module Rake
  require 'rake/alt_system'

  # Win 32 interface methods for Rake. Windows specific functionality
  # will be placed here to collect that knowledge in one spot.
  module Win32

    # Error indicating a problem in locating the home directory on a
    # Win32 system.
    class Win32HomeError < RuntimeError
    end

    class << self
      # True if running on a windows system.
      def windows?
        AltSystem::WINDOWS
      end

      # Run a command line on windows.
      def rake_system(*cmd)
        AltSystem.system(*cmd)
      end

      # The standard directory containing system wide rake files on
      # Win 32 systems. Try the following environment variables (in
      # order):
      #
      # * HOME
      # * HOMEDRIVE + HOMEPATH
      # * APPDATA
      # * USERPROFILE
      #
      # If the above are not defined, the return nil.
      def win32_system_dir #:nodoc:
        win32_shared_path = ENV['HOME']
        if win32_shared_path.nil? && ENV['HOMEDRIVE'] && ENV['HOMEPATH']
          win32_shared_path = ENV['HOMEDRIVE'] + ENV['HOMEPATH']
        end

        win32_shared_path ||= ENV['APPDATA']
        win32_shared_path ||= ENV['USERPROFILE']
        raise Win32HomeError,
          "Unable to determine home path environment variable." if
            win32_shared_path.nil? or win32_shared_path.empty?
        normalize(File.join(win32_shared_path, 'Rake'))
      end

      # Normalize a win32 path so that the slashes are all forward slashes.
      def normalize(path)
        path.gsub(/\\/, '/')
      end

    end
  end
end