<?php
/****************************************
 * Core.php Datei
 ***************************************/
declare(strict_types=1);

session_start();

/**
 * Hauptklasse mit Datenbank
 */
class Core {

    /**
     * Handle zur verbundenen Datenbank
     */
    private static $link = null;

    /**
     * Verbinde zur Datenbank und speichere das Handle $link
     * @throws \Exception on error
     */
    public static function connectDB(): void {

        require('conf.php'); // Datenbank Zugangsdaten
        Core::$link = new mysqli($conf["host"], $conf["user"], $conf["password"], $conf["name"]);

        // check connection
        if (mysqli_connect_errno())
            throw new \Exception('Connect failed: ' . mysqli_connect_error());

        if (!Core::$link->set_charset("utf8"))
            throw new \Exception('Error loading character set utf8: ' . Core::$link->error);
    }

    /**
     * Schliesst die Datenbank (Braucht man aber fast nie, da die Datenbank \
     * beim Beenden automatisch geschlossen wird.)
     */
    public static function closeDB() {
        Core::$link->close();
    }

    /**
     * Get Staff List
     * @param array $user Benutzer
     * @return array Benutzerdaten
     * @throws \Exception on error
     */
    public static function getStaffList(array $user): array {
        try {
            Core::connectDB();

            if ($user['role'] === 'admin') {
                $stmt = Core::$link->prepare('SELECT * FROM staff');
            }
            else {
                $stmt = Core::$link->prepare('SELECT * FROM staff WHERE surname=?');
                $stmt->bind_param('s', $user['name']);
            }

            $stmt->execute();

            $result = $stmt->get_result();

            if (!$result)
                throw new \Exception(mysqli_error(Core::$link));

            $staff = [];

            while ($row = $result->fetch_array(MYSQLI_ASSOC)) {
                if ($row['birthday'] !== '0000-00-00')
                    $row['birthday'] = date("d.m.Y", strtotime($row['birthday']));
                else
                    $row['birthday'] = '';

                $staff[] = $row;
            }

            return $staff;
        }
        catch(Exception $e) {
            throw new \Exception($e->getMessage());
        }
    }
}