class userAuth {
    // create an empty id variable to hold the user id
    private $id;
    private $email;
    private $key = "16FD8C979FC40CCB97457F4AD79B32A73758771B4D1943C379FB3266EECE0C3E";

    // Checks if the user exists in the database
    private function validUser($email, $password) {
        $conn = new mysqli(DBSERVER, DBUSERNAME, DBPASSWORD, DBNAME);
        if ($conn->connect_error) {
            die("Connection failed: " . $conn->connect_error);
        }
        $truepassword = hash('sha256', $password); // password hashing using SHA256
        $query = $conn->query("select * from  users where ( username='$email' OR email = '$email') and password='$truepassword'");
        $count = mysqli_num_rows($query);
        if($count == 1) {
            $row = mysqli_fetch_array($query);
            $this->id = $row['id'];
            $this->email = $row['email'];
            return true;
        }else{
            return false;
        }
    }
    private function genJWT() {
        // Make an array for the JWT Payload
        $payload = array(
            "id" => $this->id,
            "email" => $this->email,
            "exp" => time() + (60 * 60)
        );

        // encode the payload using our secretkey and return the token
        return JWT::encode($payload, $this->key);
    }

    public function checkUser($email, $password) {
        // check if the user exists
        if ($this->validUser($email, $password)) {
            // generate JSON web token and store as variable
            $token = $this->genJWT();
            $resultJSON = array(
              'email' => $this->email,
              'token' => $token
            );
            return json_encode($resultJSON);
        } else {
            return 'We Couldn't Find You In Our Database. Maybe Wrong Email/Password Combination';
        }
    }

    private function validJWT($token) {
        $res = array(false, '');
        // using a try and catch to verify
        try {
            //$decoded = JWT::decode($token, $this->key, array('HS256'));
            $decoded = JWT::decode($token, $this->key, array('HS256'));
        } catch (Exception $e) {
            return $res;
        }
        $res['0'] = true;
        $res['1'] = (array) $decoded;

        return $res;
    }


    public function validLogin($token) {
        // checks if an email is valid
        $tokenVal = $this->validJWT($token);

        // check if the first array value is true
        if ($tokenVal['0']) {
            // create user session and all that good stuff
            return "Everything went well, time to serve you what you need.";
        } else {
            return "There was an error validating your email. Send another link";
        }
    }
}