module OS
  module Mac
    module Xcode
      extend self

      V4_BUNDLE_ID = "com.apple.dt.Xcode"
      V3_BUNDLE_ID = "com.apple.Xcode"
      V4_BUNDLE_PATH = Pathname.new("/Applications/Xcode.app")
      V3_BUNDLE_PATH = Pathname.new("/Developer/Applications/Xcode.app")

      # Locate the "current Xcode folder" via xcode-select. See:
      # man xcode-select
      # NOTE!! use Xcode.prefix rather than this generally!
      def folder
        @folder ||= `xcode-select -print-path 2>/dev/null`.strip
      end

      # Xcode 4.3 tools hang if "/" is set
      def bad_xcode_select_path?
        folder == "/"
      end

      def latest_version
        case MacOS.version
        when "10.4"         then "2.5"
        when "10.5"         then "3.1.4"
        when "10.6"         then "3.2.6"
        when "10.7"         then "4.6.3"
        when "10.8"         then "5.0"
        when "10.9"         then "5.0.1"
        else
          # Default to newest known version of Xcode for unreleased OSX versions.
          if MacOS.version > 10.9
            "5.0.1"
          else
            raise "Mac OS X '#{MacOS.version}' is invalid"
          end
        end
      end

      def outdated?
        version < latest_version
      end

      def without_clt?
        installed? && version >= "4.3" && !MacOS::CLT.installed?
      end

      def prefix
        @prefix ||= begin
          path = Pathname.new(folder)
          if path.absolute? and File.executable? "#{path}/usr/bin/make"
            path
          elsif File.executable? '/Developer/usr/bin/make'
            # we do this to support cowboys who insist on installing
            # only a subset of Xcode
            Pathname.new('/Developer')
          elsif File.executable? "#{V4_BUNDLE_PATH}/Contents/Developer/usr/bin/make"
            # fallback for broken Xcode 4.3 installs
            Pathname.new("#{V4_BUNDLE_PATH}/Contents/Developer")
          elsif (path = bundle_path)
            path += "Contents/Developer"
            path if File.executable? "#{path}/usr/bin/make"
          end
        end
      end

      # Ask Spotlight where Xcode is. If the user didn't install the
      # helper tools and installed Xcode in a non-conventional place, this
      # is our only option. See: http://superuser.com/questions/390757
      def bundle_path
        MacOS.app_with_bundle_id(V4_BUNDLE_ID) || MacOS.app_with_bundle_id(V3_BUNDLE_ID)
      end

      def installed?
        not prefix.nil?
      end

      def version
        # may return a version string
        # that is guessed based on the compiler, so do not
        # use it in order to check if Xcode is installed.
        @version ||= uncached_version
      end

      def uncached_version
        # This is a separate function as you can't cache the value out of a block
        # if return is used in the middle, which we do many times in here.

        return "0" unless OS.mac?

        # this shortcut makes version work for people who don't realise you
        # need to install the CLI tools
        xcode43build = Pathname.new("#{prefix}/usr/bin/xcodebuild")
        if xcode43build.file?
          `#{xcode43build} -version 2>/dev/null` =~ /Xcode (\d(\.\d)*)/
          return $1 if $1
        end

        # Xcode 4.3 xc* tools hang indefinately if xcode-select path is set thus
        raise if bad_xcode_select_path?

        raise unless which "xcodebuild"
        `xcodebuild -version 2>/dev/null` =~ /Xcode (\d(\.\d)*)/
        raise if $1.nil? or not $?.success?
        $1
      rescue
        # For people who's xcode-select is unset, or who have installed
        # xcode-gcc-installer or whatever other combinations we can try and
        # supprt. See https://github.com/mxcl/homebrew/wiki/Xcode
        case MacOS.llvm_build_version.to_i
        when 1..2063 then "3.1.0"
        when 2064..2065 then "3.1.4"
        when 2366..2325
          # we have no data for this range so we are guessing
          "3.2.0"
        when 2326
          # also applies to "3.2.3"
          "3.2.4"
        when 2327..2333 then "3.2.5"
        when 2335
          # this build number applies to 3.2.6, 4.0 and 4.1
          # https://github.com/mxcl/homebrew/wiki/Xcode
          "4.0"
        else
          case (MacOS.clang_version.to_f * 10).to_i
          when 0       then "dunno"
          when 1..14   then "3.2.2"
          when 15      then "3.2.4"
          when 16      then "3.2.5"
          when 17..20  then "4.0"
          when 21      then "4.1"
          when 22..30  then "4.2"
          when 31      then "4.3"
          when 40      then "4.4"
          when 41      then "4.5"
          when 42      then "4.6"
          when 50      then "5.0"
          else "4.6"
          end
        end
      end

      def provides_autotools?
        version.to_f < 4.3
      end

      def provides_gcc?
        version.to_f < 4.3
      end

      def default_prefix?
        if version.to_f < 4.3
          %r{^/Developer} === prefix
        else
          %r{^/Applications/Xcode.app} === prefix
        end
      end
    end

    module CLT
      extend self

      STANDALONE_PKG_ID = "com.apple.pkg.DeveloperToolsCLILeo"
      FROM_XCODE_PKG_ID = "com.apple.pkg.DeveloperToolsCLI"
      STANDALONE_PKG_PATH = Pathname.new("/Library/Developer/CommandLineTools")

      # True if:
      #  - Xcode < 4.3 is installed. The tools are found under /usr.
      #  - The "Command Line Tools" package has been installed
      #    For OS X < 10.9, the tools are found under /usr. For 10.9,
      #    they are found under /Library/Developer/CommandLineTools.
      def installed?
        mavericks_dev_tools? || usr_dev_tools?
      end

      def mavericks_dev_tools?
        MacOS.dev_tools_path == Pathname("#{STANDALONE_PKG_PATH}/usr/bin") &&
          File.directory?("#{STANDALONE_PKG_PATH}/usr/include")
      end

      def usr_dev_tools?
        MacOS.dev_tools_path == Pathname("/usr/bin") && File.directory?("/usr/include")
      end

      def latest_version?
        `/usr/bin/clang --version` =~ %r{clang-(\d+)\.(\d+)\.(\d+)}
        $1.to_i >= 425 and $3.to_i >= 28
      end

      def outdated?
        !latest_version?
      end

      # Version string (a pretty damn long one) of the CLT package.
      # Note, that different ways to install the CLTs lead to different
      # version numbers.
      def version
        @version ||= detect_version
      end

      def detect_version
        [STANDALONE_PKG_ID, FROM_XCODE_PKG_ID].find do |id|
          version = MacOS.pkgutil_info(id)[/version: (.+)$/, 1]
          return version if version
        end
      end
    end
  end
end