#pragma once

// log utility
//
// created on 2022-11-30
//


#include "referer.h"
#include <string>
#include <memory>


////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

// object event
//
enum log_level
{
	LOG_LEVEL_ALL = 0,
	LOG_LEVEL_DEBUG,
	LOG_LEVEL_WARNING,
	LOG_LEVEL_FATAL,
};

class log_cls
{
	std::string	file_;
	int32_t			max_size_;
	log_level	level_;
	MUTEX		lock_;
	FILE		*dst_;

	static log_cls* inst_;

	void create_log_file(void);

protected:
	log_cls(const char* path_file, log_level level, int32_t max_size);
	~log_cls();

	void log_internal(const char* txt);

public:
	static void initialize(const char* path_file, log_level level = LOG_LEVEL_ALL, int32_t max_size = SIZE_MB(10));

	template<typename ... Args>
	static void log(log_level level, const char* fmt, Args ... args)
	{
		if (level >= log_cls::get_log_level() && log_cls::inst_)
		{
			size_t 		size = snprintf(nullptr, 0, fmt, args ...) + 1;
			std::unique_ptr<char[]> buf(new char[size]);

			snprintf(buf.get(), size, fmt, args ...);

			log_cls::inst_->log_internal(buf.get());
		}
	}
	static int32_t log_when_err(int32_t err, const char* oper_desc, log_level level = LOG_LEVEL_WARNING);	// log as: oper_desc = strerror(errno)\n. return real error number errno

	static log_level get_log_level(void);
	static std::string get_log_file(void);
};