class Emscripten < Formula
  desc "LLVM bytecode to JavaScript compiler"
  homepage "https://kripken.github.io/emscripten-site/"

  stable do
    url "https://github.com/kripken/emscripten/archive/1.37.36.tar.gz"
    sha256 "b2694e911ea7901f0afdcca74f0f38fe52d1e534358c14051552ba845083e43b"

    resource "fastcomp" do
      url "https://github.com/kripken/emscripten-fastcomp/archive/1.37.36.tar.gz"
      sha256 "9491b3136cdf8799506fa6a7c8c8648b0ab9bfb17d7965950ff02434d0ff802d"
    end

    resource "fastcomp-clang" do
      url "https://github.com/kripken/emscripten-fastcomp-clang/archive/1.37.36.tar.gz"
      sha256 "3b727be7779d4c6152cace41a1b67d7c43a06c4f5f7e3bffea7300d013323f99"
    end
  end

  bottle do
    cellar :any
    sha256 "b802c4e077d0431417357c925eb8a6bf0331bf675a966cfc8484c77119e42bba" => :high_sierra
    sha256 "79f6fbe651af93b36461c02fb3d9a03abe25d0d319c8305f1e7b54570ae56169" => :sierra
    sha256 "4c1ace0e74a0632b0eec69e1e8436af74e51af23120d9384747972d05be2806e" => :el_capitan
  end

  head do
    url "https://github.com/kripken/emscripten.git", :branch => "master"

    resource "fastcomp" do
      url "https://github.com/kripken/emscripten-fastcomp.git", :branch => "master"
    end

    resource "fastcomp-clang" do
      url "https://github.com/kripken/emscripten-fastcomp-clang.git", :branch => "master"
    end
  end

  needs :cxx11

  depends_on "python@2" if MacOS.version <= :snow_leopard
  depends_on "cmake" => :build
  depends_on "node"
  depends_on "closure-compiler" => :optional
  depends_on "yuicompressor"

  def install
    ENV.cxx11
    # OSX doesn't provide a "python2" binary so use "python" instead.
    python2_shebangs = `grep --recursive --files-with-matches ^#!/usr/bin/.*python2$ #{buildpath}`
    python2_shebang_files = python2_shebangs.lines.sort.uniq
    python2_shebang_files.map! { |f| Pathname(f.chomp) }
    python2_shebang_files.reject! &:symlink?
    inreplace python2_shebang_files, %r{^(#!/usr/bin/.*python)2$}, "\\1"

    # All files from the repository are required as emscripten is a collection
    # of scripts which need to be installed in the same layout as in the Git
    # repository.
    libexec.install Dir["*"]

    (buildpath/"fastcomp").install resource("fastcomp")
    (buildpath/"fastcomp/tools/clang").install resource("fastcomp-clang")

    cmake_args = std_cmake_args.reject { |s| s["CMAKE_INSTALL_PREFIX"] }
    cmake_args = [
      "-DCMAKE_BUILD_TYPE=Release",
      "-DCMAKE_INSTALL_PREFIX=#{libexec}/llvm",
      "-DLLVM_TARGETS_TO_BUILD='X86;JSBackend'",
      "-DLLVM_INCLUDE_EXAMPLES=OFF",
      "-DLLVM_INCLUDE_TESTS=OFF",
      "-DCLANG_INCLUDE_TESTS=OFF",
      "-DOCAMLFIND=/usr/bin/false",
      "-DGO_EXECUTABLE=/usr/bin/false",
    ]

    mkdir "fastcomp/build" do
      system "cmake", "..", *cmake_args
      system "make"
      system "make", "install"
    end

    %w[em++ em-config emar emcc emcmake emconfigure emlink.py emmake
       emranlib emrun emscons].each do |emscript|
      bin.install_symlink libexec/emscript
    end
  end

  def caveats; <<~EOS
    Manually set LLVM_ROOT to
      #{opt_libexec}/llvm/bin
    and comment out BINARYEN_ROOT
    in ~/.emscripten after running `emcc` for the first time.
    EOS
  end

  test do
    system bin/"emcc"
    assert_predicate testpath/".emscripten", :exist?, "Failed to create sample config"
  end
end