{-# LANGUAGE ScopedTypeVariables #-}

module Main where

import GHC
import GHC.Utils.Monad  ( liftIO )
import Data.Maybe
import GHC.Driver.Session    ( defaultFatalMessager, defaultFlushOut )
import GHC.Types.Annotations ( AnnTarget(..), CoreAnnTarget )
import GHC.Serialized  ( deserializeWithData )
import GHC.Utils.Panic

import Config
import Annrun01_Help

import qualified Language.Haskell.TH as TH
import Data.List (sortBy)
import Data.Function

main :: IO ()
main = defaultErrorHandler defaultFatalMessager defaultFlushOut
     $ runGhc (Just cTop) $ do
    liftIO $ putStrLn "Initializing Package Database"
    dflags <- getSessionDynFlags
    let dflags' = dflags
    setSessionDynFlags dflags'

    let mod_nm = mkModuleName "Annrun01_Help"

    liftIO $ putStrLn "Setting Target"
    setTargets [Target (TargetModule mod_nm) True (homeUnitId_ dflags) Nothing]
    liftIO $ putStrLn "Loading Targets"
    load LoadAllTargets

    liftIO $ putStrLn "Finding Module"
    mod <- findModule mod_nm Nothing
    liftIO $ putStrLn "Getting Module Info"
    mod_info <- fromJust <$> getModuleInfo mod

    liftIO $ putStrLn "Showing Details For Module"
    showTargetAnns (ModuleTarget mod)
    liftIO $ putStrLn "Showing Details For Exports"
    let exports = sortBy (compare `on` getOccName) $ modInfoExports mod_info
    mapM_ (showTargetAnns . NamedTarget) exports

showTargetAnns :: CoreAnnTarget -> Ghc ()
showTargetAnns target = do
    (int_anns     :: [Int])        <- findGlobalAnns deserializeWithData target
    (mb_bool_anns :: [Maybe Bool]) <- findGlobalAnns deserializeWithData target
    (string_anns  :: [String])     <- findGlobalAnns deserializeWithData target
    (name_anns    :: [TH.Name])    <- findGlobalAnns deserializeWithData target
    liftIO $ print (int_anns, mb_bool_anns, string_anns, name_anns)