dros/src/log/log-writer.js

import { LOG_DIR } from './log-path.js';
import path from 'path';
import fs from 'fs';

const MAX_SIZE = 2 * 1024 * 1024; // 2 MB

function getBaseName() {
  return new Date().toISOString().slice(0, 10);
}
function pad(n) { return n.toString().padStart(3, '0'); }

function currentLogFile() {
  let idx = 0;
  while (true) {
    const name = `${getBaseName()}_${pad(idx)}.log`;
    const p = path.join(LOG_DIR, name);
    try {
      const stat = fs.statSync(p);
      if (stat.size < MAX_SIZE) return p;
      idx++;
    } catch {
      return p; // 文件不存在，直接用它
    }
  }
}

export function writeLog(level, msg) {
  const line = `[${new Date().toISOString()}] [${level}] ${msg}\n`;
  fs.appendFileSync(currentLogFile(), line);
}