SCOPENET Map viewer: shared canvas engine, launcher window and claim terrain, admin map card; BlueMap/Vantage UI removed

shared/map/feed.ts

@@ -0,0 +1,51 @@
+import type { MapInfo, MapOverlay } from './types';
+
+export interface FeedOptions {
+  loadInfo: () => Promise<MapInfo>;
+  loadOverlay: () => Promise<MapOverlay>;
+  onInfo: (info: MapInfo) => void;
+  onOverlay: (overlay: MapOverlay) => void;
+  onError?: (message: string) => void;
+  /** How often players move on the map. */
+  overlayMs?: number;
+}
+
+/**
+ * Keeps a map fresh: the overlay (players, claims, pins) every couple of seconds while the window is visible, and the info
+ * (which carries the tile key) when it is about to expire. Returns a function that stops everything.
+ */
+export function startFeed(o: FeedOptions): () => void {
+  let stopped = false;
+  let infoTimer: ReturnType<typeof setTimeout> | undefined;
+  let overlayTimer: ReturnType<typeof setTimeout> | undefined;
+  let ready = false;
+
+  const fail = (e: unknown) => o.onError?.(typeof e === 'string' ? e : (e as { message?: string })?.message ?? 'Could not reach the map');
+
+  async function info() {
+    try {
+      const next = await o.loadInfo();
+      if (stopped) return;
+      ready = next.ready;
+      o.onInfo(next);
+      // The tile key is good for an hour: renew it with plenty of time to spare. While waiting for the first tiles, check often.
+      const wait = next.ready ? Math.max(30, Math.min(next.token_ttl_secs * 0.6, 1200)) * 1000 : 8000;
+      infoTimer = setTimeout(info, wait);
+    } catch (e) {
+      fail(e);
+      if (!stopped) infoTimer = setTimeout(info, 10000);
+    }
+  }
+
+  async function overlay() {
+    if (stopped) return;
+    if (ready && !document.hidden) {
+      try { o.onOverlay(await o.loadOverlay()); } catch (e) { fail(e); }
+    }
+    if (!stopped) overlayTimer = setTimeout(overlay, o.overlayMs ?? 2500);
+  }
+
+  info();
+  overlayTimer = setTimeout(overlay, 600);
+  return () => { stopped = true; clearTimeout(infoTimer); clearTimeout(overlayTimer); };
+}