feat(backend): automatisches taegliches SQLite-Online-Backup

server/backup.js

@@ -0,0 +1,34 @@
+const path = require('path');
+const fs = require('fs');
+const { db, DATA_DIR } = require('./db');
+
+const BACKUP_DIR = path.join(DATA_DIR, 'backups');
+const KEEP = 14;
+
+async function runBackup(now) {
+  fs.mkdirSync(BACKUP_DIR, { recursive: true });
+  const stamp = now.replace(/[:.]/g, '-');
+  const dest = path.join(BACKUP_DIR, `dienstplan-${stamp}.db`);
+  await db.backup(dest); // Online-Backup-API von SQLite — konsistent, ohne cp-Risiko
+  prune();
+  return dest;
+}
+
+function prune() {
+  const files = fs.readdirSync(BACKUP_DIR)
+    .filter(f => f.startsWith('dienstplan-') && f.endsWith('.db'))
+    .sort(); // ISO-abgeleiteter Stamp → lexikografisch == chronologisch
+  const excess = files.length - KEEP;
+  for (let i = 0; i < excess; i++) {
+    fs.unlinkSync(path.join(BACKUP_DIR, files[i]));
+  }
+}
+
+function scheduleBackups() {
+  const tick = () => runBackup(new Date().toISOString())
+    .catch(e => console.error('Backup fehlgeschlagen:', e));
+  tick();
+  setInterval(tick, 24 * 60 * 60 * 1000);
+}
+
+module.exports = { runBackup, scheduleBackups, BACKUP_DIR };

server/backup.test.js

@@ -0,0 +1,17 @@
+const { test } = require('node:test');
+const assert = require('node:assert');
+const fs = require('fs');
+const os = require('os');
+const path = require('path');
+
+process.env.DATA_DIR = fs.mkdtempSync(path.join(os.tmpdir(), 'dp-backup-'));
+const { putDoc } = require('./db');
+const { runBackup, BACKUP_DIR } = require('./backup');
+
+test('runBackup erzeugt eine nicht-leere DB-Datei', async () => {
+  putDoc('employees', ['Max'], '2026-07-07T10:00:00.000Z');
+  const dest = await runBackup('2026-07-07T10:00:00.000Z');
+  assert.ok(fs.existsSync(dest), 'Backup-Datei existiert');
+  assert.ok(fs.statSync(dest).size > 0, 'Backup ist nicht leer');
+  assert.ok(dest.startsWith(BACKUP_DIR), 'Backup liegt im BACKUP_DIR');
+});

server/index.js

@@ -1,6 +1,7 @@
 const path = require('path');
 const express = require('express');
 const { getDoc, putDoc } = require('./db');
+const { scheduleBackups } = require('./backup');
 
 const app = express();
 app.use(express.json({ limit: '5mb' }));
@@ -36,7 +37,10 @@ app.use(express.static(path.join(__dirname, '..')));
 
 if (require.main === module) {
   const PORT = process.env.PORT || 3000;
-  app.listen(PORT, '0.0.0.0', () => console.log(`Dienstplan-Pro auf :${PORT}`));
+  app.listen(PORT, '0.0.0.0', () => {
+    console.log(`Dienstplan-Pro auf :${PORT}`);
+    scheduleBackups();
+  });
 }
 
 module.exports = app;