class DropletKit::PaginatedResource

def ==(other)
  each_with_index.each.all? { |object, index| object == other[index] }
end

def [](index)
  @collection[index]
end

def each(start = 0, &block)
  # Start off with the first page if we have no idea of anything yet
  fetch_next_page if total.nil?
  return to_enum(:each, start) unless block
  Array(@collection[start..-1]).each(&block)
  unless last?
    start = [@collection.size, start].max
    fetch_next_page
    each(start, &block)
  end
  self
end

def fetch_next_page
  @current_page += 1
  retrieve(@current_page)
end

def initialize(action, resource, *args)
  @current_page = 0
  @total = nil
  @action = action
  @resource = resource
  @collection = []
  @args = args
  @options = args.last.is_a?(Hash) ? args.last : {}
end

def last?
  return true if total.nil?
  @current_page == total_pages || total.zero?
end

def per_page
  @options[:per_page] || PER_PAGE
end

def retrieve(page, per_page = self.per_page)
  invoker = ResourceKit::ActionInvoker.new(action, resource, *@args)
  invoker.options[:per_page] ||= per_page
  invoker.options[:page]       = page
  @collection += invoker.handle_response
  if total.nil?
    meta = MetaInformation.extract_single(invoker.response.body, :read)
    self.total = meta.total.to_i
  end
end

def total_pages
  return nil if total.nil?
  (total.to_f / per_page).ceil
end