Change RSS feeds (#18356)

* Change RSS feeds

- Use date and time for titles instead of ellipsized text
- Use full content in body, even when there is a content warning
- Use media extensions

* Change feed icons and add width and height attributes to custom emojis

* Fix custom emoji animate on hover breaking

* Fix tests

6 files changed, 180 insertions, 55 deletions

diff --git a/app/lib/rss/builder.rb b/app/lib/rss/builder.rb
new file mode 100644
index 000000000..a9b3f08c5
--- /dev/null
+++ b/app/lib/rss/builder.rb
@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+class RSS::Builder
+  attr_reader :dsl
+
+  def self.build
+    new.tap do |builder|
+      yield builder.dsl
+    end.to_xml
+  end
+
+  def initialize
+    @dsl = RSS::Channel.new
+  end
+
+  def to_xml
+    ('<?xml version="1.0" encoding="UTF-8"?>'.dup << Ox.dump(wrap_in_document, effort: :tolerant)).force_encoding('UTF-8')
+  end
+
+  private
+
+  def wrap_in_document
+    Ox::Document.new(version: '1.0').tap do |document|
+      document << Ox::Element.new('rss').tap do |rss|
+        rss['version']        = '2.0'
+        rss['xmlns:webfeeds'] = 'http://webfeeds.org/rss/1.0'
+        rss['xmlns:media']    = 'http://search.yahoo.com/mrss/'
+
+        rss << @dsl.to_element
+      end
+    end
+  end
+end
diff --git a/app/lib/rss/channel.rb b/app/lib/rss/channel.rb
new file mode 100644
index 000000000..1dba94e47
--- /dev/null
+++ b/app/lib/rss/channel.rb
@@ -0,0 +1,49 @@
+# frozen_string_literal: true
+
+class RSS::Channel < RSS::Element
+  def initialize
+    super()
+
+    @root = create_element('channel')
+  end
+
+  def title(str)
+    append_element('title', str)
+  end
+
+  def link(str)
+    append_element('link', str)
+  end
+
+  def last_build_date(date)
+    append_element('lastBuildDate', date.to_formatted_s(:rfc822))
+  end
+
+  def image(url, title, link)
+    append_element('image') do |image|
+      image << create_element('url', url)
+      image << create_element('title', title)
+      image << create_element('link', link)
+    end
+  end
+
+  def description(str)
+    append_element('description', str)
+  end
+
+  def generator(str)
+    append_element('generator', str)
+  end
+
+  def icon(str)
+    append_element('webfeeds:icon', str)
+  end
+
+  def logo(str)
+    append_element('webfeeds:logo', str)
+  end
+
+  def item(&block)
+    @root << RSS::Item.with(&block)
+  end
+end
diff --git a/app/lib/rss/element.rb b/app/lib/rss/element.rb
new file mode 100644
index 000000000..7142fa039
--- /dev/null
+++ b/app/lib/rss/element.rb
@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+class RSS::Element
+  def self.with(*args, &block)
+    new(*args).tap(&block).to_element
+  end
+
+  def create_element(name, content = nil)
+    Ox::Element.new(name).tap do |element|
+      yield element if block_given?
+      element << content if content.present?
+    end
+  end
+
+  def append_element(name, content = nil)
+    @root << create_element(name, content).tap do |element|
+      yield element if block_given?
+    end
+  end
+
+  def to_element
+    @root
+  end
+end
diff --git a/app/lib/rss/item.rb b/app/lib/rss/item.rb
new file mode 100644
index 000000000..c02991ace
--- /dev/null
+++ b/app/lib/rss/item.rb
@@ -0,0 +1,45 @@
+# frozen_string_literal: true
+
+class RSS::Item < RSS::Element
+  def initialize
+    super()
+
+    @root = create_element('item')
+  end
+
+  def title(str)
+    append_element('title', str)
+  end
+
+  def link(str)
+    append_element('guid', str) do |guid|
+      guid['isPermaLink'] = 'true'
+    end
+
+    append_element('link', str)
+  end
+
+  def pub_date(date)
+    append_element('pubDate', date.to_formatted_s(:rfc822))
+  end
+
+  def description(str)
+    append_element('description', str)
+  end
+
+  def category(str)
+    append_element('category', str)
+  end
+
+  def enclosure(url, type, size)
+    append_element('enclosure') do |enclosure|
+      enclosure['url']    = url
+      enclosure['length'] = size
+      enclosure['type']   = type
+    end
+  end
+
+  def media_content(url, type, size, &block)
+    @root << RSS::MediaContent.with(url, type, size, &block)
+  end
+end
diff --git a/app/lib/rss/media_content.rb b/app/lib/rss/media_content.rb
new file mode 100644
index 000000000..7aefd8b40
--- /dev/null
+++ b/app/lib/rss/media_content.rb
@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+class RSS::MediaContent < RSS::Element
+  def initialize(url, type, size)
+    super()
+
+    @root = create_element('media:content') do |content|
+      content['url']      = url
+      content['type']     = type
+      content['fileSize'] = size
+    end
+  end
+
+  def medium(str)
+    @root['medium'] = str
+  end
+
+  def rating(str)
+    append_element('media:rating', str) do |rating|
+      rating['scheme'] = 'urn:simple'
+    end
+  end
+
+  def description(str)
+    append_element('media:description', str) do |description|
+      description['type'] = 'plain'
+    end
+  end
+end
diff --git a/app/lib/rss/serializer.rb b/app/lib/rss/serializer.rb
deleted file mode 100644
index d44e94221..000000000
--- a/app/lib/rss/serializer.rb
+++ /dev/null
@@ -1,55 +0,0 @@
-# frozen_string_literal: true
-
-class RSS::Serializer
-  include FormattingHelper
-
-  private
-
-  def render_statuses(builder, statuses)
-    statuses.each do |status|
-      builder.item do |item|
-        item.title(status_title(status))
-            .link(ActivityPub::TagManager.instance.url_for(status))
-            .pub_date(status.created_at)
-            .description(status_description(status))
-
-        status.ordered_media_attachments.each do |media|
-          item.enclosure(full_asset_url(media.file.url(:original, false)), media.file.content_type, media.file.size)
-        end
-      end
-    end
-  end
-
-  def status_title(status)
-    preview = status.proper.spoiler_text.presence || status.proper.text
-
-    if preview.length > 30 || preview[0, 30].include?("\n")
-      preview = preview[0, 30]
-      preview = preview[0, preview.index("\n").presence || 30] + '…'
-    end
-
-    preview = "#{status.proper.spoiler_text.present? ? 'CW ' : ''}“#{preview}”#{status.proper.sensitive? ? ' (sensitive)' : ''}"
-
-    if status.reblog?
-      "#{status.account.acct} boosted #{status.reblog.account.acct}: #{preview}"
-    else
-      "#{status.account.acct}: #{preview}"
-    end
-  end
-
-  def status_description(status)
-    if status.proper.spoiler_text?
-      status.proper.spoiler_text
-    else
-      html = status_content_format(status.proper).to_str
-      after_html = ''
-
-      if status.proper.preloadable_poll
-        poll_options_html = status.proper.preloadable_poll.options.map { |o| "[ ] #{o}" }.join('<br />')
-        after_html = "<p>#{poll_options_html}</p>"
-      end
-
-      "#{html}#{after_html}"
-    end
-  end
-end