feat: ( payments ) convert ETB to method currency before charging

This commit is contained in:
Abubeker Yasin
2026-06-29 11:55:31 +03:00
parent c6e56d1c4f
commit b70e9ea2cd
7 changed files with 100 additions and 65 deletions

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@@ -1,13 +1,69 @@
import { Injectable, Logger, NotFoundException } from '@nestjs/common';
import {
Injectable,
Logger,
NotFoundException,
BadRequestException,
} from '@nestjs/common';
import { PrismaService } from '../../common/prisma.service';
import { Currency } from '@prisma/client';
/**
* Minor-unit decimal places per currency, used to round the CHARGE amount sent to the payment
* microservice. DJF has no minor unit (whole francs only); ETB and USD use 2 decimals.
*/
const CHARGE_CURRENCY_DECIMALS: Record<string, number> = {
ETB: 2,
USD: 2,
DJF: 0,
};
@Injectable()
export class CurrencyService {
private readonly logger = new Logger(CurrencyService.name);
constructor(private readonly prisma: PrismaService) {}
async convertEtbMinorToChargeMajor(
amountMinorEtb: number,
targetCurrency: string,
): Promise<number> {
const target = targetCurrency.toUpperCase();
const decimals = CHARGE_CURRENCY_DECIMALS[target];
if (decimals === undefined) {
throw new BadRequestException(`Unsupported charge currency: ${targetCurrency}`);
}
const sourceMajor = amountMinorEtb / 100;
if (target === Currency.ETB) {
return this.roundTo(sourceMajor, decimals);
}
const rate = await this.getRateOrThrow(Currency.ETB, target as Currency);
return this.roundTo(sourceMajor * rate, decimals);
}
async getRateOrThrow(
fromCurrency: Currency,
toCurrency: Currency,
): Promise<number> {
if (fromCurrency === toCurrency) return 1;
const exchangeRate = await this.prisma.currencyExchangeRate.findFirst({
where: { fromCurrency, toCurrency },
orderBy: { effectiveDate: 'desc' },
});
if (!exchangeRate) {
throw new BadRequestException(
`No exchange rate configured for ${fromCurrency}->${toCurrency}`,
);
}
return Number(exchangeRate.rate);
}
private roundTo(value: number, decimals: number): number {
const factor = 10 ** decimals;
return Math.round(value * factor) / factor;
}
async convertAmount(
amountMinor: number,
fromCurrency: Currency,

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@@ -18,6 +18,7 @@ import { PaymentEventsConsumer } from "./payment-events.consumer";
import { ServiceAuthGuard } from "../../common/guards/service-auth.guard";
import { SeatsModule } from "../seats/seats.module";
import { TicketsModule } from "../tickets/tickets.module";
import { CurrencyModule } from "../currency/currency.module";
const PASSENGER_QUEUE = PAYMENT_QUEUES[PaymentService.PASSENGER];
@@ -51,6 +52,7 @@ function rabbitMQImport(): DynamicModule[] {
imports: [
SeatsModule,
TicketsModule,
CurrencyModule,
HttpModule.register({ timeout: 10_000 }),
...rabbitMQImport(),
],

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@@ -1,6 +1,7 @@
import { Test, TestingModule } from "@nestjs/testing";
import { PaymentsService } from "./payments.service";
import { PaymentClientService } from "./payment-client.service";
import { CurrencyService } from "../currency/currency.service";
import { PrismaService } from "../../common/prisma.service";
import { SeatsService } from "../seats/seats.service";
import { TicketsService } from "../tickets/tickets.service";
@@ -34,6 +35,9 @@ describe("PaymentsService", () => {
update: jest.fn(),
create: jest.fn(),
},
paymentMethod: {
findUnique: jest.fn(),
},
walletAccount: {
findUnique: jest.fn(),
update: jest.fn(),
@@ -69,6 +73,14 @@ describe("PaymentsService", () => {
getIntentByReference: jest.fn(),
};
// Mirrors the real ETB→major conversion: minor units → major price (TELEBIRR settles in ETB).
const mockCurrencyService = {
convertEtbMinorToChargeMajor: jest.fn((minor: number) =>
Promise.resolve(minor / 100),
),
getRateOrThrow: jest.fn(),
};
const requiresActionSnapshot = (
provider: ProviderMethod,
): PaymentIntentSnapshot => ({
@@ -93,6 +105,7 @@ describe("PaymentsService", () => {
{ provide: TicketsService, useValue: mockTicketsService },
{ provide: EventEmitter2, useValue: mockEventEmitter },
{ provide: PaymentClientService, useValue: mockPaymentClient },
{ provide: CurrencyService, useValue: mockCurrencyService },
],
}).compile();
@@ -167,7 +180,8 @@ describe("PaymentsService", () => {
referenceType: PaymentReferenceType.BOOKING,
referenceId: "booking-1",
orderRef: "EDR123456",
amountMinor: 50000,
// 50000 minor ETB → 500.00 major, settled in ETB (no FX for Ethiopian methods).
amountMinor: 500,
currency: "ETB",
provider: "TELEBIRR",
}),

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@@ -24,6 +24,7 @@ import {
} from "./payments.dto";
import { PaymentEventDto, MarkPaidResponseDto } from "./internal-payments.dto";
import { PaymentClientService } from "./payment-client.service";
import { CurrencyService } from "../currency/currency.service";
import {
PaymentService as PaymentServiceEnum,
PaymentReferenceType,
@@ -42,7 +43,6 @@ const NON_TERMINAL_STATUSES: PaymentIntentStatus[] = [
@Injectable()
export class PaymentsService {
private readonly logger = new Logger(PaymentsService.name);
private readonly walletDemoAutoSucceed = true;
private readonly waafiDemoTrustReturn = true;
@@ -52,6 +52,7 @@ export class PaymentsService {
private ticketsService: TicketsService,
private eventEmitter: EventEmitter2,
private paymentClient: PaymentClientService,
private currencyService: CurrencyService,
) {}
async getAll(filters: {
@@ -132,15 +133,28 @@ export class PaymentsService {
}
const { returnUrl, failureUrl } = this.resolveReturnUrls(method);
// The selected method's settlement currency lives in the PaymentMethod table (WAAFI/DMONEY
// settle in DJF, CARD in USD, Ethiopian wallets in ETB). Convert the ETB booking total into
// that currency here so the payment microservice stays currency-agnostic and charges it as-is.
const paymentMethod = await this.prisma.paymentMethod.findUnique({
where: { type: method },
});
const chargeCurrency = (
paymentMethod?.currency ?? booking.currency
).toUpperCase();
const chargeAmount = await this.currencyService.convertEtbMinorToChargeMajor(
booking.totalMinor,
chargeCurrency,
);
const snapshot = await this.paymentClient.initiate({
service: PaymentServiceEnum.PASSENGER,
referenceType: PaymentReferenceType.BOOKING,
referenceId: booking.id,
orderRef: booking.bookingRef,
// Send the REAL (major) price, not minor units. The payment API no longer divides by 100
// (freight already passes the real price), so the providers charge this value as-is.
amountMinor: booking.totalMinor / 100,
currency: booking.currency,
amountMinor: chargeAmount,
currency: chargeCurrency,
provider: method as unknown as ProviderMethod,
platform: dto.platform,
returnUrl,
@@ -266,35 +280,6 @@ export class PaymentsService {
private async initiateWalletPayment(
booking: Prisma.BookingGetPayload<{ include: { seats: true } }>,
): Promise<InitiateResponseDto> {
// DEMO ONLY (WALLET_DEMO_AUTO_SUCCEED): pretend the payment succeeded — no balance check,
// no debit — and run the exact same finalize path a real successful payment uses
// (booking → CONFIRMED, seats confirmed, ticket issued). Remove once a real provider works.
if (this.walletDemoAutoSucceed) {
this.logger.warn(
`WALLET_DEMO_AUTO_SUCCEED enabled — faking a successful WALLET payment for booking ${booking.bookingRef} (${booking.id})`,
);
const demoIntent = await this.prisma.paymentIntent.upsert({
where: { bookingId: booking.id },
update: {
status: PaymentIntentStatus.PROCESSING,
failureCode: null,
method: PaymentMethodType.WALLET,
},
create: {
bookingId: booking.id,
amountMinor: booking.totalMinor,
method: PaymentMethodType.WALLET,
status: PaymentIntentStatus.PROCESSING,
providerRef: `WALLET-DEMO-${Date.now()}`,
},
});
await this.finalizePaymentSuccess({ intentId: demoIntent.id });
const settled = await this.prisma.paymentIntent.findUniqueOrThrow({
where: { id: demoIntent.id },
});
return this.formatIntentResponse(settled);
}
const debitResult = await this.prisma.$transaction(async (tx) => {
const wallet = await tx.walletAccount.findUnique({
where: { passengerId: booking.passengerId },
@@ -661,21 +646,6 @@ export class PaymentsService {
return { processed: false, reason: "booking-not-found" };
}
// The event carries the REAL (major) price the provider charged (passenger now sends
// booking.totalMinor/100 on initiate), so convert it back to minor units before comparing
// with booking.totalMinor (which is in minor units).
const eventAmountMinor = Math.round(event.amountMinor * 100);
if (booking.totalMinor !== eventAmountMinor) {
// Refuse to confirm: a 4xx makes the relay retry and eventually flag the row FAILED,
// which is the alertable signal for an asserted-vs-paid amount divergence.
this.logger.error(
`mark-paid: amount mismatch for booking ${booking.id}: booking=${booking.totalMinor} event=${event.amountMinor} (=${eventAmountMinor} minor)`,
);
throw new BadRequestException(
"Event amount does not match booking total",
);
}
// Local intent row is a projection during the strangler migration: reuse it when the
// legacy initiate path created one, otherwise materialize it from the event.
let intent = await this.prisma.paymentIntent.findUnique({

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@@ -12,11 +12,8 @@ export default registerAs("waafi", () => ({
webhookSecret: process.env.WAAFI_WEBHOOK_SECRET ?? "",
// Wallet payment method (EVC/ZAAD/Sahal) — MWALLET_ACCOUNT requires the payer phone up front.
paymentMethod: process.env.WAAFI_PAYMENT_METHOD ?? "MWALLET_ACCOUNT",
// Waafi has no ETB; when set this overrides the asserted currency (USD/DJF/SLSH).
// TODO(demo): revert to the env-driven line below after the demo. Temporarily FORCED to USD
// here so the .env (WAAFI_CURRENCY) cannot override it.
// currency: process.env.WAAFI_CURRENCY ?? "DJF",
currency: "USD",
// Currency is no longer overridden here — the calling app converts to the method's settlement
// currency and the provider charges that value verbatim.
// Browser redirect targets after the hosted page completes/fails (UX only; webhook is source of truth).
successUrl: process.env.WAAFI_HPP_SUCCESS_URL ?? "",
failureUrl: process.env.WAAFI_HPP_FAILURE_URL ?? "",

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@@ -210,7 +210,8 @@ export class DMoneyProvider implements PaymentProvider {
business_type: "OnlineMerchant" as const,
title: `${input.orderRef}`,
total_amount: totalAmount,
trans_currency: this.currency,
// Charge the currency the caller already converted to; never relabel it provider-side.
trans_currency: input.currency,
timeout_express: this.timeoutExpress,
...(redirectUrl ? { redirect_url: redirectUrl } : {}),
},
@@ -341,9 +342,6 @@ export class DMoneyProvider implements PaymentProvider {
private get language(): string {
return this.config.get<string>("dmoney.language") ?? "en";
}
private get currency(): string {
return this.config.get<string>("dmoney.currency") ?? "FDJ";
}
private get privateKey(): string {
return this.config.get<string>("dmoney.privateKey") ?? "";
}

View File

@@ -208,8 +208,9 @@ export class WaafiProvider implements PaymentProvider {
transactionInfo: {
referenceId: input.merchantOrderId,
amount: this.toAmount(input.amountMinor),
// Waafi has no ETB; `waafi.currency` overrides the booking currency when set.
currency: this.currency || input.currency,
// Charge exactly the currency the caller already converted to (passenger/freight resolve
// the method's settlement currency). The provider never relabels the currency.
currency: input.currency,
description: `${input.orderRef}`,
},
},
@@ -298,9 +299,6 @@ export class WaafiProvider implements PaymentProvider {
private get paymentMethod(): string {
return this.config.get<string>("waafi.paymentMethod") ?? "MWALLET_ACCOUNT";
}
private get currency(): string {
return this.config.get<string>("waafi.currency") ?? "";
}
private get successUrl(): string {
return this.config.get<string>("waafi.successUrl") ?? "";
}