module Scrivito

  class CmsDispatchController < ActionController::Metal
    include ActionController::Redirecting
    include Rails.application.routes.url_helpers
    include Scrivito::RoutingHelper

    def process(action)
      CmsEnv.new(env).load

      if !obj_not_found? && action == 'legacy'
        if Scrivito::Configuration.legacy_routing
          action = 'index'
        else
          redirect_to scrivito_path(loaded_obj)
          return self.response
        end
      end

      if obj_not_found? && editing_context.workspace_changed?
        redirect_to scrivito_path(Obj.homepage)
        return self.response
      end

      controller = target_controller(env)
      env["action_dispatch.request.path_parameters"]["controller"] = controller.controller_path

      if !obj_not_found? && action == 'index'
        action = loaded_obj.controller_action_name
      end

      env["action_dispatch.request.path_parameters"]["action"] = action

      self.response = controller.action(action).call(env)
    end

    private

    def main_app
      Rails.application.routes.url_helpers
    end

    def scrivito_engine
      Scrivito::SdkEngine.routes.url_helpers
    end

    def editing_context
      EditingContextMiddleware.from_request(request)
    end

    def target_controller(env)
      return default_controller if obj_not_found?
      controller = "#{loaded_obj.controller_name}Controller".constantize

      if controller.respond_to?(:use_for_obj_dispatch?) && controller.use_for_obj_dispatch?
        controller
      else
        default_controller
      end
    rescue NameError
      default_controller
    end

    def loaded_obj
      env[CmsEnv::OBJ_ENV_KEY]
    end

    def obj_not_found?
      loaded_obj.is_a?(StandardError)
    end

    def default_controller
      CmsController
    rescue NameError => e
      if e.message.include?('CmsController')
        raise 'Your application does not define the "CmsController" needed for Scrivito. '\
          'Did you forget to run "rails generate scrivito:install"?'
      else
        raise
      end
    end
  end

end