discourse/app/controllers/extra_locales_controller.rb

# frozen_string_literal: true

class ExtraLocalesController < ApplicationController
  layout false

  skip_before_action :check_xhr,
                     :preload_json,
                     :redirect_to_login_if_required,
                     :redirect_to_profile_if_required,
                     :verify_authenticity_token

  OVERRIDES_BUNDLE = "overrides"
  MD5_HASH_LENGTH = 32
  MF_BUNDLE = "mf"
  BUNDLES = [OVERRIDES_BUNDLE, MF_BUNDLE]

  class << self
    def js_digests
      @js_digests ||= {}
    end

    def bundle_js_hash(bundle)
      bundle_key = "#{bundle}_#{I18n.locale}"
      if bundle.in?(BUNDLES)
        site = RailsMultisite::ConnectionManagement.current_db

        js_digests[site] ||= {}
        js_digests[site][bundle_key] ||= begin
          js = bundle_js(bundle)
          js.present? ? Digest::MD5.hexdigest(js) : nil
        end
      else
        js_digests[bundle_key] ||= Digest::MD5.hexdigest(bundle_js(bundle))
      end
    end

    def url(bundle)
      "#{Discourse.base_path}/extra-locales/#{bundle}?v=#{bundle_js_hash(bundle)}"
    end

    def client_overrides_exist?
      bundle_js_hash(OVERRIDES_BUNDLE).present?
    end

    def bundle_js(bundle)
      locale_str = I18n.locale.to_s
      bundle_str = "#{bundle}_js"

      case bundle
      when OVERRIDES_BUNDLE
        JsLocaleHelper.output_client_overrides(locale_str)
      when MF_BUNDLE
        JsLocaleHelper.output_MF(locale_str)
      else
        JsLocaleHelper.output_extra_locales(bundle_str, locale_str)
      end
    end

    def bundle_js_with_hash(bundle)
      js = bundle_js(bundle)
      [js, Digest::MD5.hexdigest(js)]
    end

    def clear_cache!
      site = RailsMultisite::ConnectionManagement.current_db
      js_digests.delete(site)
    end
  end

  def show
    bundle = params[:bundle]
    raise Discourse::InvalidAccess.new if !valid_bundle?(bundle)

    version = params[:v]
    if version.present?
      raise Discourse::InvalidParameters.new(:v) unless version.to_s.size == MD5_HASH_LENGTH
    end

    content, hash = ExtraLocalesController.bundle_js_with_hash(bundle)
    immutable_for(1.year) if hash == version

    render plain: content, content_type: "application/javascript"
  end

  private

  def valid_bundle?(bundle)
    bundle.in?(BUNDLES) || (bundle =~ /\A(admin|wizard)\z/ && current_user&.staff?)
  end
end