import { delay } from 'redux-saga';
import { race, take, call, put, spawn } from 'redux-saga/effects';

import { ActionTypes } from '../actions/abActions';

export function* waitForChooseExperiment(internalAction, abTestName) {
  let payload;
  // Busy waiting to take actually get the desired action
  // since there might be more than one action with the same type
  while (true) {
    payload = (yield take(ActionTypes.CHOOSE_EXPERIMENT)).payload;
    if (payload.name === abTestName) {
      break;
    }
  }
  yield put(internalAction);
}

/**
 * Returns a generator which calls a saga if the sepecific experiment is loaded or the timeout runs out.
 *
 * @param {string} abTest - The name of the A/B test, the saga should wait for
 * @param {number} timeout - Maximal timeout, default is 1000ms
 */
export function waitForOptimize(abTest, timeout = 1000) {
  // Create an action which then can be used internally
  const internalActionType = `@doodle/ab/internal/DEPEND_ON_${abTest}`;
  const internalAction = { type: internalActionType };
  return function*(saga, ...args) {
    // If abTest is undefined, just call the wrapped saga
    if (abTest) {
      // Here we fork the saga to not block the generator.
      // This enables us to afterwards take the internal action
      yield spawn(waitForChooseExperiment, internalAction, abTest);
      yield race({
        action: take(internalActionType),
        timeout: delay(timeout),
      });
    }
    return yield call(saga, ...args);
  };
}