session-desktop/ts/session/onions/onionSend.ts

// tslint:disable: cyclomatic-complexity

import { OnionPaths } from '.';
import { FinalRelayOptions, sendOnionRequestLsrpcDest, SnodeResponse } from '../snode_api/onions';
import _, { toNumber } from 'lodash';
import { PROTOCOLS } from '../constants';
import { toHex } from '../utils/String';
import pRetry from 'p-retry';
import { Snode } from '../../data/data';

type OnionFetchOptions = {
  method: string;
  body?: string;
  headers?: Record<string, string>;
};

type OnionFetchBasicOptions = {
  retry?: number;
  noJson?: boolean;
};

type OnionPayloadObj = {
  method: string;
  endpoint: string;
  body: any;
  headers: Record<string, any>;
};

const buildSendViaOnionPayload = (url: URL, fetchOptions: OnionFetchOptions): OnionPayloadObj => {
  let tempHeaders = fetchOptions.headers || {};
  const payloadObj = {
    method: fetchOptions.method || 'GET',
    body: fetchOptions.body || ('' as any),
    // safety issue with file server, just safer to have this
    // no initial /
    endpoint: url.pathname.replace(/^\//, ''),
    headers: {},
  };
  if (url.search) {
    payloadObj.endpoint += url.search;
  }

  // from https://github.com/sindresorhus/is-stream/blob/master/index.js
  if (
    payloadObj.body &&
    typeof payloadObj.body === 'object' &&
    typeof payloadObj.body.pipe === 'function'
  ) {
    const fData = payloadObj.body.getBuffer();
    const fHeaders = payloadObj.body.getHeaders();
    tempHeaders = { ...tempHeaders, ...fHeaders };
    // update headers for boundary
    // update body with base64 chunk
    payloadObj.body = {
      fileUpload: fData.toString('base64'),
    };
  }
  payloadObj.headers = tempHeaders;
  return payloadObj;
};

export const getOnionPathForSending = async () => {
  let pathNodes: Array<Snode> = [];
  try {
    pathNodes = await OnionPaths.getOnionPath();
  } catch (e) {
    window?.log?.error(`sendViaOnion - getOnionPath Error ${e.code} ${e.message}`);
  }
  if (!pathNodes?.length) {
    window?.log?.warn('sendViaOnion - failing, no path available');
    // should we retry?
    return null;
  }
  return pathNodes;
};

const initOptionsWithDefaults = (options: OnionFetchBasicOptions) => {
  const defaultFetchBasicOptions = {
    retry: 0,
    noJson: false,
  };
  return _.defaults(options, defaultFetchBasicOptions);
};

const sendViaOnionRetryable = async ({
  castedDestinationX25519Key,
  finalRelayOptions,
  payloadObj,
  abortSignal,
}: {
  castedDestinationX25519Key: string;
  finalRelayOptions: FinalRelayOptions;
  payloadObj: OnionPayloadObj;
  abortSignal?: AbortSignal;
}) => {
  const pathNodes = await getOnionPathForSending();

  if (!pathNodes) {
    throw new Error('getOnionPathForSending is emtpy');
  }

  // this call throws a normal error (which will trigger a retry) if a retryable is got (bad path or whatever)
  // it throws an AbortError in case the retry should not be retried again (aborted, or )
  const result = await sendOnionRequestLsrpcDest(
    pathNodes,
    castedDestinationX25519Key,
    finalRelayOptions,
    payloadObj,
    abortSignal
  );

  return result;
};

/**
 *
 * This function can be used to make a request via onion to a non snode server.
 *
 * A non Snode server is for instance the Push Notification server or an OpengroupV2 server.
 *
 * FIXME the type for this is not correct for open group api v2 returned values
 * result is status_code and whatever the body should be
 */
export const sendViaOnionToNonSnode = async (
  destinationX25519Key: string,
  url: URL,
  fetchOptions: OnionFetchOptions,
  options: OnionFetchBasicOptions = {},
  abortSignal?: AbortSignal
): Promise<{
  result: SnodeResponse;
  txtResponse: string;
  response: string;
} | null> => {
  const castedDestinationX25519Key =
    typeof destinationX25519Key !== 'string' ? toHex(destinationX25519Key) : destinationX25519Key;
  // FIXME audric looks like this might happen for opengroupv1
  if (!destinationX25519Key || typeof destinationX25519Key !== 'string') {
    window?.log?.error('sendViaOnion - called without a server public key or not a string key');
  }

  const defaultedOptions = initOptionsWithDefaults(options);

  const payloadObj = buildSendViaOnionPayload(url, fetchOptions);
  // if protocol is forced to 'http:' => just use http (without the ':').
  // otherwise use https as protocol (this is the default)
  const forcedHttp = url.protocol === PROTOCOLS.HTTP;
  const finalRelayOptions: FinalRelayOptions = {
    host: url.hostname,
  };

  if (forcedHttp) {
    finalRelayOptions.protocol = 'http';
  }
  if (forcedHttp) {
    finalRelayOptions.port = url.port ? toNumber(url.port) : 80;
  }

  let result: SnodeResponse;
  try {
    result = await pRetry(
      async () => {
        return sendViaOnionRetryable({
          castedDestinationX25519Key,
          finalRelayOptions,
          payloadObj,
          abortSignal,
        });
      },
      {
        retries: 4, // each path can fail 3 times before being dropped, we have 3 paths at most
        factor: 1,
        minTimeout: 100,
        maxTimeout: 4000,
        onFailedAttempt: e => {
          window?.log?.warn(
            `sendViaOnionRetryable attempt #${e.attemptNumber} failed. ${e.retriesLeft} retries left...`
          );
        },
      }
    );
  } catch (e) {
    window?.log?.warn('sendViaOnionRetryable failed ', e);
    return null;
  }

  // If we expect something which is not json, just return the body we got.
  if (defaultedOptions.noJson) {
    return {
      result,
      txtResponse: result.body,
      response: result.body,
    };
  }

  // get the return variables we need
  let txtResponse = '';

  let { body } = result;
  if (typeof body === 'string') {
    // adn does uses this path
    // log.info(`sendViaOnion - got text response ${url.toString()}`);
    txtResponse = result.body;
    try {
      body = JSON.parse(result.body);
    } catch (e) {
      window?.log?.error("sendViaOnion Can't decode JSON body", typeof result.body, result.body);
    }
  }
  // result.status has the http response code
  if (!txtResponse) {
    txtResponse = JSON.stringify(body);
  }
  return { result, txtResponse, response: body };
};