refactor: split the services to multiple service classes (#202)

packages/server/src/services/Purchases/BillPayments/DeleteBillPayment.ts

@@ -0,0 +1,71 @@
+import { Knex } from 'knex';
+import UnitOfWork from '@/services/UnitOfWork';
+import { BillPaymentValidators } from './BillPaymentValidators';
+import { EventPublisher } from '@/lib/EventPublisher/EventPublisher';
+import HasTenancyService from '@/services/Tenancy/TenancyService';
+import { Inject, Service } from 'typedi';
+import {
+  IBillPaymentDeletingPayload,
+  IBillPaymentEventDeletedPayload,
+} from '@/interfaces';
+import events from '@/subscribers/events';
+
+@Service()
+export class DeleteBillPayment {
+  @Inject()
+  private tenancy: HasTenancyService;
+
+  @Inject()
+  private eventPublisher: EventPublisher;
+
+  @Inject()
+  private uow: UnitOfWork;
+
+  @Inject()
+  private validators: BillPaymentValidators;
+
+  /**
+   * Deletes the bill payment and associated transactions.
+   * @param  {number} tenantId - Tenant id.
+   * @param  {Integer} billPaymentId - The given bill payment id.
+   * @return {Promise}
+   */
+  public async deleteBillPayment(tenantId: number, billPaymentId: number) {
+    const { BillPayment, BillPaymentEntry } = this.tenancy.models(tenantId);
+
+    // Retrieve the bill payment or throw not found service error.
+    const oldBillPayment = await BillPayment.query()
+      .withGraphFetched('entries')
+      .findById(billPaymentId);
+
+    // Validates the bill payment existance.
+    this.validators.validateBillPaymentExistance(oldBillPayment);
+
+    // Deletes the bill transactions with associated transactions under
+    // unit-of-work envirement.
+    return this.uow.withTransaction(tenantId, async (trx: Knex.Transaction) => {
+      // Triggers `onBillPaymentDeleting` payload.
+      await this.eventPublisher.emitAsync(events.billPayment.onDeleting, {
+        tenantId,
+        trx,
+        oldBillPayment,
+      } as IBillPaymentDeletingPayload);
+
+      // Deletes the bill payment assocaited entries.
+      await BillPaymentEntry.query(trx)
+        .where('bill_payment_id', billPaymentId)
+        .delete();
+
+      // Deletes the bill payment transaction.
+      await BillPayment.query(trx).where('id', billPaymentId).delete();
+
+      // Triggers `onBillPaymentDeleted` event.
+      await this.eventPublisher.emitAsync(events.billPayment.onDeleted, {
+        tenantId,
+        billPaymentId,
+        oldBillPayment,
+        trx,
+      } as IBillPaymentEventDeletedPayload);
+    });
+  }
+}