{-# LANGUAGE DeriveGeneric #-}

module Distribution.Backpack.FullUnitId
  ( FullUnitId (..)
  , FullDb
  , expandOpenUnitId
  , expandUnitId
  ) where

import Distribution.Backpack
import Distribution.Compat.Prelude
import Distribution.Types.ComponentId

-- Unlike OpenUnitId, which could direct to a UnitId.
data FullUnitId = FullUnitId ComponentId OpenModuleSubst
  deriving (Show, Generic)

type FullDb = DefUnitId -> FullUnitId

expandOpenUnitId :: FullDb -> OpenUnitId -> FullUnitId
expandOpenUnitId _db (IndefFullUnitId cid subst) =
  FullUnitId cid subst
expandOpenUnitId db (DefiniteUnitId uid) =
  expandUnitId db uid

expandUnitId :: FullDb -> DefUnitId -> FullUnitId
expandUnitId db uid = db uid