From 4eb8a12f0671be988d3ee6326c544439f33d012e Mon Sep 17 00:00:00 2001
From: Seweryn Kras <seweryn.kras@golem.network>
Date: Wed, 29 May 2024 11:00:36 +0200
Subject: [PATCH] feat: remove start method from agreement payment process and
 start it automatically

---
 src/lease-process/lease.module.ts             |  6 +-
 src/payment/agreement_payment_process.spec.ts |  3 +
 src/payment/agreement_payment_process.ts      | 59 ++++++++-----------
 3 files changed, 29 insertions(+), 39 deletions(-)

diff --git a/src/lease-process/lease.module.ts b/src/lease-process/lease.module.ts
index acdcc6511..2414ba9bd 100644
--- a/src/lease-process/lease.module.ts
+++ b/src/lease-process/lease.module.ts
@@ -10,7 +10,7 @@ import { LeaseProcessPool, LeaseProcessPoolOptions } from "./lease-process-pool"
 export interface LeaseModule {
   /**
    * Factory that creates a new lease process that's fully configured.
-   * This method will also create and start the payment process for the agreement.
+   * This method will also create the payment process for the agreement.
    *
    */
   createLease(agreement: Agreement, allocation: Allocation, options?: LeaseProcessOptions): LeaseProcess;
@@ -51,10 +51,6 @@ export class LeaseModuleImpl implements LeaseModule {
       this.deps.logger.child("lease-process"),
       options,
     );
-    paymentProcess.start();
-    lease.events.once("finalized", () => {
-      paymentProcess.stop();
-    });
     return lease;
   }
 
diff --git a/src/payment/agreement_payment_process.spec.ts b/src/payment/agreement_payment_process.spec.ts
index e6797279f..9d19cfec1 100644
--- a/src/payment/agreement_payment_process.spec.ts
+++ b/src/payment/agreement_payment_process.spec.ts
@@ -7,6 +7,7 @@ import { DebitNote } from "./debit_note";
 import { GolemPaymentError, PaymentErrorCode } from "./error";
 import { GolemUserError } from "../shared/error/golem-error";
 import { IPaymentApi } from "./types";
+import { Subject } from "rxjs";
 
 const agreementMock = mock(Agreement);
 const allocationMock = mock(Allocation);
@@ -30,6 +31,8 @@ beforeEach(() => {
 
   when(agreementMock.getProviderInfo()).thenReturn(testProviderInfo);
   when(invoiceMock.provider).thenReturn(testProviderInfo);
+  when(mockPaymentApi.receivedInvoices$).thenReturn(new Subject());
+  when(mockPaymentApi.receivedDebitNotes$).thenReturn(new Subject());
 });
 
 describe("AgreementPaymentProcess", () => {
diff --git a/src/payment/agreement_payment_process.ts b/src/payment/agreement_payment_process.ts
index e2e4494a8..86f7515af 100644
--- a/src/payment/agreement_payment_process.ts
+++ b/src/payment/agreement_payment_process.ts
@@ -35,7 +35,9 @@ export interface PaymentProcessOptions {
 }
 
 /**
- * Process manager that controls the logic behind processing events related to an agreement which result with payments
+ * Process manager that controls the logic behind processing payments for an agreement (debit notes and invoices).
+ * The process is started automatically and ends when the final invoice is received.
+ * You can stop the process earlier by calling the `stop` method. You cannot restart the process after stopping it.
  */
 export class AgreementPaymentProcess {
   private invoice: Invoice | null = null;
@@ -51,7 +53,7 @@ export class AgreementPaymentProcess {
 
   public readonly logger: Logger;
 
-  private cleanup: (() => void) | null = null;
+  private readonly cleanupSubscriptions: () => void;
 
   constructor(
     public readonly agreement: Agreement,
@@ -65,6 +67,19 @@ export class AgreementPaymentProcess {
       invoiceFilter: options?.invoiceFilter || (() => true),
       debitNoteFilter: options?.debitNoteFilter || (() => true),
     };
+
+    const invoiceSubscription = this.paymentApi.receivedInvoices$
+      .pipe(filter((invoice) => invoice.agreementId === this.agreement.id))
+      .subscribe((invoice) => this.addInvoice(invoice));
+
+    const debitNoteSubscription = this.paymentApi.receivedDebitNotes$
+      .pipe(filter((debitNote) => debitNote.agreementId === this.agreement.id))
+      .subscribe((debitNote) => this.addDebitNote(debitNote));
+
+    this.cleanupSubscriptions = () => {
+      invoiceSubscription.unsubscribe();
+      debitNoteSubscription.unsubscribe();
+    };
   }
 
   /**
@@ -191,6 +206,11 @@ export class AgreementPaymentProcess {
     }
   }
 
+  private finalize(invoice: Invoice) {
+    this.invoice = invoice;
+    this.cleanupSubscriptions();
+  }
+
   private async applyInvoice(invoice: Invoice) {
     this.logger.debug("Applying invoice for agreement", {
       invoiceId: invoice.id,
@@ -218,7 +238,7 @@ export class AgreementPaymentProcess {
       );
     }
 
-    this.invoice = invoice;
+    this.finalize(invoice);
 
     let acceptedByFilter = false;
     try {
@@ -298,39 +318,10 @@ export class AgreementPaymentProcess {
   }
 
   public isStarted() {
-    return this.cleanup !== null;
-  }
-
-  /**
-   * Subscribe to payment events and add each invoice and debit note
-   * to the payment process.
-   * To stop the subscription, call `.stop()`.
-   */
-  public start(): void {
-    if (this.isStarted()) {
-      throw new GolemUserError("Payment process already started");
-    }
-    const invoiceSubscription = this.paymentApi.receivedInvoices$
-      .pipe(filter((invoice) => invoice.agreementId === this.agreement.id))
-      .subscribe(async (invoice) => {
-        await this.addInvoice(invoice);
-      });
-
-    const debitNoteSubscription = this.paymentApi.receivedDebitNotes$
-      .pipe(filter((debitNote) => debitNote.agreementId === this.agreement.id))
-      .subscribe(async (debitNote) => {
-        await this.addDebitNote(debitNote);
-      });
-    this.cleanup = () => {
-      invoiceSubscription.unsubscribe();
-      debitNoteSubscription.unsubscribe();
-    };
+    return this.cleanupSubscriptions !== null;
   }
 
   public stop(): void {
-    if (!this.isStarted()) {
-      throw new GolemUserError("Payment process not started");
-    }
-    this.cleanup?.();
+    this.cleanupSubscriptions();
   }
 }