feat(auth): add processing user requests

packages/auth/src/Domain/UseCase/ProcessUserRequest/ProcessUserRequest.ts

@@ -0,0 +1,46 @@
+import { DomainEventPublisherInterface } from '@standardnotes/domain-events'
+import { inject, injectable } from 'inversify'
+import { UserRequestType } from '@standardnotes/common'
+
+import TYPES from '../../../Bootstrap/Types'
+import { DomainEventFactoryInterface } from '../../Event/DomainEventFactoryInterface'
+import { UserSubscriptionRepositoryInterface } from '../../Subscription/UserSubscriptionRepositoryInterface'
+
+import { UseCaseInterface } from '../UseCaseInterface'
+import { ProcessUserRequestDTO } from './ProcessUserRequestDTO'
+import { ProcessUserRequestResponse } from './ProcessUserRequestResponse'
+
+@injectable()
+export class ProcessUserRequest implements UseCaseInterface {
+  constructor(
+    @inject(TYPES.UserSubscriptionRepository) private userSubscriptionRepository: UserSubscriptionRepositoryInterface,
+    @inject(TYPES.DomainEventFactory) private domainEventFactory: DomainEventFactoryInterface,
+    @inject(TYPES.DomainEventPublisher) private domainEventPublisher: DomainEventPublisherInterface,
+  ) {}
+
+  async execute(dto: ProcessUserRequestDTO): Promise<ProcessUserRequestResponse> {
+    if (dto.requestType !== UserRequestType.ExitDiscount) {
+      return {
+        success: false,
+      }
+    }
+
+    const subscription = await this.userSubscriptionRepository.findOneByUserUuid(dto.userUuid)
+    if (subscription === null || !subscription.cancelled) {
+      return {
+        success: false,
+      }
+    }
+
+    await this.domainEventPublisher.publish(
+      this.domainEventFactory.createExitDiscountApplyRequestedEvent({
+        userEmail: dto.userEmail,
+        discountCode: 'exit-20',
+      }),
+    )
+
+    return {
+      success: true,
+    }
+  }
+}