// @flow

import retry from 'retry';

import createDebug from './createDebug';

import {

UnexpectedResponseError

} from './errors';

const debug = createDebug('attemptRequest');

const defaultConfiguration = {

factor: 2,

maxTimeout: Infinity,

minTimeout: 1000,

randomize: false,

retries: 0

};

export default (

requestHandler: RequestHandlerType,

validateResponse: ValidateResponseType,

userRetryConfiguration: RetryConfigurationType = {}

): Promise<ResponseType> => {

return new Promise((resolve, reject) => {

let currentAttempt;

const retryConfiguration = Object.assign({}, defaultConfiguration, userRetryConfiguration);

const operation = retry.operation(retryConfiguration);

currentAttempt = -1;

operation

.attempt(async () => {

++currentAttempt;

debug('making %d request attempt (%d allowed retries)', currentAttempt + 1, retryConfiguration.retries);

const response = await requestHandler(currentAttempt);

debug('received response (status code) %d', response.status);

try {

const responseIsValid = await validateResponse(response, currentAttempt);

if (responseIsValid === true) {

resolve(response);

} else {

throw new UnexpectedResponseError(response);

}

} catch (error) {

if (error instanceof UnexpectedResponseError) {

if (!operation.retry(error)) {

debug('maximum number of attempts has been exhausted');

reject(error);

return;

}

debug('response is invalid... going to make another attempt', {

headers: response.headers,

status: response.status

});

} else {

reject(error);

}

}

});

});

};