server.js

var express = require('express');
//logs rquests and errors in the terminal and the amount 
//of time it  takes to get that page
var morgan = require('morgan');
var mongoose = require('mongoose');
var bodyParser = require('body-parser');
var ejs = require('ejs');
var engine = require('ejs-mate');
var session = require('express-session');
// session id is an encryption signature
// session is stored on the server
// session doesn't persist after browser is closed 
var cookieParser = require('cookie-parser');
// users cookies to store a session id in a users browser
// on value cookie to retrieve information stored on the server 
// server side storage
// cookies store on the visitors browser
// cookies has sessions encryted in their cookies
var flash = require('express-flash');
var MongoStore = require('connect-mongo/es5')(session);
// this is the db for storing the session
// this will be saved into mongo db 
// mongo store is specifically to store sessions on the server side
// mongo store library is depending on expression session
// we need to know that a session will be based on an express
// session library
var passport = require('passport');
// oauth login support


var secret =require('./config/secret');
var User = require('./models/user');

// config files store database information 
// passport is a library for authentication

var Category = require('./models/category');
var cartLength = require('./middlewares/middlewares');


var app = express();


// connect mongoose to the db
//  'mongodb://...' is a path to the database
// what went here instead of this?
// we studued just a path to the local host and maybe a route 
// connection

mongoose.connect(secret.database, function(err){
  if (err) {
    console.log(err);
  }
  else{
    console.log("Connected to the Database");
  }

});

// middleware.. almost everything you require 
// you have to use
app.use(express.static(__dirname + '/public'));
app.use(morgan('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({extended: true}));
app.use(cookieParser());
app.use(session({

  resave: true,
  saveUninitialized: true,
  secret: secret.secretKey,
  store: new MongoStore({url: secret.database, autoReconnect: true})
}));

// flash is dependent on session and cookie
app.use(flash());
app.use(passport.initialize());
// acts as a middleware to alter the req object
// and change the user value that is currently the session id
// from the client cookie into the true deserialized user object

app.use(passport.session());

// this function below will have every user able to
// have the user object by default in every route
// without having to specify the object in every route
// why did we not use the universal /* here 
app.use(function(req, res, next){

// whats does locals mean- local variable
// user is the name of the object you want to use
  res.locals.user = req.user;
  next();
});


app.use(cartLength);

app.use(function(req, res, next){
// in the catergories case we have to query it in order to
// store it in the local variable below
// as opposed to the above middlewae for users
// we already the req.user object so we don't have to query it
// we got the req.user made with serialize.. why wasn't category 
// serialized ??
Category.find({}, function(err, categories){
// the above means we are finding all the categories in this object
// if you don't put anything in the brackets that means that you want all
// the categories documents in the db
  if (err)
    return next(err);
  // this is storing that list of categories in a local variable named
  //  categories..... you can name local.___ anything but we name it
  // locals.categories
  // what is a local variable ??
  // we are going to use this local variable we created in the navbar
  res.locals.categories = categories;

  next();

  });
});

app.engine('ejs', engine);
app.set('view engine', 'ejs');

// all route files need to be required in the server
var mainRoutes = require('./routes/main');
var userRoutes = require('./routes/user');
var adminRoutes = require('./routes/admin');
var apiRoutes = require('./api/api');

app.use(mainRoutes);
app.use(userRoutes);
app.use(adminRoutes);
// we are adding 'api' here so that all the apis
// associated w/ this routes file will will be a sub url
// of api. This allows us to avoid prefixing all the api's
// that could come up with api/...
app.use('/api',apiRoutes);





// to see the value of the cookie
app.get('/*', function(req, res, next){

  if(typeof req.cookies['connet.sid'] !== 'undefined'){

    console.log(req.cookies['connect.sid']);
  }

  next();
});

app.listen(secret.heroku || secret.port, function(err) {

  if (err) throw err;
  console.log("Server is Running on Port" + secret.port);
});