module RFlags

# File lib/rflags.rb, line 7
  def flag(definition)
    name, backend = resolve_flag_params(definition)
    instance_variable_set("@#{name}".to_sym, backend)
    instance_eval <<-MTD, __FILE__, __LINE__
      def #{name}
        @#{name}
      end
    MTD
  end

# File lib/rflags.rb, line 17
  def lazy_flag(name, &block)
    if !block
      raise "RFlags##{__method__} needs a block"
    end

    resolve = -> do
      opts = block.call
      resolve_flag_backend_class(opts).new(*opts)
    end

    instance_variable_set(:"@#{name}_block", resolve)
    instance_eval(<<-MTD, __FILE__, __LINE__)
      def #{name}
        @#{name} ||= @#{name}_block.call
      end
    MTD
  end

# File lib/rflags.rb, line 53
def resolve_flag_backend_class(opts)
  case opts
  when String, Pathname
    RFlags::FileFlag
  when Array
    class_name = opts[0].class
    ::Object.const_get("::RFlags::#{class_name}Flag")
  else
    raise TypeError, "Can't handle #{opts.class}"
  end
end

# File lib/rflags.rb, line 37
def resolve_flag_params(definition)
  case definition
  when String, Symbol
    [definition, RFlags::Flag.new]
  when Hash
    name = definition.keys[0]

    backend_opts = definition[name]
    backend_class = resolve_flag_backend_class(backend_opts)

    [name, backend_class.new(*backend_opts)]
  else
    raise TypeError, "Can't handle #{definition.class}"
  end
end