class JsonDSL

  attr_reader :dsl_attributes

  def initialize(to_eval, eval_args = nil)
    @dsl_attributes = {}
    if to_eval.is_a? String
      instance_eval File.read(to_eval), to_eval
    else
      instance_exec eval_args, &to_eval
    end
  end

  def array!(opts, &blk)
    if opts.is_a? Hash
      sym, items = opts.first
      @dsl_attributes[sym] = []
      items.each do |item|
        @dsl_attributes[sym] << JsonDSL.new(blk, item).dsl_attributes
      end
    else
      @dsl_attributes = []
      opts.each do |item|
        @dsl_attributes << JsonDSL.new(blk, item).dsl_attributes
      end
    end
  end

  def extract!(target, *attrs)
    attrs.each do |att|
      @dsl_attributes[att] = if target.is_a? Hash
                               target[att] if target.key? att
                             else
                               begin
                                 target.send(att)
                               rescue
                                 nil
                               end
                             end
    end
  end

  def method_missing(sym, *args, &blk)
    @dsl_attributes[sym] = if ::Kernel.block_given?
                             JsonDSL.new(blk).dsl_attributes
                           else
                             if args.count.zero?
                               nil
                             elsif args.count == 1
                               args[0]
                             else
                               args
                             end
                           end
  end

end