require 'md5'

module LeapCli
  module Util
    extend self

    ##
    ## QUITTING
    ##

    #
    # quit and print help
    #
    def help!(message=nil)
      ENV['GLI_DEBUG'] = "false"
      help_now!(message)
      #say("ERROR: " + message)
    end

    #
    # quit with a message that we are bailing out.
    #
    def bail!(message="")
      say(message)
      say("Bailing out.")
      raise SystemExit.new
      #ENV['GLI_DEBUG'] = "false"
      #exit_now!(message)
    end

    #
    # quit with no message
    #
    def quit!(message='')
      say(message)
      raise SystemExit.new
    end

    #
    # bails out with message if assertion is false.
    #
    def assert!(boolean, message)
      bail!(message) unless boolean
    end

    #
    # assert that the command is available
    #
    def assert_bin!(cmd_name)
      assert! `which #{cmd_name}`.strip.any?, "Sorry, bailing out, the command '%s' is not installed." % cmd_name
    end

    ##
    ## FILES AND DIRECTORIES
    ##

    def relative_path(path)
      path.sub(/^#{Regexp.escape(Path.provider)}\//,'')
    end

    def progress_created(path)
      progress 'created %s' % relative_path(path)
    end

    def progress_updated(path)
      progress 'updated %s' % relative_path(path)
    end

    def progress_nochange(path)
      progress 'no change %s' % relative_path(path)
    end

    def progress_removed(path)
      progress 'removed %s' % relative_path(path)
    end

    #
    # creates a directory if it doesn't already exist
    #
    def ensure_dir(dir)
      unless File.directory?(dir)
        if File.exists?(dir)
          bail! 'Unable to create directory "%s", file already exists.' % dir
        else
          FileUtils.mkdir_p(dir)
          unless dir =~ /\/$/
            dir = dir + '/'
          end
          progress_created dir
        end
      end
    end

    NAMED_PATHS = {
      :user_ssh => 'users/#{arg}/#{arg}_ssh.pub',
      :user_pgp => 'users/#{arg}/#{arg}_pgp.pub'
    }

    #
    # read a file, exit if the file doesn't exist.
    #
    def read_file!(file_path)
      if !File.exists?(file_path)
        bail!("File '%s' does not exist." % file_path)
      else
        File.readfile(file_path)
      end
    end

    def write_file!(*args)
      if args.first.is_a? Symbol
        write_named_file!(*args)
      else
        write_to_path!(*args)
      end
    end

    def remove_file!(file_path)
      if File.exists?(file_path)
        File.unlink(file_path)
        progress_removed(file_path)
      end
    end

    #
    # saves a named file
    #
    def write_named_file!(name, arg, contents)
      assert!(NAMED_PATHS[name], "Error, I don't know the path for #{arg}")

      filename = eval('"' + NAMED_PATHS[name] + '"')
      fullpath = Path.provider + '/' + filename

      write_to_path!(fullpath, contents)
    end

    def write_to_path!(filepath, contents)
      ensure_dir File.dirname(filepath)
      existed = File.exists?(filepath)
      if existed
        if file_content_is?(filepath, contents)
          progress_nochange filepath
          return
        end
      end

      File.open(filepath, 'w') do |f|
        f.write contents
      end

      if existed
        progress_updated filepath
      else
        progress_created filepath
      end
    end

    private

    def file_content_is?(filepath, contents)
      output = `md5sum '#{filepath}'`.strip
      if $?.to_i == 0
        return output.split(" ").first == MD5.md5(contents).to_s
      else
        return false
      end
    end

  end
end