mastodon/app/controllers/application_controller.rb

# frozen_string_literal: true

class ApplicationController < ActionController::Base
  # Prevent CSRF attacks by raising an exception.
  # For APIs, you may want to use :null_session instead.
  protect_from_forgery with: :exception

  force_ssl if: :https_enabled?

  include Localized
  include UserTrackingConcern
  include SessionTrackingConcern

  helper_method :current_account
  helper_method :current_session
  helper_method :current_theme
  helper_method :single_user_mode?
  helper_method :use_seamless_external_login?

  rescue_from ActionController::RoutingError, with: :not_found
  rescue_from ActiveRecord::RecordNotFound, with: :not_found
  rescue_from ActionController::InvalidAuthenticityToken, with: :unprocessable_entity
  rescue_from ActionController::UnknownFormat, with: :not_acceptable
  rescue_from Mastodon::NotPermittedError, with: :forbidden

  before_action :store_current_location, except: :raise_not_found, unless: :devise_controller?
  before_action :check_user_permissions, if: :user_signed_in?

  def raise_not_found
    raise ActionController::RoutingError, "No route matches #{params[:unmatched_route]}"
  end

  private

  def https_enabled?
    Rails.env.production?
  end

  def authorized_fetch_mode?
    ENV['AUTHORIZED_FETCH'] == 'true'
  end

  def public_fetch_mode?
    !authorized_fetch_mode?
  end

  def store_current_location
    store_location_for(:user, request.url) unless request.format == :json
  end

  def require_admin!
    forbidden unless current_user&.admin?
  end

  def require_staff!
    forbidden unless current_user&.staff?
  end

  def check_user_permissions
    forbidden if current_user.disabled? || current_user.account.suspended?
  end

  def after_sign_out_path_for(_resource_or_scope)
    new_user_session_path
  end

  protected

  def truthy_param?(key)
    ActiveModel::Type::Boolean.new.cast(params[key])
  end

  def forbidden
    respond_with_error(403)
  end

  def not_found
    respond_with_error(404)
  end

  def gone
    respond_with_error(410)
  end

  def unprocessable_entity
    respond_with_error(422)
  end

  def not_acceptable
    respond_with_error(406)
  end

  def single_user_mode?
    @single_user_mode ||= Rails.configuration.x.single_user_mode && Account.exists?
  end

  def use_seamless_external_login?
    Devise.pam_authentication || Devise.ldap_authentication
  end

  def current_account
    return @current_account if defined?(@current_account)

    @current_account = current_user&.account
  end

  def current_session
    return @current_session if defined?(@current_session)

    @current_session = SessionActivation.find_by(session_id: cookies.signed['_session_id']) if cookies.signed['_session_id'].present?
  end

  def current_theme
    return Setting.theme unless Themes.instance.names.include? current_user&.setting_theme
    current_user.setting_theme
  end

  def cache_collection(raw, klass)
    return raw unless klass.respond_to?(:with_includes)

    raw                    = raw.cache_ids.to_a if raw.is_a?(ActiveRecord::Relation)
    cached_keys_with_value = Rails.cache.read_multi(*raw).transform_keys(&:id)
    uncached_ids           = raw.map(&:id) - cached_keys_with_value.keys

    klass.reload_stale_associations!(cached_keys_with_value.values) if klass.respond_to?(:reload_stale_associations!)

    unless uncached_ids.empty?
      uncached = klass.where(id: uncached_ids).with_includes.each_with_object({}) { |item, h| h[item.id] = item }

      uncached.each_value do |item|
        Rails.cache.write(item, item)
      end
    end

    raw.map { |item| cached_keys_with_value[item.id] || uncached[item.id] }.compact
  end

  def respond_with_error(code)
    respond_to do |format|
      format.any  { head code }

      format.html do
        set_locale
        render "errors/#{code}", layout: 'error', status: code
      end
    end
  end

  def render_cached_json(cache_key, **options)
    options[:expires_in] ||= 3.minutes
    cache_public           = options.key?(:public) ? options.delete(:public) : true
    content_type           = options.delete(:content_type) || 'application/json'

    data = Rails.cache.fetch(cache_key, { raw: true }.merge(options)) do
      yield.to_json
    end

    expires_in options[:expires_in], public: cache_public
    render json: data, content_type: content_type
  end

  def set_cache_headers
    response.headers['Vary'] = public_fetch_mode? ? 'Accept' : 'Accept, Signature'
  end
end