Glitch-Shrike/app/services/fetch_atom_service.rb

53 lines
1.5 KiB
Ruby

# frozen_string_literal: true
class FetchAtomService < BaseService
def call(url)
return if url.blank?
response = http_client.head(url)
Rails.logger.debug "Remote status HEAD request returned code #{response.code}"
response = http_client.get(url) if response.code == 405
Rails.logger.debug "Remote status GET request returned code #{response.code}"
return nil if response.code != 200
return [url, fetch(url)] if response.mime_type == 'application/atom+xml'
return process_headers(url, response) unless response['Link'].blank?
process_html(fetch(url))
rescue OpenSSL::SSL::SSLError => e
Rails.logger.debug "SSL error: #{e}"
end
private
def process_html(body)
Rails.logger.debug 'Processing HTML'
page = Nokogiri::HTML(body)
alternate_link = page.xpath('//link[@rel="alternate"]').find { |link| link['type'] == 'application/atom+xml' }
return nil if alternate_link.nil?
[alternate_link['href'], fetch(alternate_link['href'])]
end
def process_headers(url, response)
Rails.logger.debug 'Processing link header'
link_header = LinkHeader.parse(response['Link'].is_a?(Array) ? response['Link'].first : response['Link'])
alternate_link = link_header.find_link(%w(rel alternate), %w(type application/atom+xml))
return process_html(fetch(url)) if alternate_link.nil?
[alternate_link.href, fetch(alternate_link.href)]
end
def fetch(url)
http_client.get(url).to_s
end
def http_client
HTTP.timeout(:per_operation, write: 10, connect: 10, read: 10).follow
end
end