server.js

// server.js

// Set up the Twitter library.
var Twit = require('twit')
function createTwitClient() {
  return new Twit({
    consumer_key: 'Z2LyQpbFs0OzmFRQHPJmmzhoS',
    consumer_secret: '5T5Ep2yQHjf0XiGDUgSRJC38iliTdJg7teutnu50S4Z4e4nMEm',
    access_token: '3837516989-IgSf9kbiEa2Df9EhD0Rut7sPh0QVh5cOJHsMk2j',
    access_token_secret: 'rk40a0TCd7mGcy5HvOqj5gn15VwqgMJpX9S51kgg3iUn3'
  });
}

// Set up express for serving the client.
var express = require('express');
var app = express();

// Specify the directory for static files.
app.use(express.static(__dirname + '/client'));

// Serve the index to clients.
app.get('/', function(req, res) {
  res.sendFile(__dirname + '/index.html');
});

// Set up the http server for sockets.
var http = require('http').Server(app);
var io = require('socket.io')(http);

// Listen for connections on the default port.
http.listen(process.env.PORT, function() {
  console.log('listening on *:' + process.env.PORT);
});

// Listen for connections.
io.on('connection', function(client) {
  console.log("* client " + client.id + " connected");

  var streams = [];
  var streamType = null;
  var client_location = null;
  var keyword = null;
  var twitter = createTwitClient();
  var lastTweetTime = new Date();
  var paused = false;

  // Listen for disconnects.
  client.on('disconnect', function() {
    console.log("* client " + client.id + " disconnected");

    // Stop all streams.
    disconnectAllStreams();
  });

  var disconnectAllStreams = function() {
    streams.forEach(function (stream) {
      stream.stop();
    });

    streams = [];
  }

  client.on('toggle-pause', function() {
    console.log("* toggling pause...");
    paused = !paused;
  });

  // Aggregate function for location and keyword streams.
  var handleTweet = function(tweet) {
    // Ignore retweets.
    if (tweet.hasOwnProperty('retweeted_status')) {
      if (tweet.retweeted_status.retweet_count > 0) {
        //console.log("* client " + client.id + " ignoring retweet");
        return;
      }
    }

    // Ignore potentially sensitive tweets.
    if (tweet.hasOwnProperty('possibly_sensitive')) {
      if (tweet.possibly_sensitive) {
        console.log("* client " + client.id + " ignoring sensitive content");
        return;
      }
    }

    if(tweet.place === null || tweet.place.country_code != "MX"){
      // If a keyword filter has not been set just do location
      if(keyword === null ){
        console.log("* keyword not defined, falling back to location");
        sendTweet(client, tweet)
      }
      else{
        var tweetString = tweet.text.toLowerCase();
        var regexExpression = "(\\b" + keyword + ")\\w*\\b";
        var regex = new RegExp(regexExpression, 'g');
        var matches = tweetString.match(regex);
        // console.log("* found matches: " +  matches);

        // Send the tweet to the client.
        if (matches != null || streamType == "Keyword Based"){
          sendTweet(client, tweet)
        }
      }
    }
  };

  var sendTweet = function(client, tweet) {
    // Skip tweets while we're paused.
    if (paused) {
      console.log("* currently paused, skipping tweet");
      return;
    }

    // Only send 1 tweet per second.
    var currentTime = new Date();
    var timeElapsed = ((currentTime - lastTweetTime) / 1000);
    if (timeElapsed < 1) {
      // console.log("* skipping tweet, only " + timeElapsed + "s elapsed");
      return;
    } else {
      console.log("* " + timeElapsed + "s elapsed, sending tweet");
      lastTweetTime = currentTime;
    }

    console.log("* client " + client.id + " was sent tweet: " + tweet.id);
    client.emit('tweets', tweet);
  }

  //Listen for start stream button
  client.on('start', function(data){
    // Clear any previous streams.
    disconnectAllStreams();

    keyword = data.keyword;
    streamType = data.type;

    //Checking what type of stream to set up
    //Location Stream
    if(streamType == "Location Based"){
      console.log("Starting Location Stream");
      var stream = twitter.stream('statuses/filter', { locations: client_location});

      // Push to streams array for multiple streams.
      streams.push(stream);

      // What to do with tweets
      stream.on('tweet', function (tweet) {
        handleTweet(tweet);
      });
    }
    //Keyword Stream
    else{
        console.log("Starting Keyword Stream with keyword: " + keyword);

        var stream = twitter.stream('statuses/filter', { track: keyword});

        // Push to streams array for multiple streams.
        streams.push(stream);

        // What to do with tweets
        stream.on('tweet', function (tweet) {
          handleTweet(tweet);
        });
    }
  });

  // Listen for location notifications sent from the client.
  client.on('location', function(data) {
    console.log("* client " + client.id + " sent location: " + JSON.stringify(data));
    // Set up a new stream to feed to the client.

    // Set up stream based upon client location
    client_location = [data.longitude - 1, data.latitude, data.longitude, data.latitude + 1];
  });
// End IO connection
});