Implement client-side resilience UI

Create NetworkErrorBanner, SubmissionQueueIndicator, and enhanced retry progress UI components. Integrate them into the application using a ResilienceProvider to manage network status and submission queue states. Update App.tsx to include the ResilienceProvider.

src/hooks/useSubmissionQueue.ts

@@ -0,0 +1,119 @@
+import { useState, useEffect, useCallback } from 'react';
+import { QueuedSubmission } from '@/components/submission/SubmissionQueueIndicator';
+import { useNetworkStatus } from './useNetworkStatus';
+
+// This is a placeholder implementation
+// In a real app, this would interact with IndexedDB and the actual submission system
+
+interface UseSubmissionQueueOptions {
+  autoRetry?: boolean;
+  retryDelayMs?: number;
+  maxRetries?: number;
+}
+
+export function useSubmissionQueue(options: UseSubmissionQueueOptions = {}) {
+  const {
+    autoRetry = true,
+    retryDelayMs = 5000,
+    maxRetries = 3,
+  } = options;
+
+  const [queuedItems, setQueuedItems] = useState<QueuedSubmission[]>([]);
+  const [lastSyncTime, setLastSyncTime] = useState<Date | null>(null);
+  const [nextRetryTime, setNextRetryTime] = useState<Date | null>(null);
+  const { isOnline } = useNetworkStatus();
+
+  // Load queued items from IndexedDB on mount
+  useEffect(() => {
+    loadQueueFromStorage();
+  }, []);
+
+  // Auto-retry when back online
+  useEffect(() => {
+    if (isOnline && autoRetry && queuedItems.length > 0) {
+      const timer = setTimeout(() => {
+        retryAll();
+      }, retryDelayMs);
+
+      setNextRetryTime(new Date(Date.now() + retryDelayMs));
+
+      return () => clearTimeout(timer);
+    }
+  }, [isOnline, autoRetry, queuedItems.length, retryDelayMs]);
+
+  const loadQueueFromStorage = useCallback(async () => {
+    // Placeholder: Load from IndexedDB
+    // In real implementation, this would query the offline queue
+    try {
+      // const items = await getQueuedSubmissions();
+      // setQueuedItems(items);
+    } catch (error) {
+      console.error('Failed to load queue:', error);
+    }
+  }, []);
+
+  const retryItem = useCallback(async (id: string) => {
+    setQueuedItems(prev =>
+      prev.map(item =>
+        item.id === id
+          ? { ...item, status: 'retrying' as const }
+          : item
+      )
+    );
+
+    try {
+      // Placeholder: Retry the submission
+      // await retrySubmission(id);
+      
+      // Remove from queue on success
+      setQueuedItems(prev => prev.filter(item => item.id !== id));
+      setLastSyncTime(new Date());
+    } catch (error) {
+      // Mark as failed
+      setQueuedItems(prev =>
+        prev.map(item =>
+          item.id === id
+            ? {
+                ...item,
+                status: 'failed' as const,
+                retryCount: (item.retryCount || 0) + 1,
+                error: error instanceof Error ? error.message : 'Unknown error',
+              }
+            : item
+        )
+      );
+    }
+  }, []);
+
+  const retryAll = useCallback(async () => {
+    const pendingItems = queuedItems.filter(
+      item => item.status === 'pending' || item.status === 'failed'
+    );
+
+    for (const item of pendingItems) {
+      if ((item.retryCount || 0) < maxRetries) {
+        await retryItem(item.id);
+      }
+    }
+  }, [queuedItems, maxRetries, retryItem]);
+
+  const removeItem = useCallback((id: string) => {
+    setQueuedItems(prev => prev.filter(item => item.id !== id));
+  }, []);
+
+  const clearQueue = useCallback(async () => {
+    // Placeholder: Clear from IndexedDB
+    setQueuedItems([]);
+  }, []);
+
+  return {
+    queuedItems,
+    lastSyncTime,
+    nextRetryTime,
+    retryItem,
+    retryAll,
+    removeItem,
+    clearQueue,
+    refresh: loadQueueFromStorage,
+  };
+}