Restore an evicted server copy from an online holder

server/server.js

@@ -53,7 +53,7 @@ import { P2P } from './p2p-config.js';
 import * as p2pDb from './p2p-db.js';
 import { registerP2pRoutes } from './p2p-routes.js';
 import { registerIntakeRoutes } from './p2p-intake.js';
-import { createP2pHub, holdersPayload } from './p2p-hub.js';
+import { createP2pHub, holdersPayload, createRehydrator } from './p2p-hub.js';
 import { sha256Range } from './hash.js';
 import * as innertube from './innertube.js';
 import QRCode from 'qrcode';
@@ -711,6 +711,16 @@ app.get('/api/streams', async (c) => {
       },
     });
   } catch (err) {
+    // The source failed. If a device holds a verified copy, ask it to send one
+    // to the server so the video comes back (P2P flow 8).
+    let restoring = false;
+    try { restoring = await p2pRehydrate(videoId); } catch { /* best effort */ }
+    if (restoring) {
+      return c.json({
+        ok: false, restoring: true,
+        error: 'This video is unavailable at the source — a device that has it is sending a copy to the server. Try again in a minute.',
+      }, 503);
+    }
     return c.json({ ok: false, error: err.message }, 500);
   }
 });
@@ -1989,6 +1999,14 @@ const intake = registerIntakeRoutes(app, {
   validateMedia: (path, expected, opts) => validateMedia(path, expected,
     { ...opts, ffmpeg: FFMPEG, ffprobe: process.env.FFPROBE_PATH || 'ffprobe' }),
   adopt: (videoId, path, info) => media.adoptFile(videoId, path, info),
+  serverHasCid: async (cid) => !!(await fileForCid(cid)),
+});
+
+// Source gone + server copy evicted → ask one online holder to send it back
+// through intake (docs/p2p-architecture.md flow 8).
+const p2pRehydrate = createRehydrator({
+  p2pDb, hub: p2pHub, enabled: () => P2P.enabled,
+  hasServerCopy: async (id) => !!(await media.getReady(id).catch(() => null)),
 });
 
 // ============================================================================