express_server.js

const express = require('express');
const app = express();
const cookieSession = require('cookie-session');
const PORT = 8080;
const bcrypt = require('bcrypt');
const bodyParser = require('body-parser');
const helper = require('./helpers');
app.use(bodyParser.urlencoded({extended: true}));
app.set('view engine', 'ejs');
app.use(cookieSession({
  name: 'user_Id',
  keys: ['asdfghjkl','rvneve']
}));


const users = {
};

const urlDatabase = {
};

app.get('/urls.json', (req, res) => {
  res.json(urlDatabase);
});

app.get('/urls', (req, res) => {
  let templateVars;
  const userId = req.session.user_Id;
  if (!users[userId]) {
    templateVars =  { urls: urlDatabase, email: '', id:'' };
  } else {
    templateVars = { urls: urlDatabase, email: users[userId].email, id: users[userId].id };
  }
  res.render('urls_index', templateVars);
});
app.post("/urls", (req, res) => {
  let shortURL = helper.generateRandomString();
  urlDatabase[shortURL] = {longURL:req.body.longURL, id: req.session.user_Id};
  res.redirect(`/urls/${shortURL}`);
});

app.get("/", (req, res) => {
  res.redirect('/urls')
})
app.get('/urls/new', (req, res) => {
  const userId = req.session.user_Id;
  let templateVars =  { shortURL: req.params.shortURL, longURL: urlDatabase[req.params.shortURL], email: '' };
  if (users[userId]) {
    templateVars.email = users[userId].email;
    return res.render('urls_new', templateVars);
  }
  res.redirect('/login');
});

app.get('/urls/:shortURL', (req, res) => {
  let templateVars = { shortURL: req.params.shortURL, longURL: urlDatabase[req.params.shortURL].longURL, email: '' };
  const userId = req.session.user_Id;
  if (users[userId]) {
    templateVars.email = users[userId].email;
  }
  res.render('urls_show', templateVars);
});

app.post('/urls/:shortURL/delete', (req, res) => {
  const userId = req.session.user_Id;
  if (users[userId].id === urlDatabase[req.params.shortURL].id) {
    delete urlDatabase[req.params.shortURL];
  }
  res.redirect('/urls');
});

app.get('/urls/:shortURL/edit', (req, res) => {
  res.redirect(`/urls/${req.params.shortURL}`);
});

app.post('/urls/:shortURL/edit', (req, res) => {
  let longURL = req.body.longURL;
  const userId = req.session.user_Id;
  if (users[userId].id === urlDatabase[req.params.shortURL].id) {
    urlDatabase[req.params.shortURL].longURL = longURL;
  }
  res.redirect(`/urls`);
});

app.get("/u/:shortURL", (req, res) => {
  const longURL = urlDatabase[req.params.shortURL].longURL;
  res.redirect(longURL);
});

app.get("/login", (req, res) => {
  const userId = req.session.user_Id;
  let templateVars;
  if (!users[userId]) {
    templateVars = {shortURL: req.params.shortURL, longURL: urlDatabase[req.params.shortURL], email: ''};
  } else {
    templateVars = {shortURL: req.params.shortURL, longURL: urlDatabase[req.params.shortURL], email: users[userId].email};
  }
  res.render('urls_login', templateVars);
});


app.post("/login", (req, res) => {
  const { email, password } = req.body;
  const userClient = helper.getUserByEmail(email, users);
  if (userClient && bcrypt.compareSync(password, userClient.password)) {
    if (!userClient) {
      templateVars = {shortURL: req.params.shortURL, longURL: urlDatabase[req.params.shortURL], email: ''};
    } else {
      templateVars = {shortURL: req.params.shortURL, longURL: urlDatabase[req.params.shortURL], email: userClient.email};
    }
    req.session.user_Id = userClient.id;
    return res.redirect('/urls');
  }
  return res.redirect(`/login`);
});

app.post("/logout", (req, res) => {
  delete req.session.user_Id;
  res.redirect('/urls');
});


app.get("/register", (req, res) => {
  let templateVars = { shortURL: req.params.shortURL, longURL: urlDatabase[req.params.shortURL], email: users[req.body.email] };
  res.render('urls_register', templateVars);
});
const userExists = function(email) {
  for (const userId in users) {
    const currentUser = users[userId];
    if (currentUser.email === email) {
      return true;
    }
  }
  return false;
};
app.post("/register", (req, res) => {
  let { id, email, password } = req.body;
  id = 'a' + Math.floor(Math.random() * 1000);
  if (userExists(email) === false && email !== '' && password !== '') {
    users[id] = {id, email, password: bcrypt.hashSync(password, 10)};
    req.session.user_Id = users[id].id;
    res.redirect('/urls');
  } else {
    res.send(400);
  }
});

app.listen(PORT, () => {
  console.log(`Example app listening on port ${PORT}`);
});