//////// Event loop test

function eventLoopTest(config) {
  const { prefix, type, depth = 2 } = config;

  if (depth >= 0) {
    const callback = () => {
      process.nextTick(() => console.log(prefix + ": next tick #" + depth));
      Promise.resolve().then(() => console.log(prefix + ": promise #" + depth));
      setImmediate(() => console.log(prefix + ": immediate #" + depth));
      setTimeout(() => console.log(prefix + ": timeout #" + depth), 0);

      eventLoopTest({ prefix, type, depth: depth - 1 });
    };
    switch (type) {
      case 'promise': {
        Promise.resolve().then(callback);
        break;
      }

      case 'nextTick': {
        process.nextTick(callback);
        break;
      }
    }
  }
}

process.on('uncaughtException', err => {
  console.error('uncaught: ' + err.message);
});

// setImmediate(() => console.log('immediate'));
// eventLoopTest({ prefix: 1, type: 'nextTick' });
// process.nextTick(() => {
//   throw new Error;
// });
// eventLoopTest({ prefix: 2, type: 'promise' });

////////////////////// Promises handling

process.on('unhandledRejection', (err, promise) => {
  console.log('handled', err);
  promise.catch(error => (console.log('lateCatch', error == err), error));
});
process.on('rejectionHandled', (promise) => {
  console.log('rejection', promise);
});

// Promise.reject(new Error('unhandled!'))
  // .catch((err) => console.log(err))

///////////////////// Promise chaining

function onSuccess(a) {
  console.log('success: ' + a);
  return a + a;
}

function onFailedSuccess(a) {
  console.log('success: ' + a);
  const err = new Error(a);
  console.log('throw: ' + err.message);
  throw err;
}

function onFailure(err) {
  console.log('fail: ' + err.message);
  return err.message + err.message;
}

function onFailedFailure(err) {
  console.log('fail: ' + err.message);
  err.message += err.message;
  console.log('throw: ' + err.message);
  throw err;
}

// Promise.resolve(1)
//   .then(onSuccess)
//   .then(onSuccess)
//   .catch(onFailedFailure)
//   .then(onFailedSuccess)
//   .catch(onFailedFailure)
//   .catch(onFailedFailure)
//   .catch(onFailure)
//   .then(onSuccess);