From 425acecfdb15093a265b191120fb2d4e4c4135c4 Mon Sep 17 00:00:00 2001
From: "Akihiko Odaki (@fn_aki@pawoo.net)" <akihiko.odaki.4i@stu.hosei.ac.jp>
Date: Tue, 11 Jul 2017 20:37:05 +0900
Subject: [PATCH] Wrap methods of ProcessFeedService::ProcessEntry in classes
 (#4151)

ProcessFeedService::ProcessEntry had many methods, so wrap them in classes
representing activities.
---
 app/services/process_feed_service.rb | 433 ++++++++++++++-------------
 1 file changed, 225 insertions(+), 208 deletions(-)

diff --git a/app/services/process_feed_service.rb b/app/services/process_feed_service.rb
index c335d2159..19ab0c858 100644
--- a/app/services/process_feed_service.rb
+++ b/app/services/process_feed_service.rb
@@ -22,268 +22,285 @@ class ProcessFeedService < BaseService
   class ProcessEntry
     def call(xml, account)
       @account = account
-      @xml     = xml
+      @fetched = Activity.new(xml)
 
-      return if skip_unsupported_type?
+      return unless [:activity, :note, :comment].include?(@fetched.type)
 
-      case verb
-      when :post, :share
-        return create_status
-      when :delete
-        return delete_status
-      end
+      klass = case @fetched.verb
+              when :post
+                PostActivity
+              when :share
+                ShareActivity
+              when :delete
+                DeletionActivity
+              else
+                return
+              end
+
+      @fetched = klass.new(xml, account)
+      @fetched.perform
     rescue ActiveRecord::RecordInvalid => e
       Rails.logger.debug "Nothing was saved for #{id} because: #{e}"
       nil
     end
 
-    private
-
-    def create_status
-      if redis.exists("delete_upon_arrival:#{@account.id}:#{id}")
-        Rails.logger.debug "Delete for status #{id} was queued, ignoring"
-        return
+    class Activity
+      def initialize(xml, account = nil)
+        @xml = xml
+        @account = account
       end
 
-      status, just_created = nil
-
-      Rails.logger.debug "Creating remote status #{id}"
-
-      if verb == :share
-        original_status = shared_status_from_xml(@xml.at_xpath('.//activity:object', activity: TagManager::AS_XMLNS))
-        return nil if original_status.nil?
+      def verb
+        raw = @xml.at_xpath('./activity:verb', activity: TagManager::AS_XMLNS).content
+        TagManager::VERBS.key(raw)
+      rescue
+        :post
       end
 
-      ApplicationRecord.transaction do
-        status, just_created = status_from_xml(@xml)
+      def type
+        raw = @xml.at_xpath('./activity:object-type', activity: TagManager::AS_XMLNS).content
+        TagManager::TYPES.key(raw)
+      rescue
+        :activity
+      end
 
-        return if status.nil?
-        return status unless just_created
+      def id
+        @xml.at_xpath('./xmlns:id', xmlns: TagManager::XMLNS).content
+      end
 
-        if verb == :share
-          status.reblog = original_status.reblog? ? original_status.reblog : original_status
+      def url
+        link = @xml.at_xpath('./xmlns:link[@rel="alternate"]', xmlns: TagManager::XMLNS)
+        link.nil? ? nil : link['href']
+      end
+
+      private
+
+      def find_status(uri)
+        if TagManager.instance.local_id?(uri)
+          local_id = TagManager.instance.unique_tag_to_local_id(uri, 'Status')
+          return Status.find_by(id: local_id)
         end
 
-        status.save!
+        Status.find_by(uri: uri)
       end
 
-      if thread?(@xml) && status.thread.nil?
-        Rails.logger.debug "Trying to attach #{status.id} (#{id(@xml)}) to #{thread(@xml).first}"
-        ThreadResolveWorker.perform_async(status.id, thread(@xml).second)
-      end
-
-      notify_about_mentions!(status) unless status.reblog?
-      notify_about_reblog!(status) if status.reblog? && status.reblog.account.local?
-
-      Rails.logger.debug "Queuing remote status #{status.id} (#{id}) for distribution"
-
-      LinkCrawlWorker.perform_async(status.id) unless status.spoiler_text?
-      DistributionWorker.perform_async(status.id)
-
-      status
-    end
-
-    def notify_about_mentions!(status)
-      status.mentions.includes(:account).each do |mention|
-        mentioned_account = mention.account
-        next unless mentioned_account.local?
-        NotifyService.new.call(mentioned_account, mention)
+      def redis
+        Redis.current
       end
     end
 
-    def notify_about_reblog!(status)
-      NotifyService.new.call(status.reblog.account, status)
-    end
+    class CreationActivity < Activity
+      def perform
+        if redis.exists("delete_upon_arrival:#{@account.id}:#{id}")
+          Rails.logger.debug "Delete for status #{id} was queued, ignoring"
+          return
+        end
 
-    def delete_status
-      Rails.logger.debug "Deleting remote status #{id}"
-      status = Status.find_by(uri: id, account: @account)
+        Rails.logger.debug "Creating remote status #{id}"
+        # Return early if status already exists in db
+        status = find_status(id)
 
-      if status.nil?
-        redis.setex("delete_upon_arrival:#{@account.id}:#{id}", 6 * 3_600, id)
-      else
-        RemoveStatusService.new.call(status)
-      end
-    end
+        return [status, false] unless status.nil?
 
-    def skip_unsupported_type?
-      !([:post, :share, :delete].include?(verb) && [:activity, :note, :comment].include?(type))
-    end
+        return [nil, false] if @account.suspended?
 
-    def shared_status_from_xml(entry)
-      status = find_status(id(entry))
+        status = Status.create!(
+          uri: id,
+          url: url,
+          account: @account,
+          reblog: reblog,
+          text: content,
+          spoiler_text: content_warning,
+          created_at: published,
+          reply: thread?,
+          language: content_language,
+          visibility: visibility_scope,
+          conversation: converstation_to_persistent&.first,
+          thread: thread? ? find_status(thread.first) : nil
+        )
 
-      return status unless status.nil?
+        save_mentions(status)
+        save_hashtags(status)
+        save_media(status)
 
-      FetchRemoteStatusService.new.call(url(entry))
-    end
+        if thread? && status.thread.nil?
+          Rails.logger.debug "Trying to attach #{status.id} (#{id}) to #{thread.first}"
+          ThreadResolveWorker.perform_async(status.id, thread.second)
+        end
 
-    def status_from_xml(entry)
-      # Return early if status already exists in db
-      status = find_status(id(entry))
+        Rails.logger.debug "Queuing remote status #{status.id} (#{id}) for distribution"
 
-      return [status, false] unless status.nil?
+        LinkCrawlWorker.perform_async(status.id) unless status.spoiler_text?
+        DistributionWorker.perform_async(status.id)
 
-      account = @account
-
-      return [nil, false] if account.suspended?
-
-      status = Status.create!(
-        uri: id(entry),
-        url: url(entry),
-        account: account,
-        text: content(entry),
-        spoiler_text: content_warning(entry),
-        created_at: published(entry),
-        reply: thread?(entry),
-        language: content_language(entry),
-        visibility: visibility_scope(entry),
-        conversation: find_or_create_conversation(entry),
-        thread: thread?(entry) ? find_status(thread(entry).first) : nil
-      )
-
-      mentions_from_xml(status, entry)
-      hashtags_from_xml(status, entry)
-      media_from_xml(status, entry)
-
-      [status, true]
-    end
-
-    def find_or_create_conversation(xml)
-      uri = xml.at_xpath('./ostatus:conversation', ostatus: TagManager::OS_XMLNS)&.attribute('ref')&.content
-      return if uri.nil?
-
-      if TagManager.instance.local_id?(uri)
-        local_id = TagManager.instance.unique_tag_to_local_id(uri, 'Conversation')
-        return Conversation.find_by(id: local_id)
+        [status, true]
       end
 
-      Conversation.find_by(uri: uri) || Conversation.create!(uri: uri)
-    end
-
-    def find_status(uri)
-      if TagManager.instance.local_id?(uri)
-        local_id = TagManager.instance.unique_tag_to_local_id(uri, 'Status')
-        return Status.find_by(id: local_id)
+      def content
+        @xml.at_xpath('./xmlns:content', xmlns: TagManager::XMLNS).content
       end
 
-      Status.find_by(uri: uri)
-    end
-
-    def mentions_from_xml(parent, xml)
-      processed_account_ids = []
-
-      xml.xpath('./xmlns:link[@rel="mentioned"]', xmlns: TagManager::XMLNS).each do |link|
-        next if [TagManager::TYPES[:group], TagManager::TYPES[:collection]].include? link['ostatus:object-type']
-
-        mentioned_account = account_from_href(link['href'])
-
-        next if mentioned_account.nil? || processed_account_ids.include?(mentioned_account.id)
-
-        mentioned_account.mentions.where(status: parent).first_or_create(status: parent)
-
-        # So we can skip duplicate mentions
-        processed_account_ids << mentioned_account.id
+      def content_language
+        @xml.at_xpath('./xmlns:content', xmlns: TagManager::XMLNS)['xml:lang']&.presence || 'en'
       end
-    end
 
-    def account_from_href(href)
-      url = Addressable::URI.parse(href).normalize
-
-      if TagManager.instance.web_domain?(url.host)
-        Account.find_local(url.path.gsub('/users/', ''))
-      else
-        Account.where(uri: href).or(Account.where(url: href)).first || FetchRemoteAccountService.new.call(href)
+      def content_warning
+        @xml.at_xpath('./xmlns:summary', xmlns: TagManager::XMLNS)&.content || ''
       end
-    end
 
-    def hashtags_from_xml(parent, xml)
-      tags = xml.xpath('./xmlns:category', xmlns: TagManager::XMLNS).map { |category| category['term'] }.select(&:present?)
-      ProcessHashtagsService.new.call(parent, tags)
-    end
+      def visibility_scope
+        @xml.at_xpath('./mastodon:scope', mastodon: TagManager::MTDN_XMLNS)&.content&.to_sym || :public
+      end
 
-    def media_from_xml(parent, xml)
-      do_not_download = DomainBlock.find_by(domain: parent.account.domain)&.reject_media?
+      def published
+        @xml.at_xpath('./xmlns:published', xmlns: TagManager::XMLNS).content
+      end
 
-      xml.xpath('./xmlns:link[@rel="enclosure"]', xmlns: TagManager::XMLNS).each do |link|
-        next unless link['href']
+      def thread?
+        !@xml.at_xpath('./thr:in-reply-to', thr: TagManager::THR_XMLNS).nil?
+      end
 
-        media = MediaAttachment.where(status: parent, remote_url: link['href']).first_or_initialize(account: parent.account, status: parent, remote_url: link['href'])
-        parsed_url = Addressable::URI.parse(link['href']).normalize
+      def thread
+        thr = @xml.at_xpath('./thr:in-reply-to', thr: TagManager::THR_XMLNS)
+        [thr['ref'], thr['href']]
+      end
 
-        next if !%w(http https).include?(parsed_url.scheme) || parsed_url.host.empty?
+      private
 
-        media.save
+      def converstation_to_persistent
+        uri = @xml.at_xpath('./ostatus:conversation', ostatus: TagManager::OS_XMLNS)&.attribute('ref')&.content
+        return if uri.nil?
 
-        next if do_not_download
+        if TagManager.instance.local_id?(uri)
+          local_id = TagManager.instance.unique_tag_to_local_id(uri, 'Conversation')
+          return Conversation.find_by(id: local_id)
+        end
 
-        begin
-          media.file_remote_url = link['href']
-          media.save!
-        rescue ActiveRecord::RecordInvalid
-          next
+        found = Conversation.find_by(uri: uri)
+        found ? [found, false] : [Conversation.create!(uri: uri), true]
+      end
+
+      def save_mentions(parent)
+        processed_account_ids = []
+
+        @xml.xpath('./xmlns:link[@rel="mentioned"]', xmlns: TagManager::XMLNS).each do |link|
+          next if [TagManager::TYPES[:group], TagManager::TYPES[:collection]].include? link['ostatus:object-type']
+
+          mentioned_account = account_from_href(link['href'])
+
+          next if mentioned_account.nil? || processed_account_ids.include?(mentioned_account.id)
+
+          mentioned_account.mentions.where(status: parent).first_or_create(status: parent)
+
+          # So we can skip duplicate mentions
+          processed_account_ids << mentioned_account.id
+        end
+      end
+
+      def save_hashtags(parent)
+        tags = @xml.xpath('./xmlns:category', xmlns: TagManager::XMLNS).map { |category| category['term'] }.select(&:present?)
+        ProcessHashtagsService.new.call(parent, tags)
+      end
+
+      def save_media(parent)
+        do_not_download = DomainBlock.find_by(domain: parent.account.domain)&.reject_media?
+
+        @xml.xpath('./xmlns:link[@rel="enclosure"]', xmlns: TagManager::XMLNS).each do |link|
+          next unless link['href']
+
+          media = MediaAttachment.where(status: parent, remote_url: link['href']).first_or_initialize(account: parent.account, status: parent, remote_url: link['href'])
+          parsed_url = Addressable::URI.parse(link['href']).normalize
+
+          next if !%w(http https).include?(parsed_url.scheme) || parsed_url.host.empty?
+
+          media.save
+
+          next if do_not_download
+
+          begin
+            media.file_remote_url = link['href']
+            media.save!
+          rescue ActiveRecord::RecordInvalid
+            next
+          end
+        end
+      end
+
+      def account_from_href(href)
+        url = Addressable::URI.parse(href).normalize
+
+        if TagManager.instance.web_domain?(url.host)
+          Account.find_local(url.path.gsub('/users/', ''))
+        else
+          Account.where(uri: href).or(Account.where(url: href)).first || FetchRemoteAccountService.new.call(href)
         end
       end
     end
 
-    def id(xml = @xml)
-      xml.at_xpath('./xmlns:id', xmlns: TagManager::XMLNS).content
+    class ShareActivity < CreationActivity
+      def perform
+        status, just_created = super
+        NotifyService.new.call(reblog.account, status) if reblog&.account&.local? && just_created
+        status
+      end
+
+      def object
+        @xml.at_xpath('.//activity:object', activity: TagManager::AS_XMLNS)
+      end
+
+      private
+
+      def status
+        reblog && super
+      end
+
+      def reblog
+        return @reblog if defined? @reblog
+
+        original_status = RemoteActivity.new(object).perform
+        @reblog = original_status.reblog? ? original_status.reblog : original_status
+      end
     end
 
-    def verb(xml = @xml)
-      raw = xml.at_xpath('./activity:verb', activity: TagManager::AS_XMLNS).content
-      TagManager::VERBS.key(raw)
-    rescue
-      :post
+    class PostActivity < CreationActivity
+      def perform
+        status, just_created = super
+
+        if just_created
+          status.mentions.includes(:account).each do |mention|
+            mentioned_account = mention.account
+            next unless mentioned_account.local?
+            NotifyService.new.call(mentioned_account, mention)
+          end
+        end
+
+        status
+      end
+
+      private
+
+      def reblog
+        nil
+      end
     end
 
-    def type(xml = @xml)
-      raw = xml.at_xpath('./activity:object-type', activity: TagManager::AS_XMLNS).content
-      TagManager::TYPES.key(raw)
-    rescue
-      :activity
+    class DeletionActivity < Activity
+      def perform
+        Rails.logger.debug "Deleting remote status #{id}"
+        status = Status.find_by(uri: id, account: @account)
+
+        if status.nil?
+          redis.setex("delete_upon_arrival:#{@account.id}:#{id}", 6 * 3_600, id)
+        else
+          RemoveStatusService.new.call(status)
+        end
+      end
     end
 
-    def url(xml = @xml)
-      link = xml.at_xpath('./xmlns:link[@rel="alternate"]', xmlns: TagManager::XMLNS)
-      link.nil? ? nil : link['href']
-    end
-
-    def content(xml = @xml)
-      xml.at_xpath('./xmlns:content', xmlns: TagManager::XMLNS).content
-    end
-
-    def content_language(xml = @xml)
-      xml.at_xpath('./xmlns:content', xmlns: TagManager::XMLNS)['xml:lang']&.presence || 'en'
-    end
-
-    def content_warning(xml = @xml)
-      xml.at_xpath('./xmlns:summary', xmlns: TagManager::XMLNS)&.content || ''
-    end
-
-    def visibility_scope(xml = @xml)
-      xml.at_xpath('./mastodon:scope', mastodon: TagManager::MTDN_XMLNS)&.content&.to_sym || :public
-    end
-
-    def published(xml = @xml)
-      xml.at_xpath('./xmlns:published', xmlns: TagManager::XMLNS).content
-    end
-
-    def thread?(xml = @xml)
-      !xml.at_xpath('./thr:in-reply-to', thr: TagManager::THR_XMLNS).nil?
-    end
-
-    def thread(xml = @xml)
-      thr = xml.at_xpath('./thr:in-reply-to', thr: TagManager::THR_XMLNS)
-      [thr['ref'], thr['href']]
-    end
-
-    def account?(xml = @xml)
-      !xml.at_xpath('./xmlns:author', xmlns: TagManager::XMLNS).nil?
-    end
-
-    def redis
-      Redis.current
+    class RemoteActivity < Activity
+      def perform
+        find_status(id) || FetchRemoteStatusService.new.call(url)
+      end
     end
   end
 end