osunyorg/admin

module Backlinkable
  extend ActiveSupport::Concern

  # TODO: Optimize this method
  def backlinks_pages(website)
    special_page_ids = website.pages.where.not(type: nil).pluck(:id)
    backlinks(
      "Communication::Website::Page::Localization",
      website
    )
    .reject { |page_l10n| special_page_ids.include?(page_l10n.about_id) }
  end

  def backlinks_posts(website)
    backlinks(
      "Communication::Website::Post::Localization",
      website
    )
  end

  def backlinks_agenda_events(website)
    backlinks(
      "Communication::Website::Agenda::Event::Localization",
      website
    )
  end

  def backlinks_portfolio_projects(website)
    backlinks(
      "Communication::Website::Portfolio::Project::Localization",
      website
    )
  end

  protected

  def backlinks(kind, website)
    backlinks_object_ids = published_backlinks_blocks(website).map { |block|
      block.about_id if backlink_in_block?(block, kind, website)
    }.compact
    kind.safe_constantize.published.where(communication_website_id: website.id, id: backlinks_object_ids)
  end

  def backlink_in_block?(block, kind, website)
    block.about_type == kind && # Correct kind
    block.about_id.in?(published_backlinks_localization_ids(website, kind)) && # About published
    self.about_id.in?(block.template.children_ids) # Mentioning self
  end

  def published_backlinks_localization_ids(website, kind)
    # Looking for published localization IDs within the website, for current language
    # Memoize to avoid multiple queries for the same website and kind
    @published_backlinks_localization_ids ||= {}
    @published_backlinks_localization_ids[website.id] ||= {}
    @published_backlinks_localization_ids[website.id][kind] ||= kind.safe_constantize
                                                              .published
                                                              .where(communication_website_id: website.id, language_id: language_id)
                                                              .pluck(:id)
  end

  def published_backlinks_blocks(website)
    # Memoize to avoid multiple queries for the same website
    @published_backlinks_blocks ||= {}
    @published_backlinks_blocks[website.id] ||= backlinks_blocks(website).published
  end

  def backlinks_blocks(website)
    raise NotImplementedError
  end
end