hometown/app/services/fetch_atom_service.rb
2017-10-04 09:51:42 +02:00

84 lines
2.8 KiB
Ruby

# frozen_string_literal: true
class FetchAtomService < BaseService
include JsonLdHelper
def call(url)
return if url.blank?
result = process(url)
# retry without ActivityPub
result ||= process(url) if @unsupported_activity
result
rescue OpenSSL::SSL::SSLError => e
Rails.logger.debug "SSL error: #{e}"
nil
rescue HTTP::ConnectionError => e
Rails.logger.debug "HTTP ConnectionError: #{e}"
nil
end
private
def process(url, terminal = false)
@url = url
perform_request
process_response(terminal)
end
def perform_request
accept = 'text/html'
accept = 'application/activity+json, application/ld+json, application/atom+xml, ' + accept unless @unsupported_activity
@response = Request.new(:get, @url)
.add_headers('Accept' => accept)
.perform
end
def process_response(terminal = false)
return nil if @response.code != 200
if @response.mime_type == 'application/atom+xml'
[@url, { prefetched_body: @response.to_s }, :ostatus]
elsif ['application/activity+json', 'application/ld+json; profile="https://www.w3.org/ns/activitystreams"'].include?(@response.mime_type)
json = body_to_json(@response.to_s)
if supported_context?(json) && json['type'] == 'Person' && json['inbox'].present?
[json['id'], { id: true }, :activitypub]
else
@unsupported_activity = true
nil
end
elsif @response['Link'] && !terminal
process_headers
elsif @response.mime_type == 'text/html' && !terminal
process_html
end
end
def process_html
page = Nokogiri::HTML(@response.to_s)
json_link = page.xpath('//link[@rel="alternate"]').find { |link| ['application/activity+json', 'application/ld+json; profile="https://www.w3.org/ns/activitystreams"'].include?(link['type']) }
atom_link = page.xpath('//link[@rel="alternate"]').find { |link| link['type'] == 'application/atom+xml' }
result ||= process(json_link['href'], terminal: true) unless json_link.nil? || @unsupported_activity
result ||= process(atom_link['href'], terminal: true) unless atom_link.nil?
result
end
def process_headers
link_header = LinkHeader.parse(@response['Link'].is_a?(Array) ? @response['Link'].first : @response['Link'])
json_link = link_header.find_link(%w(rel alternate), %w(type application/activity+json)) || link_header.find_link(%w(rel alternate), ['type', 'application/ld+json; profile="https://www.w3.org/ns/activitystreams"'])
atom_link = link_header.find_link(%w(rel alternate), %w(type application/atom+xml))
result ||= process(json_link.href, terminal: true) unless json_link.nil? || @unsupported_activity
result ||= process(atom_link.href, terminal: true) unless atom_link.nil?
result
end
end