express_server.js

/*========================Modules==============================*/
const express = require("express");
const bcrypt = require("bcrypt"); 
const app = express();
const methodOverride = require("method-override");
const bodyParser = require("body-parser");

app.set("view engine", "ejs");
app.use(express.static("images"));
app.use(bodyParser.urlencoded({extended: true}));
app.use(methodOverride("_method"));


/*==========================Port===============================*/
var PORT = 8080;
app.listen(PORT, () => {
    console.log("Server is up and running!");
});

/*======================Encrypted Cookies======================*/
var cookieSession = require("cookie-session");
app.use(cookieSession({
    name: "session",
    keys: ["secretkey"]
}));


/*=========================Database============================*/
const urlDatabase = {};
// urlDatabase = {
//     shortURL: {
//         longURL: "http://www.lighthouselabs.com",
//         userID: "3kds3kse",
//         visitors: [],
//         uniqueVisitors: ["3kds3kse", "288jnssw"],
//         time: []
//     }
// }

const users = {};
// users = {
//     userID: {
//         id: "3kds3kse",
//         email: "test@test.com",
//         password: "bcryptpassword"
//     }
// }


/*=========================Functions===========================*/
// Generates 8 digit unique id
function generateRandomString() {
    let shortLink = Math.random().toString(36).substr(2, 8);
    return shortLink;
};

// Returns user ID if login or registration email matches
function emailLookup(input) {
    for (let userID in users) {
        if (input === users[userID].email) {
            return users[userID].id;
        }
    }
};

// Creates object with all of user's short and long URLs
function urlsForUser(id) {
    let userDatabase = {};
    for (let shortURL in urlDatabase) {
        if (urlDatabase[shortURL].userID === id) {
            userDatabase[shortURL] = urlDatabase[shortURL]["longURL"];
        }
    }
    return userDatabase;
};

function uniqueID(shortURL, userID) {
    let array = urlDatabase[shortURL].uniqueVisitors;
    let count = 0;
    // Check if userID is in unique views
    for (i = 0; i < array.length; i++) {
        if (userID === array[i]) {
            count = 1;
        }
    }
    // Add new userID array of unique visitors
    if (count === 0) {
        array.push(userID);
    }
};


/*===========================GET===============================*/

// Home Page
app.get("/", (req, res) => {
    if (req.session.userid) {
        res.redirect("/urls");
    } else {
        res.redirect("urls/login")
    };
});

// Display all URLs created by logged in user
app.get("/urls", (req, res) => {
    let userDatabase = urlsForUser(req.session.userid);
    let templateVars = { user: users[req.session.userid], 
        urls: userDatabase, visit: urlDatabase.visitors };
    res.render("urls_index", templateVars);
});

// Creating new URL page
app.get("/urls/new", (req, res) => {
    let templateVars = { user: users[req.session.userid] };
    if (req.session.userid === undefined) {
        res.redirect("/urls");
    };
    res.render("urls_new", templateVars);
});

// Login page
app.get("/urls/login", (req, res) => {
    let templateVars = { user: users[req.session.userid] };
    res.render("login", templateVars); 
});


// Registration page
app.get("/urls/register", (req, res) => {
    let templateVars = { user: users[req.session.userid] };
    res.render("register", templateVars);
});

// Page for each unique short URL
app.get("/urls/:shortURL", (req, res) => {
    
    if (req.session.userid) {
    urlDatabase[req.params.shortURL].visitors.push(req.session.userid);
    uniqueID(req.params.shortURL, req.session.userid);
    urlDatabase[req.params.shortURL].time.push(Date());
    }; // Adds view counts 
    
    let templateVars = {
        shortURL: req.params.shortURL,
        user: users[req.session.userid],
        longURL: urlDatabase[req.params.shortURL].longURL, 
        visit: urlDatabase[req.params.shortURL].visitors, 
        unique: urlDatabase[req.params.shortURL].uniqueVisitors.length,
        time: urlDatabase[req.params.shortURL].time
    };
    res.render("urls_show", templateVars);
});

// Redirects to page of the stored url
app.get("/u/:shortURL", (req, res) => {
    let templateVars = { user: users[req.session.userid] };
    let long = urlDatabase[req.params.shortURL].longURL;
    res.redirect(long);
});

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

app.get("/easteregg", (req, res) => {
    res.send("<html><body>Hey you found me!</body></html>\n");
});



/*===========================POST==============================*/
// Generates random short URL and stores into database. 
app.post("/urls/", (req, res) => {
    let shortURL = generateRandomString();
    urlDatabase[shortURL] = {"longURL": req.body.longURL, "userID": req.session.userid};
    urlDatabase[shortURL].visitors = []; // Initializes visitor count array
    urlDatabase[shortURL].time = []; // Initializes timestamp array
    urlDatabase[shortURL].uniqueVisitors = []; // Initializes unique visitor array
    res.redirect(`/urls/${shortURL}`); 
});

// Deletes URL and all other and associated information in database
app.delete("/urls/:shortURL/delete", (req, res) => {
    if (urlDatabase[req.params.shortURL]["userID"] === req.session.userid) {
        delete urlDatabase[req.params.shortURL];
    };
    res.redirect("/urls");
});

// Updates the long URL to existing short URL
app.put("/urls/:shortURL/update", (req, res) => {
    urlDatabase[req.params.shortURL].longURL = req.body.newlongURL ;
    res.redirect("/urls");
});

// Login handling
app.post("/urls/login", (req, res) => {
    let id = emailLookup(req.body.email);
    // Errors out if email or password is incorrect
    if (id !== undefined && bcrypt.compareSync(req.body.password, users[id]["password"]) === true ) {
        req.session.userid = id;
        res.redirect("/urls");
    } else {
        res.status(403).send("HTTP 403 - NOT FOUND: E-MAIL OR PASSWORD INCORRECT!");
    }
});

// Registration handling
app.post("/register", (req, res) => {
    // Errors out if inputted email does not match any in database
    if (emailLookup(req.body.email) !== undefined) {
        res.status(400).send("HTTP 400 - BAD REQUEST: E-MAIL ALREADY USED!").end();
    } else {
        // Encrypts all passwords with bcrypt
        let userID = generateRandomString();
        const hashedPassword = bcrypt.hashSync(req.body.password, 10);
        users[userID] = {id: userID, email: req.body.email, password: hashedPassword};
        req.session.userid = userID;
        res.redirect("/urls");
    };
});

// Clears cookies upon logging out
app.post("/logout", (req, res) => {
    req.session = null;
    res.redirect("/urls");
});