module Blackbox

  class Registry
    module Query
      def registry
        @registry ||= Blackbox::Registry.new
      end

      def configure
        yield registry
        registry
      end
    end

    extend Blackbox::Registry::Query

    def initialize(default={})
      @data = default.with_indifferent_access
    end

    def include?(*fields)
      field = fields.shift
      return @data.has_key?(field) if fields.empty?
      @data[field].include?(*fields)
    end

    def set!(field, value)
      @data[field] = value
      define_hash_accessor! field
      value
    end

    private

    def define_hash_accessor!(field)
      self.instance_eval <<-EODEF
        def #{field}
          if block_given?
            returning(Blackbox::Registry.new) do |registry|
              @data[:#{field}] = registry
              yield registry
            end
          else
            return @data[:#{field}]
          end
        end

        def #{field}=(value)
          @data[:#{field}] = value
        end
      EODEF
    end

    def method_missing(method, *args)
      if method.to_s =~ /=$/
        method = method.to_s.gsub('=', '').to_sym
        set! method, args.first
      elsif block_given?
        registry = Blackbox::Registry.new
        yield registry
        set! method, registry
      else
        set! method, nil
      end
    end
  end
end