roll.js

'use strict';

var http = require('http');
var url = require('url');

function rollDie(max){
  return Math.floor(Math.random() * (max - 1 + 1)) + 1;
}

function startRollServer(port, ip){
  var server = http.createServer(function(req, res){
    var parsed = url.parse(req.url, true);
    if(parsed.pathname === '/roll'){
      var diceData = parsed.query.text.split('d');
      var numDice = parseInt(diceData[0], 10);
      var diceType = parseInt(diceData[1], 10);
      var results = 0;
      var roll = 0;

      console.log('request', req.url);

      if(!isNaN(numDice) && !isNaN(diceType)){
        console.log('valid request, rolling dice');
        numDice = numDice > 10 ? 10 : numDice;
        diceType = diceType > 20 ? 20 : diceType;
        for(var i = 0; i < numDice; i++){
          roll = rollDie(diceType);
          results += roll;
        }
      }
      var output = diceData.join('d')+': '+results;
      res.end(output);
    } else {
      res.end('nope');
    }
  });
  server.listen(port, ip);
  console.log('listening on', ip+':'+port)
}

if(!module.parent){
  startRollServer(process.argv[3] || 3000, process.argv[2] || '127.0.0.1');
}