module OS
  module Mac
    module Xcode
      extend self

      V4_BUNDLE_ID = "com.apple.dt.Xcode"
      V3_BUNDLE_ID = "com.apple.Xcode"

      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 "5.1.1"
        when "10.9"  then "6.0.1"
        when "10.10" then "6.1"
        else
          # Default to newest known version of Xcode for unreleased OSX versions.
          if MacOS.version > "10.10"
            "6.1"
          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      def outdated?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
            dir = MacOS.active_developer_dir

            if dir.empty? || dir == CLT::MAVERICKS_PKG_PATH || !File.directory?(dir)
              path = bundle_path
              path.join("Contents", "Developer") if path
            else
              Pathname.new(dir)
            end
          end
      end

      def toolchain_path
        Pathname.new("#{prefix}/Toolchains/XcodeDefault.xctoolchain") if installed? && version >= "4.3"
      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, 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?

        %W[#{prefix}/usr/bin/xcodebuild #{which("xcodebuild")}].uniq.each do |path|
          if File.file? path
            `#{path} -version 2>/dev/null` =~ /Xcode (\d(\.\d)*)/
            return $1 if $1
          end
        end

        # The remaining logic provides a fake Xcode version for CLT-only
        # systems. This behavior only exists because Homebrew used to assume
        # Xcode.version would always be non-nil. This is deprecated, and will
        # be removed in a future version. To remain compatible, guard usage of
        # Xcode.version with an Xcode.installed? check.
        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/Homebrew/homebrew/blob/master/share/doc/homebrew/Xcode.md
          "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"
          when 51      then "5.1"
          when 60      then "6.0"
          else "6.0"
          end
        end
      end

      def provides_autotools?
        version < "4.3"
      end

      def provides_gcc?
        version < "4.3"
      end

      def provides_cvs?
        version < "5.0"
      end

      def default_prefix?
        if version < "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"
      MAVERICKS_PKG_ID = "com.apple.pkg.CLTools_Executables"
      MAVERICKS_NEW_PKG_ID = "com.apple.pkg.CLTools_Base" # obsolete
      MAVERICKS_PKG_PATH = "/Library/Developer/CommandLineTools"

      # Returns true even if outdated tools are installed, e.g.
      # tools from Xcode 4.x on 10.9
      def installed?
        !!detect_version
      end

      def latest_version
        case MacOS.version
        when "10.10" then "600.0.54"
        when "10.9"  then "600.0.51"
        when "10.8"  then "503.0.40"
        else
          "425.0.28"
        end
      end

      def outdated?
        if MacOS.version >= :mavericks
          version = `#{MAVERICKS_PKG_PATH}/usr/bin/clang --version`
        else
          version = `/usr/bin/clang --version`
        end
        version = version[%r{clang-(\d+\.\d+\.\d+)}, 1] || "0"
        version < latest_version
      end

      # Version string (a pretty 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
        [MAVERICKS_PKG_ID, MAVERICKS_NEW_PKG_ID, STANDALONE_PKG_ID, FROM_XCODE_PKG_ID].find do |id|
          if MacOS.version >= :mavericks
            next unless File.exist?("#{MAVERICKS_PKG_PATH}/usr/bin/clang")
          end
          version = MacOS.pkgutil_info(id)[/version: (.+)$/, 1]
          return version if version
        end
      end
    end
  end
end