module ActiveAdmin::ViewHelpers::FormHelper

def fields_for_params(params, options = {})
  namespace = options[:namespace]
  except = Array.wrap(options[:except]).map &:to_s
  params.flat_map do |k, v|
    next if namespace.nil? && %w(controller action commit utf8).include?(k.to_s)
    next if except.include?(k.to_s)
    if namespace
      k = "#{namespace}[#{k}]"
    end
    case v
    when String
      { k => v }
    when Symbol
      { k => v.to_s }
    when Hash
      fields_for_params(v, namespace: k)
    when Array
      v.map do |v|
        { "#{k}[]" => v }
      end
    when nil
      { k => "" }
    when TrueClass, FalseClass
      { k => v }
    else
      raise "I don't know what to do with #{v.class} params: #{v.inspect}"
    end
  end.compact
end