failure_app.rb

# frozen_string_literal: true

require "action_controller/metal"

module Devise
  # Failure application that will be called every time :warden is thrown from
  # any strategy or hook. It is responsible for redirecting the user to the sign
  # in page based on current scope and mapping. If no scope is given, it
  # redirects to the default_url.
  class FailureApp < ActionController::Metal
    include ActionController::UrlFor
    include ActionController::Redirecting

    include Rails.application.routes.url_helpers
    include Rails.application.routes.mounted_helpers

    include Devise::Controllers::StoreLocation

    delegate :flash, to: :request

    include AbstractController::Callbacks
    around_action do |failure_app, action|
      I18n.with_locale(failure_app.i18n_locale, &action)
    end

    def self.call(env)
      @respond ||= action(:respond)
      @respond.call(env)
    end

    # Try retrieving the URL options from the parent controller (usually
    # ApplicationController). Instance methods are not supported at the moment,
    # so only the class-level attribute is used.
    def self.default_url_options(*args)
      if defined?(Devise.parent_controller.constantize)
        Devise.parent_controller.constantize.try(:default_url_options) || {}
      else
        {}
      end
    end

    def respond
      if http_auth?
        http_auth
      elsif warden_options[:recall]
        recall
      else
        redirect
      end
    end

    def http_auth
      self.status = 401
      self.headers["WWW-Authenticate"] = %(Basic realm=#{Devise.http_authentication_realm.inspect}) if http_auth_header?
      self.content_type = request.format.to_s
      self.response_body = http_auth_body
    end

    def recall
      header_info = if relative_url_root?
        base_path = Pathname.new(relative_url_root)
        full_path = Pathname.new(attempted_path)

        { "SCRIPT_NAME" => relative_url_root,
          "PATH_INFO" => '/' + full_path.relative_path_from(base_path).to_s }
      else
        { "PATH_INFO" => attempted_path }
      end

      header_info.each do | var, value|
        if request.respond_to?(:set_header)
          request.set_header(var, value)
        else
          request.env[var]  = value
        end
      end

      flash.now[:alert] = i18n_message(:invalid) if is_flashing_format?
      self.response = recall_app(warden_options[:recall]).call(request.env).tap { |response|
        response[0] = Rack::Utils.status_code(
          response[0].in?(300..399) ? Devise.responder.redirect_status : Devise.responder.error_status
        )
      }
    end

    def redirect
      store_location!
      if is_flashing_format?
        if flash[:timedout] && flash[:alert]
          flash.keep(:timedout)
          flash.keep(:alert)
        else
          flash[:alert] = i18n_message
        end
      end
      redirect_to redirect_url
    end

  protected

    def i18n_options(options)
      options
    end

    def i18n_message(default = nil)
      message = warden_message || default || :unauthenticated

      if message.is_a?(Symbol)
        options = {}
        options[:resource_name] = scope
        options[:scope] = "devise.failure"
        options[:default] = [message]
        auth_keys = scope_class.authentication_keys
        keys = (auth_keys.respond_to?(:keys) ? auth_keys.keys : auth_keys).map { |key| scope_class.human_attribute_name(key) }
        options[:authentication_keys] = keys.join(I18n.t(:"support.array.words_connector"))
        options = i18n_options(options)

        I18n.t(:"#{scope}.#{message}", **options)
      else
        message.to_s
      end
    end

    def i18n_locale
      warden_options[:locale]
    end

    def redirect_url
      if warden_message == :timeout
        flash[:timedout] = true if is_flashing_format?

        path = if request.get?
          attempted_path
        else
          request.referrer
        end

        path || scope_url
      else
        scope_url
      end
    end

    def route(scope)
      :"new_#{scope}_session_url"
    end

    def scope_url
      opts  = {}

      # Initialize script_name with nil to prevent infinite loops in
      # authenticated mounted engines in rails 4.2 and 5.0
      opts[:script_name] = nil

      route = route(scope)

      opts[:format] = request_format unless skip_format?

      router_name = Devise.mappings[scope].router_name || Devise.available_router_name
      context = send(router_name)

      if relative_url_root?
        opts[:script_name] = relative_url_root

      # We need to add the rootpath to `script_name` manually for applications that use a Rails
      # version lower than 5.1. Otherwise, it is going to generate a wrong path for Engines
      # that use Devise. Remove it when the support of Rails 5.0 is dropped.
      elsif root_path_defined?(context) && !rails_51_and_up?
        rootpath = context.routes.url_helpers.root_path
        opts[:script_name] = rootpath.chomp('/') if rootpath.length > 1
      end

      if context.respond_to?(route)
        context.send(route, opts)
      elsif respond_to?(:root_url)
        root_url(opts)
      else
        "/"
      end
    end

    def skip_format?
      %w(html */* turbo_stream).include? request_format.to_s
    end

    # Choose whether we should respond in an HTTP authentication fashion,
    # including 401 and optional headers.
    #
    # This method allows the user to explicitly disable HTTP authentication
    # on AJAX requests in case they want to redirect on failures instead of
    # handling the errors on their own. This is useful in case your AJAX API
    # is the same as your public API and uses a format like JSON (so you
    # cannot mark JSON as a navigational format).
    def http_auth?
      if request.xhr?
        Devise.http_authenticatable_on_xhr
      else
        !(request_format && is_navigational_format?)
      end
    end

    # It doesn't make sense to send authenticate headers in AJAX requests
    # or if the user disabled them.
    def http_auth_header?
      scope_class.http_authenticatable && !request.xhr?
    end

    def http_auth_body
      return i18n_message unless request_format
      method = "to_#{request_format}"
      if method == "to_xml"
        { error: i18n_message }.to_xml(root: "errors")
      elsif {}.respond_to?(method)
        { error: i18n_message }.send(method)
      else
        i18n_message
      end
    end

    def recall_app(app)
      controller, action = app.split("#")
      controller_name  = ActiveSupport::Inflector.camelize(controller)
      controller_klass = ActiveSupport::Inflector.constantize("#{controller_name}Controller")
      controller_klass.action(action)
    end

    def warden
      request.respond_to?(:get_header) ? request.get_header("warden") : request.env["warden"]
    end

    def warden_options
      request.respond_to?(:get_header) ? request.get_header("warden.options") : request.env["warden.options"]
    end

    def warden_message
      @message ||= warden.message || warden_options[:message]
    end

    def scope
      @scope ||= warden_options[:scope] || Devise.default_scope
    end

    def scope_class
      @scope_class ||= Devise.mappings[scope].to
    end

    def attempted_path
      warden_options[:attempted_path]
    end

    # Stores requested URI to redirect the user after signing in. We can't use
    # the scoped session provided by warden here, since the user is not
    # authenticated yet, but we still need to store the URI based on scope, so
    # different scopes would never use the same URI to redirect.
    def store_location!
      store_location_for(scope, attempted_path) if request.get? && !http_auth?
    end

    def is_navigational_format?
      Devise.navigational_formats.include?(request_format)
    end

    # Check if flash messages should be emitted. Default is to do it on
    # navigational formats
    def is_flashing_format?
      request.respond_to?(:flash) && is_navigational_format?
    end

    def request_format
      @request_format ||= request.format.try(:ref)
    end

    def relative_url_root
      @relative_url_root ||= begin
        config = Rails.application.config

        config.try(:relative_url_root) || config.action_controller.try(:relative_url_root)
      end
    end

    def relative_url_root?
      relative_url_root.present?
    end

    ActiveSupport.run_load_hooks(:devise_failure_app, self)

    private

    def root_path_defined?(context)
      defined?(context.routes) && context.routes.url_helpers.respond_to?(:root_path)
    end

    def rails_51_and_up?
      Rails.gem_version >= Gem::Version.new("5.1")
    end
  end
end