var express = require('express');
var app = express();
var fs = require("fs");
var bodyParser = require('body-parser');
app.use(bodyParser.json());
// Create application/x-www-form-urlencoded parser
var urlencodedParser = bodyParser.urlencoded({ extended: false })
var authenticatedUser = null;
app.use(express.static('Front End'));
var arrays;
// Email validation funciton
function validateEmail(email)
{
    // using regular expression.
    if (email.length > 0)
    {
        var re = /^(([^<>()\[\]\\.,;:\s@"]+(\.[^<>()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/;
        return re.test(email);
    }
    else
        return false;
}

// Password validation function
function validatePassword(pass)
{
    if (pass.length < 5)
        return false;
    else
        return true;
}

// Username validation function
function validateUsername(name)
{
    if (name.length > 0)
        return /^[a-zA-Z]*$/.test(name);
    else
        return false;
}
// Number of users already registered
var usersCount = 0;

/**** This part to handle default request url= localhost:8081 ******/
app.get('/', function (req, res) {
  res.sendFile( __dirname + "/" + "homepage.html" );
})

app.get('/homepage.html', function (req, res) {
  res.sendFile( __dirname + "/" + "homepage.html" );
})

app.post('/login', urlencodedParser, function (req, res) {

  // Get the values of the input text email & password
  email = req.body.email;
  password = req.body.password;
  console.log(email);
  console.log(password);

  // Read JSON file containing the users to verify that the user is already registered and have access
  fs.readFile( __dirname + "/" + "users.json", 'utf8', function (err, data) {
    // Note that err here is for handling any error occuring in opening the file
    if (err)
    {
       return console.error(err);
    }
    data = JSON.parse(data);
    var flag = 0;
    for (var user in data)
    {
      if(email == data[user].email)
      {
        flag = 1;
        authenticatedUser = user;
        break;
      }
      else
      {
        flag = 0;
      }
    }
    if(flag == 1)
    {
        if (password == data[authenticatedUser].password)
        {
            console.log("This is the tasks page");
            res.sendFile( __dirname + "/" + "ProjectPh1V1.html");
        }
        else
        {
            res.sendFile( __dirname + "/" + "homepage.html");
        }
    }
    // Handle invalid login by redirecting the user to the login page once again
    else {
        console.log("User Not found");
        res.sendFile( __dirname + "/" + "homepage.html");
    }
  })
 })

app.post('/array', function(req, res) {
    console.log("harby's herbyes");
    var data = req.body;
    console.log(data);
    arrays = data;
    fs.writeFile(__dirname + "/" + "user.json", JSON.stringify(data), function (err) {
        if (err) return console.log(err);
        //console.log(JSON.stringify(data));
    });
    res.send('success');
});

 app.post('/register', urlencodedParser, function(req, res)
 {
    username = req.body.username;
    email = req.body.email;
    password = req.body.password;
    console.log(username);
    console.log(email);
    console.log(password);

    var f = 0
    if (validateUsername(username))
        f++;
    if (validateEmail(email))
        f++;
    if(validatePassword(password))
        f++;

    if (f == 3)
    {
        newUser = {
            "password" : password,
            "username" : username,
            "email" : email
        }
        var flag = 0;
        // Make sure this is a unique email address
        fs.readFile( __dirname + "/" + "users.json", 'utf8', function (err, data) {
            if (err)
                return console.error(err);
            data = JSON.parse(data);
            usersCount = 0;
            flag = 0;
            console.log('Going to check if there are duplicates');
            for (var user in data)
            {
                if(email == data[user].email)
                {
                    flag=1;
                    break;
                }
                usersCount++;
            }

            if (flag == 0)
            {
                console.log("ok no duplicates");
                // Add user to the JSON file database and show the homepage again
                fs.readFile( __dirname + "/" + "users.json", 'utf8', function (err, data) {
                    newUser = {
                        "password" : password,
                        "username" : username,
                        "email" : email
                    }
                    console.log("read users file!");
                    if (err)
                        return console.error(err);

                   data = JSON.parse(data); // Converting it to string.
                   data[usersCount] = newUser;
                   console.log(data);
                   res.sendFile( __dirname + "/" + "homepage.html" );
                   app.get('/homepage.html', function (req, res) {
                        res.sendFile( __dirname + "/" + "homepage.html" );
                    })
                   fs.writeFile(__dirname + "/" + "users.json",JSON.stringify(data), function (err) {
                       if (err)
                           return console.log(err);
                       console.log(JSON.stringify(data));
                   })
                });
            }
            else
            {
                console.log("Yes, duplicates");
                // Show error message and freeze modal
                res.sendFile( __dirname + "/" + "homepage.html");
            }
        })
    }
    else
    {
        // Show error message and freeze modal
        res.sendFile( __dirname + "/" + "error.html");
    }
 })

app.get('/ProjectPh1V1.html', function(req, res){
    res.sendFile( __dirname + "/" + "ProjectPh1V1.html" );
})

var server = app.listen(8081, function () {
    var host = server.address().address
    var port = server.address().port
    console.log("App listening at http://%s:%s", host, port)
})