craft-ai/src/request.js

import _ from 'lodash';
import Debug from 'debug';
import { IN_BROWSER } from './constants';
import { version } from '../package.json';
import {
  CraftAiBadRequestError,
  CraftAiCredentialsError,
  CraftAiInternalError,
  CraftAiLongRequestTimeOutError,
  CraftAiNetworkError,
  CraftAiUnknownError
} from './errors';

const fetch = !IN_BROWSER && typeof fetch === 'undefined'
  ? require('node-fetch')
  : window.fetch;

const debug = Debug('craft-ai:client');

const USER_AGENT = `craft-ai-client-js/${version} [${IN_BROWSER ? navigator.userAgent : `Node.js ${process.version}`}]`;

debug(`Client user agent set to '${USER_AGENT}'`);

function parseBody(req, resBody) {
  let resBodyUtf8;
  try {
    resBodyUtf8 = resBody.toString('utf-8');
  }
  catch (err) {
    debug(`Invalid response format from ${req.method} ${req.path}: ${resBody}`, err);
    throw new CraftAiInternalError(
      'Internal Error, the craft ai server responded in an invalid format.', {
        request: req
      }
    );
  }
  let resBodyJson;
  try {
    if (resBodyUtf8.length > 0) {
      resBodyJson = JSON.parse(resBodyUtf8);
    }
    else {
      resBodyJson = {};
    }
  }
  catch (err) {
    debug(`Invalid json response from ${req.method} ${req.path}: ${resBody}`, err);
    throw new CraftAiInternalError(
      'Internal Error, the craft ai server responded an invalid json document.', {
        more: resBodyUtf8,
        request: req
      }
    );
  }
  return resBodyJson;
}

function parseBulk(req, res, resBody) {
  if (_.isArray(JSON.parse(resBody))) {
    return { body: parseBody(req, resBody) };
  }
  else {
    throw new CraftAiBadRequestError({
      message: parseBody(req, resBody).message,
      request: req
    });
  }
}

function parseResponse(req, res, resBody) {
  switch (res.status) {
    case 200:
    case 201:
    case 204:
      return {
        body: parseBody(req, resBody),
        nextPageUrl: res.headers.get('x-craft-ai-next-page-url')
      };
    case 202:
      throw new CraftAiLongRequestTimeOutError({
        message: parseBody(req, resBody).message,
        request: req
      });
    case 207:
      return parseBulk(req, res, resBody);
    case 401:
    case 403:
      throw new CraftAiCredentialsError({
        message: parseBody(req, resBody).message,
        request: req
      });
    case 400:
    case 404:
      return parseBulk(req, res, resBody);
    case 413:
      throw new CraftAiBadRequestError({
        message: 'Given payload is too large',
        request: req
      });
    case 500:
      throw new CraftAiInternalError(parseBody(req, resBody).message, {
        request: req
      });
    case 504:
      throw new CraftAiInternalError({
        message: 'Response has timed out',
        request: req,
        status: res.status
      });
    default:
      throw new CraftAiUnknownError({
        more: parseBody(req, resBody).message,
        request: req,
        status: res.status
      });
  }
}

function createHttpAgent(proxy = undefined) {
  if (IN_BROWSER) {
    return undefined;
  }
  else if (proxy) {
    const HttpProxyAgent = require('http-proxy-agent');

    return new HttpProxyAgent(proxy);
  }
  else {
    const http = require('http');

    return new http.Agent({
      keepAlive: true
    });
  }
}

function createHttpsAgent(proxy = undefined) {
  if (IN_BROWSER) {
    return undefined;
  }
  else if (proxy) {
    const HttpsProxyAgent = require('https-proxy-agent');

    return new HttpsProxyAgent(proxy);
  }
  else {
    const https = require('https');

    return new https.Agent({
      keepAlive: true
    });
  }
}

export default function createRequest(cfg) {
  const defaultHeaders = {
    'Authorization': `Bearer ${cfg.token}`,
    'Content-Type': 'application/json; charset=utf-8',
    'Accept': 'application/json'
  };

  if (!IN_BROWSER) {
    // Don't set the user agent in browsers it can cause CORS issues
    // e.g. Safari v10.1.2 (12603.3.8)
    defaultHeaders['User-Agent'] = USER_AGENT;
  }

  const baseUrl = `${cfg.url}/api/v1/${cfg.owner}/${cfg.project}`;

  const agent = baseUrl.slice(0, 5) === 'https' ? createHttpsAgent(cfg.proxy) : createHttpAgent(cfg.proxy);

  return (req) => {
    req = _.defaults(req || {}, {
      agent,
      method: 'GET',
      path: '',
      body: undefined,
      query: {},
      headers: {}
    });

    req.url = req.url || `${baseUrl}${req.path}`;

    const queryStr = _(req.query)
      .map((value, key) => ([key, value]))
      .filter(([key, value]) => !_.isUndefined(value))
      .map((keyVal) => keyVal.join('='))
      .join('&');

    if (queryStr.length > 0) {
      req.url += `?${queryStr}`;
    }
    req.headers = _.defaults(req.headers, defaultHeaders);

    req.body = req.body && JSON.stringify(req.body);

    return fetch(req.url, req)
      .catch((err) => {
        debug(`Network error while executing ${req.method} ${req.path}`, err);
        return Promise.reject(new CraftAiNetworkError({
          more: err.message
        }));
      })
      .then((res) => res.text()
        .catch((err) => {
          debug(`Invalid response from ${req.method} ${req.path}`, err);

          throw new CraftAiInternalError('Internal Error, the craft ai server responded an invalid response, see err.more for details.', {
            request: req,
            more: err.message
          });
        })
        .then((resBody) => parseResponse(req, res, resBody))
      );
  };
}