create or replace function match_thoughts(
  query_embedding vector(1536),
  match_threshold float default 0.7,
  match_count int default 10,
  filter jsonb default '{}'::jsonb
)
returns table (
  id uuid,
  content text,
  metadata jsonb,
  similarity float,
  created_at timestamptz
)
language plpgsql
as $$
begin
  return query
  select
    t.guid,
    t.content,
    t.metadata,
    1 - (t.embedding <=> query_embedding) as similarity,
    t.created_at
  from thoughts t
  where 1 - (t.embedding <=> query_embedding) > match_threshold
    and t.archived_at is null
    and (filter = '{}'::jsonb or t.metadata @> filter)
  order by t.embedding <=> query_embedding
  limit match_count;
end;
$$;