require 'rails_admin/config/fields/types/belongs_to_association'

module RailsAdmin
  module Config
    module Fields
      module Types
        class PolymorphicAssociation < RailsAdmin::Config::Fields::Types::BelongsToAssociation
          # Register field type for the type loader
          RailsAdmin::Config::Fields::Types::register(self)

          register_instance_option :partial do
            :form_polymorphic_association
          end

          # Accessor whether association is visible or not. By default
          # association checks that any of the child models are included in
          # configuration.
          register_instance_option :visible? do
            associated_model_config.length > 0
          end

          register_instance_option :sortable do
            false
          end

          register_instance_option :searchable do
            false
          end

          # TODO not supported yet
          register_instance_option :associated_collection_cache_all do
            false
          end

          # TODO not supported yet
          register_instance_option :associated_collection_scope do
            nil
          end

          register_instance_option :allowed_methods do
            [children_fields]
          end

          def associated_collection(type)
            return [] if type.blank?
            config = RailsAdmin.config(type)
            config.abstract_model.all.map do |object|
              [object.send(config.object_label_method), object.id]
            end
          end

          def associated_model_config
            @associated_model_config ||= association[:model_proc].call.map{|type| RailsAdmin.config(type) }.select{|config| !config.excluded? }
          end

          def polymorphic_type_collection
            associated_model_config.map do |config|
              [config.label, config.abstract_model.model.name]
            end
          end

          def polymorphic_type_urls
            types = associated_model_config.map do |config|
              [config.abstract_model.model.name, config.abstract_model.to_param]
            end

            ::Hash[*types.collect { |v|
                  [v[0], bindings[:view].index_path(v[1])]
                }.flatten]
          end

          # Reader for field's value
          def value
            bindings[:object].send(association[:name])
          end
        end
      end
    end
  end
end