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/1.37.38.tar.gz"
    sha256 "e83f94672c2b73f5c56ae14445613abb79443aee799e06487ffff3f2a188a39a"

    resource "fastcomp" do
      url "https://github.com/kripken/emscripten-fastcomp/archive/1.37.38.tar.gz"
      sha256 "6b4cd054e2cc59f5cfb01ff646256580f0520ae17a98e795213eb0804f1337a3"
    end

    resource "fastcomp-clang" do
      url "https://github.com/kripken/emscripten-fastcomp-clang/archive/1.37.38.tar.gz"
      sha256 "d0f0597780383e446fc680b0f0ee64c71ac7794667af27494407a33c0090b449"
    end
  end

  bottle do
    cellar :any
    sha256 "a44c87271c85bbfb3ef49138f1f561454f6f34a842805433dffe6e86997f13c9" => :high_sierra
    sha256 "ef6b9bed0984d8cfd19e18eee63a84843a4b1bc7d46a6739c0aa1d0892034355" => :sierra
    sha256 "5b32732451e6b91b6f969bd97f78179666068bfdabb8eef989e95f125bf4f1ba" => :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"
  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