require 'formula'

class NeedsSnowLeopard < Requirement
  satisfy MacOS.version >= :snow_leopard

  def message; <<-EOS.undent
    GHC requires OS X 10.6 or newer. The binary releases no longer work on
    Leopard. See the following issue for details:
        http://hackage.haskell.org/trac/ghc/ticket/6009
    EOS
  end
end

class Ghcbinary < Formula
  if Hardware.is_64_bit? and not build.build_32_bit?
    url 'http://www.haskell.org/ghc/dist/7.4.2/ghc-7.4.2-x86_64-apple-darwin.tar.bz2'
    sha1 '7c655701672f4b223980c3a1068a59b9fbd08825'
  else
    url 'http://www.haskell.org/ghc/dist/7.4.2/ghc-7.4.2-i386-apple-darwin.tar.bz2'
    sha1 '60f749893332d7c22bb4905004a67510992d8ef6'
  end
  version '7.4.2'
end

class Ghctestsuite < Formula
  url 'https://github.com/ghc/testsuite/tarball/ghc-7.4.2-release'
  sha1 '6b1f161a78a70638aacc931abfdef7dd50c7f923'
end

class Ghc < Formula
  homepage 'http://haskell.org/ghc/'
  url 'http://www.haskell.org/ghc/dist/7.4.2/ghc-7.4.2-src.tar.bz2'
  sha1 '73b3b39dc164069bc80b69f7f2963ca1814ddf3d'

  env :std

  depends_on NeedsSnowLeopard

  option '32-bit'
  option 'tests', 'Verify the build using the testsuite in Fast Mode, 5 min'

  bottle do
    revision 1
    sha1 '45b4f126123e71613564084851a8470fa4b06e6b' => :mountain_lion
    sha1 'a93d9aab9e3abfe586f9091f14057c6d90f6fdc0' => :lion
    sha1 '7d284bd3f3263be11229ac45f340fbf742ebbea6' => :snow_leopard
  end

  fails_with :clang do
    cause <<-EOS.undent
      Building with Clang configures GHC to use Clang as its preprocessor,
      which causes subsequent GHC-based builds to fail.
      EOS
  end

  def patches
    # Explained: http://hackage.haskell.org/trac/ghc/ticket/7040
    # Discussed: https://github.com/mxcl/homebrew/issues/13519
    # Remove: version > 7.4.2
    'http://hackage.haskell.org/trac/ghc/raw-attachment/ticket/7040/ghc7040.patch'
  end

  def install
    # Move the main tarball contents into a subdirectory
    (buildpath+'Ghcsource').install Dir['*']

    # Define where the subformula will temporarily install itself
    subprefix = buildpath+'subfo'

    Ghcbinary.new.brew do
      system "./configure", "--prefix=#{subprefix}"
      # Temporary j1 to stop an intermittent race condition
      system 'make', '-j1', 'install'
      ENV.prepend 'PATH', subprefix/'bin', ':'
    end

    cd 'Ghcsource' do
      # Fix an assertion when linking ghc with llvm-gcc
      # https://github.com/mxcl/homebrew/issues/13650
      ENV['LD'] = 'ld'

      if Hardware.is_64_bit? and not build.build_32_bit?
        arch = 'x86_64'
      else
        ENV.m32 # Need to force this to fix build error on internal libgmp.
        arch = 'i386'
      end

      system "./configure", "--prefix=#{prefix}",
                            "--build=#{arch}-apple-darwin"
      system 'make'
      if build.include? 'tests'
        Ghctestsuite.new.brew do
          (buildpath+'Ghcsource/config').install Dir['config/*']
          (buildpath+'Ghcsource/driver').install Dir['driver/*']
          (buildpath+'Ghcsource/mk').install Dir['mk/*']
          (buildpath+'Ghcsource/tests').install Dir['tests/*']
          (buildpath+'Ghcsource/timeout').install Dir['timeout/*']
          cd (buildpath+'Ghcsource/tests') do
            system 'make', 'CLEANUP=1', "THREADS=#{ENV.make_jobs}", 'fast'
          end
        end
      end
      ENV.j1 # Fixes an intermittent race condition
      system 'make', 'install'
    end
  end

  def caveats; <<-EOS.undent
    This brew is for GHC only; you might also be interested in haskell-platform.
    EOS
  end
end