import Distribution.Helper
import System.Environment.Extra (lookupEnv)
import System.Posix.Env (setEnv)
import System.Process
import System.Exit
import Data.Maybe
import Data.Version
import Data.Functor
import Control.Exception as E
import Control.Arrow
import Prelude

import CabalHelper.Common
import CabalHelper.Compile
import CabalHelper.Types


main :: IO ()
main = do
  flip (setEnv "HOME") True =<< fromMaybe "/tmp" <$> lookupEnv "TMPDIR"
  _ <- rawSystem "cabal" ["update"]

  writeAutogenFiles' $ defaultQueryEnv "." "./dist"

  let parseVer' "HEAD" = Left HEAD
      parseVer' v = Right $ parseVer v

  let vers :: [(Version, [Either HEAD Version])]
      vers = map (parseVer *** map parseVer') [
               ("7.4", [ -- "1.14.0" -- not supported at runtime
                       ]),

               ("7.6", [ "1.16.0"
                       , "1.16.0.1"
                       , "1.16.0.2"
                       , "1.16.0.3"
                       ]),

               ("7.8", [
                         "1.18.0"
                       , "1.18.1"
                       , "1.18.1.1"
                       , "1.18.1.2"
                       , "1.18.1.3"
                       , "1.18.1.4"
                       , "1.18.1.5"
                       , "1.18.1.6"
                       , "1.18.1.7"

                       , "1.20.0.0"
                       , "1.20.0.1"
                       , "1.20.0.2"
                       , "1.20.0.3"
                       , "1.20.0.4"
                       , "1.22.0.0"
                       , "1.22.1.0"
                       , "1.22.1.1"
                       ]),

               ("7.10", [
                         "1.22.2.0"
                       , "1.22.3.0"
                       , "1.22.4.0"
                       , "1.22.5.0"
                       , "1.22.6.0"
                       , "1.22.7.0"
                       , "1.22.8.0"
                       ]),
               ("8.0", [
                         "1.24.0.0"
                       , "1.24.1.0"
                       , "1.24.2.0"
                       , "HEAD"
                       ])
             ]

  ghcVer <- majorVer <$> ghcVersion defaultOptions

  let cabalVers = reverse $ concat $ map snd $ dropWhile ((<ghcVer) . fst) vers

  rvs <- mapM compilePrivatePkgDb cabalVers

  let printStatus (cv, rv) = putStrLn $ "- Cabal "++show cv++" "++status
        where status = case rv of
                         Right _ ->
                             "suceeded"
                         Left rvc ->
                             "failed (exit code "++show rvc++")"

  let drvs = cabalVers `zip` rvs

  mapM_ printStatus (cabalVers `zip` rvs)
  if any isLeft' $ map snd $ filter ((/=Left HEAD) . fst) drvs
     then exitFailure
     else exitSuccess

 where
   isLeft' (Left _) = True
   isLeft' (Right _) = False

data HEAD = HEAD deriving (Eq, Show)

compilePrivatePkgDb :: Either HEAD Version -> IO (Either ExitCode FilePath)
compilePrivatePkgDb (Left HEAD) = do
    _ <- rawSystem "rm" [ "-r", "/tmp/.ghc-mod" ]
    (db, commit) <- installCabalHEAD defaultOptions { verbose = True } `E.catch`
        \(SomeException ex) ->
            error $ "Installing cabal HEAD failed: " ++ show ex
    compileWithPkg "." (Just db) (Left commit)
compilePrivatePkgDb (Right cabalVer) = do
    _ <- rawSystem "rm" [ "-r", "/tmp/.ghc-mod" ]
    db <- installCabal defaultOptions { verbose = True } cabalVer `E.catch`
        \(SomeException _) ->
            errorInstallCabal cabalVer "dist"
    compileWithPkg "." (Just db) (Right cabalVer)

compileWithPkg :: FilePath
               -> Maybe FilePath
               -> Either String Version
               -> IO (Either ExitCode FilePath)
compileWithPkg chdir mdb ver =
    compile "dist" defaultOptions { verbose = True } $
      Compile chdir Nothing mdb ver [cabalPkgId ver]

cabalPkgId :: Either String Version -> String
cabalPkgId (Left _commitid) = "Cabal"
cabalPkgId (Right v) = "Cabal-" ++ showVersion v