server.js

var http = require('http');
var fs = require('fs');
var path = require('path');
var mime = require('mime');

var chatServer = require("./lib/chat_server");

var cache = {};

function send404(response){
	response.writeHead(404, {'Content-Type': 'text/plain'});
	response.write('Error 404: resource not found.');
	response.end();
}

function sendFile(response, filePath, fileContents){
	response.writeHead(
		200,
		{'Content-Type': mime.lookup(path.basename(filePath))}
	);
	response.end(fileContents);
}

function serveStatic(response, cache, absPath){
	if(cache[absPath]){
		sendFile(response, absPath, cache[absPath]);
	}else{
		fs.exists(absPath, function(exists){
			if(exists){
				fs.readFile(absPath, function(err, data){
					if(err){
						send404(response);
					}else{
						cache[absPath] = data;
						sendFile(response, absPath, data);
					}
				});
			}else{
				send404(response);
			}
		});
	}
}

var server = http.createServer(function(request, response){
	var filePath = false;
	if(request.url == "/"){
		filePath = "public/index.html";
	}else{
		filePath = "public" + request.url;
	}
	var absPath = "./" + filePath;
	serveStatic(response, cache, absPath);
});

server.listen(3000, function(){
	console.log("Server listening on port 3000.");
});


chatServer.listen(server);