search.js

var _ = require('lodash');
var P = require('bluebird');
var apac = require('apac');
var OperationHelper = apac.OperationHelper;

var opHelper = new OperationHelper({
  awsId: process.env.AMAZON_AWS_ID,
  awsSecret: process.env.AMAZON_AWS_SECRET,
  assocId: process.env.AMAZON_SITE_ID
});

function search(term, page) {
  var itemSearch = P.promisify(opHelper.execute, opHelper);
  return itemSearch('ItemSearch', {
    SearchIndex: 'Books',
    Keywords: term,
    ResponseGroup: 'Small,ItemAttributes,Images,EditorialReview,OfferSummary',
    ItemPage: page || 1
  }).then(function(results) {
    console.log(results);
    function v(item) {
      return (item || [])[0];
    }

    function o(item) {
      return item || {};
    }

    results = o(v(o(o(v(results)).ItemSearchResponse).Items)).Item;
    return _.map(results, function(item) {
      var a = o(v(item.ItemAttributes));
      var offer = o(v(item.OfferSummary));

      var ret = {
        image: v(o(v(o(item.LargeImage))).URL),
        title: v(a.Title),
        manufacturer: v(a.Manufacturer),
        author: v(a.Author),
        isbn: v(a.ISBN),
        buyback: v(o(v(a.TradeInValue)).FormattedPrice),
        newPrice: v(o(v(offer.LowestNewPrice)).FormattedPrice),
        usedPrice: v(o(v(offer.LowestUsedPrice)).FormattedPrice),
        list: v(o(v(a.ListPrice)).FormattedPrice),
        desc: v(o(v(o(v(item.EditorialReviews)).EditorialReview)).Content),
        url: v(item.DetailPageURL),
        slug: require('slug')(v(a.Title))
      };

      return ret;
    });
  });
}

/**
 * Search the amazon API with 3 retries.
 */
function searchWithRetry(term, page, tries) {
  if (typeof tries === 'undefined') tries = 3;

  if (tries === 0) {
    return P.resolve([]);
  }

  return search(term, page).then(function(results) {
    if (results.length === 0) {
      return searchWithRetry(term, page, tries - 1);
    }
    return results;
  });
}

module.exports = searchWithRetry;