feat: implement smart foreground quota refresh with debounce

- Trigger immediate quota poll when main window gains focus.
- Add 10s debounce to prevent API spam on frequent window switching.
- Add concurrency guard to prevent overlapping poll requests.
- Reset background polling interval after manual refresh.
- Add unit tests for polling, debounce, and concurrency logic.

src/tests/unit/cloud-monitor.test.ts

@@ -0,0 +1,194 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
+import { CloudMonitorService } from '../../services/CloudMonitorService';
+import { CloudAccountRepo } from '../../ipc/database/cloudHandler';
+import { GoogleAPIService } from '../../services/GoogleAPIService';
+import { AutoSwitchService } from '../../services/AutoSwitchService';
+import { logger } from '../../utils/logger';
+
+// Mock dependencies
+vi.mock('../../ipc/database/cloudHandler');
+vi.mock('../../services/GoogleAPIService');
+vi.mock('../../services/AutoSwitchService');
+vi.mock('../../utils/logger');
+
+describe('CloudMonitorService', () => {
+  beforeEach(() => {
+    vi.useFakeTimers();
+    vi.clearAllMocks();
+    CloudMonitorService.resetStateForTesting();
+  });
+
+  afterEach(() => {
+    CloudMonitorService.stop();
+    vi.useRealTimers();
+  });
+
+  it('should start polling on start() and set up interval', async () => {
+    const pollSpy = vi.spyOn(CloudMonitorService, 'poll').mockResolvedValue(undefined);
+
+    CloudMonitorService.start();
+
+    // Should call initial poll
+    expect(pollSpy).toHaveBeenCalledTimes(1);
+
+    // Fast forward 5 minutes
+    await vi.advanceTimersByTimeAsync(1000 * 60 * 5);
+    expect(pollSpy).toHaveBeenCalledTimes(2);
+
+    pollSpy.mockRestore();
+  });
+
+  it('should poll accounts correctly', async () => {
+    const mockAccounts = [
+      {
+        id: 'acc1',
+        email: '[email protected]',
+        token: { access_token: 'valid_token', expiry_timestamp: Date.now() / 1000 + 3600 },
+      },
+    ];
+
+    vi.mocked(CloudAccountRepo.getAccounts).mockResolvedValue(mockAccounts as never);
+    vi.mocked(GoogleAPIService.fetchQuota).mockResolvedValue({ models: {} } as never);
+
+    // Start poll but don't await immediately, as it pauses
+    const pollPromise = CloudMonitorService.poll();
+
+    // Advance time to pass the 1s sleep
+    await vi.advanceTimersByTimeAsync(1000);
+
+    // Now await
+    await pollPromise;
+
+    expect(CloudAccountRepo.getAccounts).toHaveBeenCalled();
+    expect(GoogleAPIService.fetchQuota).toHaveBeenCalledWith('valid_token');
+    expect(CloudAccountRepo.updateQuota).toHaveBeenCalledWith('acc1', expect.anything());
+    expect(CloudAccountRepo.updateLastUsed).toHaveBeenCalledWith('acc1');
+    expect(AutoSwitchService.checkAndSwitchIfNeeded).toHaveBeenCalled();
+  });
+
+  it('should refresh token if expired during poll', async () => {
+    const mockAccounts = [
+      {
+        id: 'acc1',
+        email: '[email protected]',
+        token: {
+          access_token: 'old_token',
+          refresh_token: 'ref_token',
+          expiry_timestamp: Math.floor(Date.now() / 1000) - 100, // Expired
+        },
+      },
+    ];
+
+    vi.mocked(CloudAccountRepo.getAccounts).mockResolvedValue(mockAccounts as never);
+    vi.mocked(GoogleAPIService.refreshAccessToken).mockResolvedValue({
+      access_token: 'new_token',
+      expires_in: 3600,
+      token_type: 'Bearer',
+    });
+    vi.mocked(GoogleAPIService.fetchQuota).mockResolvedValue({ models: {} } as never);
+
+    // Same async pattern
+    const pollPromise = CloudMonitorService.poll();
+    await vi.advanceTimersByTimeAsync(1000);
+    await pollPromise;
+
+    expect(GoogleAPIService.refreshAccessToken).toHaveBeenCalledWith('ref_token');
+    expect(CloudAccountRepo.updateToken).toHaveBeenCalled();
+    expect(GoogleAPIService.fetchQuota).toHaveBeenCalledWith('new_token');
+  });
+
+  describe('handleAppFocus (Smart Refresh)', () => {
+    it('should trigger poll when focused after debounce time', async () => {
+      const pollSpy = vi.spyOn(CloudMonitorService, 'poll').mockResolvedValue(undefined);
+
+      CloudMonitorService.start();
+      vi.setSystemTime(Date.now() + 20000);
+
+      await CloudMonitorService.handleAppFocus();
+
+      // Called once by start, once by focus
+      expect(pollSpy).toHaveBeenCalledTimes(2);
+    });
+
+    it('should NOT trigger poll if debounced (focused too soon)', async () => {
+      const pollSpy = vi.spyOn(CloudMonitorService, 'poll').mockResolvedValue(undefined);
+
+      CloudMonitorService.start();
+
+      vi.setSystemTime(Date.now() + 1000);
+
+      await CloudMonitorService.handleAppFocus();
+
+      // Called once by start, 0 by focus
+      expect(pollSpy).toHaveBeenCalledTimes(1);
+      expect(logger.info).toHaveBeenCalledWith(expect.stringContaining('debounce active'));
+    });
+
+    it('should NOT trigger poll if already polling (concurrency guard)', async () => {
+      // Let's spy on poll to silence start's poll
+      const pollSpy = vi.spyOn(CloudMonitorService, 'poll').mockResolvedValue(undefined);
+      CloudMonitorService.start();
+      pollSpy.mockRestore(); // Restore so we can test the real guard logic
+
+      vi.setSystemTime(Date.now() + 20000);
+
+      // 2. Mock getAccounts to delay
+      let resolveGetAccounts: (value: unknown) => void;
+      const getAccountsPromise = new Promise((resolve) => {
+        resolveGetAccounts = resolve;
+      });
+      vi.mocked(CloudAccountRepo.getAccounts).mockImplementation(() => getAccountsPromise as never);
+
+      // 3. Trigger first focus -> starts poll, hangs at getAccounts or sleep
+      // Actually poll() calls getAccounts first thing.
+      const p1 = CloudMonitorService.handleAppFocus();
+
+      // Allow p1 to start execution and enter poll()
+      // We invoke one run loop
+      // But since everything is sync until first await, it should enter poll, set isPolling=true, call getAccounts, and await.
+
+      // 4. Trigger second focus immediately
+      const p2 = CloudMonitorService.handleAppFocus();
+
+      // 5. Release the first poll
+      resolveGetAccounts!([
+        { id: '1', token: { access_token: 'tok', expiry_timestamp: 9999999999 } },
+      ]);
+
+      // Advance timer for the 1s sleep inside poll
+      await vi.advanceTimersByTimeAsync(1000);
+
+      await Promise.all([p1, p2]);
+
+      expect(logger.info).toHaveBeenCalledWith(
+        expect.stringContaining('polling is already in progress'),
+      );
+      // getAccounts should be called once (by the first unblocked poll)
+      // The second one blocked by guard before calling poll
+      expect(CloudAccountRepo.getAccounts).toHaveBeenCalledTimes(1);
+    });
+
+    it('should reset interval after successful focus poll', async () => {
+      const clearIntervalSpy = vi.spyOn(global, 'clearInterval');
+      const setIntervalSpy = vi.spyOn(global, 'setInterval');
+
+      // Spy on poll to consume the start() call
+      const pollSpy = vi.spyOn(CloudMonitorService, 'poll').mockResolvedValue(undefined);
+      CloudMonitorService.start();
+      pollSpy.mockRestore(); // Restore real poll
+
+      vi.setSystemTime(Date.now() + 20000);
+
+      // Needs to handle async poll
+      vi.mocked(CloudAccountRepo.getAccounts).mockResolvedValue([]);
+
+      const focusPromise = CloudMonitorService.handleAppFocus();
+      await vi.advanceTimersByTimeAsync(1000); // For poll sleep
+      await focusPromise;
+
+      expect(clearIntervalSpy).toHaveBeenCalled();
+      // 1 for start (initial), 1 for reset = 2
+      expect(setIntervalSpy).toHaveBeenCalledTimes(2);
+    });
+  });
+});