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/1.37.10.tar.gz"
    sha256 "acd756abf7bb687d1fef733c49b3fb45305da6c777381f2699aa1a91b2ffbf9c"

    emscripten_tag = version.to_s
    resource "fastcomp" do
      url "https://github.com/kripken/emscripten-fastcomp/archive/#{emscripten_tag}.tar.gz"
      sha256 "68c2b3f7c3ba3c5fc65a1a2bbb4362c2633baf8410c23895c13fbf945b53e4a8"
    end

    resource "fastcomp-clang" do
      url "https://github.com/kripken/emscripten-fastcomp-clang/archive/#{emscripten_tag}.tar.gz"
      sha256 "b647336a964e252d1f13f94a191dbd58cc8b398cc6f83d66f49349f948283d3d"
    end
  end

  bottle do
    cellar :any
    sha256 "f67a25acc1f4d71d1cf3e8c85da143f178cf78aa71e67a7765f58e9130f12bd2" => :sierra
    sha256 "60a8ed033902c63ae70b56578d2cb86f8aafaabebb879d946acdf0f6e66b4f9d" => :el_capitan
    sha256 "23cb3b65b6fb2ab34de60bf889741906a09e41f1b6ebac14af1d5856052ef3fb" => :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