# Setrip — Payment Roadmap

Rencana implementasi flow pembayaran: handle trip gratis, halaman detail payment, dan integrasi Midtrans.

> **Prinsip:** Sumber kebenaran pembayaran = record di tabel khusus, bukan timestamp di `TripParticipant`. Manual transfer & Midtrans = dua provider dari pipeline yang sama. Trip gratis = first-class case (bukan paid trip dengan amount 0).

---

## Audit state sekarang (baseline)

- Field `TripParticipant.markedPaidAt` + `paymentConfirmedAt` — dual-timestamp manual.
- Flow: user klik "Saya sudah bayar" → organizer klik "Konfirmasi pembayaran". Tidak ada record transaksi terpisah, tidak ada bukti transfer, tidak ada amount snapshot.
- Tidak ada halaman `/trips/[id]/payment`. Tombol bayar inline di trip detail.
- **Bug**: trip gratis (`price === 0`) tetap melewati flow yang sama — peserta tetap harus klik "Saya sudah bayar" dan organizer tetap harus konfirmasi.

File terkait: [server/services/trip.service.ts](server/services/trip.service.ts) (`markParticipantPayment`, `confirmParticipantPayment`), [features/booking/actions.ts](features/booking/actions.ts), [features/booking/components/organizer-payment-queue.tsx](features/booking/components/organizer-payment-queue.tsx), [features/trip/components/join-trip-button.tsx](features/trip/components/join-trip-button.tsx), [server/repositories/participant.repo.ts](server/repositories/participant.repo.ts).

---

## PR A — Free trip handling + halaman detail payment (manual flow) ✅

Selesai. `tsc --noEmit` lulus. Tanpa schema baru, tanpa migration.

**Keputusan akses control:** halaman `/trips/[id]/payment` boleh diakses peserta apapun yang aktif (PENDING/CONFIRMED). Peserta PENDING bisa lihat nominal + rekening untuk persiapan, tapi diberi notice "tunggu approve dulu sebelum transfer". Organizer trip-nya sendiri di-redirect ke trip detail.

| # | Item | Status | File |
|---|---|---|---|
| A1 | Helper `lib/trip-pricing.ts` dengan `isFreeTrip` & `isPaidTrip` | ✅ | [lib/trip-pricing.ts](lib/trip-pricing.ts) |
| A2 | Service guard: `markParticipantPayment` & `confirmParticipantPayment` reject trip gratis | ✅ | [server/services/trip.service.ts](server/services/trip.service.ts) |
| A3 | UI gate di JoinTripButton: hide flow pembayaran kalau gratis | ✅ | [features/trip/components/join-trip-button.tsx](features/trip/components/join-trip-button.tsx) |
| A4 | UI gate di trip detail: skip `OrganizerPaymentQueue` kalau gratis | ✅ | [app/trips/[id]/page.tsx](app/trips/[id]/page.tsx) |
| A5 | Halaman `/trips/[id]/payment` (server component dengan akses kontrol) | ✅ | [app/trips/[id]/payment/page.tsx](app/trips/%5Bid%5D/payment/page.tsx) |
| A6 | Konten halaman trip gratis: banner 🎉 + status keikutsertaan + CTA | ✅ | `FreeTripSection` di [page.tsx](app/trips/%5Bid%5D/payment/page.tsx) |
| A7 | Konten halaman trip berbayar: timeline + rekening organizer + tombol "Saya sudah bayar" + status | ✅ | `PaidTripSection`, `PaymentTimeline`, `BankRow` di [page.tsx](app/trips/%5Bid%5D/payment/page.tsx) |
| A8 | Link dari trip detail → `/trips/[id]/payment` (replace tombol inline) | ✅ | `showPaymentLink` di [join-trip-button.tsx](features/trip/components/join-trip-button.tsx) |
| A9 | Metadata + `robots: noindex` halaman payment | ✅ | [page.tsx](app/trips/%5Bid%5D/payment/page.tsx) — `metadata.robots: { index: false, follow: false }` |
| A+ | `MarkPaidButton` (client component) untuk action "Saya sudah bayar" | ✅ | [features/booking/components/mark-paid-button.tsx](features/booking/components/mark-paid-button.tsx) |
| A+ | `CopyButton` (client component) untuk copy nomor rekening / nominal | ✅ | [features/booking/components/copy-button.tsx](features/booking/components/copy-button.tsx) |

**Tindakan manual:** tidak ada. Tidak ada migration di PR A.

**Catatan edge case yang sudah dihandle:**
- Organizer trip-nya sendiri buka halaman → redirect ke trip detail.
- User belum login → redirect ke login dengan `callbackUrl`.
- User belum join / sudah cancel → tampil notice "kamu belum terdaftar".
- Trip dengan organizer yang belum APPROVED verifikasinya → tampil notice "rekening belum tersedia, hubungi organizer langsung" (tidak crash).
- Peserta PENDING di-warning "tunggu approve dulu sebelum transfer".
- Tombol "Saya sudah bayar" hanya muncul untuk CONFIRMED + belum mark + bank tersedia.

---

## PR B — Refactor schema ke `Booking` + `Payment` (provider MANUAL only) ✅

Selesai. `tsc --noEmit` lulus. Pondasi untuk Midtrans sudah siap.

### Schema (target)

```prisma
model Booking {
  id            String          @id @default(cuid())
  tripId        String
  trip          Trip            @relation(fields: [tripId], references: [id])
  userId        String
  user          User            @relation(fields: [userId], references: [id])
  participantId String          @unique
  participant   TripParticipant @relation(fields: [participantId], references: [id])

  /// Snapshot harga saat booking dibuat — protect dari perubahan trip.price.
  amount        Int
  currency      String          @default("IDR")
  status        BookingStatus   @default(PENDING)

  payments      Payment[]

  createdAt     DateTime        @default(now())
  updatedAt     DateTime        @updatedAt

  @@index([tripId, status])
  @@index([userId])
}

enum BookingStatus {
  PENDING       // join belum approve atau belum bayar
  AWAITING_PAY  // approved, tinggal bayar
  PAID          // lunas (manual confirm atau gateway settlement)
  CANCELLED
  REFUNDED
  EXPIRED
}

model Payment {
  id              String          @id @default(cuid())
  bookingId       String
  booking         Booking         @relation(fields: [bookingId], references: [id])

  provider        PaymentProvider
  /// order_id eksternal — untuk MANUAL referensi internal, untuk MIDTRANS dikirim ke gateway. Unik per attempt.
  externalOrderId String          @unique
  externalTxId    String?
  method          String?         // bca_va, gopay, qris, manual_transfer, dst
  amount          Int
  status          PaymentStatus   @default(PENDING)

  rawCallback     Json?
  snapToken       String?
  expiresAt       DateTime?

  paidAt          DateTime?
  failedAt        DateTime?
  rejectionReason String?

  createdAt       DateTime        @default(now())
  updatedAt       DateTime        @updatedAt

  @@index([bookingId, status])
  @@index([provider, status])
}

enum PaymentProvider {
  MANUAL
  MIDTRANS
}

enum PaymentStatus {
  PENDING
  AWAITING
  PAID
  FAILED
  EXPIRED
  CANCELLED
  REFUNDED
}
```

### Tugas

| # | Item | Status | File |
|---|---|---|---|
| B1 | Schema: tambah `Booking`, `Payment`, 3 enum (`BookingStatus`, `PaymentProvider`, `PaymentStatus`) + relasi di `User`, `Trip`, `TripParticipant` | ✅ | [prisma/schema.prisma](prisma/schema.prisma) |
| B2 | Migration `add_booking_payment` (CreateEnum + CreateTable + Index + FK) | ✅ | [prisma/migrations/20260508150000_add_booking_payment/migration.sql](prisma/migrations/20260508150000_add_booking_payment/migration.sql) |
| B3 | Backfill script TS (idempotent, skip baris yang sudah punya Booking) | ✅ | [prisma/backfill-bookings.ts](prisma/backfill-bookings.ts) |
| B4 | `bookingRepo` + `paymentRepo` | ✅ | [server/repositories/booking.repo.ts](server/repositories/booking.repo.ts), [server/repositories/payment.repo.ts](server/repositories/payment.repo.ts) |
| B5 | `bookingService` — `markPaidManual`, `confirmPaidManual`, `getByTripAndUser`, `getAwaitingManualForTrip` (idempotent, transactional dengan retry serialisasi) | ✅ | [server/services/booking.service.ts](server/services/booking.service.ts) |
| B6 | `tripService.markParticipantPayment` → delegate ke `bookingService.markPaidManual`. Tetap update `TripParticipant.markedPaidAt` untuk backcompat. | ✅ | [server/services/trip.service.ts](server/services/trip.service.ts) |
| B7 | `tripService.confirmParticipantPayment` → delegate ke `bookingService.confirmPaidManual`. Tetap update `paymentConfirmedAt`. | ✅ | [server/services/trip.service.ts](server/services/trip.service.ts) |
| B+ | `tripService.joinTrip` → upsert Booking PENDING (handle re-join dari CANCELLED) | ✅ | [server/services/trip.service.ts](server/services/trip.service.ts) |
| B+ | `tripService.confirmParticipant` → transition Booking PENDING → AWAITING_PAY (paid) atau PAID (free) | ✅ | [server/services/trip.service.ts](server/services/trip.service.ts) |
| B+ | `tripService.cancelJoin` & `rejectParticipant` → Booking → CANCELLED | ✅ | [server/services/trip.service.ts](server/services/trip.service.ts) |
| B8 | Halaman `/trips/[id]/payment` baca dari Booking + Payment (bukan timestamp lama) | ✅ | [app/trips/[id]/payment/page.tsx](app/trips/%5Bid%5D/payment/page.tsx) |
| B9 | `OrganizerPaymentQueue` di trip detail dapat data dari `bookingService.getAwaitingManualForTrip` | ✅ | [app/trips/[id]/page.tsx](app/trips/%5Bid%5D/page.tsx) |
| B10 | Deprecate `TripParticipant.markedPaidAt` + `paymentConfirmedAt` (komen `@deprecated`, tetap di-update untuk backcompat) | ✅ | [prisma/schema.prisma](prisma/schema.prisma) |
| B11 | Index optimization (`@@index([tripId, status])` di Booking, `@@index([provider, status])` di Payment, `@@index([userId])` di Booking) | ✅ | [prisma/schema.prisma](prisma/schema.prisma) |

**Tindakan manual (urutan penting):**
1. `npx prisma migrate deploy` — apply schema migration `20260508150000_add_booking_payment`.
2. `npx tsx prisma/backfill-bookings.ts` — populate Booking + Payment dari `TripParticipant` lama. Idempotent, aman dijalankan ulang.
3. Verifikasi: jumlah Booking aktif = jumlah TripParticipant aktif setelah backfill.

---

## PR C — Midtrans integration (Snap + webhook) ✅

Selesai. `tsc --noEmit` lulus. Belum test live ke sandbox Midtrans — perlu env diisi + tunneling kalau dev lokal.

### Persiapan akun & env

| Env | Keterangan |
|---|---|
| `MIDTRANS_SERVER_KEY` | Server key dari dashboard Midtrans (sandbox/production sesuai mode). Rahasia. Server-side only. |
| `NEXT_PUBLIC_MIDTRANS_CLIENT_KEY` | Client key untuk Snap.js. Aman di-expose ke frontend (NEXT_PUBLIC_). |
| `NEXT_PUBLIC_MIDTRANS_IS_PRODUCTION` | `true` untuk production, `false` (atau kosong) untuk sandbox. NEXT_PUBLIC_ supaya client tahu URL Snap.js yang benar. |

`MIDTRANS_NOTIFICATION_URL` **tidak** di env — diset langsung di dashboard Midtrans ke `<NEXT_PUBLIC_SITE_URL>/api/webhooks/midtrans`.

Sudah ditambah ke [env.example](env.example).

### Tugas

| # | Item | Status | File |
|---|---|---|---|
| C1 | Update [env.example](env.example) + 3 env baru + komentar webhook URL | ✅ | [env.example](env.example) |
| C2 | `lib/midtrans.ts` — `createSnapTransaction`, `verifyMidtransSignature` (timing-safe compare), `MIDTRANS` config helper | ✅ | [lib/midtrans.ts](lib/midtrans.ts) |
| C3 | Status mapping `mapMidtransStatus(transaction_status, fraud_status)` → `PaymentStatus` | ✅ | [lib/midtrans.ts](lib/midtrans.ts) |
| C4 | `paymentService.startMidtransPayment(bookingId, userId)` — validate, reuse Payment AWAITING aktif (idempotent re-attempt), atau buat Payment baru + call Snap API + simpan token + expiresAt | ✅ | [server/services/payment.service.ts](server/services/payment.service.ts) |
| C5 | Halaman payment: tombol "Bayar online via Midtrans" + divider "atau" + tombol manual lama | ✅ | [app/trips/[id]/payment/page.tsx](app/trips/%5Bid%5D/payment/page.tsx) |
| C6 | `MidtransPayButton` client component — load Snap.js dengan `data-client-key` dinamis, `window.snap.pay(token, callbacks)`, refresh page setelah Snap close | ✅ | [features/booking/components/midtrans-pay-button.tsx](features/booking/components/midtrans-pay-button.tsx) |
| C7 | Webhook endpoint `app/api/webhooks/midtrans/route.ts` — POST, verify signature, lookup, idempotent, return 200/401 sesuai outcome | ✅ | [app/api/webhooks/midtrans/route.ts](app/api/webhooks/midtrans/route.ts) |
| C8 | `paymentService.handleMidtransWebhook` — verifikasi signature, amount check, transaction (`Payment` + `Booking` + `TripParticipant.paymentConfirmedAt` backcompat) | ✅ | [server/services/payment.service.ts](server/services/payment.service.ts) |
| C10 | Anti-replay: skip update kalau Payment sudah final (PAID/FAILED/EXPIRED/CANCELLED/REFUNDED) | ✅ | [payment.service.ts](server/services/payment.service.ts) |
| C11 | Simpan callback mentah ke `Payment.rawCallback` (audit & dispute), termasuk untuk callback yang di-skip | ✅ | [payment.service.ts](server/services/payment.service.ts) |
| C+ | Server action `startMidtransPaymentAction` (resolve booking dari tripId, bridge ke client) | ✅ | [features/booking/actions.ts](features/booking/actions.ts) |
| C+ | Retry handling: Payment row baru dengan `midtrans-{bookingId}-{retryN}` kalau attempt lama expired/failed; idempotent reuse kalau masih AWAITING | ✅ | [payment.service.ts](server/services/payment.service.ts) |
| C9 | Cron expire Payment lama | ⏸️ skipped | Housekeeping di-handle saat user start payment (auto-expire attempt yang lewat `expiresAt`). Cron formal bisa ditambah kalau perlu cleanup massal. |
| C12 | Test scenario sandbox (settlement, deny, expire) | ⏸️ manual | Perlu env Midtrans diisi + tunneling untuk dev lokal (ngrok/cloudflared). Tidak bisa otomatis dari sini. |
| C13 | Status badge real-time | ⏸️ partial | Page refresh setelah Snap close + halaman SSR pull state baru tiap reload. Polling otomatis belum diimplementasi. |
| C14 | Email/in-app notification setelah PAID | ⏳ pending | Diluar scope PR C — masuk Phase berikutnya. |

### Mapping `transaction_status` Midtrans → `PaymentStatus`

| Midtrans | Trigger lain | `PaymentStatus` |
|---|---|---|
| `capture` | `fraud_status === "accept"` | PAID |
| `capture` | `fraud_status === "challenge"` | AWAITING (review manual di dashboard Midtrans) |
| `settlement` | — | PAID |
| `pending` | — | AWAITING |
| `deny` | — | FAILED |
| `expire` | — | EXPIRED |
| `cancel` | — | CANCELLED |
| `refund` / `partial_refund` | — | REFUNDED |

### Webhook checklist (security)

1. Verify signature: `sha512(order_id + status_code + gross_amount + SERVER_KEY) === signature_key`. Mismatch → 401, log.
2. Cek `gross_amount` cocok dengan `payment.amount` — kalau tidak sama, log anomaly, jangan PAID.
3. Lookup `Payment.externalOrderId === order_id`. Tidak ada → 200 OK + log (jangan biarkan Midtrans retry forever).
4. Idempotent: kalau status sudah final, skip update tapi tetap return 200.
5. Pakai DB transaction untuk update Payment + Booking + TripParticipant bersamaan.
6. Selalu return 200 kalau request valid (mismatch signature → 401, sisanya → 200 + log).

### Hardening pasca-audit (sebelum Midtrans live) ✅

Empat fix tambahan dari audit security/correctness:

| Fix | Issue | Solusi | File |
|---|---|---|---|
| 1 | Webhook bisa overwrite Booking CANCELLED/REFUNDED/EXPIRED jadi PAID | Re-fetch Booking di dalam serializable transaction; kalau state konflik, Payment tetap PAID (uang masuk) tapi Booking tidak di-update + `Payment.rejectionReason` di-flag untuk manual review/refund. Webhook outcome `booking_conflict` di-log warning. | [payment.service.ts](server/services/payment.service.ts), [route.ts](app/api/webhooks/midtrans/route.ts) |
| 2 | `startMidtransPayment` lupa cek trip departure date | Tambah `isTripDepartureDayPast` guard, juga di `bookingService.markPaidManual` untuk konsistensi | [payment.service.ts](server/services/payment.service.ts), [booking.service.ts](server/services/booking.service.ts) |
| 3 | `Booking` tidak punya constraint `(tripId, userId)` unique | Tambah `@@unique([tripId, userId])` + migration `20260508160000_booking_unique_trip_user`. `findByTripAndUser` switch dari `findFirst` ke `findUnique` (lebih efisien) | [schema.prisma](prisma/schema.prisma), [migration](prisma/migrations/20260508160000_booking_unique_trip_user/migration.sql), [booking.repo.ts](server/repositories/booking.repo.ts) |
| 4 | Webhook payload tidak schema-validated | Zod `midtransWebhookSchema` (passthrough untuk forward-compat). Webhook route `safeParse` → 400 kalau shape invalid. Service signature pakai type yang inferred dari schema. | [lib/midtrans.ts](lib/midtrans.ts), [route.ts](app/api/webhooks/midtrans/route.ts), [payment.service.ts](server/services/payment.service.ts) |

### Edge cases yang gampang lupa

- **Quota race**: dua user bayar bersamaan untuk slot terakhir → slot di-hold saat Booking dibuat (status AWAITING_PAY masih hitung kuota via `TripParticipant.status`). Release belum otomatis saat Payment EXPIRED — kalau perlu, tambah cron (lihat C9 yang di-skip).
- **Trip dibatalkan organizer setelah peserta bayar** → `Booking.status = REFUNDED` setelah dana balik. Implementasi refund Midtrans = PR terpisah (tidak di scope PR C ini).
- **User retry pembayaran setelah gagal** → bikin Payment baru, `externalOrderId` baru (`midtrans-{bookingId}-{retryN}`). Reuse kalau masih AWAITING & belum expired.
- **Webhook duplicate**: Midtrans bisa kirim notifikasi yang sama 2-3 kali. Idempotent: skip update kalau Payment sudah final, tapi tetap simpan callback ke `rawCallback` untuk audit.
- **Sandbox vs production**: webhook URL diset di dashboard Midtrans = `<NEXT_PUBLIC_SITE_URL>/api/webhooks/midtrans`. Dev lokal perlu tunneling (ngrok / cloudflared) supaya endpoint bisa di-reach Midtrans.
- **Booking belum approved (`PENDING`) tapi user coba bayar** — `paymentService.startMidtransPayment` reject dengan pesan jelas. UI sudah hide tombol di state ini.

---

## ❌ Anti-list (yang harus DITOLAK kalau muncul)

- **Halaman payment yang berubah jadi marketplace checkout**: upsell ("trip serupa lebih murah"), pricing comparison, "harga turun" — semua menarik framing OTA. Halaman payment fokus pada satu transaksi: lunas atau belum.
- **Multi-method abstraksi prematur**: jangan bikin "PaymentProvider" generic untuk Stripe/Xendit/Doku sekaligus sebelum salah satu jalan. Mulai dari MANUAL + MIDTRANS, baru tambah kalau perlu.
- **Auto-refund logic kompleks** sebelum manual refund di dashboard Midtrans dipakai. Refund jarang, manual cukup di Phase awal.
- **Payment retry otomatis** dari sisi server. User harus eksplisit klik "bayar lagi" untuk attempt baru — supaya tidak ambigu siapa yang trigger.
- **Multi-currency** sebelum ada permintaan eksplisit. `currency` di schema sudah default IDR, tapi tidak perlu UI selector.
- **Saving credit card / tokenization** tanpa kebutuhan jelas. PCI scope naik drastis. Snap sudah handle tanpa simpan kartu di sisi kita.

---

## Saran phasing

PR berurutan. Setiap PR mandiri (siap di-deploy):

1. **PR A** — Free trip handling + halaman payment (manual). Cepat, low-risk, no migration. **Mulai dari sini.**
2. **PR B** — Refactor ke `Booking` + `Payment`. Migration + backfill data lama. UI tetap mirip.
3. **PR C** — Tambah Midtrans Snap. Test di sandbox dulu sebelum production.

Pertanyaan terbuka sebelum mulai:

1. **Akses halaman payment**: hanya peserta CONFIRMED, atau juga PENDING (yang belum disetujui organizer)? Saya rekomendasi CONFIRMED only — peserta PENDING belum perlu lihat detail bayar.
2. **Snapshot amount di Booking**: kalau organizer ubah `trip.price` setelah booking dibuat, booking lama pakai harga lama atau baru? Saya rekomendasi tetap pakai snapshot lama (audit-friendly).
3. **Manual + Midtrans co-exist**: user pilih satu provider per booking, atau bisa retry dengan provider berbeda? Saya rekomendasi pilih satu — kalau gagal di Midtrans, bisa cancel dan buat Payment baru dengan provider MANUAL.