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/1.37.0.tar.gz"
    sha256 "ac1e399dd2655a735d40a50f3e107c41c9796e27c2acbc9973b8187d97ea68ef"

    emscripten_tag = version.to_s
    resource "fastcomp" do
      url "https://github.com/kripken/emscripten-fastcomp/archive/#{emscripten_tag}.tar.gz"
      sha256 "01ab1818816e3c0fcfe546f7ac1bb919ac92d9501bc9e6c06dc390e6b0ef30af"
    end

    resource "fastcomp-clang" do
      url "https://github.com/kripken/emscripten-fastcomp-clang/archive/#{emscripten_tag}.tar.gz"
      sha256 "2d7b7f17a135a5abf220a562969ee21b4af6137d746e9ffcdcc694538fb3460a"
    end
  end

  bottle do
    cellar :any
    sha256 "3a7d64d755a61dea8331f011bb6413b6bdbc73b061622a6b7a3c158feef482f0" => :sierra
    sha256 "dcca39987bb97df0238bace9653e01d5794537174d8b51805fc19637aa332e38" => :el_capitan
    sha256 "3ad32ee31385c00581a846f716a41088319b58e130b8df66c67db259ebbf7c64" => :yosemite
  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 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.undent
    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 "#{libexec}/llvm/bin/llvm-config", "--version"
  end
end