Bitcoin index price API with up/down arrow

webtask.js

var request = require('request@2.27.0');

function get_rate(json_body){
  // parse the response to get current price.
  return json_body.bpi.USD.rate;
}

module.exports = function (ctx, done) {
  var date = new Date();
  var current_hour = date.getHours();


  var url = "http://api.coindesk.com/v1/bpi/currentprice.json"

  // get current price
  request({
    url: url,
    json: true }, function (error, response, body) {
    
    if (error || !response.statusCode === 200) return done(error);

    var current_rate = get_rate(body);

    // retrieve last values
    ctx.storage.get(function get_history (error, data) {
        if (error) return done(error);
        // create the document if it doesn't exist
        data = data || {};

        // update last hour price
        data[date.getHours().toString()] = current_rate;
        ctx.storage.set(data, function (error) {

          // generate response
          if (error) return done(error);
          var past_hour = (date.getHours()-1).toString();
          var last_hour_close = data[past_hour];
          done(null, {current_rate: current_rate, last_hour_close: last_hour_close, 
            up: current_rate > last_hour_close});

        });
    });
  })
};