require 'rack/auth/abstract/handler'
require 'rack/auth/abstract/request'
 
module Rack
  module Auth
    # Rack::Auth::Basic implements HTTP Basic Authentication, as per RFC 2617.
    #
    # Initialize with the Rack application that you want protecting,
    # and a block that checks if a username and password pair are valid.
    #
    # See also: <tt>example/protectedlobster.rb</tt>
 
    class Basic < AbstractHandler
 
      def call(env)
        auth = Basic::Request.new(env)
 
        return unauthorized unless auth.provided?
 
        return bad_request unless auth.basic?
 
        if valid?(auth)
          env['REMOTE_USER'] = auth.username
 
          return @app.call(env)
        end
 
        unauthorized
      end
 
 
      private
 
      def challenge
        'Basic realm="%s"' % realm
      end
 
      def valid?(auth)
        @authenticator.call(*auth.credentials)
      end
 
      class Request < Auth::AbstractRequest
        def basic?
          :basic == scheme
        end
 
        def credentials
          @credentials ||= params.unpack("m*").first.split(/:/, 2)
        end
 
        def username
          credentials.first
        end
      end
 
    end
  end
end