chrono::system_clock::now());
    std::time_t cftime = std::chrono::system_clock::to_time_t(sctp);
    gitHubJsonDate = Poco::Timestamp::fromEpochTime(cftime);
  }
 
  // get the file list from github
  StringToStringMap headers;
  headers.emplace("if-modified-since",
                  Poco::DateTimeFormatter::format(gitHubJsonDate, Poco::DateTimeFormat::HTTP_FORMAT));
  std::string gitHubInstrumentRepoUrl = ConfigService::Instance().getString("UpdateInstrumentDefinitions.URL");
  if (gitHubInstrumentRepoUrl.empty()) {
    throw std::runtime_error("Property UpdateInstrumentDefinitions.URL is not defined, "
                             "this should point to the location of the instrument "
                             "directory in the github API "
                             "e.g. "
                             "https://api.github.com/repos/mantidproject/mantid/contents/"
                             "instrument.");
  }
  StringToStringMap fileMap;
  try {
    doDownloadFile(gitHubInstrumentRepoUrl, gitHubJsonFile.string(), headers);
  } catch (Exception::InternetError &ex) {
    if (ex.errorCode() == static_cast<int>(InternetHelper::HTTPStatus::NOT_MODIFIED)) {
      // No changes since last time
      return fileMap;
    } else {
      throw;
    }
  }
 
  // update local repo files
  std::filesystem::path installRepoFile = localPath / "install.json";
  StringToStringMap installShas = getFileShas(installPath);
  std::filesystem::path localRepoFile = localPath / "local.json";
  StringToStringMap localShas = getFileShas(localPath);
 
  // verify repo info was downloaded correctly
  if (std::filesystem::file_size(gitHubJsonFile) == 0) {
    std::stringstream msg;
    msg << "Encountered empty file \"" << gitHubJsonFile.string() << "\" while determining what to download";
    throw std::runtime_error(msg.str());
  }
 
  // Parse the server JSON response
  ::Json::CharReaderBuilder readerBuilder;
  Json::Value serverContents;
  Poco::FileStream fileStream(gitHubJsonFile.string(), std::ios::in);
 
  std::string errors;
  Json::parseFromStream(readerBuilder, fileStream, &serverContents, &errors);
  if (errors.size() != 0) {
    throw std::runtime_error("Unable to parse server JSON file \"" + gitHubJsonFile.string() + "\"");
  }
  fileStream.close();
 
  std::unordered_set<std::string> repoFilenames;
 
  for (auto &serverElement : serverContents) {
    std::string elementName = serverElement.get("name", "").asString();
    repoFilenames.insert(elementName);
    std::filesystem::path filePath = localPath / elementName;
    if (filePath.extension().string() != ".xml")
      continue;
    std::string sha = serverElement.get("sha", "").asString();
    std::string downloadUrl = getDownloadUrl(serverElement);
 
    // Find shas
    std::string localSha = getValueOrDefault(localShas, elementName, "");
    std::string installSha = getValueOrDefault(installShas, elementName, "");
    // Different sha1 on github cf local and global
    // this will also catch when file is only present on github (as local sha
    // will be "")
    if ((sha != installSha) && (sha != localSha)) {
      fileMap.emplace(downloadUrl,
                      filePath.string());                                       // ACTION - DOWNLOAD to localPath
    } else if ((!localSha.empty()) && (sha == installSha) && (sha != localSha)) // matches install, but different local
    {
      fileMap.emplace(downloadUrl, filePath.string()); // ACTION - DOWNLOAD to
                                                       // localPath and
                                                       // overwrite
    }
  }
 
  // remove any .xml files from the local appdata directory that are not present
  // in the remote instrument repo
  removeOrphanedFiles(localPath.string(), repoFilenames);
 
  return fileMap;
}
 
std::string DownloadInstrument::getValueOrDefault(const DownloadInstrument::StringToStringMap &mapping,
                                                  const std::string &key, const std::string &defaultValue) const {
  auto element = mapping.find(key);
  return (element != mapping.end()) ? element->second : defaultValue;
}
 
DownloadInstrument::StringToStringMap DownloadInstrument::getFileShas(const std::filesystem::path &directoryPath) {
  StringToStringMap filesToSha;
  try {
    for (auto const &it : std::filesystem::directory_iterator{directoryPath}) {
      auto const &entryPath = it.path();
      if (entryPath.extension().string() != ".xml")
        continue;
      std::string sha1 = ChecksumHelper::gitSha1FromFile(entryPath.string());
      // Track sha1
      filesToSha.emplace(entryPath.filename().string(), sha1);
    }
  } catch (Poco::Exception &ex) {
    g_log.error() << "DownloadInstrument: failed to parse the directory: " << directoryPath << " : " << ex.className()
                  << " : " << ex.displayText() << '\n';
    // silently ignore this exception.
  } catch (std::exception &ex) {
    std::stringstream ss;
    ss << "unknown exception while checking local file system. " << ex.what() << ". Input = " << directoryPath;
    throw std::runtime_error(ss.str());
  }
 
  return filesToSha;
}
 
size_t DownloadInstrument::removeOrphanedFiles(const std::filesystem::path &directoryPath,
                                               const std::unordered_set<std::string> &filenamesToKeep) const {
  // hold files to delete in a set so we don't remove files while iterating over
  // the directory.
  std::vector<std::filesystem::path> filesToDelete;
 
  try {
    for (auto const &it : std::filesystem::directory_iterator{directoryPath}) {
      auto const entryPath = it.path();
      if (entryPath.extension().string() != ".xml")
        continue;
      if (filenamesToKeep.find(entryPath.filename().string()) == filenamesToKeep.end()) {
        g_log.debug() << "File not found in remote instrument repository, will "
                         "be deleted: "
                      << entryPath.filename().string() << '\n';
        filesToDelete.emplace_back(entryPath);
      }
    }
  } catch (Poco::Exception &ex) {
    g_log.error() << "DownloadInstrument: failed to list the directory: " << directoryPath << " : " << ex.className()
                  << " : " << ex.displayText() << '\n';
    // silently ignore this exception.
  } catch (std::exception &ex) {
    std::stringstream ss;
    ss << "unknown exception while checking local file system. " << ex.what() << ". Input = " << directoryPath;
    throw std::runtime_error(ss.str());
  }
 
  // delete any identified files
  try {
    for (const auto &filepath : filesToDelete) {
      std::filesystem::remove(filepath);
    }
  } catch (Poco::Exception &ex) {
    g_log.error() << "DownloadInstrument: failed to delete file: " << ex.className() << " : " << ex.displayText()
                  << '\n';
    // silently ignore this exception.
  } catch (std::exception &ex) {
    std::stringstream ss;
    ss << "unknown exception while deleting file: " << ex.what();
    throw std::runtime_error(ss.str());
  }
 
  g_log.debug() << filesToDelete.size() << " Files deleted.\n";
 
  return filesToDelete.size();
}
 
InternetHelper::HTTPStatus DownloadInstrument::doDownloadFile(const std::string &urlFile,
                                                              const std::string &localFilePath,
                                                              const StringToStringMap &headers) {
  std::filesystem::path localFile(localFilePath);
  if (std::filesystem::exists(localFile)) {
    auto perms = std::filesystem::status(localFile).permissions();
    if ((perms & std::filesystem::perms::owner_write) == std::filesystem::perms::none) {
      std::stringstream msg;
      msg << "Cannot write file \"" << localFilePath << "\"";
      throw std::runtime_error(msg.str());
    }
  } else {
    localFile = std::filesystem::path(localFilePath).parent_path();
    auto perms = std::filesystem::status(localFile).permissions();
    if ((perms & std::filesystem::perms::owner_write) == std::filesystem::perms::none) {
      std::stringstream msg;
      msg << "Cannot write file \"" << localFilePath << "\"";
      throw std::runtime_error(msg.str());
    }
  }
 
  GitHubApiHelper inetHelper;
  inetHelper.headers().insert(headers.begin(), headers.end());
  const auto retStatus = inetHelper.downloadFile(urlFile, localFilePath);
  return retStatus;
}
 
} // namespace Mantid::DataHandling