<?php
header('Content-Type: application/json');

$body  = json_decode(file_get_contents('php://input'), true) ?? [];
$action = $body['action'] ?? '';

$allowed = ['stop', 'shutdown', 'restart'];
if (!in_array($action, $allowed, true)) {
    echo json_encode(['ok' => false, 'error' => 'invalid action']);
    exit;
}

$cmd = match($action) {
    'stop'     => '/usr/local/sbin/mdcmd stop',
    'shutdown' => '/sbin/shutdown -h now',
    'restart'  => '/sbin/shutdown -r now',
};

exec($cmd . ' > /dev/null 2>&1 &');
echo json_encode(['ok' => true]);