import { useQuery } from '@tanstack/react-query';
import { supabase } from '@/lib/supabaseClient';
import { queryKeys } from '@/lib/queryKeys';

/**
 * Hook to fetch list items with entities (batch fetching to avoid N+1)
 */
export function useListItems(listId: string | undefined, enabled = true) {
  return useQuery({
    queryKey: queryKeys.lists.items(listId || ''),
    queryFn: async () => {
      if (!listId) return [];

      // Get items
      const { data: items, error: itemsError } = await supabase
        .from('user_top_list_items')
        .select('*')
        .eq('list_id', listId)
        .order('position', { ascending: true });

      if (itemsError) throw itemsError;
      if (!items || items.length === 0) return [];

      // Group by entity type for batch fetching
      const parkIds = items.filter(i => i.entity_type === 'park').map(i => i.entity_id);
      const rideIds = items.filter(i => i.entity_type === 'ride').map(i => i.entity_id);
      const companyIds = items.filter(i => i.entity_type === 'company').map(i => i.entity_id);

      // Batch fetch all entities in parallel
      const [parksResult, ridesResult, companiesResult] = await Promise.all([
        parkIds.length > 0
          ? supabase.from('parks').select('id, name, slug, park_type, location_id').in('id', parkIds)
          : Promise.resolve({ data: [] }),
        rideIds.length > 0
          ? supabase.from('rides').select('id, name, slug, category, park_id').in('id', rideIds)
          : Promise.resolve({ data: [] }),
        companyIds.length > 0
          ? supabase.from('companies').select('id, name, slug, company_type').in('id', companyIds)
          : Promise.resolve({ data: [] }),
      ]);

      // Create entities map for quick lookup
      const entitiesMap = new Map<string, any>();
      (parksResult.data || []).forEach(p => entitiesMap.set(p.id, p));
      (ridesResult.data || []).forEach(r => entitiesMap.set(r.id, r));
      (companiesResult.data || []).forEach(c => entitiesMap.set(c.id, c));

      // Map entities to items
      return items.map(item => ({
        ...item,
        entity: entitiesMap.get(item.entity_id),
      }));
    },
    enabled: enabled && !!listId,
    staleTime: 5 * 60 * 1000, // 5 minutes
    gcTime: 15 * 60 * 1000,
    refetchOnWindowFocus: false,
  });
}