Profile is not defined

var router = require("./router.js");

//Create a web server

const http = require('http');

const hostname = '';
const port = 3000;

http.createServer((request, response) => {
  router.home(request, response);
  router.user(request, response);
}).listen(port, hostname, () => {
  console.log(`Server running at http://${port}/`);
});

// Function that handles the reading of files and merge in value

//2. Handle HTTP route GET / and POST / i.e. Home

function home(request, response) {
  if (request.url === "/"){
    response.writeHead(200, { 'Content-Type': 'text/plain' });
    response.write("Header\n");
    response.write("Search\n");
    response.end('Footer\n');
  }
}

//3. Handle HTTP route GET / :username i.e. /nicolasfernandez2

function user(request, response) {
  var username = request.url.replace("/", "");
  if (username.length > 0){
    response.writeHead(200, { 'Content-Type': 'text/plain' });
    response.write("Header\n");

    //get json from Treehouse
    var studentProfile = new Profile(username);
    studentProfile.on("end", function(profileJSON){
      //Show profile

      //Store the vaulues which we need
      var values = {
        avatarUrl: profileJSON.gravatar_url,
        username: profileJSON.profile_name,
        badges: profileJSON.badges.length,
        javascriptPoints: profileJSON.points.JavaScript
      }
      //Simple response
      response.write(values.username + " has " + values.badges + " badges\n");
      response.end('Footer\n');
    });
    //On error
    studentProfile.on("error", function(error){
      //Show error
      response.write(error.message + "/n");
      response.end('Footer\n');
    });

  }
}

module.exports.home = home;
module.exports.user = user;