-- Copyright (c) 2019 The DAML Authors. All rights reserved.
-- SPDX-License-Identifier: Apache-2.0

{-# LANGUAGE CPP               #-}
{-# LANGUAGE FlexibleInstances #-}
{-# OPTIONS_GHC -Wno-orphans #-}

-- | Orphan instances for GHC.
--   Note that the 'NFData' instances may not be law abiding.
module Development.IDE.GHC.Orphans() where

#if MIN_VERSION_ghc(9,2,0)
import           GHC.Parser.Annotation
#endif
#if MIN_VERSION_ghc(9,0,0)
import           GHC.Data.Bag
import           GHC.Data.FastString
import qualified GHC.Data.StringBuffer      as SB
import           GHC.Types.Name.Occurrence
import           GHC.Types.SrcLoc
import           GHC.Types.Unique           (getKey)
import           GHC.Unit.Info
import           GHC.Utils.Outputable
#else
import           Bag
import           GhcPlugins
import qualified StringBuffer               as SB
import           Unique                     (getKey)
#endif


import           Retrie.ExactPrint          (Annotated)

import           Development.IDE.GHC.Compat
import           Development.IDE.GHC.Util

import           Control.DeepSeq
import           Data.Aeson
import           Data.Bifunctor             (Bifunctor (..))
import           Data.Hashable
import           Data.String                (IsString (fromString))

-- Orphan instances for types from the GHC API.
instance Show CoreModule where show = prettyPrint
instance NFData CoreModule where rnf = rwhnf
instance Show CgGuts where show = prettyPrint . cg_module
instance NFData CgGuts where rnf = rwhnf
instance Show ModDetails where show = const "<moddetails>"
instance NFData ModDetails where rnf = rwhnf
instance NFData SafeHaskellMode where rnf = rwhnf
instance Show Linkable where show = prettyPrint
instance NFData Linkable where rnf = rwhnf
instance Show PackageFlag where show = prettyPrint
instance Show InteractiveImport where show = prettyPrint
instance Show PackageName  where show = prettyPrint

#if !MIN_VERSION_ghc(9,0,1)
instance Show ComponentId  where show = prettyPrint
instance Show SourcePackageId  where show = prettyPrint

instance Show GhcPlugins.InstalledUnitId where
    show = installedUnitIdString

instance NFData GhcPlugins.InstalledUnitId where rnf = rwhnf . installedUnitIdFS

instance Hashable GhcPlugins.InstalledUnitId where
  hashWithSalt salt = hashWithSalt salt . installedUnitIdString
#else
instance Show UnitId where show = prettyPrint
deriving instance Ord SrcSpan
deriving instance Ord UnhelpfulSpanReason
#endif

instance NFData SB.StringBuffer where rnf = rwhnf

instance Show Module where
    show = moduleNameString . moduleName

instance Outputable a => Show (GenLocated SrcSpan a) where show = prettyPrint

instance (NFData l, NFData e) => NFData (GenLocated l e) where
    rnf (L l e) = rnf l `seq` rnf e

instance Show ModSummary where
    show = show . ms_mod

instance Show ParsedModule where
    show = show . pm_mod_summary

instance NFData ModSummary where
    rnf = rwhnf

#if !MIN_VERSION_ghc(8,10,0)
instance NFData FastString where
    rnf = rwhnf
#endif

#if MIN_VERSION_ghc(9,2,0)
instance Ord FastString where
    compare a b = if a == b then EQ else compare (fs_sbs a) (fs_sbs b)

instance NFData (SrcSpanAnn' a) where
    rnf = rwhnf

instance Bifunctor (GenLocated) where
    bimap f g (L l x) = L (f l) (g x)

deriving instance Functor SrcSpanAnn'
#endif

instance NFData ParsedModule where
    rnf = rwhnf

instance Show HieFile where
    show = show . hie_module

instance NFData HieFile where
    rnf = rwhnf

deriving instance Eq SourceModified
deriving instance Show SourceModified
instance NFData SourceModified where
    rnf = rwhnf

#if !MIN_VERSION_ghc(9,2,0)
instance Show ModuleName where
    show = moduleNameString
#endif
instance Hashable ModuleName where
    hashWithSalt salt = hashWithSalt salt . show


instance NFData a => NFData (IdentifierDetails a) where
    rnf (IdentifierDetails a b) = rnf a `seq` rnf (length b)

instance NFData RealSrcSpan where
    rnf = rwhnf

srcSpanFileTag, srcSpanStartLineTag, srcSpanStartColTag,
    srcSpanEndLineTag, srcSpanEndColTag :: String
srcSpanFileTag = "srcSpanFile"
srcSpanStartLineTag = "srcSpanStartLine"
srcSpanStartColTag = "srcSpanStartCol"
srcSpanEndLineTag = "srcSpanEndLine"
srcSpanEndColTag = "srcSpanEndCol"

instance ToJSON RealSrcSpan where
  toJSON spn =
      object
        [ fromString srcSpanFileTag .= unpackFS (srcSpanFile spn)
        , fromString srcSpanStartLineTag .= srcSpanStartLine spn
        , fromString srcSpanStartColTag .= srcSpanStartCol spn
        , fromString srcSpanEndLineTag .= srcSpanEndLine spn
        , fromString srcSpanEndColTag .= srcSpanEndCol spn
        ]

instance FromJSON RealSrcSpan where
  parseJSON = withObject "object" $ \obj -> do
      file <- fromString <$> (obj .: fromString srcSpanFileTag)
      mkRealSrcSpan
        <$> (mkRealSrcLoc file
                <$> obj .: fromString srcSpanStartLineTag
                <*> obj .: fromString srcSpanStartColTag
            )
        <*> (mkRealSrcLoc file
                <$> obj .: fromString srcSpanEndLineTag
                <*> obj .: fromString srcSpanEndColTag
            )

instance NFData Type where
    rnf = rwhnf

instance Show a => Show (Bag a) where
    show = show . bagToList

instance NFData HsDocString where
    rnf = rwhnf

instance Show ModGuts where
    show _ = "modguts"
instance NFData ModGuts where
    rnf = rwhnf

instance NFData (ImportDecl GhcPs) where
    rnf = rwhnf

instance Show (Annotated ParsedSource) where
  show _ = "<Annotated ParsedSource>"

instance NFData (Annotated ParsedSource) where
  rnf = rwhnf

#if MIN_VERSION_ghc(9,0,1)
instance (NFData HsModule) where
#else
instance (NFData (HsModule a)) where
#endif
  rnf = rwhnf

instance Show OccName where show = prettyPrint
instance Hashable OccName where hashWithSalt s n = hashWithSalt s (getKey $ getUnique n)