netwatch/app/modules/devices/delete.php

<?php
/**
 * app/modules/devices/delete.php
 *
 * Loescht ein Geraet. Bei Abhaengigkeiten ist force=1 erforderlich.
 * Unterstuetzt GET-Redirects und AJAX-POST.
 */

$isPost = ($_SERVER['REQUEST_METHOD'] ?? '') === 'POST';
$deviceId = (int)($_POST['id'] ?? $_GET['id'] ?? 0);
$forceDelete = (int)($_POST['force'] ?? $_GET['force'] ?? 0) === 1;

if ($deviceId <= 0) {
    if ($isPost) {
        header('Content-Type: application/json; charset=utf-8');
        http_response_code(400);
        echo json_encode(['success' => false, 'message' => 'Ungueltige Geraete-ID']);
        exit;
    }
    $_SESSION['error'] = "Ungueltige Geraete-ID";
    header('Location: ?module=devices&action=list');
    exit;
}

$device = $sql->single(
    "SELECT id, name FROM devices WHERE id = ?",
    "i",
    [$deviceId]
);

if (!$device) {
    if ($isPost) {
        header('Content-Type: application/json; charset=utf-8');
        http_response_code(404);
        echo json_encode(['success' => false, 'message' => 'Geraet nicht gefunden']);
        exit;
    }
    $_SESSION['error'] = "Geraet nicht gefunden";
    header('Location: ?module=devices&action=list');
    exit;
}

$dependencies = $sql->single(
    "SELECT
        (
            SELECT COUNT(*)
            FROM device_ports dp
            WHERE dp.device_id = ?
        ) AS port_count,
        (
            SELECT COUNT(*)
            FROM device_port_modules dpm
            JOIN device_ports dp2 ON dp2.id = dpm.device_port_id
            WHERE dp2.device_id = ?
        ) AS module_count,
        (
            SELECT COUNT(*)
            FROM connections c
            WHERE ((c.port_a_type = 'device' OR c.port_a_type = 'device_ports') AND c.port_a_id IN (
                    SELECT dp3.id FROM device_ports dp3 WHERE dp3.device_id = ?
                  ))
               OR ((c.port_b_type = 'device' OR c.port_b_type = 'device_ports') AND c.port_b_id IN (
                    SELECT dp4.id FROM device_ports dp4 WHERE dp4.device_id = ?
                  ))
        ) AS connection_count",
    "iiii",
    [$deviceId, $deviceId, $deviceId, $deviceId]
);

$portCount = (int)($dependencies['port_count'] ?? 0);
$moduleCount = (int)($dependencies['module_count'] ?? 0);
$connectionCount = (int)($dependencies['connection_count'] ?? 0);
$hasDependencies = $portCount > 0 || $moduleCount > 0 || $connectionCount > 0;

if ($hasDependencies && !$forceDelete) {
    $parts = [];
    if ($connectionCount > 0) {
        $parts[] = $connectionCount . ' Verbindungen';
    }
    if ($portCount > 0) {
        $parts[] = $portCount . ' Ports';
    }
    if ($moduleCount > 0) {
        $parts[] = $moduleCount . ' Port-Module';
    }

    $dependencyMessage = "Geraet hat abhaengige Daten (" . implode(', ', $parts) . "). Loeschen bitte bestaetigen.";
    if ($isPost) {
        header('Content-Type: application/json; charset=utf-8');
        http_response_code(409);
        echo json_encode([
            'success' => false,
            'requires_force' => true,
            'message' => $dependencyMessage,
            'dependencies' => [
                'connections' => $connectionCount,
                'ports' => $portCount,
                'modules' => $moduleCount
            ]
        ]);
        exit;
    }
    $_SESSION['error'] = $dependencyMessage;
    header('Location: ?module=devices&action=edit&id=' . urlencode((string)$deviceId));
    exit;
}

// Connections referenzieren device_ports nur logisch, daher manuell entfernen.
$sql->set(
    "DELETE FROM connections
     WHERE ((port_a_type = 'device' OR port_a_type = 'device_ports') AND port_a_id IN (SELECT id FROM device_ports WHERE device_id = ?))
        OR ((port_b_type = 'device' OR port_b_type = 'device_ports') AND port_b_id IN (SELECT id FROM device_ports WHERE device_id = ?))",
    "ii",
    [$deviceId, $deviceId]
);

$deleted = $sql->set(
    "DELETE FROM devices WHERE id = ?",
    "i",
    [$deviceId]
);

if ($deleted > 0) {
    if ($isPost) {
        header('Content-Type: application/json; charset=utf-8');
        echo json_encode(['success' => true, 'message' => "Geraet geloescht: " . $device['name']]);
        exit;
    }
    $_SESSION['success'] = "Geraet geloescht: " . $device['name'];
} else {
    if ($isPost) {
        header('Content-Type: application/json; charset=utf-8');
        http_response_code(500);
        echo json_encode(['success' => false, 'message' => 'Geraet konnte nicht geloescht werden']);
        exit;
    }
    $_SESSION['error'] = "Geraet konnte nicht geloescht werden";
}

header('Location: ?module=devices&action=list');
exit;