src/utils/logger.ts

import { CONFIG } from '../config';

type Level = 'info' | 'warn' | 'error' | 'debug';

const LEVELS: Record<Level, number> = { debug: 0, info: 1, warn: 2, error: 3 };
const MIN_LEVEL = CONFIG.NODE_ENV === 'production' ? LEVELS.info : LEVELS.debug;

function log(level: Level, msg: string, meta?: Record<string, unknown>): void {
  if (LEVELS[level] < MIN_LEVEL) return;

  const entry = JSON.stringify({
    ts: new Date().toISOString(),
    level,
    msg,
    ...(meta ?? {}),
  });

  if (level === 'error') {
    process.stderr.write(entry + '\n');
  } else {
    process.stdout.write(entry + '\n');
  }
}

export const logger = {
  info: (msg: string, meta?: Record<string, unknown>) => log('info', msg, meta),
  warn: (msg: string, meta?: Record<string, unknown>) => log('warn', msg, meta),
  error: (msg: string, meta?: Record<string, unknown>) => log('error', msg, meta),
  debug: (msg: string, meta?: Record<string, unknown>) => log('debug', msg, meta),
};