app.js

const express = require("express");
const session = require("express-session");
const mongoose = require("mongoose");
const MongoStore = require("connect-mongo")(session);
const path = require("path");
const cookieParser = require("cookie-parser");
const bodyParser = require("body-parser");
const passport = require("passport");
const promisify = require("es6-promisify");
const flash = require("connect-flash");
const expressValidator = require("express-validator");
const routes = require("./routes/index");
const helpers = require("./helpers");
const errorHandlers = require("./handlers/errorHandlers");
require("./handlers/passport");

// create our Express app
const app = express();

// view engine setup
app.set("views", path.join(__dirname, "views")); // this is the folder where we keep our pug files
app.set("view engine", "pug"); // we use the engine pug, mustache or EJS work great too

// serves up static files from the public folder. Anything in public/ will just be served up as the file it is
app.use(express.static(path.join(__dirname, "public")));

// Takes the raw requests and turns them into usable properties on req.body
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true }));

// Exposes a bunch of methods for validating data. Used heavily on userController.validateRegister
app.use(expressValidator());

// populates req.cookies with any cookies that came along with the request
app.use(cookieParser());

// Sessions allow us to store data on visitors from request to request
// This keeps users logged in and allows us to send flash messages
app.use(
  session({
    secret: process.env.SECRET,
    key: process.env.KEY,
    resave: false,
    saveUninitialized: false,
    store: new MongoStore({ mongooseConnection: mongoose.connection })
  })
);

// // Passport JS is what we use to handle our logins
app.use(passport.initialize());
app.use(passport.session());

// // The flash middleware let's us use req.flash('error', 'Shit!'), which will then pass that message to the next page the user requests
app.use(flash());

// pass variables to our templates + all requests
app.use((req, res, next) => {
  res.locals.h = helpers;
  res.locals.flashes = req.flash();
  res.locals.user = req.user || null;
  res.locals.currentPath = req.path;
  next();
});

// promisify some callback based APIs
app.use((req, res, next) => {
  req.login = promisify(req.login, req);
  next();
});

// After allllll that above middleware, we finally handle our own routes!
app.use("/", routes);

// If that above routes didnt work, we 404 them and forward to error handler
app.use(errorHandlers.notFound);

// One of our error handlers will see if these errors are just validation errors
app.use(errorHandlers.flashValidationErrors);

// Otherwise this was a really bad error we didn't expect! Shoot eh
if (app.get("env") === "development") {
  /* Development Error Handler - Prints stack trace */
  app.use(errorHandlers.developmentErrors);
}

// production error handler
app.use(errorHandlers.productionErrors);

// done! we export it so we can start the site in start.js
module.exports = app;