module Lib.TopContext

import Data.IORef
import Data.SortedMap
import Data.String
import Lib.Types

-- I want unique ids, to be able to lookup, update, and a Ref so
-- I don't need good Context discipline. (I seem to have made mistakes already.)


lookup : QName -> TopContext -> Maybe TopEntry
lookup nm top = lookupMap' nm top.defs

-- TODO - look at imported namespaces, and either have a map of imported names or search imported namespaces..

lookupRaw : String -> TopContext -> Maybe TopEntry
lookupRaw raw top = go $ toList top.defs
  where
    go : List (QName × TopEntry) -> Maybe TopEntry
    go Nil = Nothing
    go (((QN ns nm), entry) :: rest) = if nm == raw then Just entry else go rest

-- Maybe pretty print?


instance Show TopContext where
  show (MkTop defs metas _ _ _ _) = "\nContext:\n (\{ joinBy "\n" $ map (show ∘ snd) $ toList defs} :: Nil)"

-- TODO need to get class dependencies working
emptyTop : ∀ io. {{Monad io}} {{HasIO io}} -> io TopContext
emptyTop = do
  mcctx <- newIORef (MC Nil 0)
  errs <- newIORef $ the (List Error) Nil
  pure $ MkTop EmptyMap mcctx False errs Nil EmptyMap


setDef : QName -> FC -> Tm -> Def -> M Unit
setDef name fc ty def = do
  top <- get
  let (Nothing) = lookupMap' name top.defs
    | Just (MkEntry fc' nm' ty' def') => error fc "\{show name} is already defined at \{show fc'}"
  modify $ \case
    MkTop defs metaCtx verbose errors loaded ops =>
      let defs = (updateMap name (MkEntry fc name ty def) top.defs) in
      MkTop defs metaCtx verbose errors loaded ops


updateDef : QName -> FC -> Tm -> Def -> M Unit
updateDef name fc ty def = do
  top <- get
  let (Just (MkEntry fc' nm' ty' def')) = lookupMap' name top.defs
    | Nothing => error fc "\{show name} not declared"
  modify $ \case
    MkTop defs metaCtx verbose errors loaded ops =>
      let defs = (updateMap name (MkEntry fc' name ty def) defs) in
      MkTop defs metaCtx verbose errors loaded ops

addError : Error -> M Unit
addError err = do
  top <- get
  modifyIORef top.errors (_::_ err)