app.js

if (process.env.NODE_ENV != "production") {
  require("dotenv").config();
}

const express = require("express");
const app = express();
const path = require("path");
const ejs = require("ejs");
const ejsMate = require("ejs-mate");
const mongoose = require("mongoose");
const methodOverride = require("method-override");
const ExpressError = require("./utils/ExpressError.js");
const session = require("express-session");
const MongoStore = require("connect-mongo");
const flash = require("connect-flash");
const User = require("./models/user.js");
const passport = require("passport");
const LocalStrategy = require("passport-local");

//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
//routers
const listingRouter = require("./routes/listings.js");
const reviewRouter = require("./routes/reviews.js");
const userRouter = require("./routes/users.js");

//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
//(let's connect our mongodb server)
let DBUrl = process.env.MONGODB_URL;

async function main() {
  try {
    await mongoose.connect(DBUrl);
    console.log("Zappy connected successfully!");
  } catch (error) {
    console.error("MongoDB connection error:", error);
    throw new ExpressError(500, "Zappy failed to connect!");
  }
}

main();

//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
//(Prerequisites)
app.use(express.static(path.join(__dirname, "public")));
app.set("view engine", "ejs");
app.set("views", path.join(__dirname, "views"));
app.engine("ejs", ejsMate);
app.use(express.urlencoded({ extended: true }));
app.use(methodOverride("_method"));

//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
//mongostore configurations
const store = MongoStore.create({
  mongoUrl: DBUrl,
  crypto: {
    secret: process.env.SESSION_SECRET,
  },
  touchAfter: 24 * 3600,
});

store.on("error", () => {
  console.log("Error in mongo session store", err);
});

//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
//session management
const sessionOptions = {
  store,
  secret: process.env.SESSION_SECRET,
  resave: false,
  saveUninitialized: true,
  cookie: {
    expires: Date.now() + 15 * 24 * 60 * 60 * 1000,
    maxAge: 15 * 24 * 60 * 60 * 1000,
    httpOnly: true,
  },
};

//using connect-flash to display our messages
app.use(session(sessionOptions));
app.use(flash());

//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
//passport configurations
app.use(passport.initialize());
app.use(passport.session());
passport.use(new LocalStrategy(User.authenticate()));
passport.serializeUser(User.serializeUser());
passport.deserializeUser(User.deserializeUser());

//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
//res.local variables
app.use((req, res, next) => {
  res.locals.successMsg = req.flash("success");
  res.locals.failureMsg = req.flash("error");
  res.locals.currentUser = req.user;
  next();
});

/* when the login operation completes
req.user will be assigned to currentUser */

//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
//(home page)
app.get("/", (req, res) => {
  res.render("listings/home.ejs");
});

//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
//(routers configuration)
app.use("/listings", listingRouter);
app.use("/listings/:id/reviews", reviewRouter);
app.use("/", userRouter);

//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
// Error handling middleware for specific cases
app.use((err, req, res, next) => {
  if (err.message.includes("Cast to ObjectId failed")) {
    return next(new ExpressError(400, "Invalid ID!"));
  } else if (err.message.includes("Cannot read properties of null")) {
    return next(new ExpressError(400, "Listing/Review does not exist!"));
  } else {
    next(err);
  }
});

//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
//(wildcard route error handling middleware)
app.all("*", (req, res, next) => {
  next(new ExpressError(404, "Page Not Found!"));
});

//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
//(global error handling middleware)
app.use((err, req, res, next) => {
  let { status = 500, message = "Something Went Wrong!" } = err;
  res.status(status).render("errors/error.ejs", { message });
});

//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
//(port : 3000)
app.listen(3000, () => {
  console.log("server is active on port http://localhost:3000");
});