/* logger.c
 *
 * Copyright 2025 Francois Techene
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * SPDX-License-Identifier: GPL-3.0-or-later
 */
 
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>

#include "logger.h"

Logger logger;

void 
init_logger(LogLevel 			level,
		 	LogOutputMethod 	out, 
		 	char* 				file_path)
{
	logger.debug 	= log_debug;
	logger.info 	= log_info;
	logger.warn 	= log_warn;
	logger.error 	= log_error;

	logger.log_level		= level;
	logger.output_method 	= out;
	logger.file_path		= file_path;
	
	if (out == CONSOLE_OUT) {
		logger.log = log_to_console;
	}
	else if (out == FILE_OUT) {
		FILE* file;
		
		logger.log = log_to_file;
	
		// Empty log file. If the file cannot be created, the log output
		// is set to NONE_OUT;
		//
		file = fopen(logger.file_path, "w");
		if(!file) {
			logger.output_method = NONE_OUT;
			logger.log = log_to_none;
			return;
		}
		fprintf(file, "");
		fclose(file);
	}
	else {
		logger.log = log_to_none;
	}
}

void 
log_to_none(char* format, ...)
{
	return;
}

void 
log_to_console(char* format, ...)
{
	va_list ap;
	
	va_start(ap, format);
	vprintf(format, ap);
	va_end(ap);
	
	printf("\n");
}
void 
log_to_file(char* format, ...)
{
	FILE* file;
	va_list ap;
	
	// Open file in Append Binary mode so the
	// new line character is not converted.
	//
	file = fopen(logger.file_path, "ab");
	if(!file) {
		return;
	}
	
	va_start(ap, format);
	vfprintf(file, format, ap);
	va_end(ap);
	
	// Using Unix New Line character for tail to 
	// read correctly on Linux.
	//
	fprintf(file, " \x0A\r");
	
	fclose(file);
}

void 
log_debug(char* format, ...)
{
	va_list ap;
	char log[256] = "";
	
	if (logger.log_level < DEBUG_LEVEL) {
		return;
	}

	va_start(ap, format);
	vsprintf(log, format, ap);
	va_end(ap);
	
	logger.log("DEBUG: %s", log);
}

void 
log_info(char* format, ...)
{
	va_list ap;
	char log[256] = "";
	
	if (logger.log_level < INFO_LEVEL) {
		return;
	}

	va_start(ap, format);
	vsprintf(log, format, ap);
	va_end(ap);
	
	logger.log("INFO: %s", log);
}

void 
log_warn(char* format, ...)
{
	va_list ap;
	char log[256] = "";
	
	if (logger.log_level < WARNING_LEVEL) {
		return;
	}
	
	va_start(ap, format);
	vsprintf(log, format, ap);
	va_end(ap);
	
	logger.log("WARNING: %s", log);
}

void 
log_error(char* format, ...)
{
	va_list ap;
	char log[256] = "";
	
	if (logger.log_level < ERROR_LEVEL) {
		return;
	}
	
	va_start(ap, format);
	vsprintf(log, format, ap);
	va_end(ap);
	
	logger.log("ERROR: %s", log);
}