translate.ts

import invariant from 'tiny-invariant';
import 'zx/globals';
import { event, info } from '../logger';

const cwd = process.cwd();
const API_URL = 'http://localhost:8080/translate';
const cacheFile = path.join(__dirname, 'translate.cache.json');
const cacheData = fs.existsSync(cacheFile)
  ? JSON.parse(fs.readFileSync(cacheFile, 'utf-8'))
  : {};
const cache = new Map(Object.entries(cacheData));

const saveCache = (key: string, value: string) => {
  cache.set(key, value);
  fs.writeFileSync(
    cacheFile,
    JSON.stringify(Object.fromEntries(cache), null, 2),
    'utf-8',
  );
};

const translate = async (opts: {
  text: string;
  sourceLang?: string;
  targetLang?: string;
}) => {
  const { text, sourceLang = 'auto', targetLang = 'ZH' } = opts;
  if (cache.has(text)) {
    info(`Cache hit.`);
    return cache.get(text);
  }
  const res = await fetch(API_URL, {
    method: 'POST',
    body: JSON.stringify({
      text,
      source_lang: sourceLang,
      target_lang: targetLang,
    }),
  });
  invariant(res.status === 200, `${res.status} ${res.statusText}`);
  const { data } = await res.json();
  saveCache(text, data);
  return data;
};

(async () => {
  info(argv);
  const file = argv._[0];
  const absFile = path.isAbsolute(file) ? file : path.join(cwd, file);

  // read file
  // TODO: 长文件拆分
  invariant(fs.existsSync(absFile), `File not found: ${absFile}`);
  const text = fs.readFileSync(absFile, 'utf-8').trim();
  info(`text length: ${text.length}`);
  invariant(text.length <= 4000, `Too long...`);

  // translate
  const translatedText = await translate({
    text,
    sourceLang: argv.sourceLang,
    targetLang: argv.targetLang,
  });

  // merge
  const textArr = text.split('\n\n');
  const translatedTextArr = translatedText.split('\n\n');
  const mergedArr = textArr.map((text, i) => {
    // don't translate code block
    if (text.startsWith('```')) {
      return text;
    } else {
      return `${text}\n\n${translatedTextArr[i]}`;
    }
  });

  // write new file
  const absNewFile = absFile.replace(/\.md/, '.translated.md');
  fs.writeFileSync(absNewFile, mergedArr.join('\n\n'), 'utf-8');
  event(`Translated to ${absNewFile}`);
})();