require 'rails_admin/config/fields/types/string'

module RailsAdmin
  module Config
    module Fields
      module Types
        class FileUpload < RailsAdmin::Config::Fields::Base
          RailsAdmin::Config::Fields::Types.register(self)

          register_instance_option :partial do
            :form_file_upload
          end

          register_instance_option :thumb_method do
            nil
          end

          register_instance_option :delete_method do
            nil
          end

          register_instance_option :cache_method do
            nil
          end

          register_instance_option :cache_value do
            bindings[:object].public_send(cache_method) if cache_method
          end

          register_instance_option :export_value do
            resource_url.to_s
          end

          register_instance_option :link_name do
            value
          end

          register_instance_option :pretty_value do
            if value.presence
              v = bindings[:view]
              url = resource_url
              if image
                thumb_url = resource_url(thumb_method)
                image_html = v.image_tag(thumb_url, class: 'img-thumbnail')
                url == thumb_url ? image_html : v.link_to(image_html, url, target: '_blank', rel: 'noopener noreferrer')
              else
                v.link_to(link_name, url, target: '_blank', rel: 'noopener noreferrer')
              end
            end
          end

          register_instance_option :image? do
            mime_type = Mime::Type.lookup_by_extension(resource_url.to_s.split('.').last)
            mime_type.to_s.match?(/^image/)
          end

          register_instance_option :allowed_methods do
            [method_name, delete_method, cache_method].compact
          end

          register_instance_option :html_attributes do
            {
              required: required? && !value.present?,
            }
          end

          # virtual class
          def resource_url
            raise 'not implemented'
          end

          def virtual?
            true
          end
        end
      end
    end
  end
end