require 'formula'

# Was a Framework build requested?
def build_framework?; ARGV.include? '--framework'; end

# Are we installed or installing as a Framework?
def as_framework?
  (self.installed? and File.exists? prefix+"Frameworks/Python.framework") or build_framework?
end

class Distribute < Formula
  url 'http://pypi.python.org/packages/source/d/distribute/distribute-0.6.27.tar.gz'
  md5 'ecd75ea629fee6d59d26f88c39b2d291'
end

 class Pip < Formula
   url 'http://pypi.python.org/packages/source/p/pip/pip-1.1.tar.gz'
   md5 '62a9f08dd5dc69d76734568a6c040508'
 end

class Python < Formula
  homepage 'http://www.python.org/'
  url 'http://www.python.org/ftp/python/2.7.3/Python-2.7.3.tar.bz2'
  md5 'c57477edd6d18bd9eeca2f21add73919'

  depends_on 'pkg-config' => :build
  depends_on 'readline' => :optional # Prefer over OS X's libedit
  depends_on 'sqlite'   => :optional # Prefer over OS X's older version
  depends_on 'gdbm'     => :optional

  def options
    [
      ["--framework", "Do a 'Framework' build instead of a UNIX-style build."],
      ["--universal", "Build for both 32 & 64 bit Intel."],
      ["--static", "Build static libraries."]
    ]
  end

  # Skip binaries so modules will load; skip lib because it is mostly Python files
  skip_clean ['bin', 'lib']

  def install
    # Python requires -fwrapv for proper Decimal division with Clang. See:
    # https://github.com/mxcl/homebrew/pull/10487
    # http://stackoverflow.com/questions/7590137/dividing-decimals-yields-invalid-results-in-python-2-5-to-2-7
    # https://trac.macports.org/changeset/87442
    ENV.append_to_cflags "-fwrapv"

    if build_framework? and ARGV.include? "--static"
      onoe "Cannot specify both framework and static."
      exit 99
    end

    args = ["--prefix=#{prefix}"]

    if ARGV.build_universal?
      args << "--enable-universalsdk=/" << "--with-universal-archs=intel"
    end

    if build_framework?
      args << "--enable-framework=#{prefix}/Frameworks"
    else
      args << "--enable-shared" unless ARGV.include? '--static'
    end

    # allow sqlite3 module to load extensions
    inreplace "setup.py",
      'sqlite_defines.append(("SQLITE_OMIT_LOAD_EXTENSION", "1"))', ''

    system "./configure", *args

    # HAVE_POLL is "broken" on OS X
    # See: http://trac.macports.org/ticket/18376
    inreplace 'pyconfig.h', /.*?(HAVE_POLL[_A-Z]*).*/, '#undef \1'

    system "make"
    ENV.j1 # Installs must be serialized
    system "make install"

    # Post-install, fix up the site-packages and install-scripts folders
    # so that user-installed Python software survives minor updates, such
    # as going from 2.7.0 to 2.7.1.

    # Remove the site-packages that Python created in its Cellar.
    site_packages.rmtree

    # Create a site-packages in the prefix.
    prefix_site_packages.mkpath

    # Symlink the prefix site-packages into the cellar.
    ln_s prefix_site_packages, site_packages

    # This is a fix for better interoperability with pyqt. See:
    # https://github.com/mxcl/homebrew/issues/6176
    if not as_framework?
      (bin+"pythonw").make_link bin+"python"
      (bin+"pythonw2.7").make_link bin+"python2.7"
    end

    # Tell distutils-based installers where to put scripts
    scripts_folder.mkpath
    (effective_lib+"python2.7/distutils/distutils.cfg").write <<-EOF.undent
      [install]
      install-scripts=#{scripts_folder}
    EOF

    # Install distribute and pip
    Distribute.new.brew { system "#{bin}/python", "setup.py", "install" }
    Pip.new.brew { system "#{bin}/python", "setup.py", "install" }
  end

  def caveats
    framework_caveats = <<-EOS.undent

      Framework Python was installed to:
        #{prefix}/Frameworks/Python.framework

      You may want to symlink this Framework to a standard OS X location:
        mkdir -p ~/Library/Frameworks/Python.framework/Versions
        ln -s "#{prefix}/Frameworks/Python.framework/Versions/2.7" ~/Library/Frameworks/Python.framework/Versions/2.7
        ln -s ~/Library/Frameworks/Python.framework/Versions/2.7 ~/Library/Frameworks/Python.framework/Versions/Current
        ln -s ~/Library/Frameworks/Python.framework/Versions/2.7/Python ~/Library/Frameworks/Python.framework/Python
        ln -s ~/Library/Frameworks/Python.framework/Versions/2.7/Resources ~/Library/Frameworks/Python.framework/Resources
    EOS

    general_caveats = <<-EOS.undent
      A "distutils.cfg" has been written to:
        #{effective_lib}/python2.7/distutils
      specifing the install-scripts folder as:
        #{scripts_folder}

      If you install Python packages via "pip install x" or "python setup.py install"
      (or the outdated easy_install), any provided scripts will go into the
      install-scripts folder above, so you may want to add it to your PATH.

      Distribute has been installed. To update distribute itself outside of Homebrew:
          #{scripts_folder}/pip install --upgrade distribute

      See: https://github.com/mxcl/homebrew/wiki/Homebrew-and-Python
    EOS

    s = general_caveats
    s += framework_caveats if as_framework?
    return s
  end

  # lib folder,taking into account whether we are a Framework build or not
  def effective_lib
    # If we're installed or installing as a Framework, then use that location.
    return prefix+"Frameworks/Python.framework/Versions/2.7/lib" if as_framework?
    # Otherwise use just 'lib'
    return lib
  end

  # include folder,taking into account whether we are a Framework build or not
  def effective_include
    # If we're installed or installing as a Framework, then use that location.
    return prefix+"Frameworks/Python.framework/Versions/2.7/include" if as_framework?
    # Otherwise use just 'include'
    return include
  end

  # The Cellar location of site-packages
  def site_packages
    effective_lib+"python2.7/site-packages"
  end

  # The HOMEBREW_PREFIX location of site-packages
  def prefix_site_packages
    HOMEBREW_PREFIX+"lib/python2.7/site-packages"
  end

  # Where distribute will install executable scripts
  def scripts_folder
    HOMEBREW_PREFIX+"share/python"
  end

  def test
    # See: https://github.com/mxcl/homebrew/pull/10487
    `#{bin}/python -c 'from decimal import Decimal; print Decimal(4) / Decimal(2)'`.chomp == '2'
  end
end