/**
* SPDX-FileCopyrightText: © 2025 Talib Kareem <taazkareem@icloud.com>
* SPDX-License-Identifier: MIT
*
* Logger module for MCP Server
*
* This module provides logging functionality that works in both Node.js and CloudFlare Workers environments.
* In Node.js: writes to log file
* In CloudFlare Workers: uses console logging
*/
import { LogLevel } from './config.js';
// Detect environment - CloudFlare Workers don't have process.env.NODE_ENV set typically
const isNode = typeof process !== 'undefined' && process.versions && process.versions.node;
const isBrowser = typeof window !== 'undefined';
// Use INFO level by default in Workers, can be overridden via env
const configuredLevel = LogLevel.INFO;
let logStream = null;
let pid = 'worker';
// Only set up file logging in Node.js environment
if (isNode && !isBrowser) {
try {
const fs = await import('fs');
const path = await import('path');
const url = await import('url');
const config = await import('./config.js');
const __dirname = path.dirname(url.fileURLToPath(import.meta.url));
pid = process.pid;
const logFileName = 'server.log';
logStream = fs.createWriteStream(path.join(__dirname, logFileName), { flags: 'w' });
logStream.write(`Logging initialized to ${path.join(__dirname, logFileName)}\n`);
}
catch (e) {
// If imports fail, we're in Workers environment - use console
console.log('Logger: Running in CloudFlare Workers mode');
}
}
// Re-export LogLevel enum
export { LogLevel };
/**
* Check if a log level is enabled based on the configured level
* @param level The log level to check
* @returns True if the level should be logged
*/
function isLevelEnabled(level) {
return level >= configuredLevel;
}
/**
* Log function that writes to file (Node.js) or console (Workers)
* @param level Log level (trace, debug, info, warn, error)
* @param message Message to log
* @param data Optional data to include in log
*/
function log(level, message, data) {
const levelEnum = level === 'trace' ? LogLevel.TRACE
: level === 'debug' ? LogLevel.DEBUG
: level === 'info' ? LogLevel.INFO
: level === 'warn' ? LogLevel.WARN
: LogLevel.ERROR;
// Skip if level is below configured level
if (!isLevelEnabled(levelEnum)) {
return;
}
const timestamp = new Date().toISOString();
// Format the log message differently based on the level and data
let logMessage = `[${timestamp}] [PID:${pid}] ${level.toUpperCase()}: ${message}`;
// Format data differently based on content and log level
if (data) {
// For debugging and trace levels, try to make the data more readable
if (level === 'debug' || level === 'trace') {
// If data is a simple object with few properties, format it inline
if (typeof data === 'object' && data !== null && !Array.isArray(data) &&
Object.keys(data).length <= 4 && Object.keys(data).every(k => typeof data[k] !== 'object' || data[k] === null)) {
const dataStr = Object.entries(data)
.map(([k, v]) => `${k}=${v === undefined ? 'undefined' :
(v === null ? 'null' :
(typeof v === 'string' ? `"${v}"` : v))}`)
.join(' ');
logMessage += ` (${dataStr})`;
}
else {
// For more complex data, keep the JSON format but on new lines
logMessage += '\n' + JSON.stringify(data, null, 2);
}
}
else {
// For other levels, keep the original JSON format
logMessage += '\n' + JSON.stringify(data, null, 2);
}
}
// Write to file (Node.js) or console (Workers)
if (logStream) {
logStream.write(logMessage + '\n');
}
else {
// CloudFlare Workers - use console
if (level === 'error') {
console.error(logMessage);
}
else if (level === 'warn') {
console.warn(logMessage);
}
else {
console.log(logMessage);
}
}
}
/**
* Shorthand for info level logs
* @param message Message to log
* @param data Optional data to include in log
*/
export function info(message, data) {
log('info', message, data);
}
/**
* Shorthand for error level logs
* @param message Message to log
* @param data Optional data to include in log
*/
export function error(message, data) {
log('error', message, data);
}
/**
* Logger class for creating context-specific loggers
*/
export class Logger {
/**
* Create a new logger with context
* @param context The context to prepend to log messages
*/
constructor(context) {
this.context = context;
}
/**
* Check if a log level is enabled for this logger
* @param level The level to check
* @returns True if logging at this level is enabled
*/
isLevelEnabled(level) {
return isLevelEnabled(level);
}
/**
* Log at trace level
* @param message Message to log
* @param data Optional data to include in log
*/
trace(message, data) {
log('trace', `[${this.context}] ${message}`, data);
}
/**
* Log at debug level
* @param message Message to log
* @param data Optional data to include in log
*/
debug(message, data) {
log('debug', `[${this.context}] ${message}`, data);
}
/**
* Log at info level
* @param message Message to log
* @param data Optional data to include in log
*/
info(message, data) {
log('info', `[${this.context}] ${message}`, data);
}
/**
* Log at warn level
* @param message Message to log
* @param data Optional data to include in log
*/
warn(message, data) {
log('warn', `[${this.context}] ${message}`, data);
}
/**
* Log at error level
* @param message Message to log
* @param data Optional data to include in log
*/
error(message, data) {
log('error', `[${this.context}] ${message}`, data);
}
}
// Handle SIGTERM for clean shutdown (Node.js only)
if (isNode && logStream) {
process.on('SIGTERM', () => {
log('info', 'Received SIGTERM signal, shutting down...');
logStream.end(() => {
process.exit(0);
});
});
}
