module Simple.SourcePlugin where

import Control.Monad.IO.Class
import Data.List (intercalate)
import Data.Maybe (isJust)
import GHC.Driver.Plugins
import GHC.Driver.Session
import GHC.Plugins
import GHC.Tc.Types
import Language.Haskell.Syntax.Extension
import GHC.Types.Avail
import GHC.Hs
import GHC.Hs.Expr
import GHC.Utils.Outputable
import GHC.Hs.ImpExp
import GHC.Hs.Decls
import GHC.Hs.Doc
import System.IO

plugin :: Plugin
plugin = defaultPlugin { parsedResultAction = parsedPlugin
                       , typeCheckResultAction = typecheckPlugin
                       , spliceRunAction = metaPlugin'
                       , interfaceLoadAction = interfaceLoadPlugin'
                       , renamedResultAction = renamedAction
                       }

parsedPlugin :: [CommandLineOption] -> ModSummary
             -> ParsedResult -> Hsc ParsedResult
parsedPlugin opts _ parsed
  = do liftIO $ putStrLn $ "parsePlugin(" ++ intercalate "," opts ++ ")"
       -- TODO: Remove #20791
       liftIO $ hFlush stdout
       return parsed

renamedAction :: [CommandLineOption]
                    -> TcGblEnv -> HsGroup GhcRn
                    -> TcM (TcGblEnv, HsGroup GhcRn)
renamedAction _ env grp
  = do liftIO $ putStrLn "typeCheckPlugin (rn)"
       -- TODO: Remove #20791
       liftIO $ hFlush stdout
       return (env, grp)

typecheckPlugin :: [CommandLineOption] -> ModSummary -> TcGblEnv -> TcM TcGblEnv
typecheckPlugin _ _ tc
  = do liftIO $ putStrLn "typeCheckPlugin (tc)"
       -- TODO: Remove #20791
       liftIO $ hFlush stdout
       return tc

metaPlugin' :: [CommandLineOption] -> LHsExpr GhcTc -> TcM (LHsExpr GhcTc)
metaPlugin' _ meta
  = do dflags <- getDynFlags
       liftIO $ putStrLn $ "metaPlugin: " ++ (showSDoc dflags $ ppr meta)
       -- TODO: Remove #20791
       liftIO $ hFlush stdout

       return meta

interfaceLoadPlugin' :: [CommandLineOption] -> ModIface -> IfM lcl ModIface
interfaceLoadPlugin' _ iface
  = do dflags <- getDynFlags
       liftIO $ putStrLn $ "interfacePlugin: "
                              ++ (showSDoc dflags $ ppr $ mi_module iface)
       -- TODO: Remove #20791
       liftIO $ hFlush stdout
       return iface