class Scipy < Formula
  desc "Software for mathematics, science, and engineering"
  homepage "https://www.scipy.org"
  url "https://github.com/scipy/scipy/releases/download/v1.0.0/scipy-1.0.0.tar.xz"
  sha256 "06b23f2a5db5418957facc86ead86b7752147c0461f3156f88a3da87f3dc6739"
  revision 3
  head "https://github.com/scipy/scipy.git"

  bottle do
    sha256 "392b0e6898425a895441cbc4919c4bba87e83151513805ff8ee48393b4dd20db" => :high_sierra
    sha256 "5d5216c4309757143271fdb1b40ea32d7c1ae02c7769d730ff167d5857e14e6d" => :sierra
    sha256 "a1275a19e2a7576e99539961b3da753751678b86ad4d6aceb34eee7884861924" => :el_capitan
  end

  option "without-python", "Build without python2 support"

  depends_on "swig" => :build
  depends_on "gcc" # for gfortran
  depends_on "numpy"
  depends_on "python@2" => :recommended if MacOS.version <= :snow_leopard
  depends_on "python" => :recommended

  cxxstdlib_check :skip

  # https://github.com/Homebrew/homebrew-python/issues/110
  # There are ongoing problems with gcc+accelerate.
  fails_with :gcc

  def install
    config = <<~EOS
      [DEFAULT]
      library_dirs = #{HOMEBREW_PREFIX}/lib
      include_dirs = #{HOMEBREW_PREFIX}/include
    EOS

    Pathname("site.cfg").write config

    # gfortran is gnu95
    Language::Python.each_python(build) do |python, version|
      ENV["PYTHONPATH"] = Formula["numpy"].opt_lib/"python#{version}/site-packages"
      ENV.prepend_create_path "PYTHONPATH", lib/"python#{version}/site-packages"
      system python, "setup.py", "build", "--fcompiler=gnu95"
      system python, *Language::Python.setup_install_args(prefix)
    end
  end

  # cleanup leftover .pyc files from previous installs which can cause problems
  # see https://github.com/Homebrew/homebrew-python/issues/185#issuecomment-67534979
  def post_install
    Language::Python.each_python(build) do |_python, version|
      rm_f Dir["#{HOMEBREW_PREFIX}/lib/python#{version}/site-packages/scipy/**/*.pyc"]
    end
  end

  def caveats
    if (build.with? "python@2") && !Formula["python@2"].installed?
      homebrew_site_packages = Language::Python.homebrew_site_packages
      user_site_packages = Language::Python.user_site_packages "python"
      <<~EOS
        If you use system python (that comes - depending on the OS X version -
        with older versions of numpy, scipy and matplotlib), you may need to
        ensure that the brewed packages come earlier in Python's sys.path with:
          mkdir -p #{user_site_packages}
          echo 'import sys; sys.path.insert(1, "#{homebrew_site_packages}")' >> #{user_site_packages}/homebrew.pth
      EOS
    end
  end

  test do
    Language::Python.each_python(build) do |python, _version|
      system python, "-c", "import scipy"
    end
  end
end