discourse/app/controllers/admin/site_settings_controller.rb

# frozen_string_literal: true

class Admin::SiteSettingsController < Admin::AdminController
  rescue_from Discourse::InvalidParameters do |e|
    render_json_error e.message, status: 422
  end

  def index
    render_json_dump(site_settings: SiteSetting.all_settings, diags: SiteSetting.diags)
  end

  def update
    params.require(:id)
    id = params[:id]
    value = params[id]
    value.strip! if value.is_a?(String)
    raise_access_hidden_setting(id)

    if SiteSetting.type_supervisor.get_type(id) == :upload
      value = Upload.find_by(url: value) || ''
    end

    update_existing_users = params[:updateExistingUsers].present?
    previous_value = SiteSetting.send(id) || "" if update_existing_users

    SiteSetting.set_and_log(id, value, current_user)

    if update_existing_users
      user_options = {
        default_email_mailing_list_mode: "mailing_list_mode",
        default_email_mailing_list_mode_frequency: "mailing_list_mode_frequency",
        default_email_level: "email_level",
        default_email_messages_level: "email_messages_level",
        default_topics_automatic_unpin: "automatically_unpin_topics",
        default_email_previous_replies: "email_previous_replies",
        default_email_in_reply_to: "email_in_reply_to",
        default_other_enable_quoting: "enable_quoting",
        default_other_enable_defer: "enable_defer",
        default_other_external_links_in_new_tab: "external_links_in_new_tab",
        default_other_dynamic_favicon: "dynamic_favicon",
        default_other_new_topic_duration_minutes: "new_topic_duration_minutes",
        default_other_auto_track_topics_after_msecs: "auto_track_topics_after_msecs",
        default_other_notification_level_when_replying: "notification_level_when_replying",
        default_other_like_notification_frequency: "like_notification_frequency",
        default_email_digest_frequency: "digest_after_minutes",
        default_include_tl0_in_digests: "include_tl0_in_digests",
        default_text_size: "text_size_key",
        default_title_count_mode: "title_count_mode_key"
      }

      new_value = value || ""

      if (user_option = user_options[id.to_sym]).present?
        if user_option == "text_size_key"
          previous_value = UserOption.text_sizes[previous_value.to_sym]
          new_value = UserOption.text_sizes[new_value.to_sym]
        elsif user_option == "title_count_mode_key"
          previous_value = UserOption.title_count_modes[previous_value.to_sym]
          new_value = UserOption.title_count_modes[new_value.to_sym]
        end

        UserOption.where(user_option => previous_value).update_all(user_option => new_value)

        if id == "default_email_digest_frequency"
          disable_digests = new_value == 0
          UserOption.where(user_option => 0, email_digests: !disable_digests).update_all(email_digests: disable_digests)
        end
      elsif id.start_with?("default_categories_")
        previous_category_ids = previous_value.split("|")
        new_category_ids = new_value.split("|")

        case id
        when "default_categories_watching"
          notification_level = NotificationLevels.all[:watching]
        when "default_categories_tracking"
          notification_level = NotificationLevels.all[:tracking]
        when "default_categories_muted"
          notification_level = NotificationLevels.all[:muted]
        when "default_categories_watching_first_post"
          notification_level = NotificationLevels.all[:watching_first_post]
        end

        (previous_category_ids - new_category_ids).each do |category_id|
          CategoryUser.where(category_id: category_id, notification_level: notification_level).delete_all
        end

        (new_category_ids - previous_category_ids).each do |category_id|
          skip_user_ids = CategoryUser.where(category_id: category_id).pluck(:user_id)

          User.where.not(id: skip_user_ids).select(:id).find_in_batches do |users|
            category_users = []
            users.each { |user| category_users << { category_id: category_id, user_id: user.id, notification_level: notification_level } }
            CategoryUser.insert_all!(category_users)
          end

          CategoryUser.where(category_id: category_id, notification_level: notification_level).first_or_create!(notification_level: notification_level)
        end
      end
    end

    render body: nil
  end

  private

  def raise_access_hidden_setting(id)
    # note, as of Ruby 2.3 symbols are GC'd so this is considered safe
    if SiteSetting.hidden_settings.include?(id.to_sym)
      raise Discourse::InvalidParameters, "You are not allowed to change hidden settings"
    end
  end

end