feat: complete account-bound profile switching and hardening (#78)

src/ipc/switchGuard.ts

@@ -0,0 +1,80 @@
+import { logger } from '../utils/logger';
+
+type SwitchOwner = 'local-account-switch' | 'cloud-account-switch';
+
+interface SwitchTask {
+  owner: SwitchOwner;
+  action: () => Promise<unknown>;
+  resolve: (value: unknown) => void;
+  reject: (reason?: unknown) => void;
+}
+
+let activeSwitchOwner: SwitchOwner | null = null;
+const pendingQueue: SwitchTask[] = [];
+let processing = false;
+
+function processQueue(): void {
+  if (processing) {
+    return;
+  }
+
+  const nextTask = pendingQueue.shift();
+  if (!nextTask) {
+    return;
+  }
+
+  processing = true;
+  activeSwitchOwner = nextTask.owner;
+  logger.info(`Acquired switch guard: ${nextTask.owner}`);
+
+  Promise.resolve()
+    .then(nextTask.action)
+    .then((result) => {
+      nextTask.resolve(result);
+    })
+    .catch((error) => {
+      nextTask.reject(error);
+    })
+    .finally(() => {
+      logger.info(`Released switch guard: ${nextTask.owner}`);
+      activeSwitchOwner = null;
+      processing = false;
+      processQueue();
+    });
+}
+
+export async function runWithSwitchGuard<T>(
+  owner: SwitchOwner,
+  action: () => Promise<T>,
+): Promise<T> {
+  return await new Promise<T>((resolve, reject) => {
+    pendingQueue.push({
+      owner,
+      action: async () => await action(),
+      resolve: (value) => {
+        resolve(value as T);
+      },
+      reject,
+    });
+    logger.info(
+      `Queued switch request: ${owner} (active=${activeSwitchOwner || 'none'}, pending=${pendingQueue.length})`,
+    );
+    processQueue();
+  });
+}
+
+export function getActiveSwitchOwner(): SwitchOwner | null {
+  return activeSwitchOwner;
+}
+
+export function getSwitchGuardSnapshot(): {
+  activeOwner: SwitchOwner | null;
+  pendingOwners: SwitchOwner[];
+  pendingCount: number;
+} {
+  return {
+    activeOwner: activeSwitchOwner,
+    pendingOwners: pendingQueue.map((item) => item.owner),
+    pendingCount: pendingQueue.length,
+  };
+}