Logger.hpp

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/*
    MIT License
 
    Copyright(c) 2023 George Fotopoulos
 
    Permission is hereby granted, free of charge, to any person obtaining a copy
    of this software and associated documentation files(the "Software"), to deal
    in the Software without restriction, including without limitation the rights
    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
    copies of the Software, and to permit persons to whom the Software is
    furnished to do so, subject to the following conditions :
 
    The above copyright notice and this permission notice shall be included in all
    copies or substantial portions of the Software.
 
    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE
    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
    SOFTWARE.
*/
 
#pragma once
 
#ifdef _MSC_VER
#pragma warning(disable : 4996)
#endif
 
#include <array>
#include <cstdarg>
#include <cstdio>
#include <ctime>
#include <mutex>
#include <string>
#include <vector>
 
class Logger {
public:
    enum class Level {
        Trace,
        Debug,
        Info,
        Warn,
        Error,
        Critical
    };
 
    Logger(const Logger &) = delete;
 
    Logger(Logger &&) = delete;
 
    Logger &operator=(const Logger &) = delete;
 
    Logger &operator=(Logger &&) = delete;
 
    static Logger &GetInstance() {
        static Logger instance;
        return instance;
    }
 
    static void SetLevel(const Level level) {
        Logger &instance = GetInstance();
        instance.mLevel = level;
    }
 
    static void EnableFileOutput() {
        Logger &instance = GetInstance();
        instance.mFileOutputEnabled = true;
    }
 
    static void DisableFileOutput() {
        Logger &instance = GetInstance();
        instance.mFileOutputEnabled = false;
    }
 
    static void SetFileOutput(const char *output) {
        Logger &instance = GetInstance();
        instance.mFileOutput = output;
    }
 
    template<typename... Args>
    static void Trace(const char *format, Args... args) {
        Log(Level::Trace, "trace", format, args...);
    }
 
    template<typename... Args>
    static void Debug(const char *format, Args... args) {
        Log(Level::Debug, "debug", format, args...);
    }
 
    template<typename... Args>
    static void Info(const char *format, Args... args) {
        Log(Level::Info, "info", format, args...);
    }
 
    template<typename... Args>
    static void Warn(const char *format, Args... args) {
        Log(Level::Warn, "warn", format, args...);
    }
 
    template<typename... Args>
    static void Error(const char *format, Args... args) {
        Log(Level::Error, "error", format, args...);
    }
 
    template<typename... Args>
    static void Critical(const char *format, Args... args) {
        Log(Level::Critical, "critical", format, args...);
    }
 
    static void Trace(const char *str) {
        Log(Level::Trace, "trace", str);
    }
 
    static void Debug(const char *str) {
        Log(Level::Debug, "debug", str);
    }
 
    static void Info(const char *str) {
        Log(Level::Info, "info", str);
    }
 
    static void Warn(const char *str) {
        Log(Level::Warn, "warn", str);
    }
 
    static void Error(const char *str) {
        Log(Level::Error, "error", str);
    }
 
    static void Critical(const char *str) {
        Log(Level::Critical, "critical", str);
    }
 
private:
    Logger() = default;
 
    ~Logger() = default;
 
    template<typename... Args>
    static void Log(const Level level, const char *tag, const char *format, Args... args) {
        Logger &instance = GetInstance();
        std::lock_guard<std::mutex> lock(instance.mMutex);
        if (instance.mLevel <= level) {
            std::time_t t = std::time(nullptr);
            std::array<char, 100> time_buf{};
            std::strftime(time_buf.data(), sizeof time_buf, "%Y-%m-%d %H:%M:%S", std::gmtime(&t));
            std::printf("[%s] [%s] ", time_buf.data(), tag);
            std::printf(format, args...);
            std::printf("\n");
            if (instance.mFileOutputEnabled) {
                std::FILE *file = std::fopen(instance.mFileOutput.c_str(), "a");
                std::fprintf(file, "[%s] [%s] ", time_buf.data(), tag);
                std::fprintf(file, format, args...);
                std::fprintf(file, "\n");
                std::fclose(file);
            }
        }
    }
 
    static void Log(const Level level, const char *tag, const char *str) {
        Logger &instance = GetInstance();
        std::lock_guard<std::mutex> lock(instance.mMutex);
        if (instance.mLevel <= level) {
            std::time_t t = std::time(nullptr);
            std::array<char, 100> time_buf{};
            std::strftime(time_buf.data(), sizeof time_buf, "%Y-%m-%d %H:%M:%S", std::gmtime(&t));
            std::printf("[%s] [%s] %s\n", time_buf.data(), tag, str);
            if (instance.mFileOutputEnabled) {
                std::FILE *file = std::fopen(instance.mFileOutput.c_str(), "a");
                std::fprintf(file, "[%s] [%s] %s\n", time_buf.data(), tag, str);
                std::fclose(file);
            }
        }
    }
 
    Level mLevel{Level::Info};
    bool mFileOutputEnabled{false};
    std::string mFileOutput{"default.log"};
    std::mutex mMutex;
};