api/service/placeholder.js

const request = require('request');
const bl = require('bl');
const _ = require('lodash');

const logger = require( 'pelias-logger' ).get( 'placeholder' );

module.exports = function setup(url) {
  if (_.isEmpty(url)) {
    logger.warn('placeholder service disabled');

    return {
      search: (text, lang, do_not_track, callback) => {
        callback(`placeholder service disabled`);
      }
    };

  }

  logger.info(`using placeholder service at ${url}`);
  return {
    search: (text, lang, do_not_track, callback) => {
      const requestUrl = `${url}/search`;

      const options = {
        method: 'GET',
        url: requestUrl,
        qs: {
          text: text,
          lang: lang
        }
      };

      if (do_not_track) {
        options.headers = {
          dnt: '1'
        };
      }

      request(options).on('response', (response) => {
        // pipe the response thru bl which will accumulate the entire body
        response.pipe(bl((err, data) => {
          if (response.statusCode === 200) {
            // parse and return w/o error unless response wasn't JSON
            try {
              const parsed = JSON.parse(data);
              return callback(null, parsed);
              
            }
            catch (err) {
              if (do_not_track) {
                logger.error(`${requestUrl} could not parse response: ${data}`);
                return callback(`${requestUrl} could not parse response: ${data}`);
              } else {
                logger.error(`${response.request.href} could not parse response: ${data}`);
                return callback(`${response.request.href} could not parse response: ${data}`);
              }

            }
          }
          else {
            // otherwise there was a non-200 status so handle generically
            if (do_not_track) {
              logger.error(`${requestUrl} returned status ${response.statusCode}: ${data}`);
              return callback(`${requestUrl} returned status ${response.statusCode}: ${data}`);
            } else {
              logger.error(`${response.request.href} returned status ${response.statusCode}: ${data}`);
              return callback(`${response.request.href} returned status ${response.statusCode}: ${data}`);
            }

          }
        }));

      })
      .on('error', (err) => {
        logger.error(`${requestUrl}: ${JSON.stringify(err)}`);
        callback(err);
      });

    }
  };

};