// first IF
if(isset($_POST['submit'])) {
?>
<script type="text/javascript">
    $(function () {                       // On DOM ready
        $('#registerModal').modal('show');   // Show the modal
    });
</script>
<?php
chmod('uploads/', 0777);
chmod('avatar_uploads/',0777);
//$_POST variables
$email = strip_tags($_POST['registeremail']);
$username = strip_tags($_POST['registerusername']);
$password = strip_tags($_POST['registerpassword']);
$password2 = strip_tags($_POST['verifypassword']);
if (empty($username) || empty($password) || empty($password2) || empty($email)) {
    $errors[] = 'Please fill all of the fields';
}
if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
    $errors[] = 'Invalid email';
}
if (mb_strlen($username) >= 50) {
    $errors[] = 'Username limit is 50 characters.';
}
if ($password != $password2) {

    $errors[] = "Passwords don't match";
}
if(preg_match('/[^A-Za-z0-9]/', $username)) {
    if ($user->usernameExists($username) == true) {
        $errors[] = "Username is taken.";
    }
}

if($user->emailExists($email) == true){
    $errors[] ="Email is taken.";
}
// checks if the username only contains letters and numbers
if(!empty($username)) {
    if (!ctype_alnum($username)) {
        $errors[] = "Wrong username format. only letters and numbers are allowed.";
    }
}
//if errors array is empty then hide modal and $user->register()
if (count($errors) == 0) {
    ?>
    <script type="text/javascript">
        alert("You have registered.");
        $(function () {                       // On DOM ready
            $('#registerModal').modal('hide');   // hide the modal
        });
    </script>
    <?php

    $password = password_hash($password, PASSWORD_BCRYPT);
    $avatar = 'http://placehold.it/180x180';
    $user->register($email, $username, $password, $avatar);
}