app.js

// Require all libraries in use
var mustache   = require('mustache');
var harp       = require("harp");
var express    = require("express");
var http       = require("http");
var fs         = require("fs");
var cookieparse= require("cookie-parser");
var bodyParser = require('body-parser');
var app        = express();

// Add body parsing stuff
app.use(bodyParser());

// Set Up Databases
// Setup Product Database
var db         = require('node-persist');
db.initSync({dir:'db/product'});
// Setup Order Database
var odb         = require('node-persist-o');
odb.initSync({dir:'db/orders'});
// Setup User database
var udb         = require('node-persist-u');
udb.initSync({dir:'db/users'});

// Set Main App Variables
app.set('port', process.env.PORT || 3000);
app.set('pass', process.env.PASS || 'word')

app.use(harp.mount(__dirname + "/public"));
app.use(express.static(__dirname + "/public"));
app.use(cookieparse());

// Start Number Formatter Code
// Make Number human friendly, and resolving any Integer/Float Conversion issues.
function formatNum(n) {
    return n.toFixed(2).replace(/(\d)(?=(\d{3})+\.)/g, "$1,");
}
// End Number Formatter

// Start String Hasher
// Take a string, and then generate a non-reversible hash, for safer cookie storage.
String.prototype.hashCode = function() {
  var hash = 0, i, chr, len;
  if (this.length == 0) return hash;
  for (i = 0, len = this.length; i < len; i++) {
    chr   = this.charCodeAt(i);
    hash  = ((hash << 5) - hash) + chr;
    hash |= 0; // Convert to 32bit integer
  }
  return hash;
};
// End String Hasher

// Start User cookie generator/tester
function placeCookie(res,user,pass){
  // Place a session cookie which holds basic user data, include name, and a hash of the user's password.
  res.cookie("user",JSON.encode({user: user, pass: pass.hashCode()}));
}
function testLogin(req){
  // Check for existence of user session cookie.
  if(req.cookies['user']){
    var x = req.cookies['user'].split(" ");
    var y = udb.getItem(x[0]);
    console.log(x[0]);
    console.log(y);
    var z = y.pass;
    if(z.hashCode()==x[1]){
      // User is allowed in, as session data matches the database.
      console.log('true');
      return true;
    }else{
      // User is rejected, as user session data and user data in the databse, do not match.
      console.log('false');
      return false;
    }
  }else{
    // User is rejected, on grounds of not having a user session, yet.
    console.log('false2');
    return false;
  }
}
// End User cookie generator/tester

// Start Home Page/Product Listings
app.get('/',function(req,res){
  var s, u, user;
  // Log to console whether or not there is user session data, and if so, what it is.
  console.log(req.cookies['user']);
  // Invert the boolean response of "testLogin", so that the "if" expression recieves "true" if the user is not logged in, and false, if the user is logged in.
  // Note: The "!" is the symbol which inverts the response of the "testLogin" function.
  if(!testLogin(req)){
    // User is not logged in, therefore variable "s" is set to "false", so that the template engine knows there is no user logged in.
    s = false;
    }else{
    // User is logged in, therefore variable "s" is set to "true", so that the template engine knows there is a user logged in.
    s = true;
    // Variable "u" is set as the usernme of the logged in user. This is later given to the template.
    u = req.cookies['user'].split(" ")[0];
    // Variable "user" set as an object containing data on the user, from the database.
    // This variable is passed to the template engine, though isn't yet used by the template engine.
    // This is because later versions might make more use of supplied database data.
    user = udb.getItem(u);
    // The active username is logged to the console.
    console.log(u);
  }
  // The "db.values" function is called, so that the list of products can be collected.
  db.values(function(vals){
    // Note variable "vals" is an array which contains holds each and every product record, as an object.
    // Then, the server responds with the page, after it has been passed to the template engine.
    // The Template engine uses the file: "list.html", in directory "template/", which has been converted to a string, and is then evaluated, processing in the given data, and then returns a string response. 
    res.send(mustache.render(fs.readFileSync("template/list.html").toString(),{
      vals: vals, l: s, user: u, udata: user
    }));
  }
)});
// End Home Page/Product Listings

// Start product page
app.get('/product/:id', function(req, res){
  // Set variable "id" as the url path, after "/product/".
  // E.G. if path is "/product/donut", then "id" is set to "donut".
  var id      = req.params.id;
  // Set variable "data" to be an object containg the record data within the product database for that product. 
  var data    = db.getItem(id);
  // Then respond with the generated page.
  res.send(
    // Generate page, using the file "product.html" in the directory "template/", alongside the data variable.
    // The data variable contains the title, description, image url, and any other vital data.
    mustache.render(fs.readFileSync("template/product.html").toString(),data)
  );
});
// End Product Page

// Start "add to cart" system
app.get('/cart/add', function(req,res){
  // Set a cookie, named after the product, which has the data for the number of products in use.
  // The "Math.max" function sets a minimum of 1 of these products in the cart.
  // You don't want 0 lots of a product in the cart!
  // The req.param fetches supplied HTTP GET request data for "id" and "q", from the browser.
  res.cookie(req.param('id'), Math.max(req.param('q'),1));
  // Once the Cookie is added, redirect the user to the "ordered" message page.
  res.redirect('/m/ordered');
});
// End "add to cart" system

// Start "remove from cart" system
app.get('/cart/clear/', function(req,res){
  // Find out the supplied id from the HTTP GET request data.
  // E.G. HTTP Path is "/cart/clear/?id=donut" therefore "req.param('id')" is "donut"
  // Remove the cookie, with "res.clearCookie". Without the cookie, the server no longer thinks the item is in the cart.
  res.clearCookie(req.param('id'));
  // Once the Cookie is removed, redirect the user to the "item-removed" message page.
  res.redirect('/m/item-removed');
});
// End "remove from cart" system

// Start "list the cart" system
app.get('/cart/list', function(req,res) {
  // Log to the console that we got the request.
  console.log("we got the request");
  // Try getting the list of products.
  db.values(function(vals){
    // Log to the console that we got the list of product records.
    console.log("we got the db values");
    // Start the total cost at 0.
    var totalCost = 0;
    // Start variable "x", our list of products in the cart, with no products.
    var x = [];
    // Start variable "count", our number of how many products are in use.
    var count = 0;
    // Start looping through all products.
    for(var i=0; i < vals.length; i++) {
      // Set variable "current" to contain all of the data of the current product.
      var current = {
        id: vals[i].id,
        name: vals[i].name,
        cost: vals[i].cost,
        imgurl: vals[i].imgurl,
        q: req.cookies[vals[i].id]
      };
      // Check if the current product does have a cookie(and thus, is in the cart).
      if(req.cookies[current.id] !== undefined){
        // The Product is in the cart!
        // Log to console that the product is in the cart.
        console.log("Adding "+ current.id);
        // Log to console all of the record data of that object.
        console.log("Its db entry is " + current);
        // Add the current product, to the cart, array "x".
        x.push(current);
        // Do funny maths.
        // Set the total cost to equal the cost of all products in the cart.
        // This funny addition setup is due to Javasript handling numbers weirdly.
        // 1. Multiply the quantity and cost both by 100, then by each other.
        // 2. Then Divide that number by 10000, then add it to the total cost.
        // 3. Huzzah! Problem solved. Next time use a language which allows explicitly declaring integers and floats!
        totalCost += ((vals[i].cost * 100)*(req.cookies[current.id]*100))/10000;
        // Log to the console the current product record.
        console.log(vals[i]);
        // Increment the count of the number of different products in the cart by 1.
        count++;
      }
      // Oh yeah, use this to force JavaScript to treat this number as number, and then give it pretty decimals.
      totalCost = formatNum(totalCost.toNumber());
    }
    // If someone fancied ordering this stuff, then do this.
    if(req.param('order')=="x"){
      // Add the order as a cookie.
      res.cookie('order', x);
      // Redirect the user to the make order page.
      res.redirect("/user/makeorder");
      // Else if the cart is empty...
    }else if(count==0){
      // Then redirect the user to the "Empty Cart" message page.
      res.redirect("/m/empty");
    }else{
      // If the user has products, but aren't ordering yet...
      // Respond with the rendered page.
      res.send(
        // Render the page, using the file "cart.html", in the "template" directory, alongside the the supplied product and cost data. 
        mustache.render(fs.readFileSync("template/cart.html").toString(),{list: x, cost: totalCost})
      );
    }
  });
});
// End "list the cart" system

// Start Make order system
app.get('/user/makeorder', function(req,res){
  // If the user isn't logged in, make them login.
  if(!testLogin(req)){res.redirect("/user/login?r=/user/makeorder")}else{
    // Else, add the most most recent order to the db.
    odb.setItem("recent",{order:req.cookies.order});
    // Set the response data to thank you for your order.
    // Also displays raw JSON data for order.
    // No billing, obvious reaons.
    var data = "Thanks for your order, " + req.cookies['user'].split(" ")[0] + " .<br />\n<pre>" + JSON.stringify(req.cookies.order) + "</pre><br /><a href='/user/logout'>Logout</a>";
    // Append this order, to txt file.
    var message = fs.appendFileSync('orders.txt', '\n'+data);
    // Respond with the data.
    res.send(data);
  }
});
// End Make order system

// Start user logout system
app.get('/user/logout', function(req,res){
  // Remove user session cookie.
  res.clearCookie("user");
  // Remove user order cookie.
  res.clearCookie("order");
  // Send the user back to the home page.
  res.redirect("/");
});
// End user logout system

// Start user signup system.
app.get('/user/signup', function(req, res){
  // Return rendered template, after supplying it with the template file, as well as the data required for customising the form to work. 
  res.send(mustache.render(fs.readFileSync("template/user.html").toString(),{
    message: "Enter your details, to signup.",
    formto:  "/user/signup",
    sendto: req.param('r') || "/"
  }));
});


app.post('/user/signup', function(req, res){
  // On posting a form...
  // Add some regex, a for password/user rules verifyer.
  var re = /^[a-z0-9]+$/i;
  // Set variable "uname" as the HTTP POST REQUEST "u" variable.
  var uname = req.param('u');
  // Set variable "pword" as the HTTP POST REQUEST "p" variable.
  var pword = req.param('p');
  // Set the "r" variable to homepage, or a place of their choice...
  var r = req.param('r') || "/";
  // Log to console the username and password.
  console.log(uname + " : " + pword);
  // If the username and password pass the regex code...
  if(re.test(uname)&&re.test(pword)){
    // Add the user to the database, as so...
    udb.setItem(uname.toString(),{
      name: uname.toString(),
      pass: pword.toString()
    });
    // Add user session cookie...
    res.cookie("user",uname + " " + pword.hashCode());
    // Send the user to where the r variable says they should go...
    res.redirect(r);
    // Else, the user is unsuccessful, try again.
  }else{res.redirect("/user/signup?r="+r);}
});
// End user signup system.

// Start user login system
app.get('/user/login', function(req, res){
  // Return rendered template, after supplying it with the template file, as well as the data required for customising the form to work. 
  res.send(mustache.render(fs.readFileSync("template/user.html").toString(),{
    message: "Enter your details, to login.",
    formto:  "/user/login",
    sendto: req.param('r') || "/"
  }));
});

app.post('/user/login', function(req, res){
  // On posting a form...
  // Set variable "uname" as the HTTP POST REQUEST "u" variable.
  var uname = req.param('u');
  // Set variable "pword" as the HTTP POST REQUEST "p" variable.
  var pword = req.param('p');
  // Set the "r" variable to homepage, or a place of their choice...
  var r = req.param('r') || "/";
  // Log to console the username and password.
  console.log(uname + " : " + pword);
  // Double check if the supplied username exists.
  // If it doesn't, let the user know.
  if(!udb.getItem(uname)){res.send("User doesn't exist");}
  // If the username exists, load data to the "u" variable.
  var u = udb.getItem(uname);
  // If passwords match, then...
  if(u.pass == pword){
    // Add user session cookie, with username, space, and then a  hash of the pass code.
    res.cookie("user",uname + " " + pword.hashCode());
    // Send the user to where the r variable says they should go...
    res.redirect(r);
  }else{
    // If the credentials don't match, send the user back to the login page.
    res.redirect("/user/login?r="+r);
  }
});
// End user login system

// Launch
http.createServer(app).listen(app.get('port'), function(){
  // Log to the console some info.
  console.log('Express server listening on port ' + app.get('port'));
});
// DONE!;