Refactor: Optimize user role fetching

src/hooks/useUserRole.ts

@@ -1,6 +1,7 @@
-import { useState, useEffect } from 'react';
+import { useQuery } from '@tanstack/react-query';
 import { supabase } from '@/integrations/supabase/client';
 import { useAuth } from '@/hooks/useAuth';
+import { queryKeys } from '@/lib/queryKeys';
 
 export type UserRole = 'admin' | 'moderator' | 'user' | 'superuser';
 
@@ -15,53 +16,54 @@ export interface UserPermissions {
 
 export function useUserRole() {
   const { user } = useAuth();
-  const [roles, setRoles] = useState<UserRole[]>([]);
-  const [permissions, setPermissions] = useState<UserPermissions | null>(null);
-  const [loading, setLoading] = useState(true);
 
-  useEffect(() => {
-    if (!user) {
-      setRoles([]);
-      setLoading(false);
-      return;
-    }
+  // Fetch user roles with TanStack Query for automatic caching
+  const rolesQuery = useQuery({
+    queryKey: queryKeys.userRoles(user?.id),
+    queryFn: async () => {
+      if (!user) return [];
       
-    const fetchRoles = async () => {
-      try {
-        // Fetch user roles
-        const { data: rolesData, error: rolesError } = await supabase
+      const { data, error } = await supabase
         .from('user_roles')
         .select('role')
         .eq('user_id', user.id);
       
-        if (rolesError) {
-          console.error('Error fetching user roles:', rolesError);
-          setRoles([]);
-        } else {
-          setRoles(rolesData?.map(r => r.role as UserRole) || []);
+      if (error) {
+        console.error('Error fetching user roles:', error);
+        return [];
       }
       
-        // Fetch user permissions using the new function
-        const { data: permissionsData, error: permissionsError } = await supabase
+      return data?.map(r => r.role as UserRole) || [];
+    },
+    enabled: !!user,
+    staleTime: 5 * 60 * 1000, // 5 minutes - roles don't change often
+    gcTime: 10 * 60 * 1000,    // 10 minutes garbage collection
+  });
+
+  // Fetch user permissions with TanStack Query for automatic caching
+  const permissionsQuery = useQuery({
+    queryKey: queryKeys.userPermissions(user?.id),
+    queryFn: async () => {
+      if (!user) return null;
+      
+      const { data, error } = await supabase
         .rpc('get_user_management_permissions', { _user_id: user.id });
       
-        if (permissionsError) {
-          console.error('Error fetching user permissions:', permissionsError);
-          setPermissions(null);
-        } else {
-          setPermissions(permissionsData as unknown as UserPermissions);
+      if (error) {
+        console.error('Error fetching user permissions:', error);
+        return null;
       }
-      } catch (error: unknown) {
-        console.error('Error fetching user roles:', error);
-        setRoles([]);
-        setPermissions(null);
-      } finally {
-        setLoading(false);
-      }
-    };
       
-    fetchRoles();
-  }, [user]);
+      return data as unknown as UserPermissions;
+    },
+    enabled: !!user,
+    staleTime: 5 * 60 * 1000, // 5 minutes - permissions don't change often
+    gcTime: 10 * 60 * 1000,    // 10 minutes garbage collection
+  });
+
+  const roles = rolesQuery.data || [];
+  const permissions = permissionsQuery.data || null;
+  const loading = rolesQuery.isLoading || permissionsQuery.isLoading;
 
   const hasRole = (role: UserRole) => roles.includes(role);
   const isModerator = () => hasRole('admin') || hasRole('moderator') || hasRole('superuser');

src/lib/queryInvalidation.ts

@@ -0,0 +1,72 @@
+/**
+ * Query invalidation helpers for TanStack Query
+ * 
+ * Use these helpers to invalidate cached queries when data changes.
+ * This ensures UI stays in sync with backend state.
+ */
+
+import { useQueryClient } from '@tanstack/react-query';
+import { queryKeys } from './queryKeys';
+
+/**
+ * Hook providing query invalidation helpers
+ */
+export function useQueryInvalidation() {
+  const queryClient = useQueryClient();
+
+  return {
+    /**
+     * Invalidate user roles cache
+     * Call this after assigning/revoking roles
+     */
+    invalidateUserRoles: (userId?: string) => {
+      if (userId) {
+        queryClient.invalidateQueries({ queryKey: queryKeys.userRoles(userId) });
+      } else {
+        queryClient.invalidateQueries({ queryKey: ['user-roles'] });
+      }
+    },
+
+    /**
+     * Invalidate user permissions cache
+     * Call this after role changes that affect permissions
+     */
+    invalidateUserPermissions: (userId?: string) => {
+      if (userId) {
+        queryClient.invalidateQueries({ queryKey: queryKeys.userPermissions(userId) });
+      } else {
+        queryClient.invalidateQueries({ queryKey: ['user-permissions'] });
+      }
+    },
+
+    /**
+     * Invalidate both roles and permissions for a user
+     * Use this as a convenience method after role updates
+     */
+    invalidateUserAuth: (userId?: string) => {
+      if (userId) {
+        queryClient.invalidateQueries({ queryKey: queryKeys.userRoles(userId) });
+        queryClient.invalidateQueries({ queryKey: queryKeys.userPermissions(userId) });
+      } else {
+        queryClient.invalidateQueries({ queryKey: ['user-roles'] });
+        queryClient.invalidateQueries({ queryKey: ['user-permissions'] });
+      }
+    },
+
+    /**
+     * Invalidate moderation queue
+     * Call this after moderation actions
+     */
+    invalidateModerationQueue: () => {
+      queryClient.invalidateQueries({ queryKey: ['moderation-queue'] });
+    },
+
+    /**
+     * Invalidate moderation stats
+     * Call this after queue changes
+     */
+    invalidateModerationStats: () => {
+      queryClient.invalidateQueries({ queryKey: queryKeys.moderationStats() });
+    },
+  };
+}

src/lib/queryKeys.ts

@@ -0,0 +1,18 @@
+/**
+ * Centralized query key definitions for TanStack Query
+ * 
+ * This ensures consistent query keys across the application
+ * and makes cache invalidation easier to manage.
+ */
+
+export const queryKeys = {
+  // User-related queries
+  userRoles: (userId?: string) => ['user-roles', userId] as const,
+  userPermissions: (userId?: string) => ['user-permissions', userId] as const,
+  
+  // Moderation queue queries
+  moderationQueue: (config: Record<string, any>) => ['moderation-queue', config] as const,
+  moderationStats: () => ['moderation-stats'] as const,
+  
+  // Add more query keys as needed
+} as const;