chore: add discount logic to apply to the plan price and ...

src/modules/discounts/providers/discounts.service.ts

@@ -2,9 +2,11 @@ import { randomBytes } from "node:crypto";
 
 import { BadRequestException, Injectable } from "@nestjs/common";
 import dayjs from "dayjs";
+import { Decimal } from "decimal.js";
 import { DataSource, QueryRunner } from "typeorm";
 
 import { DiscountMessage } from "../../../common/enums/message.enum";
+import { SubscriptionPlan } from "../../subscriptions/entities/subscription.entity";
 import { SubscriptionsService } from "../../subscriptions/providers/subscriptions.service";
 import { CreateDiscountDto } from "../DTO/create-discount.dto";
 import { SearchDiscountQueryDto } from "../DTO/search-discount-query.dto";
@@ -142,6 +144,7 @@ export class DiscountsService {
 
     for (const subscriptionPlan of subscriptionPlans) {
       subscriptionPlan.directDiscount = discount;
+      await this.updatePlanPrice(subscriptionPlan, discount);
       await queryRunner.manager.save(subscriptionPlan);
     }
 
@@ -232,9 +235,22 @@ export class DiscountsService {
 
     for (const subscriptionPlan of subscriptionPlans) {
       subscriptionPlan.directDiscount = discount;
+      await this.updatePlanPrice(subscriptionPlan, discount);
       await queryRunner.manager.save(subscriptionPlan);
     }
 
     await queryRunner.manager.save(discount);
   }
+  //************************************ */
+  private async updatePlanPrice(subscriptionPlan: SubscriptionPlan, discount: Discount) {
+    if (!subscriptionPlan.originalPrice) subscriptionPlan.originalPrice = new Decimal(subscriptionPlan.price);
+
+    let discountAmount: Decimal;
+    if (discount.type === DiscountType.PERCENTAGE) {
+      discountAmount = subscriptionPlan.originalPrice.mul(discount.value).div(100);
+    } else {
+      discountAmount = new Decimal(discount.value);
+    }
+    subscriptionPlan.price = subscriptionPlan.originalPrice.sub(discountAmount);
+  }
 }