discourse/app/models/theme_site_setting.rb

# frozen_string_literal: true

# Copies the same schema as SiteSetting, since the values and
# data types are identical. This table is used as a way for themes
# to overrride specific site settings that we make available in
# core based on the `themeable` designation on a site setting.
#
# Creation, updating, and deletion of theme site settings is done
# via the `Themes::ThemeSiteSettingManager` service.
class ThemeSiteSetting < ActiveRecord::Base
  belongs_to :theme

  has_many :upload_references, as: :target, dependent: :destroy

  after_save do
    if saved_change_to_value?
      if self.data_type == SiteSettings::TypeSupervisor.types[:upload]
        UploadReference.ensure_exist!(upload_ids: [self.value], target: self)
      elsif self.data_type == SiteSettings::TypeSupervisor.types[:objects] && self.value.present?
        upload_ids =
          SchemaSettingsObjectValidator.property_values_of_type(
            schema: SiteSetting.type_supervisor.type_hash(self.name.to_sym)[:schema],
            objects: JSON.parse(self.value),
            type: "upload",
          )

        UploadReference.ensure_exist!(upload_ids: upload_ids, target: self) if upload_ids.any?
      end
    end
  end

  # Gets a list of themes that have theme site setting records
  # and the associated values for those settings, where the
  # value is different from the default site setting value.
  #
  # @return [Array<Hash>] an array of hashes where each hash contains:
  #   - :theme_id [Integer] the ID of the theme
  #   - :theme_name [String] the name of the theme
  #   - :setting_name [Symbol] the name of the setting
  #   - :value [String] the value of the setting
  #   - :data_type [Integer] the data type of the setting
  def self.themes_with_overridden_settings
    sql = <<~SQL
      SELECT theme.id AS theme_id, theme.name AS theme_name,
        tss.name AS setting_name, tss.value, tss.data_type
      FROM themes theme
      INNER JOIN theme_site_settings tss ON theme.id = tss.theme_id
      WHERE theme.component = false AND tss.name IN (:setting_names)
      ORDER BY tss.name, theme.name
    SQL

    DB
      .query(sql, setting_names: SiteSetting.themeable_site_settings)
      .each { |row| row.setting_name = row.setting_name.to_sym }
      .select do |row|
        # Do not consider this as an "overridden" setting if the value
        # is the same as the default site setting value.
        row.value !=
          SiteSetting
            .type_supervisor
            .to_db_value(row.setting_name, SiteSetting.defaults[row.setting_name])
            .first
      end
      .each do |row|
        row.value =
          SiteSetting.type_supervisor.to_rb_value(row.setting_name, row.value, row.data_type)
      end
  end

  def self.can_access_db?
    !GlobalSetting.skip_redis? && !GlobalSetting.skip_db? &&
      ActiveRecord::Base.connection.table_exists?(self.table_name)
  end

  # Generates a map of theme IDs to their site setting values. When
  # there is no theme site setting for a given theme, the default
  # site setting value is used.
  #
  # @return [Hash] a map where keys are theme IDs and values are hashes:
  #
  # {
  #   123 => {
  #     setting_name_1 => value_1,
  #     setting_name_2 => value_2,
  #     ...
  #   }
  # }
  def self.generate_theme_map
    # Similar to what SiteSettings::DbProvider and SiteSettings::LocalProcessProvider do
    # for their #all method, we can't try to load settings if the DB is not available,
    # since this method is called within SiteSetting.refresh! which is called on boot.
    return {} if !can_access_db?

    theme_site_setting_values_map = {}
    Theme
      .includes(:theme_site_settings)
      .not_components
      .each do |theme|
        SiteSetting.themeable_site_settings.each do |setting_name|
          setting = theme.theme_site_settings.find { |s| s.name == setting_name.to_s }

          value =
            if setting.nil?
              SiteSetting.defaults[setting_name]
            else
              SiteSetting.type_supervisor.to_rb_value(
                setting.name.to_sym,
                setting.value,
                setting.data_type,
              )
            end

          theme_site_setting_values_map[theme.id] ||= {}
          theme_site_setting_values_map[theme.id][setting_name] = value
        end
      end

    theme_site_setting_values_map
  end

  def self.generate_defaults_map
    SiteSetting.themeable_site_settings.to_h do |setting_name|
      [setting_name, SiteSetting.defaults[setting_name]]
    end
  end

  def setting_rb_value
    SiteSetting.type_supervisor.to_rb_value(self.name, self.value, self.data_type)
  end
end

# == Schema Information
#
# Table name: theme_site_settings
#
#  id         :bigint           not null, primary key
#  theme_id   :integer          not null
#  name       :string           not null
#  data_type  :integer          not null
#  value      :text
#  created_at :datetime         not null
#  updated_at :datetime         not null
#
# Indexes
#
#  index_theme_site_settings_on_theme_id           (theme_id)
#  index_theme_site_settings_on_theme_id_and_name  (theme_id,name) UNIQUE
#