enhance subcribe to workshop

src/WorkshopSubscription/workshopsubscription.schema.ts

@@ -7,6 +7,7 @@ import {
 } from '@smatch-corp/nestjs-pothos'
 import { Builder } from '../Graphql/graphql.builder'
 import { PrismaService } from '../Prisma/prisma.service'
+import { DateTimeUtils } from 'src/common/utils/datetime.utils'
 
 @Injectable()
 export class WorkshopSubscriptionSchema extends PothosSchema {
@@ -88,7 +89,23 @@ export class WorkshopSubscriptionSchema extends PothosSchema {
         resolve: async (_query, _root, args, ctx) => {
           if (ctx.isSubscription) throw new Error('Not allowed in subscription')
           const userId = ctx.http.me?.id
+          // retrieve the workshop
+          const workshop = await this.prisma.workshop.findUnique({
+            where: { id: args.workshopId },
+          })
+          if (!workshop) throw new Error('Workshop not found')
           if (!userId) throw new Error('User not authenticated')
+          // check if workshop is in the future
+          if (workshop.date < DateTimeUtils.now().toJSDate())
+            throw new Error('Workshop has already started or is over')
+          // check if user is already subscribed to the workshop
+          const existingSubscription =
+            await this.prisma.workshopSubscription.findFirst({
+              where: { userId, workshopId: args.workshopId },
+            })
+          if (existingSubscription)
+            throw new Error('User already subscribed to workshop')
+          // create the workshop subscription
           return await this.prisma.workshopSubscription.create({
             data: {
               userId,