<?php
header('Content-Type: application/json; charset=utf-8');
require_once '../../bbs/db_conn.php';
$pdo = db_conn();
$group = $_GET['group_code'] ?? '';
try {
    if ($group !== '') {
        $stmt = $pdo->prepare("SELECT * FROM edu_codes WHERE group_code = ? ORDER BY code");
        $stmt->execute([$group]);
    } else {
        $stmt = $pdo->query("SELECT * FROM edu_codes ORDER BY group_code, code");
    }
    $codes = $stmt->fetchAll(PDO::FETCH_ASSOC);
    echo json_encode(['codes' => $codes], JSON_UNESCAPED_UNICODE);
} catch (Exception $e) {
    echo json_encode(['error' => $e->getMessage()], JSON_UNESCAPED_UNICODE);
}
?>