////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2011-2022 The Octave Project Developers
//
// See the file COPYRIGHT.md in the top-level directory of this
// distribution or <https://octave.org/copyright/>.
//
// This file is part of Octave.
//
// Octave is free software: you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Octave is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Octave; see the file COPYING.  If not, see
// <https://www.gnu.org/licenses/>.
//
////////////////////////////////////////////////////////////////////////

#if defined (HAVE_CONFIG_H)
#  include "config.h"
#endif

#include <cstdio>

#include <QMutex>
#include <QMutexLocker>
#include <QProcessEnvironment>

#include "Logger.h"

namespace octave
{

  Logger *Logger::s_instance = nullptr;
  QMutex *Logger::s_mutex = nullptr;

  Logger::Logger (void)
    : m_debugEnabled (false)
  {
    QProcessEnvironment pe (QProcessEnvironment::systemEnvironment ());

    if (pe.value ("QTHANDLES_DEBUG", "0") != "0")
      m_debugEnabled = true;
  }

  Logger::~Logger (void)
  { }

  Logger *
  Logger::instance (void)
  {
    if (! s_instance)
      {
        s_instance = new Logger ();
        s_mutex = new QMutex ();
      }

    return s_instance;
  }

#define STATIC_LOGGER(fcn) \
  void Logger::fcn (const char *fmt, ...) \
  { \
    QMutexLocker lock (s_mutex); \
    va_list vl; \
    va_start (vl, fmt); \
    instance ()->fcn ## V (fmt, vl); \
    va_end (vl); \
  }

  STATIC_LOGGER (debug)

  void
  Logger::debugV (const char *fmt, va_list arg)
  {
    if (m_debugEnabled)
      {
        vfprintf (stderr, fmt, arg);
        fprintf (stderr, "\n");
      }
  }

}