Sound of Text - Browser client

soundoftext.js

const soundoftext = (() => {
  const API_URL = 'https://api.soundoftext.com';

  const urls = {
    base: 'https://api.soundoftext.com',
    request: () => `${urls.base}/sounds`,
    status: id => `${urls.base}/sounds/${id}`,
  };

  const bodies = {
    request: ({engine = 'Google', text, voice}) =>
      JSON.stringify({engine, data: {text, voice}}),
  };

  const options = {
    default: {
      headers: {
        'Content-Type': 'application/json',
        'User-Agent': 'SoundOfTextClient',
      },
    },
    request: ({text, voice}) => ({
      ...options.default,
      method: 'POST',
      body: bodies.request({text, voice}),
    }),
    status: () => ({...options.default, method: 'GET'}),
  };

  const request = (url, options) =>
    fetch(url, options)
      .then(res => res.json())
      .then(res => (res.message ? Promise.reject(res.message) : res));

  const retry = (func, timeout) =>
    new Promise(resolve => setTimeout(() => resolve(func()), timeout));

  const location = ({id, timeout = 1000}) =>
    operations.status({id}).then(res => {
      if (res.status == 'Error') throw res.message;
      if (res.status == 'Done') return res.location;
      if (timeout > 30 * 1000) throw 'Operation timed out';

      return retry(() => location({id, timeout: timeout * 2}), timeout);
    });

  const create = ({text, voice}) =>
    operations.request({text, voice}).then(operations.location);

  const operations = {
    create,
    location,
    request: ({text, voice}) =>
      request(urls.request(), options.request({text, voice})),
    status: ({id}) => request(urls.status(id), options.status()),
  };

  const client = {sounds: operations};

  return client;
})();