{-# LANGUAGE CPP #-}
{-# LANGUAGE ConstraintKinds #-}
{-# LANGUAGE PatternSynonyms #-}

module Refact.Compat (
  -- * ApiAnnotation / GHC.Parser.ApiAnnotation
  AnnKeywordId (..),
  DeltaPos(..),

  -- * BasicTypes / GHC.Types.Basic
  Fixity(..),
  SourceText (..),

  -- * DynFlags / GHC.Driver.Session
  FlagSpec (..),
  GeneralFlag (..),
  gopt_set,
  gopt_unset,
  parseDynamicFilePragma,
  xopt_set,
  xopt_unset,
  xFlags,

  -- * ErrUtils
  Errors,
  ErrorMessages,
  onError,

  -- * FastString / GHC.Data.FastString
  FastString,
  mkFastString,

  -- * HeaderInfo / GHC.Parser.Header
  getOptions,

  -- * HsExpr / GHC.Hs.Expr
  GRHS (..),
  HsExpr (..),
  HsMatchContext (..),
  HsStmtContext (..),
  Match (..),
  MatchGroup (..),
  StmtLR (..),

  -- * HsSyn / GHC.Hs
#if __GLASGOW_HASKELL__ >= 810
  module GHC.Hs,
#else
  module HsSyn,
#endif

  -- * Name / OccName / GHC.Types.Name
  nameOccName,
  occName,
  occNameString,
  ppr,

  -- * Outputable / GHC.Utils.Outputable
  showSDocUnsafe,

  -- * Panic / GHC.Utils.Panic
  handleGhcException,

  -- * RdrName / GHC.Types.Name.Reader
  RdrName (..),
  rdrNameOcc,

  -- * SrcLoc / GHC.Types.SrcLoc
  GenLocated (..),
  pattern RealSrcLoc',
  pattern RealSrcSpan',
  RealSrcSpan (..),
  SrcSpanLess,
  combineSrcSpans,
  composeSrcSpan,
  decomposeSrcSpan,

  -- * StringBuffer
  stringToStringBuffer,

  -- * Misc
  impliedXFlags,

  -- * Non-GHC stuff
  -- AnnKeyMap,
  FunBind,
  DoGenReplacement,
  Module,
  MonadFail',
  ReplaceWorker,
  annSpanToSrcSpan,
  badAnnSpan,
  mkErr,
  parseModuleName,
  setAnnSpanFile,
  setRealSrcSpanFile,
  setSrcSpanFile,
  srcSpanToAnnSpan,
  AnnSpan,
) where

#if __GLASGOW_HASKELL__ >= 900
import GHC.Data.Bag (unitBag, bagToList )
import GHC.Data.FastString (FastString, mkFastString)
import GHC.Data.StringBuffer (stringToStringBuffer)
import GHC.Driver.Session hiding (initDynFlags)
import GHC.Parser.Annotation
import GHC.Parser.Header (getOptions)
import GHC.Types.Fixity  ( Fixity(..) )
import GHC.Utils.Error hiding (mkErr)
import GHC.Types.Name (nameOccName, occName, occNameString)
import GHC.Types.Name.Reader (RdrName (..), rdrNameOcc)
import GHC.Types.SrcLoc hiding (spans)
import GHC.Types.SourceText
import GHC.Utils.Panic (pprPanic)
import GHC.Utils.Outputable
  ( ppr,
    showSDocUnsafe,
    text,
    vcat,
  )
import GHC.Utils.Panic (handleGhcException)
#else
import ApiAnnotation
#if __GLASGOW_HASKELL__ == 810
import Bag (unitBag)
#endif
import BasicTypes (Fixity (..), SourceText (..))
import ErrUtils
  ( ErrorMessages,
    pprErrMsgBagWithLoc,
#if __GLASGOW_HASKELL__ == 810
    mkPlainErrMsg,
#endif
  )
import DynFlags hiding (initDynFlags)
import FastString (FastString, mkFastString)
import GHC.LanguageExtensions.Type (Extension (..))
import HeaderInfo (getOptions)
import Name (nameOccName)
import OccName (occName, occNameString)
import Outputable
  ( ppr,
    showSDocUnsafe,
#if __GLASGOW_HASKELL__ == 810
    pprPanic,
    text,
    vcat,
#endif
  )
import Panic (handleGhcException)
import RdrName (RdrName (..), rdrNameOcc)
import SrcLoc hiding (spans)
import StringBuffer (stringToStringBuffer)
#endif

#if __GLASGOW_HASKELL__ >= 810
import GHC.Hs hiding (Pat, Stmt)
#elif __GLASGOW_HASKELL__ <= 808
import HsSyn hiding (Pat, Stmt)
#endif

import Control.Monad.Trans.State.Strict (StateT)
import Data.Data (Data)
import qualified GHC
import Language.Haskell.GHC.ExactPrint.Parsers (Parser)
import Language.Haskell.GHC.ExactPrint.Utils
import Refact.Types (Refactoring)

#if __GLASGOW_HASKELL__ <= 806
type MonadFail' = Monad
#else
type MonadFail' = MonadFail
#endif

#if __GLASGOW_HASKELL__ >= 900
type Module = Located HsModule
#else
type Module = Located (HsModule GhcPs)
#endif

#if __GLASGOW_HASKELL__ >= 810
type Errors = ErrorMessages
onError :: String -> Errors -> a
onError s = pprPanic s . vcat . ppp
ppp :: Errors -> [SDoc]
ppp pst = concatMap unDecorated $ fmap errMsgDiagnostic $ bagToList pst
#else
type Errors = (SrcSpan, String)
onError :: String -> Errors -> a
onError _ = error . show
#endif

#if __GLASGOW_HASKELL__ >= 900
type FunBind = HsMatchContext GhcPs
#else
type FunBind = HsMatchContext RdrName
#endif

pattern RealSrcLoc' :: RealSrcLoc -> SrcLoc
#if __GLASGOW_HASKELL__ >= 900
pattern RealSrcLoc' r <- RealSrcLoc r _ where
  RealSrcLoc' r = RealSrcLoc r Nothing
#else
pattern RealSrcLoc' r <- RealSrcLoc r where
  RealSrcLoc' r = RealSrcLoc r
#endif
{-# COMPLETE RealSrcLoc', UnhelpfulLoc #-}

pattern RealSrcSpan' :: RealSrcSpan -> SrcSpan
#if __GLASGOW_HASKELL__ >= 900
pattern RealSrcSpan' r <- RealSrcSpan r _ where
  RealSrcSpan' r = RealSrcSpan r Nothing
#else
pattern RealSrcSpan' r <- RealSrcSpan r where
  RealSrcSpan' r = RealSrcSpan r
#endif
{-# COMPLETE RealSrcSpan', UnhelpfulSpan #-}

#if __GLASGOW_HASKELL__ <= 806 || __GLASGOW_HASKELL__ >= 900
composeSrcSpan :: a -> a
composeSrcSpan = id

decomposeSrcSpan :: a -> a
decomposeSrcSpan = id

type SrcSpanLess a = a
#endif

type AnnSpan = RealSrcSpan
badAnnSpan :: AnnSpan
badAnnSpan =
#if __GLASGOW_HASKELL__ >= 900
  badRealSrcSpan
#else
  noSrcSpan
#endif

srcSpanToAnnSpan :: SrcSpan -> AnnSpan
srcSpanToAnnSpan =
#if __GLASGOW_HASKELL__ >= 900
  \case RealSrcSpan l _ -> l; _ -> badRealSrcSpan
#else
  id
#endif

annSpanToSrcSpan :: AnnSpan -> SrcSpan
annSpanToSrcSpan =
#if __GLASGOW_HASKELL__ >= 900
  flip RealSrcSpan Nothing
#else
  id
#endif

setSrcSpanFile :: FastString -> SrcSpan -> SrcSpan
setSrcSpanFile file s
  | RealSrcLoc' start <- srcSpanStart s,
    RealSrcLoc' end <- srcSpanEnd s =
    let start' = mkSrcLoc file (srcLocLine start) (srcLocCol start)
        end' = mkSrcLoc file (srcLocLine end) (srcLocCol end)
     in mkSrcSpan start' end'
setSrcSpanFile _ s = s

setRealSrcSpanFile :: FastString -> RealSrcSpan -> RealSrcSpan
setRealSrcSpanFile file s = mkRealSrcSpan start' end'
  where
    start = realSrcSpanStart s
    end = realSrcSpanEnd s
    start' = mkRealSrcLoc file (srcLocLine start) (srcLocCol start)
    end' = mkRealSrcLoc file (srcLocLine end) (srcLocCol end)

setAnnSpanFile :: FastString -> AnnSpan -> AnnSpan
setAnnSpanFile =
#if __GLASGOW_HASKELL__ >= 900
  setRealSrcSpanFile
#else
  setSrcSpanFile
#endif

mkErr :: DynFlags -> SrcSpan -> String -> Errors
#if __GLASGOW_HASKELL__ >= 810
mkErr _df l s = unitBag (mkPlainMsgEnvelope l (text s))
#else
mkErr = const (,)
#endif

parseModuleName :: SrcSpan -> Parser (LocatedA GHC.ModuleName)
parseModuleName ss _ _ s =
  let newMN =  GHC.L (GHC.noAnnSrcSpan ss) (GHC.mkModuleName s)
#if __GLASGOW_HASKELL__ >= 900
#else
      newAnns = relativiseApiAnns newMN mempty
#endif
  in pure newMN

#if __GLASGOW_HASKELL__ <= 806 || __GLASGOW_HASKELL__ >= 900
type DoGenReplacement an ast a =
  (Data ast, Data a) =>
  a ->
  (LocatedAn an ast -> Bool) ->
  LocatedAn an ast ->
  LocatedAn an ast ->
  StateT Bool IO (LocatedAn an ast)
#else
type DoGenReplacement ast a =
  (Data (SrcSpanLess ast), HasSrcSpan ast, Data a) =>
  a ->
  (ast -> Bool) ->
  ast ->
  ast ->
  StateT ((Anns, AnnKeyMap), Bool) IO ast
#endif

#if __GLASGOW_HASKELL__ <= 806 || __GLASGOW_HASKELL__ >= 900
type ReplaceWorker a mod =
  (Data a, Data mod) =>
  mod ->
  Parser (GHC.LocatedA a) ->
  Int ->
  Refactoring SrcSpan ->
  IO mod
#else
type ReplaceWorker a mod =
  (Data a, HasSrcSpan a, Data mod, Data (SrcSpanLess a)) =>
  Anns ->
  mod ->
  AnnKeyMap ->
  Parser a ->
  Int ->
  Refactoring SrcSpan ->
  IO (Anns, mod, AnnKeyMap)
#endif

#if __GLASGOW_HASKELL__ < 900
-- | Copied from "Language.Haskell.GhclibParserEx.GHC.Driver.Session", in order to
-- support GHC 8.6
impliedXFlags :: [(Extension, Bool, Extension)]
impliedXFlags
-- See Note [Updating flag description in the User's Guide]
  = [ (RankNTypes,                True, ExplicitForAll)
    , (QuantifiedConstraints,     True, ExplicitForAll)
    , (ScopedTypeVariables,       True, ExplicitForAll)
    , (LiberalTypeSynonyms,       True, ExplicitForAll)
    , (ExistentialQuantification, True, ExplicitForAll)
    , (FlexibleInstances,         True, TypeSynonymInstances)
    , (FunctionalDependencies,    True, MultiParamTypeClasses)
    , (MultiParamTypeClasses,     True, ConstrainedClassMethods)  -- c.f. #7854
    , (TypeFamilyDependencies,    True, TypeFamilies)

    , (RebindableSyntax, False, ImplicitPrelude)      -- NB: turn off!

    , (DerivingVia, True, DerivingStrategies)

    , (GADTs,            True, GADTSyntax)
    , (GADTs,            True, MonoLocalBinds)
    , (TypeFamilies,     True, MonoLocalBinds)

    , (TypeFamilies,     True, KindSignatures)  -- Type families use kind signatures
    , (PolyKinds,        True, KindSignatures)  -- Ditto polymorphic kinds

    -- TypeInType is now just a synonym for a couple of other extensions.
    , (TypeInType,       True, DataKinds)
    , (TypeInType,       True, PolyKinds)
    , (TypeInType,       True, KindSignatures)

    -- AutoDeriveTypeable is not very useful without DeriveDataTypeable
    , (AutoDeriveTypeable, True, DeriveDataTypeable)

    -- We turn this on so that we can export associated type
    -- type synonyms in subordinates (e.g. MyClass(type AssocType))
    , (TypeFamilies,     True, ExplicitNamespaces)
    , (TypeOperators, True, ExplicitNamespaces)

    , (ImpredicativeTypes,  True, RankNTypes)

        -- Record wild-cards implies field disambiguation
        -- Otherwise if you write (C {..}) you may well get
        -- stuff like " 'a' not in scope ", which is a bit silly
        -- if the compiler has just filled in field 'a' of constructor 'C'
    , (RecordWildCards,     True, DisambiguateRecordFields)

    , (ParallelArrays, True, ParallelListComp)

    , (JavaScriptFFI, True, InterruptibleFFI)

    , (DeriveTraversable, True, DeriveFunctor)
    , (DeriveTraversable, True, DeriveFoldable)

    -- Duplicate record fields require field disambiguation
    , (DuplicateRecordFields, True, DisambiguateRecordFields)

    , (TemplateHaskell, True, TemplateHaskellQuotes)
    , (Strict, True, StrictData)
#if __GLASGOW_HASKELL__ >= 810
    , (StandaloneKindSignatures, False, CUSKs)
#endif
  ]
#endif