{-# LANGUAGE CPP #-}
{-# LANGUAGE NoImplicitPrelude #-}
{-# LANGUAGE OverloadedStrings #-}

#ifdef USE_GIT_INFO
{-# LANGUAGE TemplateHaskell #-}
#endif

-- Extracted from Main so that the Main module does not use CPP or TH,
-- and therefore doesn't need to be recompiled as often.
module BuildInfo
  ( versionString'
  , maybeGitHash
  , hpackVersion
  ) where

import Stack.Prelude
import qualified Paths_stack as Meta
import qualified Distribution.Text as Cabal (display)
import           Distribution.System (buildArch)

#ifndef HIDE_DEP_VERSIONS
import qualified Build_stack
#endif

#ifdef USE_GIT_INFO
import           GitHash (giCommitCount, giHash, tGitInfoCwdTry)
#endif

#ifdef USE_GIT_INFO
import           Options.Applicative.Simple (simpleVersion)
#endif

#ifdef USE_GIT_INFO
import           Data.Version (versionBranch)
#else
import           Data.Version (showVersion, versionBranch)
#endif

versionString' :: String
#ifdef USE_GIT_INFO
versionString' = concat $ concat
    [ [$(simpleVersion Meta.version)]
      -- Leave out number of commits for --depth=1 clone
      -- See https://github.com/commercialhaskell/stack/issues/792
    , case giCommitCount <$> $$tGitInfoCwdTry of
        Left _ -> []
        Right 1 -> []
        Right count -> [" (", show count, " commits)"]
    , [afterVersion]
    ]
#else
versionString' = showVersion Meta.version ++ afterVersion
#endif
  where
    afterVersion = concat
      [ preReleaseString
      , ' ' : Cabal.display buildArch
      , depsString
      , warningString
      ]
    preReleaseString =
      case versionBranch Meta.version of
        (_:y:_) | even y -> " PRE-RELEASE"
        (_:_:z:_) | even z -> " RELEASE-CANDIDATE"
        _ -> ""
#ifdef HIDE_DEP_VERSIONS
    depsString = " hpack-" ++ VERSION_hpack
#else
    depsString = "\nCompiled with:\n" ++ unlines (map ("- " ++) Build_stack.deps)
#endif
#ifdef SUPPORTED_BUILD
    warningString = ""
#else
    warningString = unlines
      [ ""
      , "Warning: this is an unsupported build that may use different versions of"
      , "dependencies and GHC than the officially released binaries, and therefore may"
      , "not behave identically.  If you encounter problems, please try the latest"
      , "official build by running 'stack upgrade --force-download'."
      ]
#endif

-- | If USE_GIT_INFO is enabled, the Git hash in the build directory, otherwise Nothing.
maybeGitHash :: Maybe String
maybeGitHash =
#ifdef USE_GIT_INFO
        (either (const Nothing) (Just . giHash) $$tGitInfoCwdTry)
#else
        Nothing
#endif

-- | Hpack version we're compiled against
hpackVersion :: String
hpackVersion = VERSION_hpack