managarten/memoro/apps/mobile/features/memos/services/optimizedMemoQueries.ts

import { createAuthClient } from '@/supabase/supabaseClient';

/**
 * Optimized query to fetch memos filtered by multiple tags
 * Replaces N+1 query pattern with a single efficient query
 */
export async function fetchMemosByTags(tagIds: string[]): Promise<string[]> {
  const supabase = await createAuthClient();
  
  // Single query that gets all memos that have ALL the specified tags
  const { data, error } = await supabase
    .rpc('get_memos_with_all_tags', {
      tag_ids: tagIds
    });
    
  if (error) {
    console.error('Error fetching memos by tags:', error);
    return [];
  }
  
  return data || [];
}

/**
 * SQL function to be added to Supabase:
 * 
 * CREATE OR REPLACE FUNCTION get_memos_with_all_tags(tag_ids uuid[])
 * RETURNS TABLE(memo_id uuid) AS $$
 * BEGIN
 *   RETURN QUERY
 *   SELECT DISTINCT mt.memo_id
 *   FROM memo_tags mt
 *   WHERE mt.tag_id = ANY(tag_ids)
 *   GROUP BY mt.memo_id
 *   HAVING COUNT(DISTINCT mt.tag_id) = array_length(tag_ids, 1);
 * END;
 * $$ LANGUAGE plpgsql SECURITY DEFINER;
 */