mastodon/app/models/concerns/remotable.rb

# frozen_string_literal: true

module Remotable
  extend ActiveSupport::Concern

  class_methods do
    def remotable_attachment(attachment_name, limit, suppress_errors: true, download_on_assign: true, attribute_name: nil)
      attribute_name ||= "#{attachment_name}_remote_url".to_sym

      define_method("download_#{attachment_name}!") do |url = nil|
        url ||= self[attribute_name]

        return if url.blank?

        begin
          parsed_url = Addressable::URI.parse(url).normalize
        rescue Addressable::URI::InvalidURIError
          return
        end

        return if !%w(http https).include?(parsed_url.scheme) || parsed_url.host.blank?

        begin
          Request.new(:get, url).perform do |response|
            raise Mastodon::UnexpectedResponseError, response unless (200...300).cover?(response.code)

            public_send("#{attachment_name}=", ResponseWithLimit.new(response, limit))
          end
        rescue Mastodon::UnexpectedResponseError, HTTP::TimeoutError, HTTP::ConnectionError, OpenSSL::SSL::SSLError => e
          Rails.logger.debug { "Error fetching remote #{attachment_name}: #{e}" }
          public_send("#{attachment_name}=", nil) if public_send("#{attachment_name}_file_name").present?
          raise e unless suppress_errors
        rescue Paperclip::Errors::NotIdentifiedByImageMagickError, Addressable::URI::InvalidURIError, Mastodon::HostValidationError, Mastodon::LengthValidationError, Paperclip::Error, Mastodon::DimensionsValidationError, Mastodon::StreamValidationError => e
          Rails.logger.debug { "Error fetching remote #{attachment_name}: #{e}" }
          public_send("#{attachment_name}=", nil) if public_send("#{attachment_name}_file_name").present?
        end

        nil
      end

      define_method("#{attribute_name}=") do |url|
        return if self[attribute_name] == url && public_send("#{attachment_name}_file_name").present?

        self[attribute_name] = url if has_attribute?(attribute_name)

        public_send("download_#{attachment_name}!", url) if download_on_assign
      end

      alias_method("reset_#{attachment_name}!", "download_#{attachment_name}!")
    end
  end
end