class ActiveModel::ArraySerializer

def embedded_in_root_associations
  @object.each_with_object({}) do |item, hash|
    serializer_for(item).embedded_in_root_associations.each_pair do |type, objects|
      next if !objects || objects.flatten.empty?
      if hash.has_key?(type)
        hash[type].concat(objects).uniq!
      else
        hash[type] = objects
      end
    end
  end
end

def initialize(object, options={})
  @object          = object
  @scope           = options[:scope]
  @root            = options.fetch(:root, self.class._root)
  @meta_key        = options[:meta_key] || :meta
  @meta            = options[@meta_key]
  @each_serializer = options[:each_serializer]
  @resource_name   = options[:resource_name]
  @only            = options[:only] ? Array(options[:only]) : nil
  @except          = options[:except] ? Array(options[:except]) : nil
  @key_format      = options[:key_format] || options[:each_serializer].try(:key_format)
end

def instrumentation_keys
  [:object, :scope, :root, :meta_key, :meta, :each_serializer, :resource_name, :key_format]
end

def json_key
  key = root.nil? ? @resource_name : root
  key_format == :lower_camel && key.present? ? key.camelize(:lower) : key
end

def serializable_object
  @object.map do |item|
    serializer_for(item).serializable_object
  end
end

def serializer_for(item)
  serializer_class = @each_serializer || Serializer.serializer_for(item) || DefaultSerializer
  serializer_class.new(item, scope: scope, key_format: key_format, only: @only, except: @except)
end