{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE RankNTypes #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE StandaloneDeriving #-}

-- |

-- This module provides the primary interface to the combined
-- AST/Tokens, and the functions here will ensure that any changes are
-- properly synced and propagated.

module Language.Haskell.Refact.Utils.MonadFunctions
       (
       -- * Conveniences for state access

         fetchAnnsFinal
       , getTypecheckedModule

       , getRefactStreamModified
       , setRefactStreamModified

       , getRefactInscopes

       , getRefactRenamed
       , putRefactRenamed

       , getRefactParsed
       , putRefactParsed

       -- * Annotations
       -- , addRefactAnns
       , setRefactAnns

       -- *
       , putParsedModule
       , clearParsedModule
       , getRefactFileName
       , getRefactTargetModule
       , getRefactModule
       , getRefactModuleName
       , getRefactNameMap
       , addToNameMap

       -- * New ghc-exactprint interfacing
       , liftT

       -- * State flags for managing generic traversals
       , getRefactDone
       , setRefactDone
       , clearRefactDone

       , setStateStorage
       , getStateStorage

       -- * Parsing source
       , parseDeclWithAnns

       -- * Utility
       , nameSybTransform, nameSybQuery
       , fileNameFromModSummary
       , mkNewGhcNamePure

       , logDataWithAnns
       , logAnns
       , logParsedSource
       , logExactprint

       -- * For use by the tests only
       , initRefactModule
       , initTokenCacheLayout
       , initRdrNameMap
       ) where

import Control.Monad.State
import Data.List

import qualified GHC           as GHC
import qualified GhcMonad      as GHC
import qualified Module        as GHC
import qualified Name          as GHC
import qualified Unique        as GHC

import qualified Data.Generics as SYB

import Language.Haskell.GHC.ExactPrint
import Language.Haskell.GHC.ExactPrint.Annotate
import Language.Haskell.GHC.ExactPrint.Parsers
import Language.Haskell.GHC.ExactPrint.Utils

import Language.Haskell.Refact.Utils.Monad
import Language.Haskell.Refact.Utils.TypeSyn
import Language.Haskell.Refact.Utils.Types

import qualified Data.Map as Map

-- ---------------------------------------------------------------------

-- |fetch the final annotations
fetchAnnsFinal :: RefactGhc Anns
fetchAnnsFinal = do
  Just tm <- gets rsModule
  let anns = (tkCache $ rsTokenCache tm) Map.! mainTid
  return anns

-- ---------------------------------------------------------------------

getTypecheckedModule :: RefactGhc GHC.TypecheckedModule
getTypecheckedModule = do
  mtm <- gets rsModule
  case mtm of
    Just tm -> return $ rsTypecheckedMod tm
    Nothing -> error "HaRe: file not loaded for refactoring"

getRefactStreamModified :: RefactGhc RefacResult
getRefactStreamModified = do
  Just tm <- gets rsModule
  return $ rsStreamModified tm

-- |For testing
setRefactStreamModified :: RefacResult -> RefactGhc ()
setRefactStreamModified rr = do
  logm $ "setRefactStreamModified:rr=" ++ show rr
  st <- get
  let (Just tm) = rsModule st
  put $ st { rsModule = Just (tm { rsStreamModified = rr })}
  return ()

getRefactInscopes :: RefactGhc InScopes
getRefactInscopes = GHC.getNamesInScope

getRefactRenamed :: RefactGhc GHC.RenamedSource
getRefactRenamed = do
  mtm <- gets rsModule
  let tm = gfromJust "getRefactRenamed" mtm
  return $ gfromJust "getRefactRenamed2" $ GHC.tm_renamed_source $ rsTypecheckedMod tm

putRefactRenamed :: GHC.RenamedSource -> RefactGhc ()
putRefactRenamed renamed = do
  st <- get
  mrm <- gets rsModule
  let rm = gfromJust "putRefactRenamed" mrm
  let tm = rsTypecheckedMod rm
  let tm' = tm { GHC.tm_renamed_source = Just renamed }
  let rm' = rm { rsTypecheckedMod = tm' }
  put $ st {rsModule = Just rm'}

getRefactParsed :: RefactGhc GHC.ParsedSource
getRefactParsed = do
  mtm <- gets rsModule
  let tm = gfromJust "getRefactParsed" mtm
  let t  = rsTypecheckedMod tm

  let pm = GHC.tm_parsed_module t
  return $ GHC.pm_parsed_source pm

putRefactParsed :: GHC.ParsedSource -> Anns -> RefactGhc ()
putRefactParsed parsed newAnns = do
  logm $ "putRefactParsed:setting rsStreamModified"
  st <- get
  mrm <- gets rsModule
  let rm = gfromJust "putRefactParsed" mrm
  let tm = rsTypecheckedMod rm
  -- let tk' = modifyAnns (rsTokenCache rm) (const newAnns)
  let tk' = modifyAnns (rsTokenCache rm) (mergeAnns newAnns)

  let pm = (GHC.tm_parsed_module tm) { GHC.pm_parsed_source = parsed }
  let tm' = tm { GHC.tm_parsed_module = pm }
  let rm' = rm { rsTypecheckedMod = tm', rsTokenCache = tk', rsStreamModified = RefacModified }
  put $ st {rsModule = Just rm'}

-- ---------------------------------------------------------------------

-- |Internal low level interface to access the current annotations from the
-- RefactGhc state.
getRefactAnns :: RefactGhc Anns
getRefactAnns =
  (Map.! mainTid) . tkCache . rsTokenCache . gfromJust "getRefactAnns"
    <$> gets rsModule

-- |Internal low level interface to access the current annotations from the
-- RefactGhc state.
setRefactAnns :: Anns -> RefactGhc ()
setRefactAnns anns = modifyRefactAnns (const anns)

-- |Internal low level interface to access the current annotations from the
-- RefactGhc state.
modifyRefactAnns :: (Anns -> Anns) -> RefactGhc ()
modifyRefactAnns f = do
  -- logm $ "modifyRefactAnns:setting rsStreamModified"
  st <- get
  mrm <- gets rsModule
  let rm = gfromJust "modifyRefactAnns" mrm
  let tk' = modifyAnns (rsTokenCache rm) f
  let rm' = rm { rsTokenCache = tk', rsStreamModified = RefacModified }
  put $ st {rsModule = Just rm'}

-- |Internal low level interface to access the current annotations from the
-- RefactGhc state.
modifyAnns :: TokenCache Anns -> (Anns -> Anns) -> TokenCache Anns
modifyAnns tk f = tk'
  where
    anns = (tkCache tk) Map.! mainTid
    tk' = tk {tkCache = Map.insert mainTid
                                   (f anns)
                                   (tkCache tk) }

-- ----------------------------------------------------------------------

putParsedModule :: [Comment] -> GHC.TypecheckedModule -> RefactGhc ()
putParsedModule cppComments tm = do
  st <- get
  put $ st { rsModule = initRefactModule cppComments tm }

clearParsedModule :: RefactGhc ()
clearParsedModule = do
  st <- get
  put $ st { rsModule = Nothing }

-- ---------------------------------------------------------------------

{-
-- |Replace the Located RdrName in the ParsedSource
replaceRdrName :: GHC.Located GHC.RdrName -> RefactGhc ()
replaceRdrName (GHC.L l newName) = do
  -- ++AZ++ TODO: move this body to somewhere appropriate
  logm $ "replaceRdrName:" ++ showGhcQual (l,newName)
  parsed <- getRefactParsed
  anns <- getRefactAnns
  logm $ "replaceRdrName:before:parsed=" ++ showGhc parsed
  let replaceRdr :: GHC.Located GHC.RdrName -> State Anns (GHC.Located GHC.RdrName)
      replaceRdr old@(GHC.L ln _)
        | l == ln = do
           an <- get
           let new = (GHC.L l newName)
           put $ replaceAnnKey old new an
           return new
      replaceRdr x = return x

      replaceHsVar :: GHC.LHsExpr GHC.RdrName -> State Anns (GHC.LHsExpr GHC.RdrName)
      replaceHsVar (GHC.L ln (GHC.HsVar _))
        | l == ln = return (GHC.L l (GHC.HsVar newName))
      replaceHsVar x = return x

      replaceHsTyVar (GHC.L ln (GHC.HsTyVar _))
        | l == ln = return (GHC.L l (GHC.HsTyVar newName))
      replaceHsTyVar x = return x

      replacePat (GHC.L ln (GHC.VarPat _))
        | l == ln = return (GHC.L l (GHC.VarPat newName))
      replacePat x = return x

      fn :: State Anns GHC.ParsedSource
      fn = do
             r <- SYB.everywhereM (SYB.mkM replaceRdr
                              `SYB.extM` replaceHsTyVar
                              `SYB.extM` replaceHsVar
                              `SYB.extM` replacePat) parsed
             return r
      (parsed',anns') = runState fn anns
  logm $ "replaceRdrName:after:parsed'=" ++ showGhc parsed'
  putRefactParsed parsed' emptyAnns
  setRefactAnns anns'
  return ()
-}

-- ---------------------------------------------------------------------

refactRunTransformId :: Transform a -> RefactGhc a
refactRunTransformId transform = do
  u <- gets rsUniqState
  ans <- getRefactAnns
  let (a,(ans',u'),logLines) = runTransformFrom u ans transform
  putUnique u'
  setRefactAnns ans'
  when (not (null logLines)) $ do
    logm $ intercalate "\n" logLines
  return a

-- ---------------------------------------------------------------------

instance HasTransform RefactGhc where
  liftT = refactRunTransformId

-- ---------------------------------------------------------------------

putUnique :: Int -> RefactGhc ()
putUnique u = do
  s <- get
  put $ s { rsUniqState = u }

-- ---------------------------------------------------------------------

getRefactTargetModule :: RefactGhc TargetModule
getRefactTargetModule = do
  mt <- gets rsCurrentTarget
  case mt of
    Nothing -> error $ "HaRe:getRefactTargetModule:no module loaded"
    Just t -> return t

-- ---------------------------------------------------------------------

getRefactFileName :: RefactGhc (Maybe FilePath)
getRefactFileName = do
  mtm <- gets rsModule
  case mtm of
    Nothing  -> return Nothing
    Just tm -> return $ Just (fileNameFromModSummary $ GHC.pm_mod_summary
                              $ GHC.tm_parsed_module $ rsTypecheckedMod tm)

-- ---------------------------------------------------------------------

fileNameFromModSummary :: GHC.ModSummary -> FilePath
fileNameFromModSummary modSummary = fileName
  where
    -- TODO: what if we are loading a compiled only client and do not
    -- have the original source?
    Just fileName = GHC.ml_hs_file (GHC.ms_location modSummary)

-- ---------------------------------------------------------------------

getRefactModule :: RefactGhc GHC.Module
getRefactModule = do
  mtm <- gets rsModule
  case mtm of
    Nothing  -> error $ "Hare.MonadFunctions.getRefactModule:no module loaded"
    Just tm -> do
      let t  = rsTypecheckedMod tm
      let pm = GHC.tm_parsed_module t
      return (GHC.ms_mod $ GHC.pm_mod_summary pm)

-- ---------------------------------------------------------------------

getRefactModuleName :: RefactGhc GHC.ModuleName
getRefactModuleName = do
  modu <- getRefactModule
  return $ GHC.moduleName modu

-- ---------------------------------------------------------------------

getRefactNameMap :: RefactGhc NameMap
getRefactNameMap = do
  mtm <- gets rsModule
  case mtm of
    Nothing  -> error $ "Hare.MonadFunctions.getRefacNameMap:no module loaded"
    Just tm -> return (rsNameMap tm)

-- ---------------------------------------------------------------------

addToNameMap :: GHC.SrcSpan -> GHC.Name -> RefactGhc ()
addToNameMap ss n = do
  s <- get
  let mtm = rsModule s
  case mtm of
    Nothing  -> error $ "Hare.MonadFunctions.addToNameMap:no module loaded"
    Just tm -> do
      let nm = rsNameMap tm
          nm' = Map.insert ss n nm
          mtm' = Just tm { rsNameMap = nm'}
      put s { rsModule = mtm'}

-- ---------------------------------------------------------------------

getRefactDone :: RefactGhc Bool
getRefactDone = do
  flags <- gets rsFlags
  logm $ "getRefactDone: " ++ (show (rsDone flags))
  return (rsDone flags)

setRefactDone :: RefactGhc ()
setRefactDone = do
  logm $ "setRefactDone"
  st <- get
  put $ st { rsFlags = RefFlags True }

clearRefactDone :: RefactGhc ()
clearRefactDone = do
  logm $ "clearRefactDone"
  st <- get
  put $ st { rsFlags = RefFlags False }

-- ---------------------------------------------------------------------

setStateStorage :: StateStorage -> RefactGhc ()
setStateStorage storage = do
  st <- get
  put $ st { rsStorage = storage }

getStateStorage :: RefactGhc StateStorage
getStateStorage = do
  storage <- gets rsStorage
  return storage

-- ---------------------------------------------------------------------

logDataWithAnns :: (SYB.Data a) => String -> a -> RefactGhc ()
logDataWithAnns str ast = do
  anns <- getRefactAnns
  logm $ str ++ showAnnData anns 0 ast

-- ---------------------------------------------------------------------

logExactprint :: (Annotate a) => String -> GHC.Located a -> RefactGhc ()
logExactprint str ast = do
  anns <- getRefactAnns
  logm $ str ++ "\n[" ++ exactPrint ast anns ++ "]"

-- ---------------------------------------------------------------------

logAnns :: String -> RefactGhc ()
logAnns str = do
  anns <- getRefactAnns
  logm $ str ++ showGhc anns

-- ---------------------------------------------------------------------

logParsedSource :: String -> RefactGhc ()
logParsedSource str = do
  parsed <- getRefactParsed
  logDataWithAnns str parsed

-- ---------------------------------------------------------------------

initRefactModule :: [Comment] -> GHC.TypecheckedModule -> Maybe RefactModule
initRefactModule cppComments tm
  = Just (RefMod { rsTypecheckedMod = tm
                 , rsNameMap = initRdrNameMap tm
                 , rsTokenCache = initTokenCacheLayout (relativiseApiAnnsWithComments
                                     cppComments
                                    (GHC.pm_parsed_source $ GHC.tm_parsed_module tm)
                                    (GHC.pm_annotations $ GHC.tm_parsed_module tm))
                 , rsStreamModified = RefacUnmodifed
                 })


initTokenCacheLayout :: a -> TokenCache a
initTokenCacheLayout a = TK (Map.fromList [((TId 0),a)]) (TId 0)

-- ---------------------------------------------------------------------

-- |We need the ParsedSource because it more closely reflects the actual source
-- code, but must be able to work with the renamed representation of the names
-- involved. This function constructs a map from every Located RdrName in the
-- ParsedSource to its corresponding name in the RenamedSource. It also deals
-- with the wrinkle that we need to Location of the RdrName to make sure we have
-- the right Name, but not all RdrNames have a Location.
-- This function is called before the RefactGhc monad is active.
initRdrNameMap :: GHC.TypecheckedModule -> NameMap
initRdrNameMap tm = r
  where
    parsed  = GHC.pm_parsed_source $ GHC.tm_parsed_module tm
    renamed = gfromJust "initRdrNameMap" $ GHC.tm_renamed_source tm

    checkRdr :: GHC.Located GHC.RdrName -> Maybe [(GHC.SrcSpan,GHC.RdrName)]
    checkRdr (GHC.L l n@(GHC.Unqual _)) = Just [(l,n)]
    checkRdr (GHC.L l n@(GHC.Qual _ _)) = Just [(l,n)]
    checkRdr (GHC.L _ _)= Nothing

    checkName :: GHC.Located GHC.Name -> Maybe [GHC.Located GHC.Name]
    checkName ln = Just [ln]

    rdrNames = gfromJust "initRdrNameMap" $ SYB.everything mappend (nameSybQuery checkRdr ) parsed
    names    = gfromJust "initRdrNameMap" $ SYB.everything mappend (nameSybQuery checkName) renamed

    nameMap = Map.fromList $ map (\(GHC.L l n) -> (l,n)) names

    -- If the name does not exist (e.g. a TH Splice that has been expanded, make a new one)
    -- No attempt is made to make sure that equivalent ones have equivalent names.
    lookupName l n i = case Map.lookup l nameMap of
      Just v -> v
      Nothing -> case n of
                   GHC.Unqual u -> mkNewGhcNamePure 'h' i Nothing  (GHC.occNameString u)
                   GHC.Qual q u -> mkNewGhcNamePure 'h' i (Just (GHC.Module (GHC.stringToPackageKey "") q)) (GHC.occNameString u)
                   _            -> error "initRdrNameMap:should not happen"

    r = Map.fromList $ map (\((l,n),i) -> (l,lookupName l n i)) $ zip rdrNames [1..]

-- ---------------------------------------------------------------------

mkNewGhcNamePure :: Char -> Int -> Maybe GHC.Module -> String -> GHC.Name
mkNewGhcNamePure c i maybeMod name =
  let un = GHC.mkUnique c i -- H for HaRe :)
      n = case maybeMod of
               Nothing   -> GHC.mkInternalName un      (GHC.mkVarOcc name) GHC.noSrcSpan
               Just modu -> GHC.mkExternalName un modu (GHC.mkVarOcc name) GHC.noSrcSpan
  in n

-- ---------------------------------------------------------------------

nameSybTransform :: (Monad m,SYB.Typeable t)
             => (GHC.Located GHC.RdrName -> m (GHC.Located GHC.RdrName)) -> t -> m t
nameSybTransform changer = q
  where
    q = SYB.mkM  worker
        `SYB.extM` workerBind
        `SYB.extM` workerExpr
        `SYB.extM` workerLIE
        `SYB.extM` workerHsTyVarBndr
        `SYB.extM` workerLHsType

    worker (pnt :: (GHC.Located GHC.RdrName))
      = changer pnt

    workerBind (GHC.L l (GHC.VarPat name))
      = do
        (GHC.L _ n) <- changer (GHC.L l name)
        return (GHC.L l (GHC.VarPat n))
    workerBind x = return x

    workerExpr ((GHC.L l (GHC.HsVar name)))
      = do
          (GHC.L _ n) <- changer (GHC.L l name)
          return (GHC.L l (GHC.HsVar n))
    workerExpr x = return x

    workerLIE ((GHC.L l (GHC.IEVar (GHC.L ln name))) :: (GHC.LIE GHC.RdrName))
      = do
          (GHC.L _ n) <- changer (GHC.L ln name)
          return (GHC.L l (GHC.IEVar (GHC.L ln n)))
    workerLIE x = return x

    workerHsTyVarBndr (GHC.L l (GHC.UserTyVar name))
      = do
          (GHC.L _ n) <- changer (GHC.L l name)
          return (GHC.L l (GHC.UserTyVar n))
    workerHsTyVarBndr x = return x

    workerLHsType (GHC.L l (GHC.HsTyVar name))
      = do
          (GHC.L _ n) <- changer (GHC.L l name)
          return (GHC.L l (GHC.HsTyVar n))
    workerLHsType x = return x

-- ---------------------------------------------------------------------

nameSybQuery :: (SYB.Typeable a, SYB.Typeable t)
             => (GHC.Located a -> Maybe r) -> t -> Maybe r
nameSybQuery checker = q
  where
    q = Nothing `SYB.mkQ`  worker
                `SYB.extQ` workerBind
                `SYB.extQ` workerExpr
                -- `SYB.extQ` workerLIE
                `SYB.extQ` workerHsTyVarBndr
                `SYB.extQ` workerLHsType

    worker (pnt :: (GHC.Located a))
      = checker pnt

    workerBind (GHC.L l (GHC.VarPat name))
      = checker (GHC.L l name)
    workerBind _ = Nothing

    workerExpr ((GHC.L l (GHC.HsVar name)))
      = checker (GHC.L l name)
    workerExpr _ = Nothing

    -- workerLIE ((GHC.L _l (GHC.IEVar (GHC.L ln name))) :: (GHC.LIE a))
    --   = checker (GHC.L ln name)
    -- workerLIE _ = Nothing

    workerHsTyVarBndr ((GHC.L l (GHC.UserTyVar name)))
      = checker (GHC.L l name)
    workerHsTyVarBndr _ = Nothing

    workerLHsType ((GHC.L l (GHC.HsTyVar name)))
      = checker (GHC.L l name)
    workerLHsType _ = Nothing

-- ---------------------------------------------------------------------

parseDeclWithAnns :: String -> RefactGhc (GHC.LHsDecl GHC.RdrName)
parseDeclWithAnns src = do
  u <- gets rsUniqState
  putUnique (u+1)
  let label = "HaRe-" ++ show (u + 1)
  r  <- GHC.liftIO $ withDynFlags (\df -> parseDecl df label src)
  case r of
    Left err -> error (show err)
    Right (anns,decl) -> do
      -- addRefactAnns anns
      liftT $ modifyAnnsT (mergeAnns anns)
      return decl

-- EOF

