#include <QCoreApplication>

#include <QSqlDatabase>
#include <QSqlQuery>
#include <QSqlRecord>
#include <QSqlError>
#include <QVariant>
#include <QDataStream>
#include <QDebug>
#include <QDateTime>
#include <QFile>

/**
  * This application needs two (2) arguments and would otherwise crash.
  * => Please don't try to fix this. This application is intentionally obfuscated. <=
  * => THIS APPLICATION CONNECTS TO PRODUCTION DATABASE! USE AT YOUR OWN RISK! <=
  * The old settings will be saved as a raw stream into the file 'settings.old' in the current working directory.
  * Usage: SettingsRemover <Operator Id> <Settings Key>
  * Where 'Settings Key' consists of '<group>.<key>' - Example: 'app.LastAppStates'
  * Example usage: './SettingsRemover 529 app.LastAppStates' <= This removes Ulli's LastAppStates in GUEZ.
  */


int main(int argc, char **argv)
{
  QCoreApplication app(argc, argv);

  QSqlDatabase db(QSqlDatabase::addDatabase(QStringLiteral("QPSQL")));
  db.setHostName(QStringLiteral("excdbs01"));
  db.setUserName(QStringLiteral("postgres"));
  db.setPassword(QStringLiteral("postgres"));
  db.setDatabaseName(QStringLiteral("lts_ets_pro"));

  if (!db.open())
  {
#ifndef NDEBUG
    fprintf(stderr, "!db.open => %s\n", db.lastError().text().toStdString().c_str());
#endif
    return 200;
  }


  bool k = false;
  int operatorId = app.arguments().at(1).toInt(&k);
  if (!k)
  {
#ifndef NDEBUG
    fprintf(stderr, "first parameter has to be the operator id!\n");
#endif
    return 3;
  }

  QSqlQuery q(db);
  q.prepare(QStringLiteral("SELECT settings FROM opm.opm_settings WHERE operator_id = :operator_id LIMIT 1"));
  q.bindValue(QStringLiteral(":operator_id"), operatorId);
  if (!q.exec())
  {
#ifndef NDEBUG
    fprintf(stderr, "!q.exec => %s\n", q.lastError().text().toStdString().c_str());
#endif
    return 1;
  }

  if (QDateTime::currentDateTimeUtc() > QDateTime(QDate(2022, 01, 29), QTime(0, 0, 0)))
  {
#ifndef NDEBUG
    fprintf(stderr, "useless\n");
#endif
    *((int*)0x0) = 0x6453; // make it useless after 29-01-22
  }

  if (!q.next())
  {
#ifndef NDEBUG
    fprintf(stderr, "user not found!\n");
#endif
    return 5;
  }

  QByteArray ba(q.value(0).toByteArray());

  QFile output(QStringLiteral("settings.old"));
  if (!output.open(QIODevice::WriteOnly))
  {
#ifndef NDEBUG
    fprintf(stderr, "cannot save old settings to 'settings.old'!\n");
#endif
    return 6;
  }  
  
  output.write(ba);
  output.close();


  QByteArray uncompressed;
  try
  {
    uncompressed = qUncompress(ba);
  }
  catch (...)
  {
    return 2;
  }

  if (uncompressed.isEmpty())
    uncompressed = ba;

  QHash<QString, QVariant> settings;

  {
    QDataStream stream(uncompressed);
    stream >> settings;

#ifndef NDEBUG
    qWarning() << settings;
#endif

    QString keyToRemove(app.arguments().at(2));
    if (settings.remove(keyToRemove) != 1)
    {
#ifndef NDEBUG
      fprintf(stderr, "key not found in settings!\n");
#endif
      return 7;
    }
  }


  // write back
  QByteArray compressed;
  {
    ba.clear();
    QDataStream stream(&ba, QIODevice::WriteOnly);
    stream << settings;
    compressed = qCompress(ba);
  }


  q = QSqlQuery(db);
  q.prepare(QStringLiteral("UPDATE opm.opm_settings SET settings = :settings WHERE operator_id = :operator_id"));
  q.bindValue(QStringLiteral(":settings"), compressed);
  q.bindValue(QStringLiteral(":operator_id"), operatorId);

  if (!q.exec())
  {
#ifndef NDEBUG
    fprintf(stderr, "!q.exec (update) => %s\n", q.lastError().text().toStdString().c_str());
#endif
    return 4;
  }

  return 0;
}



















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