Log.h

/*
 * Copyright 2026 Matteo Fusi and Contributors
 *
 * Licensed under 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.
 */
 
#ifndef SIMO_LOG_HH
#define SIMO_LOG_HH
#include <Simo/compiler/Compiler.h>
 
#include <filesystem>
#include <format>
#include <fstream>
#include <ostream>
#include <vector>
 
#include "InitializationStatus.h"
 
namespace Simo::Log {
 
enum SIMO_PUBLIC LogLevel : std::uint8_t {
  VERBOSE = 0,
  DEBUG,
  INFO,
  WARNING,
};
 
class SIMO_PUBLIC Logger {
 public:
  InitializationStatus initialize(const std::filesystem::path& sink_path_v);

  Logger& add_log_level(size_t level, std::string_view name);

  Logger& populate_default_log_levels();

  Logger& log_level(LogLevel level);
  Logger& log_level(uint8_t level);

  Logger& log_level(std::string_view level_name);
 
  [[nodiscard]] size_t log_level() const;

  Logger& enabled(bool new_enabled_value);
 
  bool enabled() const;
 
  template <typename Callable>
  Logger& log_callable(const size_t level, const bool print_level,
                       Callable&& c) {
    if (!enabled() || level < log_level()) {
      return *this;
    }
    if (print_level) {
      *sink << '[' << level_map[level] << "] ";
    }
    *sink << std::format("{}", c());
    return *this;
  }
 
  template <typename... Args>
  Logger& log_format(const size_t level, const bool print_level, Args... args) {
    if (!enabled() || level < log_level()) {
      return *this;
    }
    if (print_level) {
      *sink << '[' << level_map[level] << "] ";
    }
    *sink << std::format(std::forward<Args>(args)...);
    return *this;
  }
 
  ~Logger();

  static void flush_sink(const std::filesystem::path& path);
 
  // Flush all the registered sinks
  static void flush_all_sinks();
 
 protected:
  std::filesystem::path sink_path;
  std::ostream* sink = nullptr;
  bool tracked_sink = false;
  bool is_enabled = false;
  size_t current_log_level = 0;
  std::vector<std::string> level_map;
};
 
}  // namespace Simo::Log
 
#endif  // SIMO_LOG_HH