adding backup/restore ability

ui/src/services/backupRestoreClient.js

@@ -0,0 +1,85 @@
+/*
+ * Copyright (c) 2025 by Christian Kellner.
+ * Licensed under Apache-2.0 with Commons Clause and Attribution/Naming Clause
+ */
+
+/**
+ * Lightweight client for Backup & Restore interactions with the backend.
+ *
+ * Usage (in React components):
+ * ```js
+ * import { downloadBackup, precheckRestore, restore } from '../../services/backupRestoreClient';
+ * await downloadBackup();
+ * const info = await precheckRestore(file);
+ * await restore(file, false);
+ * ```
+ */
+
+function extractFileNameFromDisposition(disposition) {
+  const dispo = disposition || '';
+  const match = dispo.match(/filename\*=UTF-8''([^;]+)|filename="?([^";]+)"?/);
+  return decodeURIComponent(match?.[1] || match?.[2] || 'FredyBackup.zip');
+}
+
+export class BackupRestoreClient {
+  /**
+   * Trigger a backup download and save it using the filename provided by the server.
+   * @returns {Promise<void>}
+   */
+  static async downloadBackup() {
+    const resp = await fetch('/api/admin/backup', { credentials: 'include' });
+    if (!resp.ok) throw new Error('Failed to create backup');
+    const blob = await resp.blob();
+    const fileName = extractFileNameFromDisposition(resp.headers.get('Content-Disposition'));
+    const url = window.URL.createObjectURL(blob);
+    const a = document.createElement('a');
+    a.href = url;
+    a.download = fileName;
+    document.body.appendChild(a);
+    a.click();
+    a.remove();
+    window.URL.revokeObjectURL(url);
+  }
+
+  /**
+   * Upload a backup zip for analysis without restoring.
+   * @param {Blob|ArrayBuffer|Buffer} file - Backup zip content.
+   * @returns {Promise<{compatible:boolean,severity:string,message:string,backupMigration:number|null,requiredMigration:number,fredyVersion?:string|null}>>}
+   */
+  static async precheckRestore(file) {
+    const resp = await fetch('/api/admin/backup/restore?dryRun=true', {
+      method: 'POST',
+      credentials: 'include',
+      headers: { 'Content-Type': 'application/zip' },
+      body: file,
+    });
+    return resp.json();
+  }
+
+  /**
+   * Perform a database restore from a backup zip.
+   * @param {Blob|ArrayBuffer|Buffer} file - Backup zip content.
+   * @param {boolean} force - When true, proceed even if reported incompatible.
+   * @returns {Promise<{restored:true,warning:string|null,details:any}>}
+   */
+  static async restore(file, force) {
+    const resp = await fetch(`/api/admin/backup/restore?force=${force ? 'true' : 'false'}`, {
+      method: 'POST',
+      credentials: 'include',
+      headers: { 'Content-Type': 'application/zip' },
+      body: file,
+    });
+    const data = await resp.json();
+    if (!resp.ok) {
+      const err = new Error(data?.message || 'Restore failed');
+      err.payload = data;
+      throw err;
+    }
+    return data;
+  }
+}
+
+// Convenience named exports
+export const downloadBackup = (...args) => BackupRestoreClient.downloadBackup(...args);
+export const precheckRestore = (...args) => BackupRestoreClient.precheckRestore(...args);
+export const restore = (...args) => BackupRestoreClient.restore(...args);