BraveNewTalent -- Lead Engineer Technical Test -- Nik Hodgkinson

backend-rest.py

users = [{"id": 40, "name": "Joe Bloggs", "posts": 4},
         {"id": 567, "name": "Jenny Smith", "posts": 3},
         {"id": 3, "name": "Frank Jones", "posts": 54},
         {"id": 46, "name": "Samantha Wills", "posts": 0},
         {"id": 6789, "name": "Ahmed Joseph Naran", "posts": 15}]

def userTransform(user):
    name = user["name"].rsplit(" ", 1)
    return {"first_name": name[0], "last_name": name[1], "posts": user["posts"]}


filtered_users = filter(lambda entry: entry["posts"] != 0, users)
sorted_users = sorted(filtered_users, key=lambda entry: entry["posts"], reverse=True)
transformed = [userTransform(user) for user in sorted_users]

for user in transformed:
    print str(user)
    
# Results:
#
# {'first_name': 'Frank', 'last_name': 'Jones', 'posts': 54}
# {'first_name': 'Ahmed Joseph', 'last_name': 'Naran', 'posts': 15}
# {'first_name': 'Joe', 'last_name': 'Bloggs', 'posts': 4}
# {'first_name': 'Jenny', 'last_name': 'Smith', 'posts': 3}

frontend.js

// As far as I know this should work in all modern browsers >= IE7. As there is
// no good way to print something out in JavaScrpt I've collected the output and 
// returned it from the function.
var x = [
{ first_name: "Frank", last_name: "Jones", posts: 54 },
{ first_name: "Ahmed Joseph", last_name: "Naran", posts: 15},
{ first_name: "Joe", last_name: "Bloggs", posts: 4},
{ first_name: "Jenny", last_name: "Smith", posts: 3 }
];

function reformat(x) {
    var output = "";
    for (var i = 0; i < x.length; i++) {
        posts = (x[i].posts > 1) ? " posts" : "post";
        output += x[i].last_name + ", " + x[i].first_name + " - " + x[i].posts + posts + "\n";
    }
    return output;
}

// Results:
//
// Jones, Frank - 54 posts
// Naran, Ahmed Joseph - 15 posts
// Bloggs, Joe - 4 posts
// Smith, Jenny - 3 posts

middleware.js

function unsubscribe(req) {
  var email = req.query.email || req.body.email || undefined,
    defer = when.defer();
  if (typeof email == 'undefined') {
    defer.reject({ error : 'No email was specified.' });
  } else {
    when(client.request('nurture/unsubscribe', { email: email }, { method: 'POST' })).then(
      function unsubscribed(response) {
        defer.resolve(response);
      },
      function failed(response) {
        defer.reject(response);
      }
    );
  }
  return defer.promise;
}

/*
This function is designed to take an incoming unsubscribe request and proxy that request into a 
call on another service. This happens asynchronously and we don't want to block, thus we utilize
a promise as a placeholder. A promise is just as it sounds, it's a declaration or IOU that a 
value (or error) will be available at a later time when work that has to be done completes. 

To step through the function: we start by retrieving the email address from the request and create
a deferred value promise (lines 2&3). If we don't have an email address we immediately set the 
promise to signal an error (lines 4&5), otherwise we make an async call to our external 
service (line 7) tying the result (both failure and success) to our promise (lines 8-12). 
To tie our async request to the promise we utilize callbacks (code passed as an argument; lines 8 & 11) 
and within create a closure (a reference to a non-local variable; lines 9&12). Finally after 
having completed the setup, we return the promise (line 16). The calling code that receives o
ur promise may then try to retrieve the value immediately (which could block) or it could save 
it for later and only handle it when the promise is ready.
*/

persistence.sql

SELECT
  ct._name AS topic_name,
  count(ci.id) AS topic_count
FROM content_topic ct
LEFT JOIN content_item_topic cit ON (ct.id = cit.topic_id)
LEFT JOIN content_item ci ON (ci.id = cit.item_id)
WHERE ci.created >= (localtimestamp - interval '1 month') 
GROUP BY ct.name
ORDER BY topic_count DESC;

www.local.bnt.conf

server {
  server_name local.bnt;
  rewrite / $scheme://www.local.bnt$request_uri? permanent;
}

server {
  server_name www.local.bnt www.local.test;
  set $srv_base "/srv/public.bravenewtalent.com/";
  access_log /var/log/nginx/www.local.bnt.access.log main;
  error_log /var/log/nginx/www.local.bnt.error.log;
  sendfile off;
  ssi on;
  root $srv_base/www;
  index index.html;

  location /api/0/content {
    proxy_pass http://127.0.0.1:10200;
    proxy_redirect off;
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
  }

  location /home {
    proxy_pass http://127.0.0.1:3000;
    proxy_redirect off;
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
  }
}

# As a side note, it is not specified exactly how the reverse proxied service should be called. 
# Currently it passes the entire path, but could be configured differently. Additionally the 
# proxy config settings should be moved to another file and included to avoid duplicating config.