karat samples

foo.js

const counts = [ "900,google.com",
"60,mail.yahoo.com",
"10,mobile.sports.yahoo.com",
"40,sports.yahoo.com",
"300,yahoo.com",
"10,stackoverflow.com",
"20,overflow.com",
"5,com.com",
"2,en.wikipedia.org",
"1,m.wikipedia.org",
"1,mobile.sports",
"1,google.co.uk"];

function calculateClicksByDomain(counts = []) {
  const map = new Map();
  
  for (const count of counts) {
    let [clicks, url] = count.split(',');
    clicks = Number(clicks);

    const parts = url.split('.');
    
    for (let part = '', i = parts.length - 1; i >= 0; i--) {
      part = parts[i] + (part ? '.' + part : '');
      if (!map.has(part)) map.set(part, clicks);
      else map.set(part, map.get(part) + clicks);
    }
  }

  return map;
}

const map = calculateClicksByDomain(counts);
console.log(map);

const completed_purchase_user_ids = [
"3123122444","234111110", "8321125440", "99911063"]

const ad_clicks = [
"122.121.0.1,2016-11-03 11:41:19,Buy wool coats for your pets",
"96.3.199.11,2016-10-15 20:18:31,2017 Pet Mittens",
"122.121.0.250,2016-11-01 06:13:13,The Best Hollywood Coats",
"82.1.106.8,2016-11-12 23:05:14,Buy wool coats for your pets",
"92.130.6.144,2017-01-01 03:18:55,Buy wool coats for your pets",
"122.121.0.155,2017-01-01 03:18:55,Buy wool coats for your pets",
"92.130.6.145,2017-01-01 03:18:55,2017 Pet Mittens"
]

const all_user_ips = [
"2339985511,122.121.0.155",
"234111110,122.121.0.1",
"3123122444,92.130.6.145",
"39471289472,2001:0db8:ac10:fe01:0000:0000:0000:0000",
"8321125440,82.1.106.8",
"99911063,92.130.6.144"
]

function parseClick(str = '') {
  const [ip, date, name] = str.split(',');
  return { ip, date, name };
}

function parseUser(str = '') {
  const [id, ip] = str.split(',');
  return { id, ip };
}

function parse(purchases = [], clickLogs = [], ips = []) {
  let output = '';
  const results = {};
  const users = ips.map(parseUser);
  const clicks = clickLogs.map(parseClick);

  for (const click of clicks) {
    if (!(click.name in results)) {
      results[click.name] = { purchases: 0, clicks: 1 };
    } else {
      results[click.name].clicks += 1;
      const user = users.find((u) => u.ip === click.ip);
      if (user) results[click.name].purchases += 1;
    }
  }

  for (const [name, result] of Object.entries(results)) {
    if (output) output += '\n';
    output += `${result.purchases} of ${result.clicks} ${name}`;
  }

  return output;
}

const res = parse(
  completed_purchase_user_ids,
  ad_clicks,
  all_user_ips
);

console.log(res);