app.js

const createError = require("http-errors");
const express = require("express");
const path = require("path");
const bodyParser = require("body-parser");
const logger = require("morgan");
const cors = require("cors");
const mongoose = require("mongoose");
const passport = require("passport");
const session = require("express-session");
const MongoStore = require("connect-mongo")(session);
const compression = require("compression");
const User = require("./models/User");
require("dotenv").config();

// MONGODB
const forceProdDB = false;
const isProdDb =
  forceProdDB ||
  (process.env.NODE_ENV === "production" && process.env.REACT_APP_DB_PROD);
const URI = isProdDb
  ? process.env.REACT_APP_DB_PROD
  : process.env.REACT_APP_DB_DEV;

mongoose.connect(URI, {
  useNewUrlParser: true,
  useUnifiedTopology: true,
  auto_reconnect: true,
  reconnectTries: Number.MAX_SAFE_INTEGER,
  reconnectInterval: 1000,
});
const db = mongoose.connection;
db.on("error", console.error.bind(console, "*** DB connection error ***"));
db.on("disconnected", console.error.bind(console, "*** DB disconnected ***"));
db.on("reconnected", console.error.bind(console, "*** DB reconnected ***"));
db.once("open", () => {
  console.log("db connection:", isProdDb ? "prod" : "dev");
});

// PORT
const PORT = process.env.PORT || 8081;
const app = express();
const server = app.listen(PORT, () => {
  console.log(`listening at ${PORT}`);
});

// MIDDLEWARE
const corsCfg = {
  origin: "*",
  methods: "GET,HEAD,PUT,PATCH,POST,DELETE",
  preflightContinue: false,
  optionsSuccessStatus: 204,
  credentials: true,
};
app.use(cors(corsCfg));
app.use(logger("dev"));
app.use(express.json());
app.use(express.urlencoded({ extended: false }));
if (process.env.NODE_ENV === "production") {
  app.use(compression());
}

// PASSPORT
app.use(
  session({
    secret: process.env.REACT_APP_SESSION_SECRET,
    resave: false,
    saveUninitialized: true,
    store: new MongoStore({ mongooseConnection: mongoose.connection }),
  })
);
app.use(bodyParser.urlencoded({ extended: false }));
app.use(passport.initialize());
app.use(passport.session());

passport.serializeUser((user, done) => {
  done(null, user._id);
});

passport.deserializeUser((id, done) => {
  // find user based on id stored in cookie
  // save user data to req.user
  User.findById(id)
    .populate("bm.listings")
    .populate("chatrooms")
    .then((user) => {
      done(null, user);
    })
    .catch((e) => {
      done(new Error("Failed to deserialize a user"));
    });
});

// ROUTING
app.use("/api", require("./routes"));

// SOCKET IO
require("./socket").listen(server);

// VIEW ENGINE
app.set("views", path.join(__dirname, "views"));
app.set("view engine", "jade");

// FORCE HTTPS ON PROD
// eslint-disable-next-line consistent-return
app.use((req, res, next) => {
  if (
    !req.secure &&
    req.get("x-forwarded-proto") !== "https" &&
    process.env.NODE_ENV === "production"
  ) {
    return res.redirect(`https://${req.get("host")}${req.url}`);
  }
  next();
});

// PROD SERVE FRONTEND
if (process.env.NODE_ENV === "production") {
  const HALF_HOUR = 1000 * 60 * 30;
  app.use(express.static(path.join(__dirname)));
  app.use(
    express.static(path.join(__dirname, "client", "build"), {
      maxAge: HALF_HOUR,
    })
  );

  app.get("/*", (req, res) => {
    res.sendFile(path.join(__dirname, "client", "build", "index.html"));
  });
} else {
  app.use(express.static(path.join(__dirname, "public")));
}

// catch 404 and forward to error handler
app.use((req, res, next) => {
  next(createError(404));
});

// error handler
app.use((err, req, res) => {
  // set locals, only providing error in development
  res.locals.message = err.message;
  res.locals.error = req.app.get("env") === "development" ? err : {};

  // render the error page
  res.status(err.status || 500);
  res.render("error");
});

module.exports = app;