interface Priced {
  fn current_price() -> Money
}

@table(name: "products", index: [sku])
class Product {
  id:     Id
  sku:    SKU @unique
  name:   Text
  prices: multi Price
  owner:  ref Customer

  fn current_price() -> Money {
    return latest(self.prices).amount;
  }

  fn rename(name: Text) {
    self.name = name;
  }

  fn set_price(mut amount: Money) {
    self.prices = amount;
  }

  fn adopt(take other: Product) -> Product {
    return other;
  }
}

@gc
class PriceCache {
  entries: map<SKU, Money>
}

type Note {
  id:      Id
  body:    Text
  created: Timestamp = now()
}

fn discount(mut amount: Money, take pct: Int) -> Money {
  return amount;
}