//Node JS Express framework
var express = require('express');
var app = express();

//Required for parsing GET/POST parameters
var bodyParser = require('body-parser');

//Required for HTTP/HTTPS servers
var https = require('https');
var http = require('http');

//Required for reaading file streams
var fs = require('fs');

//Required to get access to MySQL databases
var mysql = require('mysql');

//Required for waiting for async functions to finish
var after = require('after');

//Required for password hashing
var bcrypt = require('bcrypt');

//Loads info about SSL certificate
var privateKey = fs.readFileSync('key.pem');
var certificate = fs.readFileSync('cert.pem');
var credentials = {key: privateKey, cert: certificate};

//Creates HTTP and HTTPS servers
var httpsServer = https.createServer(credentials, app);
var httpServer = http.createServer(function (req, res) {
    res.writeHead(301, { "Location": "https://" + req.headers['host'] + req.url });
    res.end();
});

httpsServer.listen(3000);
httpServer.listen(3001);

//Middlewares for Express
app.use(bodyParser.urlencoded({ extended: false }));
app.use(bodyParser.json());
app.use(express.static(__dirname + '/public'));

//Establishes connection to MySQL database
var connection = mysql.createConnection({
  host : 'localhost',
  port : '/var/run/mysqld/mysqld.sock',
  user : 'root',
  password : 'YourBigM@m@n4815162342',
  database : 'LLDB',
  charset: "utf8_general_ci"
});
connection.connect();

//Access to root directory
app.get('/', function (req, res) {
  //console.log("Cookies: ", req.cookies);
  res.sendFile(__dirname+ '/private/home.html');
});

//Access to signup page
app.all('/signup', function (req, res) {
  //Emails that have any of these phrases in them won't be accepted
  var bannedEmailDomains = [ "mvrht", "noicd", "10minuteemail" , "10minutemail", "20email", "dropmail"];

  //Stores final result of signup process
  var signupStatus = {};

  //Stores all errors that relate to username
  var usernameErrors = [];

  //Stores all errors that relate to email
  var emailErrors = [];

  //Stores all errors that relate to password
  var passwordErrors = [];

  //Basically a counter, that keeps track of every finished async event, before submitting response on signup process
  var finished = after(3, sendSignupStatus);

  ////////////
  //Username rules
  ////////////
  //Can't be empty and must be at least 4 characters long
  if(!req.body.username || req.body.username.length < 4) {
    usernameErrors.push("Must be at least 4 characters long");

    //Decrease couter for sending signup process status
    finished();
  }
  else {
    //Must contain only ASCII characters WITHOUT special characters such as "'?&*@# etc.
    if(!isASCII(req.body.username, false))
      usernameErrors.push("Invalid symbols");

    //Must be less than 30 characters long
    if(req.body.username.length > 30)
      usernameErrors.push("Must be less than 30 characters long");

    //If no username errors were found yet - make a query to database
    if(usernameErrors.length === 0) {
      //Find any registered users with the same username
      connection.query("SELECT * FROM user_main_info WHERE username = '"+req.body.username + "';", function(error, result, field) {

        //If someone with the same username found
        if(result.length > 0 ) {
          usernameErrors.push("Account already exists");
        }
        finished();
      });
    }
    else
      finished();
  }


  ////////////
  //Email
  ////////////
  //Can't be empty
  if(!req.body.email) {
    emailErrors.push("Email not specified");

    //Decrease couter for sending signup process status
    finished();
  }
  else {
    //Must contain only ASCII characters
    if(!isASCII(req.body.email,true))
      emailErrors.push("Invalid symbols");

    //Must be less than 30 characters long
    if(req.body.email.length > 30)
      emailErrors.push("Must be less than 30 characters long");

    //Can't contain banned parts of email
    for(var i = 0; i < bannedEmailDomains.length; i++) {
      if(req.body.email.indexOf(bannedEmailDomains[i]) !== -1) {
        emailErrors.push("Invalid email domain");
        break;
      }
    }

    //Must be in email form: contains signle "@" and no spaces;
    if(str.replace(/[^@]/g, "").length === 1|| req.body.email.indexOf(" ") !== -1)
      emailErrors.push("Invalid email");

    //If no email errors were found yet - make a query to database
    if(emailErrors.length === 0) {
      //Find any registered users with the same email
      connection.query("SELECT * FROM user_main_info WHERE email = '"+req.body.email + "';", function(error, result, field) {

        //If someone with the same email found
        if(result.length > 0 ) {
          emailErrors.push("This email is taken");
        }

        finished();
      });
    }
    else
      finished();
  }

 ////////////
  //Email
  ////////////
  //Must be at least 10 characters long
  if(!req.body.password || req.body.password.length < 10) {
    passwordErrors.push("Must be at least 10 characters long");

    //Decrease couter for sending signup process status
    finished();
  }
  else {

    //At least one digit
    if(/^[0-9]+$/.test(req.body.password) === false)
      passwordErrors.push("Must contain at least one digit");

    //At least one small letter
    if(/^[a-z]+$/.test(req.body.password) === false)
      passwordErrors.push("Must contain at least one small letter");

    //At least one capital letter
    if(/^[A-Z]+$/.test(req.body.password) === false)
      passwordErrors.push("Must contain at least one capital letter");


    finished();
  }

  //Function that sends response of signup process
  function sendSignupStatus() {

    //Generates final response out of three error checks
    signupStatus["usernameErrors"] = usernameErrors;
    signupStatus["emailErrors"] = emailErrors;
    signupStatus["passwordErrors"] = passwordErrors;

    //If any errors are present - send them as a response
    if(signupStatus["usernameErrors"].length !== 0 ||
      signupStatus["emailErrors"].length !== 0 ||
      signupStatus["passwordErrors"].length !== 0) {
      res.send(JSON.stringify(signupStatus));
    }
    else {

      //No errors are present - generate salt for the password
      bcrypt.genSalt(10, function(err, salt) {
        //Generate passsword hash
        bcrypt.hash(req.body.password, salt, function(err, hash) {
          //Send query to add user to database
          connection.query("INSERT INTO user_main_info (username, email, password, salt) VALUES ('"+ req.body.username+"', '"+req.body.email +"', '"+ hash + "', '"+salt+"');");
          res.send("1");
        });
      });
    }
  }
});

//Access to any user page
app.get('/:id', function (req, res) {

  if(req.params.id !== "profile")
  {
    res.status(404);
    res.send('Not found!');
  }

  res.sendFile(__dirname+ '/private/profile.html');
});


//Checks if string contains only ASCII characters
function isASCII(str, acceptSpecial) {
  if(acceptSpecial)
    return /^[\x00-\x7F]*$/.test(str);
  else
    return /^[0-9a-zA-Z]+$/.test(str);
}