require 'active_support/concern'
require 'active_storage/attached'

module ActiveStorageSupport
  module SupportForBase64
    extend ActiveSupport::Concern
    class_methods do
      def has_one_base64_attached(name, dependent: :purge_later)
        has_one_attached name, dependent: dependent

        generated_association_methods.class_eval <<-CODE, __FILE__, __LINE__ + 1
          def #{name}
            @active_storage_attached_#{name} ||= ActiveStorageSupport::Base64One.new("#{name}", self)
          end
          def #{name}=(attachable)
            attachment_changes["#{name}"] =
              if attachable.nil?
                ActiveStorage::Attached::Changes::DeleteOne.new("#{name}", self)
              else
                ActiveStorage::Attached::Changes::CreateOne.new(
                  "#{name}", self, ActiveStorageSupport::Base64One.from_base64(attachable)
                )
              end
          end
        CODE
      end

      def has_many_base64_attached(name, dependent: :purge_later)
        has_many_attached name, dependent: dependent

        generated_association_methods.class_eval <<-CODE, __FILE__, __LINE__ + 1
          def #{name}
            @active_storage_attached_#{name} ||= ActiveStorageSupport::Base64Many.new("#{name}", self)
          end
          def #{name}=(attachables)
            if ActiveStorage.replace_on_assign_to_many
              attachment_changes["#{name}"] =
                if Array(attachables).none?
                  ActiveStorage::Attached::Changes::DeleteMany.new("#{name}", self)
                else
                  ActiveStorage::Attached::Changes::CreateMany.new(
                    "#{name}", self, ActiveStorageSupport::Base64Many.from_base64(attachables)
                  )
                end
            else
              if Array(attachables).any?
                attachment_changes["#{name}"] =
                  ActiveStorage::Attached::Changes::CreateMany.new(
                    "#{name}", self, #{name}.blobs + ActiveStorageSupport::Base64Many.from_base64(attachables)
                  )
              end
            end
          end
        CODE
      end
    end
  end
end