Excerpt of Item's status

Model.elm

{-| These are the the states of an open item. You will notice there is a state
called `GoneTranstion` which exists under the Open. This state is a special case
that really exists only as a transition state. That is, when we want to finish
the sale of an item we cannot decide ourself it it's "sold" or "unsold" - that
is the responsibility of the server. So we will send the server a `gone` request,
which will be later decided if the item is sold or not.
So a `GoneTransition` is a very temporarye state, for until we are clear on the `SoldStatus`.
This also works the other way around. That is, when we are in `ItemClosed` state, the clerk
may still go back to `Going` or `Open` in case there was some mistake or a bid was
placed in the room in the right time.
-}
type OpenStatus
    = Open
    | Going
    | GoneTransition


type SoldStatus
    = Sold
    | Unsold


type EditableItemStatus
    = LiveOnly (EditableWebData OpenStatus)
      -- Live sale has not started, or is paused.
    | MailOnly (EditableWebData OpenStatus)


type ReadOnlyItemStatus
    = ItemClosed SoldStatus
    | SaleNotStarted
    | SaleClosed
    | Withdrawn
    | ItemNotActiveButAlreadyHasLiveBids


{-| The item status can be either open for bidding or not. We keep the exact
reason to why it could be closed.
-}
type Status
    = EditableStatus EditableItemStatus
    | ReadOnlyStatus ReadOnlyItemStatus