telegram-management-system/marketing-agent/services/ab-testing/src/utils/logger.js

import winston from 'winston';
import { config } from '../config/index.js';

const { combine, timestamp, json, printf, colorize } = winston.format;

// Custom format for console output
const consoleFormat = printf(({ level, message, timestamp, ...meta }) => {
    const metaStr = Object.keys(meta).length ? ` ${JSON.stringify(meta)}` : '';
    return `${timestamp} [${level}]: ${message}${metaStr}`;
});

// Create logger
export const logger = winston.createLogger({
    level: config.logging.level,
    format: combine(
        timestamp(),
        json()
    ),
    transports: [
        // Console transport
        new winston.transports.Console({
            format: combine(
                colorize(),
                timestamp({ format: 'YYYY-MM-DD HH:mm:ss' }),
                consoleFormat
            )
        }),
        // File transport
        new winston.transports.File({
            filename: config.logging.file,
            format: combine(
                timestamp(),
                json()
            )
        })
    ]
});

// Add error file transport in production
if (config.env === 'production') {
    logger.add(new winston.transports.File({
        filename: 'logs/error.log',
        level: 'error',
        format: combine(
            timestamp(),
            json()
        )
    }));
}