logutils.cpp

#include "logutils.h"

#include <iostream>

#include <QTime>
#include <QFile>
#include <QFileInfo>
#include <QDebug>
#include <QDir>
#include <QFileInfoList>
#include <QStandardPaths>
#include <QSettings>

namespace LogUtils
{
  static QString logFileName;
  static QString logFolderName;
  static QFile* logFile;
  static LogUtils::LogLevel currentLogLevel = LogUtils::DebugLevel;

  LogUtils::LogLevel logLevel()
  {
      return currentLogLevel;
  }

  void initLogFileName()
  {
    QString path = QStandardPaths::writableLocation(QStandardPaths::AppDataLocation);
    if (path.isEmpty()) qFatal("Cannot determine settings storage location");
    QDir d = QDir(path);
    QString appDataPath = d.absolutePath();

    logFolderName = appDataPath + "/logs";

    logFileName = QString(logFolderName + "/Log_%1__%2.txt")
                  .arg(QDate::currentDate().toString("yyyy_MM_dd"))
                  .arg(QTime::currentTime().toString("hh_mm_ss_zzz"));

    qDebug() << "LOG DIR NAME: " << logFolderName;
    qDebug() << "LOG FILE NAME: " << logFileName;

    d.mkpath(logFolderName);
    qDebug() << "LOG DIR EXISTS: " << QDir(logFolderName).exists();
  }

  void deleteOldLogs()
  {
    QDir dir;
    dir.setFilter(QDir::Files | QDir::Hidden | QDir::NoSymLinks);
    dir.setSorting(QDir::Time | QDir::Reversed);
    dir.setPath(logFolderName);

    QFileInfoList list = dir.entryInfoList();
    if (list.size() <= LOGFILES)
    {
      return; //no files to delete
    } else
    {
      for (int i = 0; i < (list.size() - LOGFILES); i++)
      {
        QString path = list.at(i).absoluteFilePath();
        QFile file(path);
        file.remove();
      }
    }
  }

  bool initLogging()
  {
      qDebug() << "LogUtils::initLogging()";
      // Create folder for logfiles if not exists
      if(!QDir(logFolderName).exists())
      {
        qDebug() << "Creating directory " << logFolderName;
        QDir().mkdir(logFolderName);
      }

      QSettings settings;
      QString level =
          settings.value("logging/level", "debug")
              .toString()
              .trimmed()
              .toLower();

      if (level == "debug")
          currentLogLevel = DebugLevel;
      else if (level == "warning")
          currentLogLevel = WarningLevel;
      else if (level == "error")
          currentLogLevel = ErrorLevel;
      else if (level == "off")
          currentLogLevel = OffLevel;
      else
          currentLogLevel = DebugLevel;

      fprintf(stderr,
              "Configured log level = %d\n",
              (int)currentLogLevel);


      deleteOldLogs(); //delete old log files
      initLogFileName(); //create the logfile name

      logFile = new QFile( logFileName );
      if(logFile->open(QIODevice::WriteOnly | QIODevice::Append))
      {
        qInstallMessageHandler(LogUtils::myMessageHandler);
        return true;
      }
      else
      {
        return false;
      }
  }

  void myMessageHandler(QtMsgType type, const QMessageLogContext &context, const QString& message)
  {
    //check file size and if needed create new log!
    {
      if (logFile->size() > LOGSIZE) //check current log size
      {
        deleteOldLogs();
        initLogFileName();
      }
    }

    switch (type) {
    case QtDebugMsg:
        if (currentLogLevel > DebugLevel)
            return;
        break;

    case QtWarningMsg:
        if (currentLogLevel > WarningLevel)
            return;
        break;

    case QtCriticalMsg:
        if (currentLogLevel > ErrorLevel)
            return;
        break;

    case QtFatalMsg:
        break;

#if QT_VERSION >= QT_VERSION_CHECK(5, 5, 0)
      case QtInfoMsg:
          if (currentLogLevel > DebugLevel)
              return;
          break;
#endif
    }

    QString levelText;
    switch(type) {
        case QtDebugMsg:
            levelText = "Debug";
            break;
        case QtInfoMsg:
            levelText = "Info";
            break;
        case QtWarningMsg:
            levelText = "Warning";
            break;
        case QtCriticalMsg:
            levelText = "Critical";
            break;
        case QtFatalMsg:
            levelText = "Fatal";
            break;
    }

    QString text = QString("%3 [%1] %2")
        .arg(levelText)
        .arg(message)
        .arg(QDateTime::currentDateTime().toString(Qt::ISODate));

    // Output to console
    QTextStream(stdout) << text << endl;

    // Output to log file
    QTextStream ts(logFile);
    ts << text << endl;
  }
}