logging.js

const winston = require("winston");
const path = require("path");

var logger;

var enumerateErrorFormat = winston.format(info => {
	if (info.message instanceof Error) {
		info.message = Object.assign({
			message: info.message.message,
			stack: info.message.stack
		}, info.message);
	}

	if (info instanceof Error) {
		return Object.assign({
			message: info.message,
			stack: info.stack
		}, info);
	}

	return info;
});

module.exports = function (directory) {
	if (!logger) {
		logger = winston.createLogger({
			transports: [
				new winston.transports.File({
					filename: path.join(__dirname, "logs", directory, "error.log"),
					level: "error"
				}),
				new winston.transports.File({
					filename: path.join(__dirname, "logs", directory, "warn.log"),
					level: "warn"
				}),
				new winston.transports.File({
					filename: path.join(__dirname, "logs", directory, "http.log"),
					level: "http"
				})
			],
			format: winston.format.combine(
				winston.format.colorize(),
				winston.format.timestamp(),
				enumerateErrorFormat(),
				winston.format.printf(info => `${info.timestamp} ${info.level}: ${info.message} ${info.stack ? `\n${info.stack}` : ""}`)
			),
			exitOnError: false
		});

		logger.stream = {
			write: (message, encoding) => {
				logger.http(message);
			}
		};
	}

	return logger;
};