import { OnboardingClient } from '../clients/OnboardingClient';
import { OnboardingStatusRequestParams, OnboardingStatusResponse } from '../entities/Onboarding';

export class OnboardingService {
  constructor(private onboardingClient: OnboardingClient, private $q: QService, private $timeout: TimeoutService) { }

  pollOnboarding(params: OnboardingStatusRequestParams, minRequestInterval: number = 1000, overallTimeout: number = 10000): Promise<OnboardingStatusResponse> {
    let overallTimeoutPromise = this.$timeout(() => null, overallTimeout);

    // Recursive function which tries again if onboarding is not ready yet
    let pollEndpoint: () => Promise<OnboardingStatusResponse> = () => {
      // Catch any HTTP errors so this promise is guaranteed to succeed eventually
      let onboardingStatus = this.onboardingClient.getOnboardingStatus(params, { timeout: overallTimeout })
        .then(success => success.data, error => ({ allAccountsExist: false }));

      // Wait *at most* for the interval specified - this ensures we don't hit the endpoint too frequently
      let waitForMinimumInterval = this.$timeout(() => null, minRequestInterval).then(_ => onboardingStatus);

      // Race this promise against the overall timeout
      // This would be easier if we had $q.race() but that is only in later Angular versions
      let deferred = this.$q.defer<OnboardingStatusResponse>();
      waitForMinimumInterval.then(deferred.resolve);
      overallTimeoutPromise.then(deferred.reject);
      return deferred.promise.then(onboardingStatus =>
        onboardingStatus.allAccountsExist ? onboardingStatus : pollEndpoint());
    }

    return pollEndpoint();
  }
}