// Copyright (c) 2022 Proton AG
//
// This file is part of Proton Mail Bridge.
//
// Proton Mail Bridge 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.
//
// Proton Mail Bridge 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 Proton Mail Bridge. If not, see <https://www.gnu.org/licenses/>.


#include "Pch.h"
#include "Log.h"


namespace
{


//****************************************************************************************************************************************************
/// \param[in] type The message type.
/// \param[in] message The message.
//****************************************************************************************************************************************************
void qtMessageHandler(QtMsgType type, QMessageLogContext const &, QString const &message)
{
    static Log &log = app().log();
    switch (type)
    {
    case QtDebugMsg:
        log.debug(message);
        break;

    case QtWarningMsg:
        log.warn(message);
        break;

    case QtCriticalMsg:
    case QtFatalMsg:
        log.error(message);
        break;

    case QtInfoMsg:
    default:
        log.info(message);
        break;
    }
}


//****************************************************************************************************************************************************
/// \param[in] level The level.
/// \return A string describing the level.
//****************************************************************************************************************************************************
QString logLevelToString(Log::Level level)
{
    switch (level)
    {
    case Log::Level::Panic: return "PANIC";
    case Log::Level::Fatal: return "FATAL";
    case Log::Level::Error: return "ERROR";
    case Log::Level::Warn: return "WARN";
    case Log::Level::Info: return "INFO";
    case Log::Level::Debug: return "DEBUG";
    case Log::Level::Trace: return "TRACE";
    default: return "UNKNOWN";
    }
}



//****************************************************************************************************************************************************
/// \brief return a string representing the log entry
///
/// \param[in] level The log entry level.
/// \param[in] message The log entry message.
/// \return The string for the log entry
//****************************************************************************************************************************************************
QString logEntryToString(Log::Level level, QString const &message)
{
    return QString("[%1] %2").arg(logLevelToString(level)).arg(message);
}


}


//****************************************************************************************************************************************************
/// the message handle process the message from the Qt logging system.
//****************************************************************************************************************************************************
void Log::installQtMessageHandler()
{
    qInstallMessageHandler(qtMessageHandler);
}


//****************************************************************************************************************************************************
//
//****************************************************************************************************************************************************
Log::Log()
    : QObject()
    , stdout_(stdout)
    , stderr_(stderr)
{
}


//****************************************************************************************************************************************************
/// \param[in] level The log level.
//****************************************************************************************************************************************************
void Log::setLevel(Log::Level level)
{
    QMutexLocker locker(&mutex_);
    level_ = level;
}


//****************************************************************************************************************************************************
/// \return The log level.
//****************************************************************************************************************************************************
Log::Level Log::level() const
{
    QMutexLocker locker(&mutex_);
    return Log::Level::Debug;
}


//****************************************************************************************************************************************************
/// \param[in] value Should the log entries be sent to STDOUT/STDERR.
//****************************************************************************************************************************************************
void Log::setEchoInConsole(bool value)
{
    QMutexLocker locker(&mutex_);
    echoInConsole_ = value;
}


//****************************************************************************************************************************************************
/// \return true iff the log entries be should sent to STDOUT/STDERR.
//****************************************************************************************************************************************************
bool Log::echoInConsole() const
{
    QMutexLocker locker(&mutex_);
    return echoInConsole_;
}


//****************************************************************************************************************************************************
/// \param[in] message The message.
//****************************************************************************************************************************************************
void Log::panic(QString const &message)
{
    return this->addEntry(Level::Panic, message);
}


//****************************************************************************************************************************************************
/// \param[in] message The message.
//****************************************************************************************************************************************************
void Log::fatal(QString const &message)
{
    return this->addEntry(Level::Fatal, message);
}


//****************************************************************************************************************************************************
/// \param[in] message The message.
//****************************************************************************************************************************************************
void Log::error(QString const &message)
{
    return this->addEntry(Level::Error, message);
}


//****************************************************************************************************************************************************
/// \param[in] message The message.
//****************************************************************************************************************************************************
void Log::warn(QString const &message)
{
    return this->addEntry(Level::Warn, message);
}


//****************************************************************************************************************************************************
/// \param[in] message The message.
//****************************************************************************************************************************************************
void Log::info(QString const &message)
{
    return this->addEntry(Level::Info, message);
}


//****************************************************************************************************************************************************
/// \param[in] message The message.
//****************************************************************************************************************************************************
void Log::debug(QString const &message)
{
    return this->addEntry(Level::Debug, message);
}


//****************************************************************************************************************************************************
/// \param[in] message The message.
//****************************************************************************************************************************************************
void Log::trace(QString const &message)
{
    return this->addEntry(Level::Trace, message);
}


//****************************************************************************************************************************************************
/// \param[in] level The level.
/// \param[in] message The message.
//****************************************************************************************************************************************************
void Log::addEntry(Log::Level level, QString const &message)
{
    QMutexLocker locker(&mutex_);
    if (qint32(level) > qint32(level_))
        return;
    emit entryAdded(level, message);

    if (echoInConsole_)
    {
        QTextStream& stream = (qint32(level) <= (qint32(Level::Warn))) ? stderr_ : stdout_;
        stream << logEntryToString(level, message) << "\n";
        stream.flush();
    }
}