Simple Link Shortener by duhow v1

<?php
    $mysql['user'] =    '';
    $mysql['pass'] =    '';
    $mysql['host'] =    '';
    $mysql['db'] =      '';
    $mysql['tbl'] =     '';

    $admin_link =       'admin';

    /* SQL BASE

    CREATE TABLE IF NOT EXISTS `links` (
        `id` int(12) unsigned NOT NULL AUTO_INCREMENT,
        `alias` varchar(256) COLLATE utf8_unicode_ci DEFAULT NULL,
        `url` varchar(1024) COLLATE utf8_unicode_ci NOT NULL,
        `count` int(12) unsigned DEFAULT '0',
        PRIMARY KEY (`id`),
        UNIQUE KEY `alias` (`alias`)
    ) ENGINE=MyISAM DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci AUTO_INCREMENT=1 ;

    -------
    .htaccess

    RewriteEngine On
    RewriteRule ^(.*)/?$    index.php?url=$1    [NC,L,QSA]

    */

$req = substr($_SERVER['REQUEST_URI'],strlen(substr($_SERVER['SCRIPT_NAME'],0,-9)));
if($req == $admin_link){
?>
<html>
<head>
<style>
    header,body{padding: 0; margin: 0; border: 0;}
    body{background: #000; color: #fff;}
    header{width: 100%; height: 80px; background: #555; margin-bottom: 20px; border-bottom: 2px solid black;}
    #content{width: 800px; margin: 0 auto;}
</style>
</head>
<body>
<header></header>
<div id="content">
    <form method="post">
        URL: <input type="url" name="url" size="100" value="http://"><br />
        Alias: <input type="text" name="alias" size="30"><br />
        <input type="submit">
    </form>
    <?php if(isset($_POST['url'])){
        $conn = mysqli_connect($mysql['host'], $mysql['user'], $mysql['pass'], $mysql['db']);
        if(empty($_POST['alias'])){
            $query = "INSERT INTO " .$mysql['tbl'] ."(url) VALUES ('" .$_POST['url'] ."');";
        }else{
            $query = "INSERT INTO " .$mysql['tbl'] ."(alias,url) VALUES ('" .$_POST['alias'] ."', '" .$_POST['url'] ."');";
        }
        mysqli_query($conn, $query);
        $query = "SELECT * FROM " .$mysql['tbl'] ." WHERE url = '" .$_POST['url'] ."'ORDER BY id DESC LIMIT 0,1;";
        $data = mysqli_fetch_array(mysqli_query($conn, $query), MYSQLI_ASSOC);
        mysqli_close($conn);

        echo "Datos Link: ";
        print_r($data);
    } ?>
</div>
</body>
</html>
<?
    exit;
}elseif($req == ""){
    header("HTTP/1.0 404 Not Found");
    die;
}else{
    $conn = mysqli_connect($mysql['host'], $mysql['user'], $mysql['pass'], $mysql['db']);
    $urlid = preg_replace("/[^0-9]/", '', $req);
    $query = "SELECT * FROM " .$mysql['tbl'] ." WHERE id = '" .$urlid ."' OR alias = '" .$req ."';";
    $result = mysqli_fetch_array(mysqli_query($conn, $query), MYSQLI_ASSOC);
    if(empty($result)){
        header("HTTP/1.0 404 Not Found");
        die;
    }else{
        if(isset($_GET['count'])){
            echo $result['count'];
            exit;
        }elseif(isset($_GET['delete'])){
            $query = "DELETE FROM " .$mysql['tbl'] ." WHERE id = '" .$urlid ."';";
            var_dump(mysqli_query($conn, $query));
            exit;
        }else{
            $query = "UPDATE " .$mysql['tbl'] ." SET count = count+1 WHERE id = '" .$urlid ."';";
            mysqli_query($conn, $query);
            mysqli_close($conn);
            header("Location: " .$result['url']);
            exit;
        }
    }
}
?>