// How does it work? Hit it with /?username=bradgessler&size=reasonably_small
// and you get your URL (and redirect). Need more documentation? RTFSC.

var http = require('http');

http.createServer(function(request, response){
  var query = require('url').parse(request.url, true).query;

  if(!query || !query.username){
    response.writeHead(412, {'Content-Type': 'text/plain'});
    response.end('You need to specify /?username=twitter_name\n');
  }
  else {
    var proxy = http.createClient(80, 'api.twitter.com');
    var proxy_request = proxy.request('GET', '/1/users/show.json?screen_name=' + query.username, {'host': 'api.twitter.com'});
    var size = (query.size ? query.size : 'normal');

    proxy_request.end();
    proxy_request.on('response', function (proxy_response) {
      var body = '';

      proxy_response.setEncoding('utf8');
      proxy_response.on('data', function (chunk) {
        body = body.concat(chunk);
      });
      proxy_response.on('end', function(foo){
        var profile = JSON.parse(body);
        var imagePath = profile.profile_image_url;
        var format = /^(.+)(normal)\.\w{3}$/;
        var url = profile.profile_image_url.replace(/(normal)\.(\w+)$/, size + '.$2');

        response.writeHead(302, {'Content-Type': 'text/plain', 'Location' : url });
        response.end(url + '\n');
      });
    });
  }

}).listen(7709);