#ifndef LOGGER_HH
#define LOGGER_HH

#include <filesystem>
#include <memory>
#include <string>

class Logger {
public:
  virtual ~Logger() = default;

  static std::unique_ptr<Logger> create_stdio();
  // Can return nullptr, will write reason to fallback.
  static std::unique_ptr<Logger> create_file(std::filesystem::path const& path,
                                             Logger* fallback);
  static std::unique_ptr<Logger> create_syslog(std::string const& prgname);
  static std::unique_ptr<Logger> create_null();

  virtual void err(char const* format, ...)
#if HAVE_ATTRIBUTE_FORMAT
    __attribute__((format(printf, 2, 3)))  // this takes up 1
#endif  // HAVE_ATTRIBUTE_FORMAT
    = 0;

  virtual void warn(char const* format, ...)
#if HAVE_ATTRIBUTE_FORMAT
    __attribute__((format(printf, 2, 3)))
#endif  // HAVE_ATTRIBUTE_FORMAT
    = 0;

  virtual void info(char const* format, ...)
#if HAVE_ATTRIBUTE_FORMAT
    __attribute__((format(printf, 2, 3)))
#endif  // HAVE_ATTRIBUTE_FORMAT
    = 0;

#ifdef NDEBUG
  void dbg(char const* format, ...)
#if HAVE_ATTRIBUTE_FORMAT
    __attribute__((format(printf, 2, 3)))
#endif  // HAVE_ATTRIBUTE_FORMAT
  {}
#else
  virtual void dbg(char const* format, ...)
#if HAVE_ATTRIBUTE_FORMAT
    __attribute__((format(printf, 2, 3)))
#endif  // HAVE_ATTRIBUTE_FORMAT
    = 0;
#endif

protected:
  Logger() = default;
  Logger(Logger const&) = delete;
  Logger& operator=(Logger const&) = delete;
};

#endif  // LOGGER_HH