session-desktop/ts/session/snode_api/lokiRpc.ts

import { default as insecureNodeFetch } from 'node-fetch';
import { Snode } from '../../data/data';

import { lokiOnionFetch, snodeHttpsAgent, SnodeResponse } from './onions';

interface FetchOptions {
  method: string;
  body?: string;
  agent?: any;
}

// A small wrapper around node-fetch which deserializes response
// returns insecureNodeFetch response or false
async function lokiFetch(
  url: string,
  options: FetchOptions,
  targetNode?: Snode,
  associatedWith?: string
): Promise<undefined | SnodeResponse> {
  const timeout = 10000;
  const method = options.method || 'GET';

  const fetchOptions = {
    ...options,
    timeout,
    method,
  };

  try {
    // Absence of targetNode indicates that we want a direct connection
    // (e.g. to connect to a seed node for the first time)
    if (window.lokiFeatureFlags.useOnionRequests && targetNode) {
      const fetchResult = await lokiOnionFetch(targetNode, fetchOptions.body, associatedWith);
      if (!fetchResult) {
        return undefined;
      }
      return fetchResult;
    }

    if (url.match(/https:\/\//)) {
      // import that this does not get set in lokiFetch fetchOptions
      fetchOptions.agent = snodeHttpsAgent;
    }
    window?.log?.warn(`insecureNodeFetch => lokiFetch of ${url}`);

    const response = await insecureNodeFetch(url, fetchOptions);

    if (!response.ok) {
      throw new window.textsecure.HTTPError('Loki_rpc error', response);
    }
    const result = await response.text();

    return {
      body: result,
      status: response.status,
    };
  } catch (e) {
    if (e.code === 'ENOTFOUND') {
      throw new window.textsecure.NotFoundError('Failed to resolve address', e);
    }
    throw e;
  }
}

/**
 * This function will throw for a few reasons.
 * The loki-important ones are
 *  -> if we try to make a request to a path which fails too many times => user will need to retry himself
 *  -> if the targetNode gets too many errors => we will need to try to do this request again with another target node
 * The
 */
export async function snodeRpc(
  method: string,
  params: any,
  targetNode: Snode,
  associatedWith?: string //the user pubkey this call is for. if the onion request fails, this is used to handle the error for this user swarm for isntance
): Promise<undefined | SnodeResponse> {
  const url = `https://${targetNode.ip}:${targetNode.port}/storage_rpc/v1`;

  // TODO: The jsonrpc and body field will be ignored on storage server
  if (params.pubKey) {
    // Ensure we always take a copy
    // tslint:disable-next-line no-parameter-reassignment
    params = {
      ...params,
      pubKey: window.getStoragePubKey(params.pubKey),
    };
  }
  const body = {
    jsonrpc: '2.0',
    id: '0',
    method,
    params,
  };

  const fetchOptions = {
    method: 'POST',
    body: JSON.stringify(body),
    headers: {
      'Content-Type': 'application/json',
    },
  };

  return lokiFetch(url, fetchOptions, targetNode, associatedWith);
}