  def self.ensure_consistency!
    update_topic_counts
  end

  def self.update_topic_counts
    DB.exec <<~SQL
      UPDATE tags t
         SET staff_topic_count = x.topic_count
        FROM (
             SELECT COUNT(topics.id) AS topic_count, tags.id AS tag_id
               FROM tags
          LEFT JOIN topic_tags ON tags.id = topic_tags.tag_id
          LEFT JOIN topics ON topics.id = topic_tags.topic_id
                          AND topics.deleted_at IS NULL
                          AND topics.archetype != 'private_message'
           GROUP BY tags.id
        ) x
       WHERE x.tag_id = t.id
         AND x.topic_count <> t.staff_topic_count
    SQL
…
    DB.exec <<~SQL
      UPDATE tags t
      SET public_topic_count = x.topic_count
      FROM (
        WITH tags_with_public_topics AS (
          SELECT
            COUNT(topics.id) AS topic_count,
            tags.id AS tag_id
          FROM tags
          INNER JOIN topic_tags ON tags.id = topic_tags.tag_id
          INNER JOIN topics ON topics.id = topic_tags.topic_id AND topics.deleted_at IS NULL AND topics.archetype != 'private_message'
          INNER JOIN categories ON categories.id = topics.category_id AND NOT categories.read_restricted
          GROUP BY tags.id
        )
        SELECT
          COALESCE(tags_with_public_topics.topic_count, 0 ) AS topic_count,
          tags.id AS tag_id
        FROM tags
        LEFT JOIN tags_with_public_topics ON tags_with_public_topics.tag_id = tags.id
      ) x
      WHERE x.tag_id = t.id
      AND x.topic_count <> t.public_topic_count;
    SQL

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