<?php
global $db;
try {
    $query = "SELECT 
                k.id,
                k.name,
                k.beschreibung,
                k.gebuehr,
                k.max_teilnehmer,
                COUNT(a.id) as belegte_plaetze,
                (k.max_teilnehmer - COUNT(a.id)) as freie_plaetze,
                CASE WHEN COUNT(a.id) >= k.max_teilnehmer THEN 0 ELSE 1 END as verfuegbar
              FROM kurse k
              LEFT JOIN anmeldungen a ON k.id = a.kurs_id
              GROUP BY k.id
              ORDER BY k.name";
    $stmt = $db->prepare($query);
    $stmt->execute();

    $kurse = [];
    while ($row = $stmt->fetch()) {
        $kurse[] = [
            'id' => (int)$row['id'],
            'name' => $row['name'],
            'beschreibung' => $row['beschreibung'],
            'gebuehr' => (float)$row['gebuehr'],
            'max_teilnehmer' => (int)$row['max_teilnehmer'],
            'belegte_plaetze' => (int)$row['belegte_plaetze'],
            'freie_plaetze' => (int)$row['freie_plaetze'],
            'verfuegbar' => (bool)$row['verfuegbar']
        ];
    }
    echo json_encode($kurse);
} catch (Exception $e) {
    error_log("Error in kurse/get.php: " . $e->getMessage());
    http_response_code(500);
    echo json_encode(['message' => 'Fehler beim Laden der Kurse']);
}