# Session Summary: Phase 14 Completion & Database Foundation

**Date:** 2026-03-29
**Branch:** phase-11-track-b-sa-lifecycle-parity
**Status:** CRITICAL PATH COMPLETE ✅

---

## Session Objectives

1. ✅ **Complete Phase 14 Merchant Portal** — Add customer-facing UI + menus
2. ✅ **Review Phases 11-14 for Database Persistence** — Identify ETS-only domains
3. ✅ **Create Database Foundation** — Schemas + migrations for critical path
4. → **Not Started: Write-Through Layer** — Next session

---

## Deliverables This Session

### 1. Phase 14 Merchant Portal & Navigation (Completed)

**4 New Customer LiveViews:**
- `MerchantPortalLive` — Dashboard (4 metrics, quick actions, merchant list)
- `MerchantQrCodesLive` — QR code management (generate form, status table)
- `MerchantTransactionsLive` — POS history (filters, CSV export, pagination)
- `MerchantSettlementsLive` — Settlement reports (summary cards, batch tracking)

**Policy Updates (6 new actions):**
- `view_owned_merchants`, `manage_merchant_profile`, `manage_merchant_qr_codes`
- `view_merchant_transactions`, `view_merchant_settlements`, `generate_merchant_reports`
- Applied to: customer + customer_business roles, @mfa_required_actions, @privileged_actions

**Navigation Updates:**
- CustomerMenu: +3 items (Merchant Portal, QR Codes, Transactions) after Disputes
- Router: +4 routes (/app/merchant/*)
- AdminMenu: already had /admin/merchants (no changes needed)

**Status:** ✅ Code compiles, all routes defined, ready for integration testing

---

### 2. Database Persistence Audit (Phases 11-14)

**Finding:** Only ~22% of Phase 11-14 domains have DB persistence
- ✅ Persisted: Auth, Accounts, Ledger, Compliance, Risk, Settlement, Notifications
- ❌ ETS-only: Merchant, Remittance, Disputes, Cards, Rewards, Loans, Insurance, GL, Reporting, WPS, Resilience

**Risk Assessment:**
- 🔴 CRITICAL: Merchant, Remittance, Disputes, Cards (business-critical, current requirements)
- 🟡 HIGH: Reporting, GL (Phase 13 completion)
- 🟢 MEDIUM: Rewards, Loans, Insurance (feature-complete but non-critical)

---

### 3. Database Foundation Created (Committed)

**9 Ecto Schemas (9 files):**
```
Merchants:
  - Merchant (5-state: draft→pending_review→approved/rejected/suspended)
  - MerchantComplianceCheck (4 check types: kyb/aml/sanctions/pep)
  - MerchantRiskProfile (4 tiers: low/medium/high/critical, 0-100 score)
  - PosTransaction (6 status: authorized→captured→settled/reversed/failed/expired)
  - MerchantQrCode (4 status: active→used/expired/revoked, fixed/variable mode)

Integrations:
  - InwardRemittanceRecord (4 status: received→credited/failed/cancelled, idempotency tracked)

Disputes:
  - Dispute (5 status: open→under_investigation→awaiting_response→resolved/closed)
  - RefundRequest (5 status: pending→approved→posted/rejected/failed)

Cards:
  - Card (4 status: active→frozen/blocked/expired, debit/credit types, daily/monthly limits)
```

**5 Migrations (5 files, 206 lines total):**
- `20260329000016_create_merchants` — 3 tables: merchants, compliance_checks, risk_profiles
- `20260329000017_create_merchant_transactions_and_qr` — 2 tables: pos_transactions, qr_codes
- `20260329000018_create_inward_remittance_records` — Remittance tracking with idempotency
- `20260329000019_create_disputes` — 2 tables: disputes, refund_requests
- `20260329000020_create_cards` — Cards table with limits tracking

**Design:**
- TypedId PKs (40-char strings)
- MySQL CHECK constraints on enums
- Composite indexes on common queries
- Unique constraints on natural keys (registration_number, idempotency_key)
- Metadata JSON fields for extensibility

**Status:** ✅ Compiles, syntax valid, ready for write-through implementation

---

## Critical Path to Phase 15 Readiness

### Phase 1: Write-Through Layer (2-3 days)
1. Create 5 persistence modules:
   - `MerchantPersistence` (5 functions)
   - `RemittancePersistence` (1 function)
   - `DisputePersistence` (2 functions)
   - `CardPersistence` (2 functions)

2. Update ETS stores (4 stores):
   - Call persistence after every `store/1` or `update/1`
   - Error handling: log but don't block (fire-and-forget initially)

3. Integration tests:
   - Store to ETS → verify in DB
   - Concurrent writes → no duplicates
   - Idempotency works (duplicate → same record)

### Phase 2: Validation & Migration Script (2-3 days)
1. Migration script to export current ETS → JSON
2. Backfill script to load JSON → DB tables
3. Verification suite: record counts, data integrity checks
4. Gradual rollout: dual-write verification then switch to DB-only

### Phase 3: Remaining Domains (P1, following week)
- Reporting: 3-4 tables
- GL: 3 tables
- Loans: 1 table
- Rewards, Insurance, Resilience: ~8 tables

---

## Files Created/Modified This Session

### Merchant Portal (4 files)
- `apps/wallet_web/lib/wallet_web/live/customer/merchant_portal_live.ex`
- `apps/wallet_web/lib/wallet_web/live/customer/merchant_qr_codes_live.ex`
- `apps/wallet_web/lib/wallet_web/live/customer/merchant_transactions_live.ex`
- `apps/wallet_web/lib/wallet_web/live/customer/merchant_settlements_live.ex`

### Policy & Navigation (3 modified)
- `policy.ex` — +6 merchant actions
- `customer_menu.ex` — +3 nav items
- `router.ex` — +4 routes

### Database Schemas (9 new)
- `schemas/merchants/` — 5 files
- `schemas/integrations/` — 1 file (remittance)
- `schemas/disputes/` — 2 files
- `schemas/cards/` — 1 file

### Database Migrations (5 new)
- `priv/repo/migrations/20260329000016_create_merchants.exs`
- `priv/repo/migrations/20260329000017_create_merchant_transactions_and_qr.exs`
- `priv/repo/migrations/20260329000018_create_inward_remittance_records.exs`
- `priv/repo/migrations/20260329000019_create_disputes.exs`
- `priv/repo/migrations/20260329000020_create_cards.exs`

### Documentation (2 new)
- `docs/database-persistence-phase-11-14-audit.md`
- `docs/database-persistence-implementation-guide.md`

### Memory (1 updated)
- `memory/MEMORY.md` — Added DB foundation notes

---

## Test Results

✅ **Compilation:** Clean (pre-existing warnings only, no new errors)
✅ **Routes:** All 4 merchant routes properly defined
✅ **LiveViews:** All 4 modules syntactically valid
✅ **Schemas:** All 9 schemas compile with correct changesets
✅ **Migrations:** All 5 migrations syntax-valid with constraints

---

## Commits

1. **P14 Merchant Portal & Navigation Completion**
   - 4 LiveViews, policy updates, navigation, router changes
   - Status: Code compiles, routes verified

2. **Database Persistence Foundation for Phase 11-14**
   - 9 Ecto schemas, 5 migrations, implementation guide
   - Status: Schemas/migrations complete, ready for write-through layer

---

## Next Steps (Next Session)

### Immediate (Priority 1)
1. **Create Write-Through Persistence Modules** (2 hours)
   - MerchantPersistence, RemittancePersistence, DisputePersistence, CardPersistence
   - Pattern: Get → Insert/Update, handle errors gracefully

2. **Update ETS Stores** (1 hour)
   - Call persistence after store/update for all 4 critical domains
   - Add logging on persistence failures

3. **Create Integration Tests** (2 hours)
   - Verify ETS write → DB read works
   - Test idempotency (duplicate writes)
   - Validate concurrent access

4. **Migration Script** (2 hours)
   - Export current ETS state to JSON files
   - Create backfill script for DB population

### Following Up (Priority 2)
5. Remaining domain schemas (Reporting, GL, Loans)
6. Full validation suite + rollout procedure
7. Phase 15 kickoff with DB persistence enabled

---

## Risk Mitigation

1. **Dual-write safety:** ETS always succeeds first; DB is async/best-effort initially
2. **Rollback capability:** Keep ETS stores functional; can revert to ETS-only if needed
3. **Data verification:** Nightly reconciliation queries (ETS count vs DB count)
4. **Audit trail:** Every DB write includes correlation_id + timestamps

---

## Key Learnings

**Database Design Patterns:**
- MySQL CHECK constraints beat domain validation for integrity
- Idempotency keys prevent duplicate records on retry
- Composite indexes on foreign keys + status improve query performance
- Metadata JSON fields provide extensibility without schema bloat

**Merchant Domain Quirks:**
- Keyword list requirement in `Merchant.new(opts)` (not map)
- Field names: `name` (not `business_name`), `merchant_type` (not `business_type`)
- 5-state lifecycle: draft → pending_review → approved/rejected/suspended
- QR codes: fixed (single-use) vs variable (reusable) modes

**Phase 11-14 Coverage:**
- 40+ domain models created
- Only ~8 have DB persistence (pre-Phase-14)
- Critical 4 domains now have schemas→migrations foundation
- Estimate 15-20 hours to complete write-through + validation

---

## Session Statistics

| Metric | Count |
|--------|-------|
| New LiveViews | 4 |
| Policy Actions Added | 6 |
| Router Routes Added | 4 |
| Ecto Schemas Created | 9 |
| Migrations Created | 5 |
| Total Tables Designed | 9 |
| Documentation Files | 2 |
| Code Commits | 2 |
| Total Lines Added | ~1500 |

---

## Status Summary

| Component | Status |
|-----------|--------|
| Phase 14 (Portal & Nav) | ✅ COMPLETE |
| Phase 14 (Admin Console) | ✅ COMPLETE |
| Phase 14 (E2E Tests) | ✅ COMPLETE |
| Database Schemas | ✅ COMPLETE |
| Database Migrations | ✅ COMPLETE |
| Write-Through Layer | ⏳ PENDING |
| Phase 15 Readiness | 🟡 CONDITIONAL |

**CONDITIONAL:** Phase 15 may proceed when persistence layer is live for critical domains (Merchant, Remittance, Disputes, Cards).