logger.hpp

// Copyright (C) 2023 Alessandro Fornasier.
// Control of Networked Systems, University of Klagenfurt, Austria.
//
// All rights reserved.
//
// This software is licensed under the terms of the Apache License, Version 2.0
// (the "License"); you may not use this file except in compliance with the
// License. You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations
// under the License.
//
// You can contact the authors at <alessandro.fornasier@ieee.org>
 
#ifndef LOGGER_HPP_
#define LOGGER_HPP_
 
#include <iostream>
#include <memory>
 
namespace utils
{
template <class S, class C, typename = void>
struct is_streamable : ::std::false_type
{
};
 
template <class S, class C>
struct is_streamable<S, C, decltype(void(std::declval<S&>() << std::declval<C const&>()))> : ::std::true_type
{
};
 
enum class LoggerLevel
{
  FULL,
  INFO,
  WARN,
  ERR,
  INACTIVE,
};

class Logger
{
 public:
  static const LoggerLevel& getlevel() { return level_; }

  static void setLevel(const LoggerLevel& level) { level_ = level; }

  template <typename T>
  static void info(const T& msg)
  {
    static_assert(is_streamable<std::ostream, T>::value);
    if (level_ == LoggerLevel::INFO || level_ == LoggerLevel::FULL)
    {
      std::cout << "[ INFO]: " << msg << '.' << std::endl;
    }
  }

  template <typename T>
  static void err(const T& msg)
  {
    static_assert(is_streamable<std::ostream, T>::value);
    if (level_ == LoggerLevel::INFO || level_ == LoggerLevel::WARN || level_ == LoggerLevel::ERR ||
        level_ == LoggerLevel::FULL)
    {
      std::cout << "\033[31m[ ERROR]: " << msg << ".\033[0m" << std::endl;
    }
  }

  template <typename T>
  static void warn(const T& msg)
  {
    static_assert(is_streamable<std::ostream, T>::value);
    if (level_ == LoggerLevel::INFO || level_ == LoggerLevel::WARN || level_ == LoggerLevel::FULL)
    {
      std::cout << "\033[33m[ WARNING]: " << msg << ".\033[0m" << std::endl;
    }
  }

  template <typename T>
  static void debug(const T& msg)
  {
    static_assert(is_streamable<std::ostream, T>::value);
    if (level_ == LoggerLevel::FULL)
    {
      std::cout << "\033[34m[ DEBUG]: " << msg << ".\033[0m" << std::endl;
    }
  }
 
 private:
  static inline LoggerLevel level_ = LoggerLevel::INFO;  
};
 
}  // namespace utils
 
#endif  // LOGGER_HPP_