class Rake::ExtensionTask

def binary(platform = nil)
  if platform == "java"
    "#{name}.#{RbConfig::MAKEFILE_CONFIG['DLEXT']}"
  else
    super
  end
end

def compiled_files
  FileList["#{@ext_dir}/#{@compiled_pattern}"]
end

def compiles_cross_platform
  [*@cross_platform].map { |p| "compile:#{p}" }
end

def cross_compiling(&block)
  @cross_compiling = block if block_given?
end

def cross_config_options(for_platform=nil)
  return @cross_config_options unless for_platform
  # apply options for this platform, only
  @cross_config_options.map do |option|
    if option.kind_of?(Hash)
      option[for_platform] || []
    else
      option
    end
  end.flatten
end

def cross_platform
  @cross_platform ||= 'i386-mingw32'
end

def define
  if (defined?(RUBY_ENGINE) && RUBY_ENGINE == 'ironruby')
    warn_once <<-EOF
ING: You're attempting to (cross-)compile C extensions from a platform
UBY_ENGINE}) that does not support native extensions or mkmf.rb.
n `rake` under MRI Ruby 1.8.x/1.9.x to cross/native compile.
    EOF
    return
  end
  super
  unless compiled_files.empty?
    warn "WARNING: rake-compiler found compiled files in '#{@ext_dir}' directory. Please remove them."
  end
  # only gems with 'ruby' platforms are allowed to define native tasks
  define_native_tasks if !@no_native && (@gem_spec && @gem_spec.platform == 'ruby')
  # only define cross platform functionality when enabled
  return unless @cross_compile
  if cross_platform.is_a?(Array) then
    cross_platform.each { |platf| define_cross_platform_tasks(platf) }
  else
    define_cross_platform_tasks(cross_platform)
  end
end

def define_compile_tasks(for_platform = nil, ruby_ver = RUBY_VERSION)
  # platform usage
  platf = for_platform || platform
  # lib_path
  lib_path = lib_dir
  # tmp_path
  tmp_path = "#{@tmp_dir}/#{platf}/#{@name}/#{ruby_ver}"
  stage_path = "#{@tmp_dir}/#{platf}/stage"
  # cleanup and clobbering
  CLEAN.include(tmp_path)
  CLEAN.include(stage_path)
  CLOBBER.include("#{lib_path}/#{binary(platf)}")
  CLOBBER.include("#{@tmp_dir}")
  # directories we need
  directory tmp_path
  directory "#{stage_path}/#{lib_path}"
  directory lib_dir
  # copy binary from temporary location to final lib
  # tmp/extension_name/extension_name.{so,bundle} => lib/
  task "copy:#{@name}:#{platf}:#{ruby_ver}" => [lib_path, "#{tmp_path}/#{binary(platf)}"] do
    install "#{tmp_path}/#{binary(platf)}", "#{lib_path}/#{binary(platf)}"
  end
  # copy binary from temporary location to staging directory
  task "copy:#{@name}:#{platf}:#{ruby_ver}" => ["#{stage_path}/#{lib_path}", "#{tmp_path}/#{binary(platf)}"] do
    cp "#{tmp_path}/#{binary(platf)}", "#{stage_path}/#{lib_path}/#{binary(platf)}"
  end
  # copy other gem files to staging directory
  if @gem_spec
    @gem_spec.files.each do |gem_file|
      # ignore directories and the binary extension
      next if File.directory?(gem_file) || gem_file == "#{lib_path}/#{binary(platf)}"
      stage_file = "#{stage_path}/#{gem_file}"
      # copy each file from base to stage directory
      unless Rake::Task.task_defined?(stage_file) then
        directory File.dirname(stage_file)
        file stage_file => [File.dirname(stage_file), gem_file] do
          cp gem_file, stage_file
        end
      end
      # append each file to the copy task
      task "copy:#{@name}:#{platf}:#{ruby_ver}" => [stage_file]
    end
  end
  # binary in temporary folder depends on makefile and source files
  # tmp/extension_name/extension_name.{so,bundle}
  file "#{tmp_path}/#{binary(platf)}" => ["#{tmp_path}/Makefile"] + source_files do
    jruby_compile_msg = <<-EOF
iling a native C extension on JRuby. This is discouraged and a
 extension should be preferred.
    EOF
    warn_once(jruby_compile_msg) if defined?(JRUBY_VERSION)
    chdir tmp_path do
      sh make
    end
  end
  # makefile depends of tmp_dir and config_script
  # tmp/extension_name/Makefile
  file "#{tmp_path}/Makefile" => [tmp_path, extconf] do |t|
    options = @config_options.dup
    # include current directory
    include_dirs = ['.'].concat(@config_includes).uniq.join(File::PATH_SEPARATOR)
    cmd = [Gem.ruby, "-I#{include_dirs}"]
    # build a relative path to extconf script
    abs_tmp_path = (Pathname.new(Dir.pwd) + tmp_path).realpath
    abs_extconf = (Pathname.new(Dir.pwd) + extconf).realpath
    # now add the extconf script
    cmd << abs_extconf.relative_path_from(abs_tmp_path)
    # rbconfig.rb will be present if we are cross compiling
    if t.prerequisites.include?("#{tmp_path}/rbconfig.rb") then
      options.push(*cross_config_options(platf))
    end
    # add options to command
    cmd.push(*options)
    # add any extra command line options
    unless extra_options.empty?
      cmd.push(*extra_options)
    end
    chdir tmp_path do
      # FIXME: Rake is broken for multiple arguments system() calls.
      # Add current directory to the search path of Ruby
      sh cmd.join(' ')
    end
  end
  # compile tasks
  unless Rake::Task.task_defined?('compile') then
    desc "Compile all the extensions"
    task "compile"
  end
  # compile:name
  unless Rake::Task.task_defined?("compile:#{@name}") then
    desc "Compile #{@name}"
    task "compile:#{@name}"
  end
  # Allow segmented compilation by platform (open door for 'cross compile')
  task "compile:#{@name}:#{platf}" => ["copy:#{@name}:#{platf}:#{ruby_ver}"]
  task "compile:#{platf}" => ["compile:#{@name}:#{platf}"]
  # Only add this extension to the compile chain if current
  # platform matches the indicated one.
  if platf == RUBY_PLATFORM then
    # ensure file is always copied
    file "#{lib_path}/#{binary(platf)}" => ["copy:#{name}:#{platf}:#{ruby_ver}"]
    task "compile:#{@name}" => ["compile:#{@name}:#{platf}"]
    task "compile" => ["compile:#{platf}"]
  end
end

def define_cross_platform_tasks(for_platform)
  if ruby_vers = ENV['RUBY_CC_VERSION']
    ruby_vers = ENV['RUBY_CC_VERSION'].split(':')
  else
    ruby_vers = [RUBY_VERSION]
  end
  multi = (ruby_vers.size > 1) ? true : false
  ruby_vers.each do |version|
    # save original lib_dir
    orig_lib_dir = @lib_dir
    # tweak lib directory only when targeting multiple versions
    if multi then
      version =~ /(\d+.\d+)/
      @lib_dir = "#{@lib_dir}/#{$1}"
    end
    define_cross_platform_tasks_with_version(for_platform, version)
    # restore lib_dir
    @lib_dir = orig_lib_dir
  end
end

def define_cross_platform_tasks_with_version(for_platform, ruby_ver)
  config_path = File.expand_path("~/.rake-compiler/config.yml")
  # warn the user about the need of configuration to use cross compilation.
  unless File.exist?(config_path)
    define_dummy_cross_platform_tasks
    return
  end
  config_file = YAML.load_file(config_path)
  # tmp_path
  tmp_path = "#{@tmp_dir}/#{for_platform}/#{@name}/#{ruby_ver}"
  # lib_path
  lib_path = lib_dir
  unless rbconfig_file = config_file["rbconfig-#{for_platform}-#{ruby_ver}"] then
    warn "no configuration section for specified version of Ruby (rbconfig-#{for_platform}-#{ruby_ver})"
    return
  end
  # mkmf
  mkmf_file = File.expand_path(File.join(File.dirname(rbconfig_file), '..', 'mkmf.rb'))
  # define compilation tasks for cross platform!
  define_compile_tasks(for_platform, ruby_ver)
  # chain fake.rb, rbconfig.rb and mkmf.rb to Makefile generation
  file "#{tmp_path}/Makefile" => ["#{tmp_path}/fake.rb",
                                  "#{tmp_path}/rbconfig.rb",
                                  "#{tmp_path}/mkmf.rb"]
  # copy the file from the cross-ruby location
  file "#{tmp_path}/rbconfig.rb" => [rbconfig_file] do |t|
    File.open(t.name, 'w') do |f|
      f.write "require 'fake.rb'\n\n"
      f.write File.read(t.prerequisites.first)
    end
  end
  # copy mkmf from cross-ruby location
  file "#{tmp_path}/mkmf.rb" => [mkmf_file] do |t|
    cp t.prerequisites.first, t.name
  end
  # genearte fake.rb for different ruby versions
  file "#{tmp_path}/fake.rb" do |t|
    File.open(t.name, 'w') do |f|
      f.write fake_rb(for_platform, ruby_ver)
    end
  end
  # now define native tasks for cross compiled files
  if @gem_spec && @gem_spec.platform == 'ruby' then
    define_native_tasks(for_platform, ruby_ver, @cross_compiling)
  end
  # create cross task
  task 'cross' do
    # clear compile dependencies
    Rake::Task['compile'].prerequisites.reject! { |t| !compiles_cross_platform.include?(t) }
    # chain the cross platform ones
    task 'compile' => ["compile:#{for_platform}"]
    # clear lib/binary dependencies and trigger cross platform ones
    # check if lib/binary is defined (damn bundle versus so versus dll)
    if Rake::Task.task_defined?("#{lib_path}/#{binary(for_platform)}") then
      Rake::Task["#{lib_path}/#{binary(for_platform)}"].prerequisites.clear
    end
    # FIXME: targeting multiple platforms copies the file twice
    file "#{lib_path}/#{binary(for_platform)}" => ["copy:#{@name}:#{for_platform}:#{ruby_ver}"]
    # if everything for native task is in place
    if @gem_spec && @gem_spec.platform == 'ruby' then
      # double check: only cross platform native tasks should be here
      # FIXME: Sooo brittle
      Rake::Task['native'].prerequisites.reject! { |t| !natives_cross_platform.include?(t) }
      task 'native' => ["native:#{for_platform}"]
    end
  end
end

def define_dummy_cross_platform_tasks
  task 'cross' do
    Rake::Task['compile'].clear
    task 'compile' do
      raise "rake-compiler must be configured first to enable cross-compilation"
    end
  end
end

def define_native_tasks(for_platform = nil, ruby_ver = RUBY_VERSION, callback = nil)
  platf = for_platform || platform
  # tmp_path
  tmp_path = "#{@tmp_dir}/#{platf}/#{@name}/#{ruby_ver}"
  stage_path = "#{@tmp_dir}/#{platf}/stage"
  # lib_path
  lib_path = lib_dir
  # create 'native:gem_name' and chain it to 'native' task
  unless Rake::Task.task_defined?("native:#{@gem_spec.name}:#{platf}")
    task "native:#{@gem_spec.name}:#{platf}" do |t|
      # FIXME: workaround Gem::Specification limitation around cache_file:
      # http://github.com/rubygems/rubygems/issues/78
      spec = gem_spec.dup
      spec.instance_variable_set(:"@cache_file", nil) if spec.respond_to?(:cache_file)
      # adjust to specified platform
      spec.platform = Gem::Platform.new(platf)
      # clear the extensions defined in the specs
      spec.extensions.clear
      # add the binaries that this task depends on
      ext_files = []
      # go through native prerequisites and grab the real extension files from there
      t.prerequisites.each do |ext|
        # strip stage path and keep lib/... only
        ext_files << ext.sub(stage_path+"/", '')
      end
      # include the files in the gem specification
      spec.files += ext_files
      # expose gem specification for customization
      if callback
        callback.call(spec)
      end
      # Generate a package for this gem
      pkg = Gem::PackageTask.new(spec) do |pkg|
        pkg.need_zip = false
        pkg.need_tar = false
        # Do not copy any files per PackageTask, because
        # we need the files from the staging directory
        pkg.package_files.clear
      end
      # Copy from staging directory to gem package directory.
      # This is derived from the code of Gem::PackageTask
      # but uses stage_path as source directory.
      stage_files = spec.files.map do |gem_file|
        File.join(stage_path, gem_file)
      end
      file pkg.package_dir_path => stage_files do
        mkdir_p pkg.package_dir rescue nil
        spec.files.each do |ft|
          fn = File.join(stage_path, ft)
          f = File.join(pkg.package_dir_path, ft)
          fdir = File.dirname(f)
          mkdir_p(fdir) if !File.exist?(fdir)
          if File.directory?(fn)
            mkdir_p(f)
          else
            rm_f f
            safe_ln(fn, f)
          end
        end
      end
    end
  end
  # add binaries to the dependency chain
  task "native:#{@gem_spec.name}:#{platf}" => ["#{stage_path}/#{lib_dir}/#{binary(platf)}"]
  # ensure the extension get copied
  unless Rake::Task.task_defined?("#{lib_path}/#{binary(platf)}") then
    file "#{lib_path}/#{binary(platf)}" => ["copy:#{@name}:#{platf}:#{ruby_ver}"]
  end
  file "#{stage_path}/#{lib_dir}/#{binary(platf)}" => ["copy:#{@name}:#{platf}:#{ruby_ver}"]
  # Allow segmented packaging by platform (open door for 'cross compile')
  task "native:#{platf}" => ["native:#{@gem_spec.name}:#{platf}"]
  # Only add this extension to the compile chain if current
  # platform matches the indicated one.
  if platf == RUBY_PLATFORM then
    task "native:#{@gem_spec.name}" => ["native:#{@gem_spec.name}:#{platf}"]
    task "native" => ["native:#{platf}"]
  end
end

def dev_null
  windows? ? 'NUL' : '/dev/null'
end

def extconf
  "#{@ext_dir}/#{@config_script}"
end

def fake_rb(platform, version)
  <<-FAKE_RB
    class Object
      remove_const :RUBY_PLATFORM
      remove_const :RUBY_VERSION
      remove_const :RUBY_DESCRIPTION if defined?(RUBY_DESCRIPTION)
      RUBY_PLATFORM = "#{platform}"
      RUBY_VERSION = "#{version}"
      RUBY_DESCRIPTION = "ruby \#{RUBY_VERSION} (\#{RUBY_RELEASE_DATE}) [\#{RUBY_PLATFORM}]"
    end
    if RUBY_PLATFORM =~ /mswin|bccwin|mingw/
      class File
        remove_const :ALT_SEPARATOR
        ALT_SEPARATOR = "\\\\"
      end
    end
    posthook = proc do
      $ruby = "#{Gem.ruby}"
      untrace_var(:$ruby, posthook)
    end
    trace_var(:$ruby, posthook)
_RB
end

def init(name = nil, gem_spec = nil)
  super
  @config_script = 'extconf.rb'
  @source_pattern = "*.c"
  @compiled_pattern = "*.{o,obj,so,bundle,dSYM}"
  @cross_compile = false
  @cross_config_options = []
  @cross_compiling = nil
  @no_native = false
  @config_includes = []
end

def make
  unless @make
    @make =
      if RUBY_PLATFORM =~ /mswin/ then
        'nmake'
      else
        ENV['MAKE'] || %w[gmake make].find { |c|
          system("#{c} -v >> #{dev_null} 2>&1")
        }
      end
  end
  unless @make
    raise "Couldn't find a suitable `make` tool. Use `MAKE` env to set an alternative."
  end
  @make
end

def natives_cross_platform
  [*@cross_platform].map { |p| "native:#{p}" }
end