server.js

//Lets require/import the HTTP module
var http = require('http');
var MongoClient = require('mongodb').MongoClient;
var assert = require('assert');
var ObjectId = require('mongodb').ObjectID;
var mongoURL = 'mongodb://localhost:27017/test';
var fs = require('fs');
var http = require('http');
var url = require('url') ;
var util = require("util");

//Lets define a port we want to listen to
const PORT=4040;
var itemsProcessed = 0;
var total =0;
var queryData;

MongoClient.connect(mongoURL, function(err, db) {
db.ensureIndex("tweets", {
   document: "text"
  }, function(err, indexname) {
    assert.equal(null, err);
  });
});



//We need a function which handles requests and send response
function handleRequest(request, response){
  queryData = url.parse(request.url, true).query;
  MongoClient.connect(mongoURL, function(err, db) {
    assert.equal(null, err);
    console.log(queryData.page);
    if(queryData.page =="stream"){
      findTweetsStream(db, writeHTML, response);
    }
    else if(queryData.page =="find"){
      findTweets(db, writeHTML, response);
    }
    else{
      showStats(db, writeHTML, response);

    }
  });
};

var writeHTML = function(html,response,db){
  response.writeHead(200, {"Content-Type": "text/html"});
  response.write(html);
  response.end();
  db.close();
}

var showStats = function(db, callback,res) {
  var html = '';
  db.collection('tweets').count(function(err, count){
    html += '<h2> Document Count </h2>';
    html += '<p>'+JSON.stringify(count)+'</p>';
    db.stats(function(err, stats){
      html += '<h2> Stats </h2>';
      html += '<p>'+JSON.stringify(stats)+'</p>';
      callback(html,res,db);
    });
  });
};

var findTweetsStream = function(db, callback,res) {

   var cursor =db.collection('tweets').find();
   var html = '<h2> Results '+queryData.search+' </h2>';
   var counter=0;
   cursor.on('data', function(tweet) {
     if (tweet != null) {
       console.log(counter++);
        //console.dir(tweet);
        if(tweet.name !=null){
          html += '<p><b>Name:</b> ';
          html += tweet.user.name;
        }
        if(tweet.text !=null){
          html += ' <br /><b>Text:</b> '
          html += tweet.text;
        }
      }
    });

    cursor.once('end', function() {
      callback(html,res,db);
    });
};


var findTweets = function(db, callback,res) {

   var cursor =db.collection('tweets').find();
   var html = '<h2> Results '+queryData.search+' </h2>';
   cursor.each(function(err, tweet) {
      assert.equal(err, null);
      if (tweet != null) {
         //console.dir(tweet);
         html += '<p><b>Name:</b> '
         + tweet.user.name
         + ' <br /><b>Text:</b> '
         + tweet.text;
      } else {
         callback(html,res,db);
      }
   });
};

var searchTweets = function(db, callback,res) {
   var cursor = db.collection('tweets').find({
    "$text": {
      "$search": "tory"
    }
  });
   var html = '<h2> Search Results '+queryData.search +' </h2>';
   cursor.each(function(err, tweet) {
      assert.equal(err, null);
      if (tweet != null) {
         //console.dir(tweet);
         html += '<p><b>Name:</b> '
         + tweet.user.name
         + ' <br /><b>Text:</b> '
         + tweet.text;
      } else {
         callback(html,res,db);
      }
   });
};

//Create a server
var server = http.createServer(handleRequest);

//Lets start our server
server.listen(PORT, function(){
    //Callback triggered when server is successfully listening. Hurray!
    console.log("Server listening on: http://localhost:%s", PORT);
});