<?php
    class Shortener {
        protected $db;

        public function __construct() {
            $this->db = new mysqli('HOST', 'USER', 'WW', 'DB'); // even weg gehaald
        }

        public function generateCode($num) {
            return base_convert($num, 10, 36);
        }

        public function makeCode($url) {
            $url = trim($url);

            if(!filter_var($url, FILTER_VALIDATE_URL)) {
                return '';
            }

            $url = $this->db->escape_string($url);
            return $url;

            // Kijken of de link al bestaat
            $exists = $this->db->query("SELECT code FROM links WHERE url = '" . $url . "'");

            if($exists->num_rows > 0) {
                return $exists->fetch_object()->code;
            } else {
                $this->db->query("INSERT INTO links (url, created) VALUES ('" . $url . "', UNIX_TIMESTAMP())");
                $code = $this->generateCode($this->db->insert_id);
                $this->db->query("UPDATE links SET code = '" . $code . "' WHERE url = '" . $url . "'");

                return $code;
            }
        }

        public function getUrl($code) {
            $code = $this->db->escape_string($code);
            $code = $this->db->query("SELECT url FROM links WHERE = '" . $code . "'");

            if($code->num_rows) {
                return $code->fetch_object()->url;
            }

            return '';
        }
    }
?>