#include "log.h"

#include <assert.h>
#include <stdarg.h>
#include <time.h>

#include <openssl/err.h>

static const char* LOG_LEVEL_STRING_TABLE[] = {
	"ERROR",
	"WARN",
	"INFO",
	"DEBUG",
	"TRACE"
};

// Maybe add __attribute__((constructor)) in the future if available to skip _config_initialized
static bool _user_default_config_initialized = false;
static struct log_config_s _user_default_config;

static inline struct log_config_s _default_config() {
	
	if (_user_default_config_initialized) {
		return _user_default_config;
	}

	return (struct log_config_s) {
		.loc_error = stderr,
		.loc_warn  = stderr,
		.loc_info  = stdout,
		.loc_debug = NULL,
		.loc_trace = NULL,

		.timestamp = true,
	};	
}

void log_set_default_config(struct log_config_s config) {
	_user_default_config = config;
	_user_default_config_initialized = true;
}

struct logger_s log_new(const char* module_name) {
	return (struct logger_s) { 
		.module_name = module_name,
		.config = _default_config(),
	};
}

void log_log(const struct logger_s* logger, enum LOG_LEVEL log_level, const char* fmt, ...) {

	assert(logger != NULL);

	FILE* dest = NULL;
	switch (log_level) {
		case LOG_ERR:   dest = logger->config.loc_error; break;
		case LOG_WARN:  dest = logger->config.loc_warn;  break;
		case LOG_INFO:  dest = logger->config.loc_info;  break;
		case LOG_DEBUG: dest = logger->config.loc_debug; break;
		case LOG_TRACE: dest = logger->config.loc_trace; break;
		default: break;
	}

	if (dest == NULL) {
		return;
	}
	
	va_list varargs;
	va_start(varargs, fmt);

	if (logger->config.timestamp) {
		struct timespec utc_time;
		struct tm local_time;
		char time_str_buf[10+1+8+1];
		timespec_get(&utc_time, TIME_UTC);
		localtime_r(&(utc_time.tv_sec), &local_time);
		
		if(strftime(time_str_buf, sizeof(time_str_buf), "%F %T", &local_time)) {
			fprintf(dest, "[%s.%9lu] ", time_str_buf, utc_time.tv_nsec);	
		}
	}

	fprintf(dest, "[%s] %s: ", LOG_LEVEL_STRING_TABLE[log_level], logger->module_name);
	vfprintf(dest, fmt, varargs);
	fprintf(dest, "\n");
}

void log_log_ssl_err(const struct logger_s* logger, enum LOG_LEVEL log_level, unsigned long error, const char* message_fmt, ...) {
	char error_buf[256];
	ERR_error_string_n(ERR_get_error(), error_buf, sizeof(error_buf));
	
	va_list varargs;
	va_start(varargs, message_fmt);

	log_log(logger, log_level, message_fmt, varargs);
	log_log(logger, log_level, "%s", error_buf);
}