/*
 * @RDE_HEADER@
 * Copy exercise from server to evaluation server
 * $Id$
 * $HeadURL$
 * $Author$
 * Created by Christian Ehrlicher, NLSE, 2018-07-31
 */

#include "copy_database.h"

#include <ngldb/dbcommon.h>
#include <ngldb/dbconnection.h>
#include <ngldb/nsqlquery.h>
#include <ngltools/ngltools_filesystem.h>

#include <QDir>
#include <QFile>
#include <QProcess>
#include <QSettings>

namespace OcBaseDownload
{
CopyDatabase::CopyDatabase(NGL::INGLLogger &logger, QObject *parent)
  : QObject(parent)
  , m_proc(nullptr)
  , m_logger(logger)
{}

bool CopyDatabase::init(const QString &dbHost, const QString &srcDbName, const QString &dstDbName)
{
  m_dbHost = dbHost;
  m_srcDbName = srcDbName;
  m_dstDbName = dstDbName;

  return true;
}

bool CopyDatabase::doCopy()
{
  if (!runPgDump())
  {
    ERROR_LOG(m_logger) << "Error running pg_dump";
    emit copyDbFailed();
    return false;
  }
  return true;
}

bool CopyDatabase::dropDatabase(const QString &dbName)
{
  return runDropDb(dbName);
}

bool CopyDatabase::runDropDb(const QString &dbName)
{
  const QStringList args({QStringLiteral("-U"),
                          QStringLiteral("postgres"),
                          QStringLiteral("--if-exists"),
                          QStringLiteral("-h"),
                          m_dbHost,
                          dbName});

  handleProcInit(executablePath(QStringLiteral("dropdb")), args);
  connect(m_proc, QOverload<int, QProcess::ExitStatus>::of(&QProcess::finished),
          this, &CopyDatabase::onDropDbFinished);
  m_proc->start();
  return true;
}

void CopyDatabase::onDropDbFinished(int exitCode, QProcess::ExitStatus exitStatus)
{
  NOTICE_LOG(m_logger) << "onDropDbFinished: exitCode: " << exitCode << ", exitStatus: " << exitStatus;

  if (exitCode > 0)
  {
    ERROR_LOG(m_logger) << "DropDb failed";
    emit dropDatabaseFailed();
    return;
  }

  emit dropDatabaseFinished();
}

bool CopyDatabase::runPgDump()
{
  // start process
  const QStringList args(
  {
    QStringLiteral("--column-inserts"),
    QStringLiteral("-U"), QStringLiteral("postgres"),
    QStringLiteral("-f"), getDumpFile(),
    QStringLiteral("-h"), m_dbHost,
    m_srcDbName
  });

  handleProcInit(executablePath(QStringLiteral("pg_dump")), args);
  connect(m_proc, QOverload<int, QProcess::ExitStatus>::of(&QProcess::finished),
          this, &CopyDatabase::onPgDumpFinished);

  m_proc->start();

  return true;
}

void CopyDatabase::onPgDumpFinished(int exitCode, QProcess::ExitStatus exitStatus)
{
  NOTICE_LOG(m_logger) << "onProcessFinished: exitCode: " << exitCode << ", exitStatus: " << exitStatus;
  runCreatedb();
}

void CopyDatabase::runCreatedb()
{
  const QStringList args({QStringLiteral("-U"),
                          QStringLiteral("postgres"),
                          QStringLiteral("-h"),
                          m_dbHost,
                          m_dstDbName});

  handleProcInit(executablePath(QStringLiteral("createdb")), args);
  connect(m_proc, QOverload<int, QProcess::ExitStatus>::of(&QProcess::finished),
          this, &CopyDatabase::onCreateDbFinished);
  m_proc->start();
}

void CopyDatabase::onCreateDbFinished(int exitCode, QProcess::ExitStatus exitStatus)
{
  NOTICE_LOG(m_logger) << "onCreateDbFinished: exitCode: " << exitCode << ", exitStatus: " << exitStatus;

  if (exitCode > 0)
  {
    ERROR_LOG(m_logger) << "CreateDB failed";
    emit copyDbFailed();
    return;
  }
  runGrant();
  //runPgLoad();
}

void CopyDatabase::runGrant()
{

  const QString command = QStringLiteral("-c 'GRANT ALL ON DATABASE %1 to ets_exm'").arg(m_dstDbName);
  const QStringList args({ QStringLiteral("-U"),
                          QStringLiteral("postgres"),
                          command,
                          QStringLiteral("-h"),
                          m_dbHost,
                          m_dstDbName });

  handleProcInit(executablePath(QStringLiteral("psql")), args);
  connect(m_proc, QOverload<int, QProcess::ExitStatus>::of(&QProcess::finished),
    this, &CopyDatabase::runPgLoad);
  m_proc->start();
}

void CopyDatabase::runPgLoad()
{
  const QStringList args({QStringLiteral("-U"),
                          QStringLiteral("postgres"),
                          QStringLiteral("-f"),
                          getDumpFile(),
                          QStringLiteral("-h"),
                          m_dbHost,
                          m_dstDbName});

  handleProcInit(executablePath(QStringLiteral("psql")), args);
  connect(m_proc, QOverload<int, QProcess::ExitStatus>::of(&QProcess::finished),
          this, &CopyDatabase::onPgLoadFinished);
  m_proc->start();
}

void CopyDatabase::onPgLoadFinished(int exitCode, QProcess::ExitStatus exitStatus)
{
  NOTICE_LOG(m_logger) << "onPsqlFinished: exitCode: " << exitCode << ", exitStatus: " << exitStatus;

  if (exitStatus == QProcess::ExitStatus::NormalExit)
    QFile::remove(getDumpFile());

  if (exitCode > 0)
  {
    ERROR_LOG(m_logger) << "Loading db failed";
    emit copyDbFailed();
    return;
  }
  runPgSetGrant();
}

void CopyDatabase::runPgSetGrant()
{
  const QStringList args({QStringLiteral("-U"),
                          QStringLiteral("postgres"),
                          QStringLiteral("-c"), QStringLiteral("GRANT ALL ON DATABASE %1 to ets_admin").arg(m_dstDbName),
                          QStringLiteral("-h"),
                          m_dbHost,
                          m_dstDbName});

  handleProcInit(executablePath(QStringLiteral("psql")), args);
  connect(m_proc, QOverload<int, QProcess::ExitStatus>::of(&QProcess::finished),
          this, &CopyDatabase::onPgSetGrantFinished);
  m_proc->start();
}

void CopyDatabase::onPgSetGrantFinished(int exitCode, QProcess::ExitStatus exitStatus)
{
  NOTICE_LOG(m_logger) << "onPsqlFinished: exitCode: " << exitCode << ", exitStatus: " << exitStatus;

  if (exitCode > 0)
  {
    ERROR_LOG(m_logger) << "Set grants to ets_admin failed";
    emit copyDbFailed();
    return;
  }

  emit copyDbFinished();
}


void CopyDatabase::handleProcInit(const QString &program, const QStringList &args)
{
  if (m_proc)
  {
    m_proc->disconnect(this);
    m_proc->deleteLater();
  }
  m_proc = new QProcess(this);
  NOTICE_LOG(m_logger) << "Starting process '" << program << "' with args '" << args.join(QLatin1Char(' ')) << "'";
  m_proc->setProgram(program);
  m_proc->setArguments(args);
  connect(m_proc, &QProcess::errorOccurred,
          this, &CopyDatabase::onErrorOccured);
}

void CopyDatabase::handleProcFinished(int exitCode, QProcess::ExitStatus exitStatus)
{
  if (!m_proc)
    return;
  if (exitCode != 0 || exitStatus != 0)
  {
    QByteArray out = m_proc->readAllStandardError();
    if (!out.isEmpty())
      out += '\n';
    out += m_proc->readAllStandardOutput();
    ERROR_LOG(m_logger) << "Process finished - exitCode: " << exitCode << ", exitStatus = " << exitStatus << ", " << out;
  }
  m_proc->disconnect(this);
  m_proc->deleteLater();
  m_proc = nullptr;
}

void CopyDatabase::onErrorOccured(QProcess::ProcessError error)
{
  ERROR_LOG(m_logger) << "error: " << error << ", " << m_proc->readAllStandardOutput() << ", " << m_proc->readAllStandardError();
}

QString CopyDatabase::getDumpFile() const
{
  return QDir::tempPath() + QLatin1Char('/') + m_srcDbName + QStringLiteral(".dump");
}

QString CopyDatabase::executablePath(const QString &program)
{
  QString errStr;
  const QString ret = NGL::postgresExecutablePath(program, errStr);
  if (!errStr.isEmpty())
    WARNING_LOG(m_logger) << errStr;
  return ret;
}

} // namespace DBAdministration