/**
* Logging utility for ActivityWatch MCP Server
*/
import { getErrorProperties } from './type-guards.js';
export enum LogLevel {
DEBUG = 0,
INFO = 1,
WARN = 2,
ERROR = 3,
}
class Logger {
private readonly level: LogLevel;
constructor() {
// Read from environment variable, default to INFO
const envLevel = process.env.LOG_LEVEL?.toUpperCase();
this.level = LogLevel[envLevel as keyof typeof LogLevel] ?? LogLevel.INFO;
}
private log(level: LogLevel, message: string, data?: unknown): void {
if (level < this.level) return;
const timestamp = new Date().toISOString();
const levelName = LogLevel[level];
const prefix = `[${timestamp}] [${levelName}]`;
// Always log to stderr to avoid interfering with MCP stdio communication
if (data !== undefined) {
console.error(prefix, message, JSON.stringify(data, null, 2));
} else {
console.error(prefix, message);
}
}
debug(message: string, data?: unknown): void {
this.log(LogLevel.DEBUG, message, data);
}
info(message: string, data?: unknown): void {
this.log(LogLevel.INFO, message, data);
}
warn(message: string, data?: unknown): void {
this.log(LogLevel.WARN, message, data);
}
error(message: string, error?: unknown): void {
const errorProps = getErrorProperties(error);
this.log(LogLevel.ERROR, message, errorProps);
}
}
// Singleton instance
export const logger = new Logger();
