-- Copyright (C) 2015  Daniel Gröber <dxld ÄT darkboxed DOT org>
--
-- This program is free software: you can redistribute it and/or modify
-- it under the terms of the GNU Affero General Public License as published by
-- the Free Software Foundation, either version 3 of the License, or
-- (at your option) any later version.
--
-- This program is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-- GNU Affero General Public License for more details.
--
-- You should have received a copy of the GNU Affero General Public License
-- along with this program.  If not, see <http://www.gnu.org/licenses/>.

{-# LANGUAGE CPP, BangPatterns, RecordWildCards, RankNTypes, ViewPatterns #-}

#ifdef MIN_VERSION_Cabal
#undef CH_MIN_VERSION_Cabal
#define CH_MIN_VERSION_Cabal MIN_VERSION_Cabal
#endif

import Distribution.Simple.Utils (cabalVersion)
import Distribution.Simple.Configure
import Distribution.Package
  ( PackageIdentifier
  , InstalledPackageId
  , PackageId
  , packageName
  , packageVersion
  )
import Distribution.PackageDescription
  ( PackageDescription
  , GenericPackageDescription(..)
  , Flag(..)
  , FlagName(..)
  , FlagAssignment
  , Executable(..)
  , Library(..)
  , TestSuite(..)
  , Benchmark(..)
  , BuildInfo(..)
  , TestSuiteInterface(..)
  , BenchmarkInterface(..)
  , withLib
  )
import Distribution.PackageDescription.Parse
  ( readPackageDescription
  )
import Distribution.PackageDescription.Configuration
  ( flattenPackageDescription
  )
import Distribution.Simple.Program
  ( requireProgram
  , ghcProgram
  )
import Distribution.Simple.Program.Types
  ( ConfiguredProgram(..)
  )
import Distribution.Simple.Configure
  ( getPersistBuildConfig
  )
import Distribution.Simple.LocalBuildInfo
  ( LocalBuildInfo(..)
  , Component(..)
  , ComponentName(..)
  , ComponentLocalBuildInfo(..)
  , componentBuildInfo
  , externalPackageDeps
  , withComponentsLBI
  , withLibLBI
  )
import Distribution.Simple.GHC
  ( componentGhcOptions
  )
import Distribution.Simple.Program.GHC
  ( GhcOptions(..)
  , renderGhcOptions
  )
import Distribution.Simple.Setup
  ( ConfigFlags(..)
  , Flag(..)
  )
import Distribution.Simple.Build
  ( initialBuildSteps
  )
import Distribution.Simple.BuildPaths
  ( autogenModuleName
  , cppHeaderName
  , exeExtension
  )
import Distribution.Simple.Compiler
  ( PackageDB(..)
  , compilerId
  )
import Distribution.Compiler
  ( CompilerId(..)
  )
import Distribution.ModuleName
  ( components
  )
import qualified Distribution.ModuleName as C
  ( ModuleName
  )
import Distribution.Text
  ( display
  )
import Distribution.Verbosity
  ( Verbosity
  , silent
  , deafening
  , normal
  )
import Distribution.Version
  ( Version
  )

#if CH_MIN_VERSION_Cabal(1,22,0)
-- CPP >= 1.22
import Distribution.Utils.NubList
#endif

#if CH_MIN_VERSION_Cabal(1,23,0)
-- >= 1.23
import Distribution.Simple.LocalBuildInfo
  ( localUnitId
  )
#else
-- <= 1.22
import Distribution.Simple.LocalBuildInfo
  ( inplacePackageId
  )
#endif

#if CH_MIN_VERSION_Cabal(1,25,0)
-- >=1.25
import Distribution.PackageDescription
  ( unFlagName
  -- , mkFlagName
  )
import Distribution.Types.ForeignLib
  ( ForeignLib(..)
  )
import Distribution.Types.UnqualComponentName
  ( unUnqualComponentName
  )
#endif

#if CH_MIN_VERSION_Cabal(2,0,0)
-- CPP >= 2.0
import Distribution.Version
  ( versionNumbers
  , mkVersion
  )
import Distribution.Types.UnitId
  ( UnitId
  )
import Distribution.Types.MungedPackageId
  ( MungedPackageId
  )
#endif

import Control.Applicative ((<$>))
import Control.Arrow (first, second, (&&&))
import Control.Monad
import Control.Exception (catch, PatternMatchFail(..))
import Data.List
import qualified Data.Map as Map
import Data.Maybe
import Data.Monoid
import Data.IORef
import qualified Data.Version as DataVersion
import System.Environment
import System.Directory
import System.FilePath
import System.Exit
import System.IO
import System.IO.Unsafe (unsafeInterleaveIO, unsafePerformIO)
import Text.Printf

import CabalHelper.Shared.Sandbox
import CabalHelper.Shared.Common
import CabalHelper.Shared.InterfaceTypes

import CabalHelper.Runtime.Licenses

usage :: IO ()
usage = do
  prog <- getProgName
  hPutStr stderr $ "Usage: " ++ prog ++ " " ++ usageMsg
 where
   usageMsg = ""
     ++"PROJ_DIR DIST_DIR [--with-* ...] (\n"
     ++"    version\n"
     ++"  | print-lbi [--human]\n"
     ++"  | package-id\n"
     ++"  | flags\n"
     ++"  | config-flags\n"
     ++"  | non-default-config-flags\n"
     ++"  | write-autogen-files\n"
     ++"  | compiler-version\n"
     ++"  | ghc-options     [--with-inplace]\n"
     ++"  | ghc-src-options [--with-inplace]\n"
     ++"  | ghc-pkg-options [--with-inplace]\n"
     ++"  | ghc-merged-pkg-options [--with-inplace]\n"
     ++"  | ghc-lang-options [--with-inplace]\n"
     ++"  | package-db-stack\n"
     ++"  | entrypoints\n"
     ++"  | source-dirs\n"
     ++"  | licenses\n"
     ++"  ) ...\n"

commands :: [String]
commands = [ "print-lbi"
           , "package-id"
           , "flags"
           , "config-flags"
           , "non-default-config-flags"
           , "write-autogen-files"
           , "compiler-version"
           , "ghc-options"
           , "ghc-src-options"
           , "ghc-pkg-options"
           , "ghc-lang-options"
           , "package-db-stack"
           , "entrypoints"
           , "source-dirs"
           , "licenses"]

main :: IO ()
main = do
  args <- getArgs

  projdir:distdir:args' <- case args of
                    [] -> usage >> exitFailure
                    _ -> return args

  ddexists <- doesDirectoryExist distdir
  when (not ddexists) $ do
         errMsg $ "distdir '"++distdir++"' does not exist"
         exitFailure

  [cfile] <- filter isCabalFile <$> getDirectoryContents projdir

  v <- maybe silent (const deafening) . lookup  "CABAL_HELPER_DEBUG" <$> getEnvironment
  lbi <- unsafeInterleaveIO $ getPersistBuildConfig distdir
  gpd <- unsafeInterleaveIO $ readPackageDescription v (projdir </> cfile)
  let pd = localPkgDescr lbi
  let lvd = (lbi, v, distdir)

  let
      -- a =<< b $$ c   ==  (a =<< b) $$ c
      infixr 2 $$
      ($$) = ($)

      collectCmdOptions :: [String] -> [[String]]
      collectCmdOptions =
          reverse . map reverse . foldl f [] . dropWhile isOpt
       where
         isOpt = ("--" `isPrefixOf`)
         f [] x = [[x]]
         f (a:as) x
             | isOpt x = (x:a):as
             | otherwise = [x]:(a:as)

  let cmds = collectCmdOptions args'

  if any (["version"] `isPrefixOf`) cmds
    then do
      putStrLn $
       printf "using version %s of the Cabal library" (display cabalVersion)
      exitSuccess
    else return ()

  print =<< flip mapM cmds $$ \x -> do
  case x of
    "flags":[] -> do
      return $ Just $ ChResponseFlags $ sort $
        map (flagName' &&& flagDefault) $ genPackageFlags gpd

    "config-flags":[] -> do
      return $ Just $ ChResponseFlags $ sort $
        map (first unFlagName) $ configConfigurationsFlags $ configFlags lbi

    "non-default-config-flags":[] -> do
      let flagDefinitons = genPackageFlags gpd
          flagAssgnments = configConfigurationsFlags $ configFlags lbi
          nonDefaultFlags =
              [ (flag_name, val)
              | MkFlag {flagName=(unFlagName -> flag_name'), flagDefault=def_val} <- flagDefinitons
              , (unFlagName -> flag_name, val) <- flagAssgnments
              , flag_name == flag_name'
              , val /= def_val
              ]
      return $ Just $ ChResponseFlags $ sort nonDefaultFlags

    "write-autogen-files":[] -> do
      initialBuildStepsForAllComponents distdir pd lbi v
      return Nothing

    "compiler-version":[] -> do
      let CompilerId comp ver = compilerId $ compiler lbi
      return $ Just $ ChResponseVersion (show comp) (toDataVersion ver)

    "ghc-options":flags -> do
      res <- componentOptions lvd True flags id
      return $ Just $ ChResponseCompList (res ++ [(ChSetupHsName, [])])

    "ghc-src-options":flags -> do
      res <- componentOptions lvd False flags $ \opts -> mempty {
               -- Not really needed but "unexpected package db stack: []"
               ghcOptPackageDBs      = [GlobalPackageDB, UserPackageDB],

               ghcOptCppOptions      = ghcOptCppOptions opts,
               ghcOptCppIncludePath  = ghcOptCppIncludePath opts,
               ghcOptCppIncludes     = ghcOptCppIncludes opts,
               ghcOptFfiIncludes     = ghcOptFfiIncludes opts,
               ghcOptSourcePathClear = ghcOptSourcePathClear opts,
               ghcOptSourcePath      = ghcOptSourcePath opts
              }
      return $ Just $ ChResponseCompList (res ++ [(ChSetupHsName, [])])

    "ghc-pkg-options":flags -> do
      res <- componentOptions lvd True flags $ \opts -> mempty {
                       ghcOptPackageDBs = ghcOptPackageDBs opts,
                       ghcOptPackages   = ghcOptPackages opts,
                       ghcOptHideAllPackages = ghcOptHideAllPackages opts
                   }
      return $ Just $ ChResponseCompList (res ++ [(ChSetupHsName, [])])

    "ghc-merged-pkg-options":flags -> do
      res <- mconcat . map snd <$> (componentOptions' lvd True flags (\_ _ o -> return o) $ \opts -> mempty {
                       ghcOptPackageDBs = [],
                       ghcOptHideAllPackages = NoFlag,
                       ghcOptPackages   = ghcOptPackages opts
                   })

      let res' = nubPackageFlags $ res { ghcOptPackageDBs = withPackageDB lbi
                                       , ghcOptHideAllPackages = Flag True
                                       }

      Just . ChResponseList <$> renderGhcOptions' lbi v res'

    "ghc-lang-options":flags -> do
      res <- componentOptions lvd False flags $ \opts -> mempty {
                       ghcOptPackageDBs      = [GlobalPackageDB, UserPackageDB],

                       ghcOptLanguage = ghcOptLanguage opts,
                       ghcOptExtensions = ghcOptExtensions opts,
                       ghcOptExtensionMap = ghcOptExtensionMap opts
                   }
      return $ Just $ ChResponseCompList (res ++ [(ChSetupHsName, [])])

    "package-db-stack":[] -> do
      let
          pkgDb GlobalPackageDB = ChPkgGlobal
          pkgDb UserPackageDB   = ChPkgUser
          pkgDb (SpecificPackageDB s) = ChPkgSpecific s

      -- TODO: Setup.hs has access to the sandbox as well: ghc-mod#478
      return $ Just $ ChResponsePkgDbs $ map pkgDb $ withPackageDB lbi

    "entrypoints":[] -> do
      eps <- componentsMap lbi v distdir $ \c _clbi _bi ->
               return $ componentEntrypoints c
      -- MUST append Setup component at the end otherwise CabalHelper gets
      -- confused
      let eps' = eps ++ [(ChSetupHsName, ChSetupEntrypoint)]
      return $ Just $ ChResponseEntrypoints eps'

    "source-dirs":[] -> do
      res <- componentsMap lbi v distdir $$ \_ _ bi -> return $ hsSourceDirs bi
      return $ Just $ ChResponseCompList (res ++ [(ChSetupHsName, [])])

    "licenses":[] -> do
      return $ Just $ ChResponseLicenses $
             map (second (map (second toDataVersion))) $
                 displayDependencyLicenseList $
                     groupByLicense $ getDependencyInstalledPackageInfos lbi

    "print-lbi":flags ->
      case flags of
        ["--human"] -> print lbi >> return Nothing
        []          -> return $ Just $ ChResponseLbi $ show lbi

    cmd:_ | not (cmd `elem` commands) ->
            errMsg ("Unknown command: " ++ cmd) >> usage >> exitFailure
    _ ->
            errMsg "Invalid usage!" >> usage >> exitFailure

flagName' = unFlagName . flagName

-- getLibrary :: PackageDescription -> Library
-- getLibrary pd = unsafePerformIO $ do
--   lr <- newIORef (error "libraryMap: empty IORef")
--   withLib pd (writeIORef lr)
--   readIORef lr

getLibraryClbi pd lbi = unsafePerformIO $ do
  lr <- newIORef Nothing

  withLibLBI pd lbi $ \ lib clbi ->
      writeIORef lr $ Just (lib,clbi)

  readIORef lr


componentsMap :: LocalBuildInfo
              -> Verbosity
              -> FilePath
              -> (   Component
                  -> ComponentLocalBuildInfo
                  -> BuildInfo
                  -> IO a)
              -> IO [(ChComponentName, a)]
componentsMap lbi _v _distdir f = do
    let pd = localPkgDescr lbi

    lr <- newIORef []

    -- withComponentsLBI is deprecated but also exists in very old versions
    -- it's equivalent to withAllComponentsInBuildOrder in newer versions
    withComponentsLBI pd lbi $ \c clbi -> do
        let bi = componentBuildInfo c
            name = componentNameFromComponent c

        l' <- readIORef lr
        r <- f c clbi bi
        writeIORef lr $ (componentNameToCh name, r):l'

    reverse <$> readIORef lr

componentOptions' (lbi, v, distdir) inplaceFlag flags rf f = do
  let pd = localPkgDescr lbi
  componentsMap lbi v distdir $ \c clbi bi -> let
           outdir = componentOutDir lbi c
           (clbi', adopts) = case flags of
                               _ | not inplaceFlag -> (clbi, mempty)
                               ["--with-inplace"] -> (clbi, mempty)
                               [] -> removeInplaceDeps v lbi pd clbi
           opts = componentGhcOptions normal lbi bi clbi' outdir
           opts' = f opts

         in rf lbi v $ nubPackageFlags $ opts' `mappend` adopts

componentOptions (lbi, v, distdir) inplaceFlag flags f =
    componentOptions' (lbi, v, distdir) inplaceFlag flags renderGhcOptions' f

gmModuleName :: C.ModuleName -> ChModuleName
gmModuleName = ChModuleName . intercalate "." . components

exeOutDir :: LocalBuildInfo -> String -> FilePath
exeOutDir lbi exeName' =
  ----- Copied from Distribution/Simple/GHC.hs:buildOrReplExe
  let targetDir = (buildDir lbi) </> exeName'
      exeDir    = targetDir </> (exeName' ++ "-tmp")
  in exeDir


removeInplaceDeps :: Verbosity
                  -> LocalBuildInfo
                  -> PackageDescription
                  -> ComponentLocalBuildInfo
                  -> (ComponentLocalBuildInfo, GhcOptions)
removeInplaceDeps _v lbi pd clbi = let
    (ideps, deps) = partition (isInplaceDep lbi) (componentPackageDeps clbi)
    hasIdeps = not $ null ideps
    libopts =
      case getLibraryClbi pd lbi of
        Just (lib, libclbi) | hasIdeps ->
          let
            libbi = libBuildInfo lib
            liboutdir = componentOutDir lbi (CLib lib)
          in
            (componentGhcOptions normal lbi libbi libclbi liboutdir) {
                ghcOptPackageDBs = []
            }
        _ -> mempty
    clbi' = clbi { componentPackageDeps = deps }
  in (clbi', libopts)

initialBuildStepsForAllComponents distdir pd lbi v =
  initialBuildSteps distdir pd lbi v






#if !CH_MIN_VERSION_Cabal(1,25,0)
-- CPP < 1.25
unFlagName (FlagName n) = n
-- mkFlagName n = FlagName n
#endif

toDataVersion :: Version -> DataVersion.Version
--fromDataVersion :: DataVersion.Version -> Version
#if CH_MIN_VERSION_Cabal(2,0,0)
toDataVersion v = DataVersion.Version (versionNumbers v) []
--fromDataVersion (DataVersion.Version vs _) = mkVersion vs
#else
toDataVersion = id
--fromDataVersion = id
#endif

componentNameToCh CLibName = ChLibName
#if CH_MIN_VERSION_Cabal(1,25,0)
-- CPP >= 1.25
componentNameToCh (CSubLibName n) = ChSubLibName $ unUnqualComponentName' n
componentNameToCh (CFLibName   n) = ChFLibName $ unUnqualComponentName' n
#endif
componentNameToCh (CExeName n) = ChExeName $ unUnqualComponentName' n
componentNameToCh (CTestName n) = ChTestName $ unUnqualComponentName' n
componentNameToCh (CBenchName n) = ChBenchName $ unUnqualComponentName' n

#if CH_MIN_VERSION_Cabal(1,25,0)
-- CPP >= 1.25
unUnqualComponentName' = unUnqualComponentName
#else
unUnqualComponentName' = id
#endif

#if !CH_MIN_VERSION_Cabal(1,25,0)
-- CPP < 1.25
componentNameFromComponent (CLib Library {}) = CLibName
#elif CH_MIN_VERSION_Cabal(1,25,0)
-- CPP >= 1.25 (redundant)
componentNameFromComponent (CLib Library { libName = Nothing }) = CLibName
componentNameFromComponent (CLib Library { libName = Just n })  = CSubLibName n
componentNameFromComponent (CFLib ForeignLib {..}) = CFLibName foreignLibName
#endif
componentNameFromComponent (CExe Executable {..}) = CExeName exeName
componentNameFromComponent (CTest TestSuite {..}) = CTestName testName
componentNameFromComponent (CBench Benchmark {..}) = CBenchName benchmarkName

componentOutDir lbi (CLib Library {..})= buildDir lbi
componentOutDir lbi (CExe Executable {..})= exeOutDir lbi (unUnqualComponentName' exeName)
componentOutDir lbi (CTest TestSuite { testInterface = TestSuiteExeV10 _ _, ..}) =
    exeOutDir lbi (unUnqualComponentName' testName)
componentOutDir lbi (CTest TestSuite { testInterface = TestSuiteLibV09 _ _, ..}) =
    exeOutDir lbi (unUnqualComponentName' testName ++ "Stub")
componentOutDir lbi (CBench Benchmark { benchmarkInterface = BenchmarkExeV10 _ _, ..})=
    exeOutDir lbi (unUnqualComponentName' benchmarkName)

componentEntrypoints :: Component -> ChEntrypoint
componentEntrypoints (CLib Library {..})
    = ChLibEntrypoint
        (map gmModuleName exposedModules)
        (map gmModuleName $ otherModules libBuildInfo)
componentEntrypoints (CExe Executable {..})
    = ChExeEntrypoint modulePath (map gmModuleName $ otherModules buildInfo)
componentEntrypoints (CTest TestSuite { testInterface = TestSuiteExeV10 _ fp, ..})
    = ChExeEntrypoint fp (map gmModuleName $ otherModules testBuildInfo)
componentEntrypoints (CTest TestSuite { testInterface = TestSuiteLibV09 _ mn, ..})
    = ChLibEntrypoint [gmModuleName mn] (map gmModuleName $ otherModules testBuildInfo)
componentEntrypoints (CTest TestSuite {})
    = ChLibEntrypoint [] []
componentEntrypoints (CBench Benchmark { benchmarkInterface = BenchmarkExeV10 _  fp, ..})
    = ChExeEntrypoint fp (map gmModuleName $ otherModules benchmarkBuildInfo)
componentEntrypoints (CBench Benchmark {})
    = ChLibEntrypoint [] []


#if CH_MIN_VERSION_Cabal(2,0,0)
isInplaceDep :: LocalBuildInfo -> (UnitId, MungedPackageId) -> Bool
isInplaceDep lbi (mpid, pid) = localUnitId lbi == mpid
#else
isInplaceDep :: LocalBuildInfo -> (InstalledPackageId, PackageId) -> Bool
#  if CH_MIN_VERSION_Cabal(1,23,0)
-- CPP >= 1.23
isInplaceDep lbi (ipid, _pid) = localUnitId lbi == ipid
#  else
-- CPP <= 1.22
isInplaceDep _lbi (ipid, pid) = inplacePackageId pid == ipid
#  endif
#endif

#if CH_MIN_VERSION_Cabal(1,22,0)
-- CPP >= 1.22
-- >= 1.22 uses NubListR
nubPackageFlags opts = opts
#else
nubPackageFlags opts = opts { ghcOptPackages = nub $ ghcOptPackages opts }
#endif

renderGhcOptions' :: LocalBuildInfo
                  -> Verbosity
                  -> GhcOptions
                  -> IO [String]
#if !CH_MIN_VERSION_Cabal(1,20,0)
renderGhcOptions' lbi v opts = do
-- CPP < 1.20
  (ghcProg, _) <- requireProgram v ghcProgram (withPrograms lbi)
  let Just ghcVer = programVersion ghcProg
  return $ renderGhcOptions ghcVer opts
#elif CH_MIN_VERSION_Cabal(1,20,0) && !CH_MIN_VERSION_Cabal(1,24,0)
renderGhcOptions' lbi _v opts = do
-- CPP >= 1.20 && < 1.24
  return $ renderGhcOptions (compiler lbi) opts
#else
renderGhcOptions' lbi _v opts = do
-- CPP >= 1.24
  return $ renderGhcOptions (compiler lbi) (hostPlatform lbi) opts
#endif