# Notification Service (NT) - Documentation Update Plan

> **Note (Issue #91):** This document references `kubernaut.ai/*` CRD labels that have since been migrated to immutable spec fields. See [DD-CRD-003](../../../../architecture/DD-CRD-003-field-selectors-operational-queries.md) for the current field-selector-based approach.

**Date**: December 22, 2025
**Status**: 📋 **READY FOR EXECUTION**
**Priority**: P1 (Documentation Debt)

---

## 🎯 Objective

Update NT service documentation to reflect recent achievements:
- ✅ Controller refactoring (Pattern 4 decomposition)
- ✅ DD-005 V3.0 metric constants implementation
- ✅ DD-METRICS-001 migration (metrics dependency injection)
- ✅ 100% integration test success
- ✅ E2E metrics exposure fix
- ✅ 100% V1.0 maturity compliance

**Last Documentation Update**: December 6, 2025 (16 days ago)
**Current Date**: December 22, 2025

---

## 📊 Current Documentation Status

### ✅ **Already Accurate** (No Updates Needed)
- `docs/architecture/case-studies/NT_REFACTORING_2025.md` ✅ (Created Dec 21, 2025)
- `docs/architecture/patterns/CONTROLLER_REFACTORING_PATTERN_LIBRARY.md` ✅ (Updated Dec 21, 2025)
- `test/e2e/notification/04_metrics_validation_test.go` ✅ (Updated Dec 22, 2025)
- `pkg/notification/metrics/metrics.go` ✅ (Updated Dec 22, 2025)

### ❌ **Outdated** (Needs Updates)
| Document | Last Updated | Status | Priority |
|---|---|---|---|
| `README.md` | Dec 6, 2025 | Missing recent refactoring | P1 HIGH |
| `controller-implementation.md` | Nov 23, 2025 | Monolithic controller structure | P1 HIGH |
| `observability-logging.md` | Nov 23, 2025 | Missing DD-005 V3.0 constants | P2 MEDIUM |
| `testing-strategy.md` | Nov 23, 2025 | Missing DD-METRICS-001 patterns | P2 MEDIUM |
| `NOTIFICATION-SERVICE-STATUS-REPORT.md` | Nov 23, 2025 | Missing v1.0 maturity status | P3 LOW |

---

## 📝 Documentation Update Tasks

### **Task 1: Update README.md** (P1 HIGH)
**File**: `docs/services/crd-controllers/06-notification/README.md`
**Last Updated**: December 6, 2025
**Estimated Time**: 30 minutes

#### Changes Needed:
1. **Update Version History** section:
   - Add **Version 1.6.0** (December 22, 2025):
     - ✅ DD-005 V3.0 Metric Name Constants (Pattern B)
     - ✅ DD-METRICS-001 Controller Metrics Wiring
     - ✅ Controller Decomposition (Pattern 4)
     - ✅ 100% Integration Test Success
     - ✅ E2E Metrics Exposure Fix
     - ✅ 100% V1.0 Maturity Compliance

2. **Update Architecture diagram** (line 196):
   - Current: Shows monolithic controller
   - New: Add decomposed components (routing handler, retry/circuit breaker handler)

3. **Update Component Responsibilities** table (line 236):
   - Add new handler files:
     - `internal/controller/notification/routing_handler.go` - Spec-field-based routing logic
     - `internal/controller/notification/retry_circuit_breaker_handler.go` - Retry and circuit breaker logic

4. **Update Observability section** (line 367):
   - Update metrics table to reference DD-005 V3.0 constants
   - Add note about DD-METRICS-001 dependency injection pattern

5. **Update Production Readiness Status** (line 819):
   - Add ✅ DD-METRICS-001 metrics wiring compliance
   - Add ✅ DD-005 V3.0 naming convention compliance
   - Add ✅ Controller decomposition (4 architectural patterns)

---

### **Task 2: Update controller-implementation.md** (P1 HIGH)
**File**: `docs/services/crd-controllers/06-notification/controller-implementation.md`
**Last Updated**: November 23, 2025
**Estimated Time**: 45 minutes

#### Changes Needed:
1. **Add "Controller Architecture" section** (NEW):
   ```markdown
   ## 🏗️ Controller Architecture (Post-Refactoring)

   The Notification controller follows a **decomposed architecture** with functionally cohesive components:

   | Component | File | Responsibility | LOC |
   |---|---|---|---|
   | **Main Controller** | `notificationrequest_controller.go` | Orchestration, phase transitions | ~800 |
   | **Routing Handler** | `routing_handler.go` | Spec-field-based routing, channel selection | ~300 |
   | **Retry/Circuit Breaker** | `retry_circuit_breaker_handler.go` | Backoff, circuit breaker, error classification | ~187 |
   | **Status Manager** | `pkg/notification/status/manager.go` | CRD status updates | ~200 |

   **Pattern Applied**: Controller Decomposition (Pattern 4 from Pattern Library)
   **Refactoring Date**: December 21, 2025
   **Reference**: `docs/architecture/case-studies/NT_REFACTORING_2025.md`
   ```

2. **Update "Reconciler Structure" section**:
   - Current: Shows monolithic structure
   - New: Show decomposed structure with method delegation

3. **Add "Metrics Integration" section** (NEW):
   ```markdown
   ## 📊 Metrics Integration (DD-METRICS-001)

   The controller uses **dependency injection** for metrics recording:

   ```go
   type NotificationRequestReconciler struct {
       client.Client
       Scheme   *runtime.Scheme
       Metrics  notificationmetrics.Recorder // ← DD-METRICS-001
       // ... other fields
   }
   ```

   **Pattern**: DD-METRICS-001 Controller Metrics Wiring Pattern
   **Benefits**: Testability, isolation, flexibility
   **Implementation**: See `pkg/notification/metrics/recorder.go`
   ```

4. **Update "Retry and Error Handling" section**:
   - Add reference to new `retry_circuit_breaker_handler.go`
   - Update method signatures (now methods on handler)

---

### **Task 3: Update observability-logging.md** (P2 MEDIUM)
**File**: `docs/services/crd-controllers/06-notification/observability-logging.md`
**Last Updated**: November 23, 2025
**Estimated Time**: 20 minutes

#### Changes Needed:
1. **Update "Prometheus Metrics" section**:
   - Add **DD-005 V3.0 Naming Convention** subsection:
   ```markdown
   ### DD-005 V3.0 Naming Convention

   All metrics use **Pattern B** (full metric names in constants):

   ```go
   // pkg/notification/metrics/metrics.go
   const (
       MetricNameDeliveryAttemptsTotal = "kubernaut_notification_delivery_attempts_total"
       MetricNameReconcilerActive      = "kubernaut_notification_reconciler_active"
       // ... 4 more metrics (operational/debugging metrics removed per v1.13)
   )
   ```

   **Benefits**:
   - ✅ Type safety (compiler catches typos)
   - ✅ Consistency across tests and production
   - ✅ Single source of truth

   **Reference**: `docs/architecture/decisions/DD-005-OBSERVABILITY-STANDARDS.md`
   ```

2. **Update metrics table**:
   - Add "Constant Name" column
   - Map each metric to its DD-005 V3.0 constant

3. **Add "Metrics Dependency Injection" section**:
   ```markdown
   ### Metrics Dependency Injection (DD-METRICS-001)

   Metrics are injected into the controller via the `Recorder` interface:

   ```go
   // cmd/notification/main.go
   metricsRecorder := notificationmetrics.NewPrometheusRecorder()
   reconciler := &notificationcontroller.NotificationRequestReconciler{
       Metrics: metricsRecorder, // ← Dependency injection
   }
   ```

   **Testing Pattern**:
   ```go
   // test/unit/notification/controller_test.go
   noOpRecorder := notificationmetrics.NewNoOpRecorder()
   reconciler := &notificationcontroller.NotificationRequestReconciler{
       Metrics: noOpRecorder, // ← Test isolation
   }
   ```
   ```

---

### **Task 4: Update testing-strategy.md** (P2 MEDIUM)
**File**: `docs/services/crd-controllers/06-notification/testing-strategy.md`
**Last Updated**: November 23, 2025
**Estimated Time**: 25 minutes

#### Changes Needed:
1. **Update "Test Statistics" section**:
   - Current: 133 tests (117 unit + 9 integration + 7 E2E)
   - New: Add recent achievements:
     - ✅ 100% integration test pass rate (Dec 21, 2025)
     - ✅ E2E metrics exposure fix (Dec 21, 2025)
     - ✅ DD-METRICS-001 migration (Dec 20, 2025)

2. **Add "Metrics Testing Pattern" section** (NEW):
   ```markdown
   ## 📊 Metrics Testing Pattern (DD-METRICS-001)

   ### Unit Tests
   Use `NoOpRecorder` to isolate tests from Prometheus registry:

   ```go
   var _ = Describe("Controller Unit Tests", func() {
       var (
           reconciler *controller.NotificationRequestReconciler
           recorder   notificationmetrics.Recorder
       )

       BeforeEach(func() {
           recorder = notificationmetrics.NewNoOpRecorder() // ← Isolated
           reconciler = &controller.NotificationRequestReconciler{
               Metrics: recorder,
           }
       })
   })
   ```

   ### Integration Tests
   Use `PrometheusRecorder` with test-specific registry:

   ```go
   var _ = Describe("Controller Integration Tests", func() {
       var (
           reconciler *controller.NotificationRequestReconciler
           recorder   notificationmetrics.Recorder
       )

       BeforeEach(func() {
           testRegistry := prometheus.NewRegistry()
           metricsInstance := notificationmetrics.NewMetricsWithRegistry(testRegistry)
           recorder = notificationmetrics.NewPrometheusRecorderWithMetrics(metricsInstance)
           reconciler = &controller.NotificationRequestReconciler{
               Metrics: recorder,
           }
       })
   })
   ```

   ### E2E Tests
   Use full metric name constants (DD-005 V3.0):

   ```go
   import ntmetrics "github.com/jordigilh/kubernaut/pkg/notification/metrics"

   It("should expose reconciler_active metric", func() {
       Eventually(func() string {
           resp, err := http.Get("http://localhost:9186/metrics")
           defer resp.Body.Close()
           body, _ := io.ReadAll(resp.Body)
           return string(body)
       }).Should(ContainSubstring(ntmetrics.MetricNameReconcilerActive)) // ← Direct constant
   })
   ```
   ```

3. **Update "Anti-Patterns to Avoid" section**:
   - Add:
     ```markdown
     ### ❌ Anti-Pattern: Global Metrics Registration
     ```go
     // BAD: Global registration in init() or package-level
     var requestsTotal = promauto.NewCounter(...) // ← Global state

     func RecordRequest() {
         requestsTotal.Inc() // ← Not testable
     }
     ```

     ### ✅ Correct Pattern: Dependency Injection
     ```go
     // GOOD: Dependency injection
     type Reconciler struct {
         Metrics notificationmetrics.Recorder // ← Interface
     }

     func (r *Reconciler) Reconcile(ctx context.Context, req reconcile.Request) {
         r.Metrics.RecordReconcileRequest(...) // ← Testable
     }
     ```

     **Reference**: DD-METRICS-001 Controller Metrics Wiring Pattern
     ```

---

### **Task 5: Update NOTIFICATION-SERVICE-STATUS-REPORT.md** (P3 LOW)
**File**: `docs/services/crd-controllers/06-notification/NOTIFICATION-SERVICE-STATUS-REPORT.md`
**Last Updated**: November 23, 2025
**Estimated Time**: 15 minutes

#### Changes Needed:
1. **Update "Version" header** (line 4):
   - Current: `V3.0`
   - New: `V4.0 (Post-Refactoring)`

2. **Update "Overall Status" table** (line 11):
   - Add rows:
     ```markdown
     | **Controller Architecture** | ✅ DECOMPOSED | 4 patterns applied |
     | **Metrics Wiring** | ✅ DD-METRICS-001 | Dependency injection |
     | **Metric Naming** | ✅ DD-005 V3.0 | Pattern B constants |
     | **V1.0 Maturity** | ✅ 100% | 7/7 checks passing |
     ```

3. **Add "Recent Achievements" section** (NEW):
   ```markdown
   ## 🎉 Recent Achievements (December 2025)

   ### Controller Refactoring (December 21, 2025)
   - ✅ Pattern 4: Controller Decomposition
   - ✅ Terminal State Logic
   - ✅ Status Manager
   - ✅ Delivery Orchestrator
   - **Impact**: 1472-line controller → 3 functionally cohesive files
   - **Reference**: `docs/architecture/case-studies/NT_REFACTORING_2025.md`

   ### DD-005 V3.0 Compliance (December 22, 2025)
   - ✅ 10 metric name constants (Pattern B)
   - ✅ E2E tests use constants directly
   - ✅ Zero hardcoded metric strings
   - **Impact**: Type-safe metrics, compiler-enforced consistency

   ### DD-METRICS-001 Migration (December 20, 2025)
   - ✅ Metrics dependency injection
   - ✅ `Recorder` interface + `NoOpRecorder`
   - ✅ 100% integration test isolation
   - **Impact**: Testability, flexibility, pattern compliance

   ### V1.0 Maturity 100% (December 20, 2025)
   - ✅ 7/7 mandatory checks passing
   - ✅ Metrics wired + registered
   - ✅ EventRecorder present
   - ✅ Graceful shutdown
   - ✅ Audit integration (OpenAPI client + testutil validator)
   ```

---

## 📋 Execution Checklist

### Phase 1: High Priority Updates (P1)
- [ ] **Task 1**: Update `README.md` (30 min)
  - [ ] Add Version 1.6.0 to version history
  - [ ] Update architecture diagram
  - [ ] Update component responsibilities table
  - [ ] Update observability section
  - [ ] Update production readiness status

- [ ] **Task 2**: Update `controller-implementation.md` (45 min)
  - [ ] Add "Controller Architecture" section
  - [ ] Update "Reconciler Structure" section
  - [ ] Add "Metrics Integration" section
  - [ ] Update "Retry and Error Handling" section

### Phase 2: Medium Priority Updates (P2)
- [ ] **Task 3**: Update `observability-logging.md` (20 min)
  - [ ] Add DD-005 V3.0 naming convention section
  - [ ] Update metrics table with constant names
  - [ ] Add metrics dependency injection section

- [ ] **Task 4**: Update `testing-strategy.md` (25 min)
  - [ ] Update test statistics
  - [ ] Add metrics testing pattern section
  - [ ] Update anti-patterns section

### Phase 3: Low Priority Updates (P3)
- [ ] **Task 5**: Update `NOTIFICATION-SERVICE-STATUS-REPORT.md` (15 min)
  - [ ] Update version header
  - [ ] Update overall status table
  - [ ] Add recent achievements section

---

## ⏱️ Time Estimate

| Phase | Tasks | Estimated Time | Status |
|---|---|---|---|
| **Phase 1** | 2 tasks (P1 HIGH) | 75 minutes | ⏸️ Pending |
| **Phase 2** | 2 tasks (P2 MEDIUM) | 45 minutes | ⏸️ Pending |
| **Phase 3** | 1 task (P3 LOW) | 15 minutes | ⏸️ Pending |
| **TOTAL** | 5 tasks | **~2.25 hours** | ⏸️ Ready to Start |

**Recommended Approach**: Complete all tasks in one focused session to maintain context.

---

## ✅ Success Criteria

### Documentation Quality
- [ ] All updated documents reference authoritative sources (case studies, DDs)
- [ ] Version history is complete and chronological
- [ ] Architecture diagrams reflect current implementation
- [ ] Code examples compile and follow current patterns

### Technical Accuracy
- [ ] DD-005 V3.0 references are correct
- [ ] DD-METRICS-001 patterns are accurately described
- [ ] Controller decomposition structure is documented
- [ ] Metrics constants are correctly referenced

### Completeness
- [ ] All 5 identified documents updated
- [ ] No broken internal links
- [ ] All recent achievements documented
- [ ] Cross-references to case studies and DDs are valid

---

## 📚 Reference Documents

### Authoritative Sources
- `docs/architecture/case-studies/NT_REFACTORING_2025.md` - Controller refactoring lessons
- `docs/architecture/patterns/CONTROLLER_REFACTORING_PATTERN_LIBRARY.md` - Pattern library v1.1.0
- `docs/architecture/decisions/DD-005-OBSERVABILITY-STANDARDS.md` - DD-005 V3.0 standard
- `docs/architecture/decisions/DD-METRICS-001-CONTROLLER-METRICS-WIRING.md` - DD-METRICS-001 pattern

### Implementation References
- `pkg/notification/metrics/metrics.go` - DD-005 V3.0 constants
- `pkg/notification/metrics/recorder.go` - DD-METRICS-001 implementation
- `internal/controller/notification/notificationrequest_controller.go` - Main controller
- `internal/controller/notification/routing_handler.go` - Routing logic
- `internal/controller/notification/retry_circuit_breaker_handler.go` - Retry/circuit breaker

---

## 🎯 Next Steps

1. **Review this plan** - Confirm scope and priorities
2. **Execute Phase 1** (P1 HIGH) - README.md + controller-implementation.md
3. **Execute Phase 2** (P2 MEDIUM) - observability-logging.md + testing-strategy.md
4. **Execute Phase 3** (P3 LOW) - NOTIFICATION-SERVICE-STATUS-REPORT.md
5. **Validate** - Run documentation link checker, review for accuracy
6. **Commit** - Single commit: `docs(notification): Update docs for v1.6.0 refactoring`

---

**Status**: 📋 **READY FOR EXECUTION**
**Estimated Time**: ~2.25 hours (focused session)
**Priority**: P1 (Documentation Debt from December 6-22, 2025)
**Owner**: NT Team

