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/1.37.1.tar.gz"
    sha256 "f553e7e5ab3611501b0478513f6d96f343027b04bd0317bb2c7239ebbfddf523"

    emscripten_tag = version.to_s
    resource "fastcomp" do
      url "https://github.com/kripken/emscripten-fastcomp/archive/#{emscripten_tag}.tar.gz"
      sha256 "e73d8852d78aa466519d2fc4dc902a2069e0e7cc3cc0446bb0264133c7e9c5c9"
    end

    resource "fastcomp-clang" do
      url "https://github.com/kripken/emscripten-fastcomp-clang/archive/#{emscripten_tag}.tar.gz"
      sha256 "d7c8761652eafca1eaec0484f6021c14a5e6fbfc922d0b2551e37be458e39c8d"
    end
  end

  bottle do
    cellar :any
    sha256 "dcffc8f923f474ed0d8ce48b67eafceeea3342903a950f76f43c130130e2683f" => :sierra
    sha256 "4fdcb331fcc82c2c8721d04895f0d261db5dfc9728c92466bfeb8066dd3aa1af" => :el_capitan
    sha256 "ec5ca32b012b0ff952d08872e2cf2bbb41c1e6011ab7173c6bf2c3028503e37f" => :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