Add tootctl preview_cards clean

lib/mastodon/cli/preview_cards.rb

@@ -7,6 +7,12 @@ module Mastodon::CLI
   class PreviewCards < Base
     include ActionView::Helpers::NumberHelper
 
+    class PreviewCardsStatus < ApplicationRecord
+      self.primary_key = [:status_id, :preview_card_id]
+      belongs_to :status
+      belongs_to :preview_card
+    end
+
     option :days, type: :numeric, default: 180
     option :concurrency, type: :numeric, default: 5, aliases: [:c]
     option :verbose, type: :boolean, aliases: [:v]
@@ -47,5 +53,43 @@ def remove
 
       say("Removed #{processed} #{link}preview cards (approx. #{number_to_human_size(aggregate)})#{dry_run_mode_suffix}", :green, true)
     end
+
+    option :days, type: :numeric, default: 14
+    option :verbose, type: :boolean, aliases: [:v]
+    option :dry_run, type: :boolean, default: false
+    desc 'clean', 'Clean unused preview card records'
+    long_desc <<-DESC
+      Clean unused preview card records.
+
+      The --days option specifies the number of days after which unused
+      preview cards are deleted. The default is 14 days. Preview cards are
+      reused if the link is reposted within two weeks of the last time,
+      so deleting them too early can result in additional overhead for
+      refetching.
+    DESC
+    def clean
+      time_ago = options[:days].days.ago
+      scope    = PreviewCardsStatus.joins(:preview_card).left_joins(:status).where(statuses: {id: nil}).where(preview_cards: {updated_at: ...time_ago}).pluck(:preview_card_id)
+      total    = scope.count
+
+      progress = create_progress_bar(total)
+
+      scope.each_slice(1000) do |preview_card_ids|
+        if !progress.total.nil? && progress.progress + 1 > progress.total
+          progress.total = nil
+        end
+
+        unless dry_run?
+          PreviewCardTrend.where(preview_card_id: preview_card_ids).delete_all
+          PreviewCardsStatus.where(preview_card_id: preview_card_ids).delete_all
+          PreviewCard.where(id: preview_card_ids).delete_all
+        end
+
+        progress.progress += preview_card_ids.count
+      end
+
+      progress.stop
+      say("Removed #{total} PreviewCard records#{dry_run_mode_suffix}", :green)
+    end
   end
 end