discourse/app/controllers/sitemap_controller.rb

# frozen_string_literal: true

class SitemapController < ApplicationController
  layout false
  skip_before_action :preload_json, :check_xhr
  before_action :check_sitemap_enabled

  def index
    @sitemaps = Sitemap
      .where(enabled: true)
      .where.not(name: Sitemap::NEWS_SITEMAP_NAME)

    render :index
  end

  def page
    index = params.require(:page)
    sitemap = Sitemap.find_by(enabled: true, name: index.to_s)
    raise Discourse::NotFound if sitemap.nil?

    @output = Rails.cache.fetch("sitemap/#{sitemap.name}/#{sitemap.max_page_size}", expires_in: 24.hours) do
      @topics = sitemap.topics
      render :page, content_type: 'text/xml; charset=UTF-8'
    end

    render plain: @output, content_type: 'text/xml; charset=UTF-8' unless performed?
  end

  def recent
    sitemap = Sitemap.touch(Sitemap::RECENT_SITEMAP_NAME)

    @output = Rails.cache.fetch("sitemap/recent/#{sitemap.last_posted_at.to_i}", expires_in: 1.hour) do
      @topics = sitemap.topics
      render :page, content_type: 'text/xml; charset=UTF-8'
    end

    render plain: @output, content_type: 'text/xml; charset=UTF-8' unless performed?
  end

  def news
    sitemap = Sitemap.touch(Sitemap::NEWS_SITEMAP_NAME)

    @output = Rails.cache.fetch("sitemap/news", expires_in: 5.minutes) do
      dlocale = SiteSetting.default_locale.downcase
      @locale = dlocale.gsub(/_.*/, '')
      @locale = dlocale.sub('_', '-') if @locale === "zh"
      @topics = sitemap.topics
      render :news, content_type: 'text/xml; charset=UTF-8'
    end

    render plain: @output, content_type: 'text/xml; charset=UTF-8' unless performed?
  end

  private

  def check_sitemap_enabled
    raise Discourse::NotFound if !SiteSetting.enable_sitemap
  end

  def build_sitemap_topic_url(slug, id, posts_count = nil)
    base_url = [Discourse.base_url, 't', slug, id].join('/')
    return base_url if posts_count.nil?

    page, mod = posts_count.divmod(TopicView.chunk_size)
    page += 1 if mod > 0

    page > 1 ? "#{base_url}?page=#{page}" : base_url
  end
  helper_method :build_sitemap_topic_url

end