create table if not exists manufacturers (
  id uuid primary key default gen_random_uuid(),
  slug text not null unique,
  name text not null,
  trust_status text not null default 'unknown' check (trust_status in ('trusted', 'unknown', 'untrusted')),
  notes text,
  created_at timestamptz not null default now(),
  updated_at timestamptz not null default now()
);

alter table products add column if not exists manufacturer_id uuid references manufacturers(id) on delete set null;

insert into manufacturers (slug, name)
select
  lower(regexp_replace(trim(brand), '[^[:alnum:]]+', '-', 'g')) as slug,
  brand as name
from products
where brand is not null
on conflict (slug) do update
set name = excluded.name,
    updated_at = now();

update products
set manufacturer_id = manufacturers.id
from manufacturers
where products.manufacturer_id is null
  and manufacturers.slug = lower(regexp_replace(trim(products.brand), '[^[:alnum:]]+', '-', 'g'));

create index if not exists products_manufacturer_id_idx on products(manufacturer_id);