module OptStruct

# File lib/opt_struct.rb, line 8
def self._inject_struct(target, source, args = [], **defaults, &callback)
  structs = Array(source.instance_variable_get(:@_opt_structs)).dup
  if args.any? || defaults.any? || block_given?
    structs << [args, defaults, callback]
  end
  target.instance_variable_set(:@_opt_structs, structs)
  if target.is_a?(Class)
    target.instance_exec do
      extend ClassMethods
      attr_reader :options
      include InstanceMethods
    end
    structs.each do |s_args, s_defaults, s_callback|
      target.expect_arguments *s_args if s_args.any?
      target.options **s_defaults     if s_defaults.any?
      target.class_exec(&s_callback)  if s_callback
    end
  else
    target.singleton_class.prepend ModuleMethods
  end
  target
end

# File lib/opt_struct.rb, line 45
def self.build(*args, **defaults, &callback)
  _inject_struct(Module.new, self, args.map(&:to_sym), **defaults, &callback)
end

# File lib/opt_struct.rb, line 31
def self.included(klass)
  _inject_struct(klass, self)
  super(klass)
end

# File lib/opt_struct.rb, line 41
def self.new(*args, **defaults, &callback)
  _inject_struct(Class.new, self, args.map(&:to_sym), **defaults, &callback)
end

# File lib/opt_struct.rb, line 36
def self.prepended(klass)
  _inject_struct(klass, self)
  super(klass)
end