class Composed

# File lib/composed.rb, line 6
def initialize(klass, interface = :new, &block)
  raise ArgumentError, "Must provide a block to define Composed Type" unless block_given?
  @klass = klass
  @injected_pos_args = Positional.new
  @injected_kw_args = Keywords.new
  @interface = interface
  @ctor = nil

  instance_eval(&block)

  singleton_class.send(:alias_method, interface, :execute_composition)
  singleton_class.send(:public, interface, :execute_composition)
  
  if interface == :call
    singleton_class.send(:alias_method, :[], :execute_composition)
    singleton_class.send(:public, :[])
  end
end

# File lib/composed.rb, line 59
def constructor(&block)
  @ctor = block
end

# File lib/composed.rb, line 52
  def define_kw_dependency(keyword, block)
    raise ArgumentError, <<~ERROR if @injected_kw_args.key?(keyword)
      Cannot inject keyword argument \"#{keyword}\" more than once."
    ERROR
    @injected_kw_args[keyword] = block
  end

# File lib/composed.rb, line 41
def dependency(keyword_or_idx = nil, &block)
  case keyword_or_idx
  when String, Symbol
    @injected_kw_args[keyword_or_idx.to_sym] = block
  when Integer
    @injected_pos_args[keyword_or_idx] = block
  else
    @injected_pos_args << block
  end
end

# File lib/composed.rb, line 27
def execute_composition(*args, **kwargs, &block)
  args = @injected_pos_args.merge(args)

  object =  if kwargs.empty? && @injected_kw_args.empty?
              @klass.send(@interface, *args, &block)
            else
              kwargs = @injected_kw_args.merge(kwargs)
              @klass.send(@interface, *args, **kwargs, &block)
            end

  object.instance_eval(&@ctor) if @ctor
  object
end

# File lib/composed.rb, line 64
def factory(method_name, &block)
  bound = self.class.new(self,&block)
  self.define_singleton_method(method_name) do |*args|
    bound.new(*args)
  end
end