{-# LANGUAGE CPP #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE TemplateHaskell #-}

module Cardano.Git.Rev
  ( gitRev
  ) where

import           Cardano.Prelude

import           Data.FileEmbed (dummySpaceWith)
import qualified Data.Text as T

import           Cardano.Git.RevFromGit (gitRevFromGit)

gitRev :: Text
gitRev :: Text
gitRev | Text
gitRevEmbed Text -> Text -> Bool
forall a. Eq a => a -> a -> Bool
/= Text
zeroRev = Text
gitRevEmbed
       | Text -> Bool
T.null Text
fromGit         = Text
zeroRev
       | Bool
otherwise              = Text
fromGit
 where
  -- Git revision embedded after compilation using
  -- Data.FileEmbed.injectWith. If nothing has been injected,
  -- this will be filled with 0 characters.
  gitRevEmbed :: Text
  gitRevEmbed :: Text
gitRevEmbed = ByteString -> Text
decodeUtf8 $(dummySpaceWith "gitrev" 40)

  -- Git revision found during compilation by running git. If
  -- git could not be run, then this will be empty.
#if defined(arm_HOST_ARCH)
  -- cross compiling to arm fails; due to a linker bug
  fromGit = ""
#else
  fromGit :: Text
fromGit = Text -> Text
T.strip (String -> Text
T.pack $(String
gitRevFromGit))
#endif

zeroRev :: Text
zeroRev :: Text
zeroRev = Text
"0000000000000000000000000000000000000000"