module Lib.TopContext

import Data.IORef
import Data.SortedMap
import Data.String
import Prelude
import Lib.Common
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 qn@(QN ns nm) top =
  case lookupMap' qn top.defs of
    Just entry => Just entry
    Nothing => case lookupMap' ns top.modules of
      Just mod => lookupMap' qn mod.modDefs
      Nothing => Nothing

-- 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 =
  case lookupMap' (QN top.ns raw) top.defs of
    Just entry => Just entry
    Nothing => go top.imported
  where
    go : List (List String) → Maybe TopEntry
    go Nil = Nothing
    go (ns :: nss) = case lookupMap' ns top.modules of
      Nothing => go nss
      Just mod => case lookupMap' (QN ns raw) mod.modDefs of
        Just entry => Just entry
        Nothing => go nss


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 EmptyMap 0 CheckAll)
  errs <- newIORef $ the (List Error) Nil
  pure $ MkTop EmptyMap Nil Nil EmptyMap mcctx False errs 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 mods imp ns defs metaCtx verbose errors ops =>
      let defs = (updateMap name (MkEntry fc name ty def) top.defs) in
      MkTop mods imp ns defs metaCtx verbose errors 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 mods imp ns defs metaCtx verbose errors ops =>
      let defs = (updateMap name (MkEntry fc' name ty def) defs) in
      MkTop mods imp ns defs metaCtx verbose errors ops

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