wip: optimizations

toju-app/src/app/infrastructure/persistence/app-resume.storage.ts

@@ -1,5 +1,6 @@
 import { STORAGE_KEY_GENERAL_SETTINGS, STORAGE_KEY_LAST_VIEWED_CHAT } from '../../core/constants';
 import { getUserScopedStorageKey } from '../../core/storage/current-user-storage';
+import { runWhenIdle } from '../../shared/rxjs';
 
 export interface GeneralSettings {
   reopenLastViewedChat: boolean;
@@ -15,10 +16,65 @@ export interface LastViewedChatSnapshot {
   channelId: string | null;
 }
 
+const pendingWrites = new Map<string, string | null>();
+
+let flushScheduled = false;
+let cancelScheduledFlush: (() => void) | null = null;
+
+function scheduleStorageFlush(): void {
+  if (flushScheduled) {
+    return;
+  }
+
+  flushScheduled = true;
+  cancelScheduledFlush = runWhenIdle(() => {
+    flushScheduled = false;
+    cancelScheduledFlush = null;
+
+    const snapshot = Array.from(pendingWrites.entries());
+
+    pendingWrites.clear();
+
+    for (const [key, value] of snapshot) {
+      try {
+        if (value === null) {
+          localStorage.removeItem(key);
+        } else {
+          localStorage.setItem(key, value);
+        }
+      } catch {
+        // storage not available
+      }
+    }
+  });
+}
+
+function scheduleStorageWrite(key: string, serialised: string): void {
+  pendingWrites.set(key, serialised);
+  scheduleStorageFlush();
+}
+
+function scheduleStorageRemove(key: string): void {
+  pendingWrites.set(key, null);
+  scheduleStorageFlush();
+}
+
+function readMaybePending(key: string): string | null {
+  if (pendingWrites.has(key)) {
+    return pendingWrites.get(key) ?? null;
+  }
+
+  try {
+    return localStorage.getItem(key);
+  } catch {
+    return null;
+  }
+}
+
 export function loadGeneralSettingsFromStorage(): GeneralSettings {
   try {
-    const raw = localStorage.getItem(getUserScopedStorageKey(STORAGE_KEY_GENERAL_SETTINGS))
-      ?? localStorage.getItem(STORAGE_KEY_GENERAL_SETTINGS);
+    const raw = readMaybePending(getUserScopedStorageKey(STORAGE_KEY_GENERAL_SETTINGS))
+      ?? readMaybePending(STORAGE_KEY_GENERAL_SETTINGS);
 
     if (!raw) {
       return { ...DEFAULT_GENERAL_SETTINGS };
@@ -36,17 +92,15 @@ export function saveGeneralSettingsToStorage(patch: Partial<GeneralSettings>): G
     ...patch
   });
 
-  try {
-    localStorage.setItem(getUserScopedStorageKey(STORAGE_KEY_GENERAL_SETTINGS), JSON.stringify(nextSettings));
-  } catch {}
+  scheduleStorageWrite(getUserScopedStorageKey(STORAGE_KEY_GENERAL_SETTINGS), JSON.stringify(nextSettings));
 
   return nextSettings;
 }
 
 export function loadLastViewedChatFromStorage(userId?: string | null): LastViewedChatSnapshot | null {
   try {
-    const raw = localStorage.getItem(getUserScopedStorageKey(STORAGE_KEY_LAST_VIEWED_CHAT, userId))
-      ?? localStorage.getItem(STORAGE_KEY_LAST_VIEWED_CHAT);
+    const raw = readMaybePending(getUserScopedStorageKey(STORAGE_KEY_LAST_VIEWED_CHAT, userId))
+      ?? readMaybePending(STORAGE_KEY_LAST_VIEWED_CHAT);
 
     if (!raw) {
       return null;
@@ -75,16 +129,41 @@ export function saveLastViewedChatToStorage(snapshot: LastViewedChatSnapshot): v
     return;
   }
 
-  try {
-    localStorage.setItem(getUserScopedStorageKey(STORAGE_KEY_LAST_VIEWED_CHAT, normalised.userId), JSON.stringify(normalised));
-  } catch {}
+  scheduleStorageWrite(
+    getUserScopedStorageKey(STORAGE_KEY_LAST_VIEWED_CHAT, normalised.userId),
+    JSON.stringify(normalised)
+  );
 }
 
 export function clearLastViewedChatFromStorage(userId?: string | null): void {
-  try {
-    localStorage.removeItem(getUserScopedStorageKey(STORAGE_KEY_LAST_VIEWED_CHAT, userId));
-    localStorage.removeItem(STORAGE_KEY_LAST_VIEWED_CHAT);
-  } catch {}
+  scheduleStorageRemove(getUserScopedStorageKey(STORAGE_KEY_LAST_VIEWED_CHAT, userId));
+  scheduleStorageRemove(STORAGE_KEY_LAST_VIEWED_CHAT);
+}
+
+/** Force-flush any pending app-resume writes (e.g. before unload). */
+export function flushAppResumeStorage(): void {
+  if (cancelScheduledFlush) {
+    cancelScheduledFlush();
+    cancelScheduledFlush = null;
+  }
+
+  flushScheduled = false;
+
+  const snapshot = Array.from(pendingWrites.entries());
+
+  pendingWrites.clear();
+
+  for (const [key, value] of snapshot) {
+    try {
+      if (value === null) {
+        localStorage.removeItem(key);
+      } else {
+        localStorage.setItem(key, value);
+      }
+    } catch {
+      // storage not available
+    }
+  }
 }
 
 function normaliseGeneralSettings(raw: Partial<GeneralSettings>): GeneralSettings {