feat(checkout): implement purchase creation and payment intent generation with QR code support

src/app/core/services/checkout.service.ts

@@ -11,13 +11,23 @@ import { BankAccount } from './tenant.interface';
 export class CheckoutService {
   private readonly http = inject(HttpClient);
 
-  async getSelectedBankAccount(tenantCode: string): Promise<BankAccount> {
+  async createPurchase(tenantCode: string, payload: any): Promise<{ id: number }> {
     const response = await firstValueFrom(
-      this.http.get<{ data: BankAccount }>(`${environment.url}tenants/${tenantCode}/bank-accounts/selected`)
+      this.http.post<{ data: { id: number } }>(`${environment.url}tenants/${tenantCode}/compras`, payload)
     );
     if (!response?.data) {
-      throw new Error('No se encontraron los datos de la cuenta bancaria seleccionada.');
+      throw new Error('Error al crear la compra.');
     }
     return response.data;
   }
+
+  async generatePaymentIntent(tenantCode: string, purchaseId: number, method: 'qr' | 'transfer' | 'telepagos'): Promise<any> {
+    const response = await firstValueFrom(
+      this.http.post<any>(`${environment.url}tenants/${tenantCode}/compras/${purchaseId}/payment-intent`, { method })
+    );
+    if (!response) {
+      throw new Error('Error al generar la intención de pago.');
+    }
+    return response;
+  }
 }