Bring simplified / cleaned up base controller into V1

- Inherits from ActionController::API
- Lots of superfluous junk removed

app/controllers/api/v1/base_controller.rb

@@ -0,0 +1,76 @@
+# frozen_string_literal: true
+
+module Api
+  module V1
+    class BaseController < ActionController::API
+      include CanCan::ControllerAdditions
+      check_authorization
+
+      attr_accessor :current_api_user
+
+      before_action :authenticate_user
+
+      rescue_from Exception, with: :error_during_processing
+      rescue_from CanCan::AccessDenied, with: :unauthorized
+      rescue_from ActiveRecord::RecordNotFound, with: :not_found
+
+      private
+
+      def spree_current_user
+        @spree_current_user ||= request.env['warden'].user
+      end
+
+      # Use logged in user (spree_current_user) for API authentication (current_api_user)
+      def authenticate_user
+        return if (@current_api_user = spree_current_user)
+
+        if api_key.blank?
+          # An anonymous user
+          @current_api_user = Spree.user_class.new
+          return
+        end
+
+        return if (@current_api_user = Spree.user_class.find_by(spree_api_key: api_key.to_s))
+
+        invalid_api_key
+      end
+
+      def error_during_processing(exception)
+        Bugsnag.notify(exception)
+
+        render json: { exception: exception.message },
+               status: :unprocessable_entity
+      end
+
+      def current_ability
+        Spree::Ability.new(current_api_user)
+      end
+
+      def api_key
+        request.headers["X-Spree-Token"] || params[:token]
+      end
+      helper_method :api_key
+
+      def invalid_resource!(resource)
+        render json: { error: I18n.t(:invalid_resource, scope: "spree.api"),
+                       errors: resource.errors },
+               status: :unprocessable_entity
+      end
+
+      def invalid_api_key
+        render json: { error: I18n.t(:invalid_api_key, key: api_key, scope: "spree.api") },
+               status: :unauthorized
+      end
+
+      def unauthorized
+        render json: { error: I18n.t(:unauthorized, scope: "spree.api") },
+               status: :unauthorized
+      end
+
+      def not_found
+        render json: { error: I18n.t(:resource_not_found, scope: "spree.api") },
+               status: :not_found
+      end
+    end
+  end
+end