Initial commit: Inventory Barcode System

utils/logger.js

@@ -0,0 +1,166 @@
+const winston = require('winston');
+const DailyRotateFile = require('winston-daily-rotate-file');
+const path = require('path');
+
+// Create logs directory if it doesn't exist
+const logsDir = path.join(__dirname, '..', 'logs');
+
+// Define log levels and colors
+const logLevels = {
+  error: 0,
+  warn: 1,
+  info: 2,
+  http: 3,
+  debug: 4
+};
+
+const logColors = {
+  error: 'red',
+  warn: 'yellow',
+  info: 'green',
+  http: 'magenta',
+  debug: 'blue'
+};
+
+winston.addColors(logColors);
+
+// Custom format for structured logging
+const logFormat = winston.format.combine(
+  winston.format.timestamp({ format: 'YYYY-MM-DD HH:mm:ss' }),
+  winston.format.errors({ stack: true }),
+  winston.format.json(),
+  winston.format.printf(({ timestamp, level, message, stack, ...meta }) => {
+    let logMessage = `${timestamp} [${level.toUpperCase()}]: ${message}`;
+    
+    // Add stack trace for errors
+    if (stack) {
+      logMessage += `\nStack: ${stack}`;
+    }
+    
+    // Add metadata if present
+    if (Object.keys(meta).length > 0) {
+      logMessage += `\nMeta: ${JSON.stringify(meta, null, 2)}`;
+    }
+    
+    return logMessage;
+  })
+);
+
+// Console format for development
+const consoleFormat = winston.format.combine(
+  winston.format.colorize({ all: true }),
+  winston.format.timestamp({ format: 'HH:mm:ss' }),
+  winston.format.printf(({ timestamp, level, message, stack }) => {
+    let logMessage = `${timestamp} ${level}: ${message}`;
+    if (stack) {
+      logMessage += `\n${stack}`;
+    }
+    return logMessage;
+  })
+);
+
+// Create transports
+const transports = [
+  // Console transport for development
+  new winston.transports.Console({
+    level: process.env.NODE_ENV === 'production' ? 'info' : 'debug',
+    format: consoleFormat,
+    handleExceptions: true,
+    handleRejections: true
+  }),
+  
+  // File transport for all logs
+  new DailyRotateFile({
+    filename: path.join(logsDir, 'application-%DATE%.log'),
+    datePattern: 'YYYY-MM-DD',
+    maxSize: '20m',
+    maxFiles: '14d',
+    level: 'debug',
+    format: logFormat,
+    handleExceptions: true,
+    handleRejections: true
+  }),
+  
+  // Separate file for errors
+  new DailyRotateFile({
+    filename: path.join(logsDir, 'error-%DATE%.log'),
+    datePattern: 'YYYY-MM-DD',
+    maxSize: '20m',
+    maxFiles: '30d',
+    level: 'error',
+    format: logFormat,
+    handleExceptions: true,
+    handleRejections: true
+  }),
+  
+  // HTTP requests log
+  new DailyRotateFile({
+    filename: path.join(logsDir, 'http-%DATE%.log'),
+    datePattern: 'YYYY-MM-DD',
+    maxSize: '20m',
+    maxFiles: '7d',
+    level: 'http',
+    format: logFormat
+  })
+];
+
+// Create logger instance
+const logger = winston.createLogger({
+  levels: logLevels,
+  transports,
+  exitOnError: false
+});
+
+// Add request logging helper
+logger.logRequest = (req, res, responseTime) => {
+  const logData = {
+    method: req.method,
+    url: req.originalUrl,
+    ip: req.ip || req.connection.remoteAddress,
+    userAgent: req.get('User-Agent'),
+    statusCode: res.statusCode,
+    responseTime: `${responseTime}ms`,
+    contentLength: res.get('Content-Length') || 0
+  };
+  
+  // Log based on status code
+  if (res.statusCode >= 500) {
+    logger.error('HTTP Request Error', logData);
+  } else if (res.statusCode >= 400) {
+    logger.warn('HTTP Request Warning', logData);
+  } else {
+    logger.http('HTTP Request', logData);
+  }
+};
+
+// Add database operation logging helper
+logger.logDbOperation = (operation, table, data = {}, duration = null) => {
+  const logData = {
+    operation,
+    table,
+    duration: duration ? `${duration}ms` : null,
+    ...data
+  };
+  
+  logger.debug('Database Operation', logData);
+};
+
+// Add error context helper
+logger.logError = (error, context = {}) => {
+  const errorData = {
+    message: error.message,
+    stack: error.stack,
+    name: error.name,
+    code: error.code,
+    ...context
+  };
+  
+  logger.error('Application Error', errorData);
+};
+
+// Add business logic logging helper
+logger.logBusinessEvent = (event, data = {}) => {
+  logger.info(`Business Event: ${event}`, data);
+};
+
+module.exports = logger;