Add cached-first TeamSnap reads

frontend/src/lib/teamSnapCache.ts

@@ -0,0 +1,86 @@
+import type { QueryKey } from "@tanstack/react-query";
+
+import { queryClient } from "./queryClient";
+import { readCachedValue, writeCachedValue } from "./offlineCache";
+
+const inFlightRequests = new Map<string, Promise<unknown>>();
+
+export function normalizeTeamSnapCacheScope(scope?: string | number | null): string {
+  const value = scope == null ? "" : String(scope).trim();
+  return value || "anonymous";
+}
+
+function buildCacheParts(scope: string | number | null | undefined, resource: string, parts: readonly unknown[]): readonly unknown[] {
+  return ["teamsnap", normalizeTeamSnapCacheScope(scope), resource, ...parts];
+}
+
+function cacheKey(parts: readonly unknown[]): string {
+  return JSON.stringify(parts);
+}
+
+function startFreshFetch<T>(
+  cacheParts: readonly unknown[],
+  queryKey: QueryKey,
+  fetchFresh: () => Promise<T>,
+): Promise<T> {
+  const key = cacheKey(cacheParts);
+  const existing = inFlightRequests.get(key);
+  if (existing) {
+    return existing as Promise<T>;
+  }
+
+  const request = fetchFresh()
+    .then((data) => {
+      writeCachedValue(cacheParts, data);
+      queryClient.setQueryData(queryKey, data);
+      return data;
+    })
+    .finally(() => {
+      inFlightRequests.delete(key);
+    });
+
+  inFlightRequests.set(key, request);
+  return request;
+}
+
+export async function staleWhileRevalidateTeamSnap<T>({
+  cacheParts,
+  queryKey,
+  fetchFresh,
+}: {
+  cacheParts: readonly unknown[];
+  queryKey: QueryKey;
+  fetchFresh: () => Promise<T>;
+}): Promise<T> {
+  const cached = readCachedValue<T>(cacheParts);
+  if (cached) {
+    void startFreshFetch(cacheParts, queryKey, fetchFresh).catch(() => undefined);
+    return cached.data;
+  }
+
+  return startFreshFetch(cacheParts, queryKey, fetchFresh);
+}
+
+export const teamSnapQueryKeys = {
+  me(scope?: string | number | null): QueryKey {
+    return buildCacheParts(scope, "me", []);
+  },
+  teams(scope?: string | number | null): QueryKey {
+    return buildCacheParts(scope, "teams", []);
+  },
+  members(scope: string | number | null | undefined, teamId: string): QueryKey {
+    return buildCacheParts(scope, "members", [teamId]);
+  },
+  events(scope: string | number | null | undefined, teamId: string): QueryKey {
+    return buildCacheParts(scope, "events", [teamId]);
+  },
+  availabilities(scope: string | number | null | undefined, teamId: string, eventId?: string): QueryKey {
+    return buildCacheParts(scope, "availabilities", [teamId, eventId ?? ""]);
+  },
+  assignments(scope: string | number | null | undefined, teamId: string, eventId?: string): QueryKey {
+    return buildCacheParts(scope, "assignments", [teamId, eventId ?? ""]);
+  },
+  eventLineup(scope: string | number | null | undefined, teamId: string, eventId: string): QueryKey {
+    return buildCacheParts(scope, "eventLineup", [teamId, eventId]);
+  },
+};