include 'core/init.php';
include 'includes/overall/header.php';

if (empty($_POST) === false) {
$username = $_POST['username'];
$password = $_POST['password'];

if (empty($username) === true || empty($password) === true) {
$errors[] = 'Uh oh! You forgot to enter your username and password';

} else if (user_exists($username) === false) {
$errors[] = 'Who is that? Have you registered?';

} else if (user_active($username) === false) {
$errors[] = 'Account is not activated.';

} else {

$login = login($username, $password);
if ($login === false) {
$errors[] = 'That username and password combination is incorrect';

} else {
    $_SESSION['user_id'] = $login;
    header('Location:index.php');
    exit();
    }
}
print_r($errors);
}

include 'includes/overall/footer.php';

function logged_in() {
return (isset($_SESSION['user_id'])) ? true : false;
}

function user_exists($username) {
$username = sanitize($username);
$query = mysql_query("SELECT COUNT(`user_id`) FROM `users` WHERE `username` = '$username'");
return (mysql_result($query, 0) == 1) ? true : false;
}


function user_active($username) {
$username = sanitize($username);
$query = mysql_query("SELECT COUNT(`user_id`) FROM `users` WHERE `username` = '$username' AND `active` = 1");
return  (mysql_result($query, 0) == 1) ? true : false;
}

function user_id_from_username($username) {
$username = sanitize($username);
return mysql_result(mysql_query("SELECT `user_id` FROM `users` WHERE `username` = '$username'"), 0, 'user_id');
}

function login($username, $password) {
$user_id = user_id_from_username($username);

$username = sanitize($username);
$password = md5($password);

$query = mysql_query("SELECT COUNT(`user_id`) FROM `users` WHERE `username` = '$username' AND `password` = '$password'");
return (mysql_result($query, 0) == 1) ? $user_id : false;
}

.....FROM `users` WHERE `username` LIKE '$username'.....