first commit

apps/frontend/lib/authenticated-media.ts

@@ -0,0 +1,41 @@
+export async function fetchAuthenticatedMediaBlob(accessUrl: string, token: string) {
+  const response = await fetch(accessUrl, {
+    headers: { Authorization: `Bearer ${token}` }
+  });
+  if (!response.ok) {
+    throw new Error('Не удалось загрузить файл');
+  }
+  return response.blob();
+}
+
+export function createBlobObjectUrl(blob: Blob) {
+  return URL.createObjectURL(blob);
+}
+
+export function revokeBlobObjectUrl(url?: string) {
+  if (url?.startsWith('blob:')) {
+    URL.revokeObjectURL(url);
+  }
+}
+
+export function triggerBlobDownload(blob: Blob, fileName: string) {
+  const objectUrl = URL.createObjectURL(blob);
+  const anchor = document.createElement('a');
+  anchor.href = objectUrl;
+  anchor.download = fileName;
+  anchor.rel = 'noopener';
+  document.body.appendChild(anchor);
+  anchor.click();
+  anchor.remove();
+  URL.revokeObjectURL(objectUrl);
+}
+
+export function mediaExpiresAtMs(expiresAt?: string) {
+  if (!expiresAt) return Date.now() + 14 * 60_000;
+  const parsed = Date.parse(expiresAt);
+  return Number.isFinite(parsed) ? parsed : Date.now() + 14 * 60_000;
+}
+
+export function shouldRefreshMedia(expiresAtMs: number, bufferMs = 60_000) {
+  return expiresAtMs - Date.now() <= bufferMs;
+}