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

namespace Kalender;

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

    /**
     * Handle zur verbundenen Datenbank
     */
    private \mysqli $link;

    /**
     * Benutzerrollen
     */
    public const GAST  = 0;
    public const USER  = 1;
    public const MOD   = 2;
    public const ADMIN = 3;

    /**
     * Constructor
     */
    public function __construct($dbconf) {
        $this->connectDB($dbconf);
    }

    /**
     * Normalize birthday
     */
    private function fixBirthday(string &$birthday): void {
        $birthday = ($birthday !== '0000-00-00') ? date("d.m.Y", strtotime($birthday)) : '' ;
    }

    /**
     * Extract staff from row
     * @param array $row Tabllenreihe aus der Datenbank
     * @return array Ausgewählte Benutzerdaten
     */
    private function extractStaffFromRow(array $row): array {
        return [
            'id_staff' => $row['id_staff'],
            'birthday' => $row['birthday'],
            'surname'  => $row['surname'],
        ];
    }

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

        $this->link = new \mysqli($dbconf["host"], $dbconf["user"], $dbconf["password"], $dbconf["name"]);

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

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

    /**
     * Get Staff List
     * @param array $user Benutzer
     * @return array Benutzerdaten
     * @throws \Exception on error
     */
    public function getStaffList(array $user): array {
        try {
            if ($user['role'] === self::ADMIN) {
                $stmt = $this->link->prepare('SELECT * FROM staff');
            }
            else {
                $stmt = $this->link->prepare('SELECT * FROM staff WHERE surname=?');
                $stmt->bind_param('s', $user['name']);
            }

            $stmt->execute();

            $result = $stmt->get_result();

            if (!$result)
                throw new \Exception(mysqli_error($this->link));

            $staff = [];

            while ($row = $result->fetch_array(MYSQLI_ASSOC)) {
                $this->fixBirthday($row['birthday']);
                $staff[] = $this->extractStaffFromRow($row);
            }

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

    /**
     * Get Staff by ID
     * @param string $id_staff Staff ID
     * @return array Benutzerdaten
     * @throws \Exception on error
     */
    public function getStaff($id_staff) {
        try {
            $stmt = $this->link->prepare('SELECT * FROM staff WHERE id_staff=?');
            $stmt->bind_param('s', $id_staff);
            $stmt->execute();

            $result = $stmt->get_result();

            if (!$result)
                throw new \Exception(mysqli_error($this->link));

            $row = $result->fetch_array(MYSQLI_ASSOC);
            $this->fixBirthday($row['birthday']);
            return $this->extractStaffFromRow($row);
        }
        catch(\Exception $e) {
            throw new \Exception($e->getMessage());
        }
    }
}