module ActiveModel::Serializer::IncludeTree::Parsing

def include_args_to_hash(included)
  case included
  when Symbol
    { included => {} }
  when Hash
    included.each_with_object({}) do |(key, value), hash|
      hash[key] = include_args_to_hash(value)
    end
  when Array
    included.reduce({}) { |a, e| a.deep_merge!(include_args_to_hash(e)) }
  when String
    include_string_to_hash(included)
  else
    {}
  end
end

def include_string_to_hash(included)
  # TODO: Needs comment walking through the process of what all this is doing.
  included.delete(' ').split(',').reduce({}) do |hash, path|
    include_tree = path.split('.').reverse_each.reduce({}) { |a, e| { e.to_sym => a } }
    hash.deep_merge!(include_tree)
  end
end