fix thumbnails

Overlord-Server/src/server/routes/client-routes.ts

@@ -253,9 +253,10 @@ export async function handleClientRoutes(
     if (!canUserAccessClient(user.userId, user.role, clientId)) {
       return new Response("Forbidden: Client access denied", { status: 403 });
     }
-    const { generateThumbnail, markThumbnailRequested, getThumbnailVersion } = await import("../../thumbnails");
+    const { requestThumbnailRegen, markThumbnailRequested, getThumbnailVersion, waitForThumbnail, clearThumbnailRequest } = await import("../../thumbnails");
     markThumbnailRequested(clientId);
     const target = clientManager.getClient(clientId);
+    const beforeVersion = getThumbnailVersion(clientId);
     if (target?.online) {
       const commandId = uuidv4();
       target.ws.send(
@@ -268,10 +269,16 @@ export async function handleClientRoutes(
       );
       metrics.recordCommand("screenshot");
     }
-    const success = await generateThumbnail(clientId);
+    const fresh = target?.online ? await waitForThumbnail(clientId, 2500) : false;
+    if (fresh) {
+      await new Promise((r) => setTimeout(r, 300));
+    } else {
+      await requestThumbnailRegen(clientId);
+    }
+    clearThumbnailRequest(clientId);
     const version = getThumbnailVersion(clientId);
     return Response.json(
-      { ok: true, updated: success, version },
+      { ok: true, updated: version > beforeVersion, version },
       { headers: deps.CORS_HEADERS },
     );
   }

Overlord-Server/src/thumbnails.ts

@@ -128,7 +128,9 @@ export async function generateThumbnail(id: string): Promise<boolean> {
       updatedAt: now,
     });
     evictThumbnailsIfFull();
-    latestFrames.delete(id);
+    if (latestFrames.get(id) === frameData) {
+      latestFrames.delete(id);
+    }
     return true;
   } catch (err) {
     console.error(`[thumbnails] Failed to generate thumbnail for client ${id}:`, err);
@@ -136,10 +138,54 @@ export async function generateThumbnail(id: string): Promise<boolean> {
   }
 }
 
+const thumbnailGenState = new Map<string, { inFlight: boolean; pending: boolean }>();
+
+export async function requestThumbnailRegen(id: string): Promise<boolean> {
+  let state = thumbnailGenState.get(id);
+  if (!state) {
+    state = { inFlight: false, pending: false };
+    thumbnailGenState.set(id, state);
+  }
+  if (state.inFlight) {
+    state.pending = true;
+    return false;
+  }
+  state.inFlight = true;
+  let didGenerate = false;
+  try {
+    while (true) {
+      state.pending = false;
+      const ok = await generateThumbnail(id);
+      if (ok) didGenerate = true;
+      if (!state.pending) break;
+    }
+  } finally {
+    state.inFlight = false;
+    if (thumbnailGenState.get(id) === state && !state.pending) {
+      thumbnailGenState.delete(id);
+    }
+  }
+  return didGenerate;
+}
+
 export function markThumbnailRequested(id: string) {
   thumbnailRequests.set(id, Date.now());
 }
 
+export function isThumbnailRequested(id: string, windowMs = 5000): boolean {
+  const ts = thumbnailRequests.get(id);
+  if (!ts) return false;
+  if (Date.now() - ts > windowMs) {
+    thumbnailRequests.delete(id);
+    return false;
+  }
+  return true;
+}
+
+export function clearThumbnailRequest(id: string) {
+  thumbnailRequests.delete(id);
+}
+
 export function consumeThumbnailRequest(id: string, windowMs = 5000): boolean {
   const ts = thumbnailRequests.get(id);
   if (!ts) return false;
@@ -150,3 +196,40 @@ export function consumeThumbnailRequest(id: string, windowMs = 5000): boolean {
   thumbnailRequests.delete(id);
   return true;
 }
+
+const thumbnailWaiters = new Map<string, Set<() => void>>();
+
+export function notifyThumbnailGenerated(id: string) {
+  const waiters = thumbnailWaiters.get(id);
+  if (!waiters) return;
+  thumbnailWaiters.delete(id);
+  for (const cb of waiters) {
+    try { cb(); } catch {}
+  }
+}
+
+export function waitForThumbnail(id: string, timeoutMs = 2500): Promise<boolean> {
+  return new Promise((resolve) => {
+    let settled = false;
+    let callback: () => void;
+    const finish = (fresh: boolean) => {
+      if (settled) return;
+      settled = true;
+      clearTimeout(timer);
+      const set = thumbnailWaiters.get(id);
+      if (set) {
+        set.delete(callback);
+        if (set.size === 0) thumbnailWaiters.delete(id);
+      }
+      resolve(fresh);
+    };
+    callback = () => finish(true);
+    const timer = setTimeout(() => finish(false), timeoutMs);
+    let set = thumbnailWaiters.get(id);
+    if (!set) {
+      set = new Set();
+      thumbnailWaiters.set(id, set);
+    }
+    set.add(callback);
+  });
+}

Overlord-Server/src/wsHandlers.ts

@@ -9,10 +9,11 @@ async function getGeoip() {
 }
 import { ClientInfo } from "./types";
 import {
-  consumeThumbnailRequest,
+  isThumbnailRequested,
   hasThumbnail,
-  generateThumbnail,
   setLatestFrame,
+  notifyThumbnailGenerated,
+  requestThumbnailRegen,
 } from "./thumbnails";
 import { upsertClientRow, type ClientDbRow } from "./db";
 import { metrics } from "./metrics";
@@ -296,10 +297,12 @@ export function handleFrame(info: ClientInfo, payload: any) {
 
   if (safeFormat) {
     const now = Date.now();
-    const thumbnailRequested = consumeThumbnailRequest(info.id);
+    const thumbnailRequested = isThumbnailRequested(info.id);
     if (thumbnailRequested || !hasThumbnail(info.id)) {
       setLatestFrame(info.id, bytes, safeFormat);
-      void generateThumbnail(info.id);
+      void requestThumbnailRegen(info.id).then((ok) => {
+        if (ok) notifyThumbnailGenerated(info.id);
+      });
     }
     info.lastSeen = now;
     info.online = true;