Files
NetForge/.planning/STATE.md
kevin-asprec df4a467a38 docs(02-04): complete billing engine plan
Tasks completed: 2/2
- Task 1: Invoice model + BillingService + InvoiceService + CreditService
- Task 2: Billing API routes + comprehensive tests (38 passing)

SUMMARY: .planning/phases/02-subscriber-and-billing-core/02-04-SUMMARY.md
2026-03-04 23:41:50 +08:00

9.1 KiB

Project State

Project Reference

See: .planning/PROJECT.md (updated 2026-03-04)

Core value: ISP owners can see exactly where their money is — who owes what, what's been collected, what's been spent, and what the business actually looks like financially — in real time. Current focus: Phase 2 - Subscriber and Billing Core

Current Position

Phase: 2 of 5 (Subscriber and Billing Core) — In progress Plan: 5 of 5 in phase 2 remaining (10/20 total complete) Status: In progress. 02-01 (COA), 02-02 (JournalEntryService), 02-03 (Subscriber), 02-04 (BillingEngine) complete. Ready for 02-05 (PaymentService). Last activity: 2026-03-04 — Completed 02-04-PLAN.md (BillingEngine, 38 tests)

Progress: [█████████░] 50% (10/20 plans across all phases)

Performance Metrics

Velocity:

  • Total plans completed: 8
  • Average duration: 9.5 min
  • Total execution time: 76 min

By Phase:

Phase Plans Total Avg/Plan
01-foundation 5/5 complete 41 min 8.2 min
02-subscriber-and-billing-core 4/5 complete 49 min 12.25 min

Recent Trend:

  • Last 8 plans: 01-02 (8 min), 01-03 (9 min), 01-04 (7 min), 01-05 (6 min), 02-01 (7 min), 02-03 (7 min), 02-02 (16 min), 02-04 (12 min)
  • Trend: stable (02-04 was complex — schema + 3 services + 4 API routes + 38 tests)

Updated after each plan completion

Accumulated Context

Decisions

Decisions are logged in PROJECT.md Key Decisions table. Recent decisions affecting current work:

  • [Roadmap]: Accounting COA and JournalEntryService built in Phase 2 before first invoice — cannot be retrofitted
  • [Roadmap]: Inventory modeled as event-ledger (immutable movements) from Phase 4 — mutable quantity columns explicitly rejected
  • [Roadmap]: Collector balances derived from transaction log, never stored as mutable fields
  • [Roadmap]: PORT-05 (online payment) scaffolded in Phase 5 but payment gateway integration deferred to v2 per project out-of-scope decision
  • [01-01]: DATABASE_URL uses Docker service name db (for app container); DATABASE_URL_LOCAL uses localhost:5432 (for host Prisma CLI)
  • [01-01]: tenantId is nullable on User — super-admins have no tenant scope, avoiding a separate SuperAdmin model
  • [01-01]: Email uniqueness is @@unique([email, tenantId]) — same email can exist across different tenants (realistic for ISP domain)
  • [01-01]: Grace period fields (suspendedAt, gracePeriodEndsAt) included on Tenant at schema creation — cannot be retrofit later
  • [01-02]: NextAuth v4 chosen over v5/Auth.js beta — credentials provider stability priority
  • [01-02]: JWT carries tenantId + roles directly — no DB lookup on each request, stateless multi-tenancy
  • [01-02]: Super-admin authorize uses OR [isSuperAdmin, tenant.status=ACTIVE] — one Prisma query handles both user types
  • [01-02]: Seed uses findFirst+create for super-admin (null tenantId) — PostgreSQL NULL != NULL in unique constraints, upsert would create duplicates
  • [01-02]: SessionProvider wrapped at root layout via Providers component — enables useSession() in all client components
  • [01-03]: withTenantContext() creates new $extends per call — correct pattern, $extends is lightweight and request-scoped context is right
  • [01-03]: findUnique cross-tenant protection routes through findFirst internally — Prisma unique key cannot have tenantId injected without changing where shape
  • [01-03]: RLS USING allows null app.current_tenant_id — super-admin mode (no tenant context) sees all rows
  • [01-03]: Initial migration baselined with migrate resolve --applied (schema was created via db push in 01-01)
  • [01-04]: createMongoAbility used throughout (not PureAbility) — string subjects require conditionsMatcher which createMongoAbility provides built-in
  • [01-04]: cannot() rules excluded when merging multi-role abilities — additive union means more roles = more (never less) access
  • [01-04]: Condition objects cast via any for string subjects — CASL infers MongoQuery for strings; tighten when Prisma models defined in Phase 2+
  • [01-04]: Technician can("read", "Subscriber") coarse-grained — data layer enforces actual scope to assigned job contacts only
  • [01-04]: withPermission() HOF wraps Next.js route handlers; authorize() as convenience alias
  • [01-05]: withSuperAdmin() implemented as standalone HOF (not via CASL) — super-admin access is binary, not permission-based
  • [01-05]: Next.js 15 route params wrapped in Promise

    — HOF awaits params before passing to handler

  • [01-05]: subscriberCount hardcoded to 0 in admin API — Subscriber model added in Phase 2; API shape is forward-compatible
  • [01-05]: Dual guard strategy for /admin: middleware.ts (JWT edge), layout.tsx (server), API handlers (endpoint) — three defense-in-depth layers
  • [02-01]: ISP COA has 28 accounts (5 category headers 1000/2000/3000/4000/5000 + 23 leaf accounts) — hierarchical for reporting
  • [02-01]: Subscriber Credits (1150) is contra-asset with CREDIT normal balance — correctly reduces AR for overpayments
  • [02-01]: seedChartOfAccounts receives Prisma tx client — works inside createTenant $transaction for atomic provisioning
  • [02-01]: Accounting periods created on-demand via getOpenPeriod() — not pre-seeded on signup (no wasted periods for unused months)
  • [02-01]: close route uses closure pattern over withPermission HOF — withPermission doesn't support dynamic params directly; POST fn closes over Next.js params
  • [02-02]: JournalEntry self-referential reversal uses reversesEntryId @unique — one-to-one Prisma relation requires unique; semantically correct (one entry reverses at most one other)
  • [02-02]: tenantId passed explicitly in $transaction callbacks — raw tx client lacks the withTenantContext() extension; must inject tenantId manually in create data
  • [02-02]: startDate added to getAccountBalance — enables date-range balance queries; needed for period-scoped reporting and test isolation
  • [02-02]: Integer cents for debit=credit validation — Math.round(n*100) avoids floating point drift on decimal amounts
  • [02-02]: SYSTEM source auto-posts (POSTED status), MANUAL entries start DRAFT for maker-checker workflow
  • [02-02]: Self-approval allowed — single-person ISP operations are common; blocking self-approval breaks common use case
  • [02-02]: JournalEntryService is sole gateway — NO other code may write to JournalEntry/JournalEntryLine directly
  • [02-03]: creditBalance on Subscriber is operational convenience (FIFO credit allocation for 02-05), NOT a ledger balance — always updated atomically with journal entries
  • [02-03]: billingDay capped at 28 — subscribers signing up on days 29-31 get billingDay=28 to avoid month-length invoice generation issues
  • [02-03]: CANCELLED -> ACTIVE transition is reversible by design — ISPs frequently reinstate cancelled accounts per CONTEXT.md
  • [02-03]: as any cast in service create() calls — Prisma static type requires tenantId but withTenantContext() extension injects at runtime; cast is intentional
  • [02-04]: Invoice.amountPaid is transactional convenience field, NOT standalone stored balance — always updated atomically with JEs (same pattern as creditBalance from 02-03)
  • [02-04]: shouldBillToday PREPAID month-wrapping: actualLeadDay = lastDayOfCurrentMonth + (billingDay - leadDays) — uses current month's last day, not previous month's
  • [02-04]: generateInvoiceForSubscriber returns null (not error) for duplicates — idempotent by design; generateMonthlyInvoices tracks in skipped array
  • [02-04]: CreditService is standalone module — applyCredit() callable from BillingService (auto-apply) and PaymentService (02-05 overpayment)
  • [02-04]: Dynamic route handlers pattern: export function GET/POST(req, { params }) wrapping withPermission()(handler)(req) — required for Next.js 15 Promise params in [id] routes

Pending Todos

None.

Blockers/Concerns

  • [Phase 1 research flag]: MikroTik RouterOS Node.js client library maintenance status is LOW confidence — verify node-routeros vs mikronode before implementing router integration (MikroTik integration is v2, but adapter interface should be planned)
  • [Phase 3 research flag]: Semaphore SMS API pricing/stability for 2026 is MEDIUM confidence — verify before any SMS work (SMS is v2, but abstraction layer design is relevant)
  • [01-04 note]: CASL condition types for string subjects use any cast — upgrade to class-based subjects when Phase 2 Prisma models (Subscriber, Invoice, etc.) are defined
  • [01-05 note]: /admin/tenants/[id] detail page is a stub link ("View") — detail view not implemented yet (out of Phase 1 scope)
  • [02-02 note]: JournalEntry afterAll cleanup needs explicit order (lines → null reversesEntryId → entries → tenant) — document for any future test that involves journal entries
  • [02-04 note]: Invoice cleanup order in tests: invoiceLines → invoices → journalEntryLines → null reversesEntryId → journalEntries → subscribers → servicePlans → tenantSettings → accountingPeriods → accounts → users → tenant

Session Continuity

Last session: 2026-03-04T15:39:35Z Stopped at: Completed 02-04-PLAN.md (BillingEngine + 38 tests, Invoice/InvoiceLine models) Resume file: None