/**
* Structured logging for OmniFocus MCP server
* Writes to stderr to avoid corrupting the MCP JSON-RPC stream on stdout
*/
enum LogLevel {
DEBUG = 0,
INFO = 1,
WARN = 2,
ERROR = 3,
SILENT = 4
}
const LOG_LEVEL_NAMES: Record<LogLevel, string> = {
[LogLevel.DEBUG]: 'DEBUG',
[LogLevel.INFO]: 'INFO',
[LogLevel.WARN]: 'WARN',
[LogLevel.ERROR]: 'ERROR',
[LogLevel.SILENT]: 'SILENT'
};
class Logger {
private level: LogLevel;
private context: string;
constructor(context: string = 'of-mcp') {
this.context = context;
this.level = this.parseLevel(process.env.LOG_LEVEL || 'info');
}
private parseLevel(level: string): LogLevel {
const normalized = level.toLowerCase();
switch (normalized) {
case 'debug': return LogLevel.DEBUG;
case 'info': return LogLevel.INFO;
case 'warn': return LogLevel.WARN;
case 'error': return LogLevel.ERROR;
case 'silent': return LogLevel.SILENT;
default: return LogLevel.INFO;
}
}
private write(level: LogLevel, message: string, data?: any): void {
if (level < this.level) return;
const timestamp = new Date().toISOString();
const levelName = LOG_LEVEL_NAMES[level];
const line = `[${timestamp}] [${levelName}] [${this.context}] ${message}`;
// Write to stderr, NOT stdout (stdout is for MCP protocol)
process.stderr.write(line + '\n');
if (data !== undefined) {
if (typeof data === 'object') {
process.stderr.write(JSON.stringify(data, null, 2) + '\n');
} else {
process.stderr.write(String(data) + '\n');
}
}
}
debug(message: string, data?: any): void {
this.write(LogLevel.DEBUG, message, data);
}
info(message: string, data?: any): void {
this.write(LogLevel.INFO, message, data);
}
warn(message: string, data?: any): void {
this.write(LogLevel.WARN, message, data);
}
error(message: string, data?: any): void {
this.write(LogLevel.ERROR, message, data);
}
/**
* Create a child logger with additional context
* Useful for tracing logs to specific modules
*/
child(subContext: string): Logger {
const child = new Logger(`${this.context}:${subContext}`);
child.level = this.level;
return child;
}
}
// Export singleton for general use
export const logger = new Logger();
// Export class for creating contextual loggers
export { Logger, LogLevel };
