Add email sent/failed structured logging

Implement email logging per observability spec:
- Add structured logging for email sent (info level) and failed (error level)
- Include userId, type, and recipient fields in log events
- Add userId parameter to email functions (sendDailyEmail, sendPeriodConfirmationEmail, sendTokenExpirationWarning)
- Update cron routes (notifications, garmin-sync) to pass userId

6 new tests added to email.test.ts (now 30 tests total)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

IMPLEMENTATION_PLAN.md

@@ -4,14 +4,14 @@ This file is maintained by Ralph. Run `./ralph-sandbox.sh plan 3` to generate ta
 
 ## Current State Summary
 
-### Overall Status: 835 tests passing across 44 test files
+### Overall Status: 841 tests passing across 44 test files
 
 ### Library Implementation
 | File | Status | Gap Analysis |
 |------|--------|--------------|
 | `cycle.ts` | **COMPLETE** | 22 tests covering all functions including dynamic phase boundaries for variable cycle lengths |
 | `nutrition.ts` | **COMPLETE** | 17 tests covering getNutritionGuidance, getSeedSwitchAlert, phase-specific carb ranges, keto guidance |
-| `email.ts` | **COMPLETE** | 24 tests covering sendDailyEmail, sendPeriodConfirmationEmail, sendTokenExpirationWarning, email formatting, subject lines |
+| `email.ts` | **COMPLETE** | 30 tests covering sendDailyEmail, sendPeriodConfirmationEmail, sendTokenExpirationWarning, email formatting, subject lines, structured logging |
 | `ics.ts` | **COMPLETE** | 33 tests covering generateIcsFeed (90 days of phase events), ICS format validation, timezone handling, period prediction feedback, CATEGORIES for calendar colors |
 | `encryption.ts` | **COMPLETE** | 14 tests covering AES-256-GCM encrypt/decrypt round-trip, error handling, key validation |
 | `decision-engine.ts` | **COMPLETE** | 8 priority rules + override handling with `getDecisionWithOverrides()`, 24 tests |
@@ -94,7 +94,7 @@ This file is maintained by Ralph. Run `./ralph-sandbox.sh plan 3` to generate ta
 | `src/app/login/page.test.tsx` | **EXISTS** - 32 tests (form rendering, auth flow, error handling, validation, accessibility, rate limiting) |
 | `src/app/page.test.tsx` | **EXISTS** - 28 tests (data fetching, component rendering, override toggles, error handling) |
 | `src/lib/nutrition.test.ts` | **EXISTS** - 17 tests (seed cycling, carb ranges, keto guidance by phase) |
-| `src/lib/email.test.ts` | **EXISTS** - 24 tests (email content, subject lines, formatting, token expiration warnings) |
+| `src/lib/email.test.ts` | **EXISTS** - 30 tests (email content, subject lines, formatting, token expiration warnings, structured logging) |
 | `src/lib/ics.test.ts` | **EXISTS** - 33 tests (ICS format validation, 90-day event generation, timezone handling, period prediction feedback, CATEGORIES for colors) |
 | `src/lib/encryption.test.ts` | **EXISTS** - 14 tests (encrypt/decrypt round-trip, error handling, key validation) |
 | `src/lib/garmin.test.ts` | **EXISTS** - 33 tests (fetchGarminData, fetchHrvStatus, fetchBodyBattery, fetchIntensityMinutes, token expiry, error handling) |
@@ -892,7 +892,7 @@ P4.* UX Polish ────────> After core functionality complete
 - [x] **decision-engine.ts** - Complete with 24 tests (`getTrainingDecision` + `getDecisionWithOverrides`)
 - [x] **pocketbase.ts** - Complete with 9 tests (`createPocketBaseClient`, `isAuthenticated`, `getCurrentUser`, `loadAuthFromCookies`)
 - [x] **nutrition.ts** - Complete with 17 tests (`getNutritionGuidance`, `getSeedSwitchAlert`, phase-specific carb ranges, keto guidance) (P3.2)
-- [x] **email.ts** - Complete with 24 tests (`sendDailyEmail`, `sendPeriodConfirmationEmail`, `sendTokenExpirationWarning`, email formatting) (P3.3, P3.9)
+- [x] **email.ts** - Complete with 30 tests (`sendDailyEmail`, `sendPeriodConfirmationEmail`, `sendTokenExpirationWarning`, email formatting, structured logging for sent/failed events) (P3.3, P3.9)
 - [x] **ics.ts** - Complete with 33 tests (`generateIcsFeed`, ICS format validation, 90-day event generation, period prediction feedback, CATEGORIES for calendar colors) (P3.4, P4.5)
 - [x] **encryption.ts** - Complete with 14 tests (AES-256-GCM encrypt/decrypt, round-trip validation, error handling) (P3.5)
 - [x] **garmin.ts** - Complete with 33 tests (`fetchGarminData`, `fetchHrvStatus`, `fetchBodyBattery`, `fetchIntensityMinutes`, `isTokenExpired`, `daysUntilExpiry`, error handling) (P2.1, P3.6)
@@ -945,7 +945,7 @@ P4.* UX Polish ────────> After core functionality complete
 ### P3: Quality and Testing
 - [x] **P3.1: Decision Engine Tests** - Complete with 24 tests covering all 8 priority rules and override combinations
 - [x] **P3.2: Nutrition Tests** - Complete with 17 tests covering seed cycling, carb ranges, keto guidance by phase
-- [x] **P3.3: Email Tests** - Complete with 24 tests covering daily emails, period confirmation, token expiration warnings
+- [x] **P3.3: Email Tests** - Complete with 30 tests covering daily emails, period confirmation, token expiration warnings, structured logging
 - [x] **P3.4: ICS Tests** - Complete with 28 tests covering ICS format validation, 90-day event generation, timezone handling, period prediction feedback
 - [x] **P3.5: Encryption Tests** - Complete with 14 tests covering AES-256-GCM round-trip, error handling, key validation
 - [x] **P3.6: Garmin Tests** - Complete with 33 tests covering API interactions, token expiry, error handling
@@ -975,7 +975,7 @@ Analysis of all specs vs implementation revealed these gaps:
 |-----|------|--------|-------|
 | Logout functionality | authentication.md | **COMPLETE** | Added POST /api/auth/logout + settings button |
 | Garmin sync structured logging | observability.md | **COMPLETE** | Added sync start/complete/failure logging |
-| Email sent/failed logging | observability.md | **PENDING** | Email events should be logged |
+| Email sent/failed logging | observability.md | **COMPLETE** | Email events now logged (info for success, error for failure) with structured data (userId, emailType, success) |
 | Period history UI | cycle-tracking.md | **PENDING** | UI for viewing/editing past periods |
 | Dashboard color-coded backgrounds | dashboard.md | **PENDING** | Phase-based background colors |
 | Toast notifications | dashboard.md | **PENDING** | Success/error toasts for user actions |

src/app/api/cron/garmin-sync/route.test.ts

@@ -424,6 +424,7 @@ describe("POST /api/cron/garmin-sync", () => {
       expect(mockSendTokenExpirationWarning).toHaveBeenCalledWith(
         "user@example.com",
         14,
+        "user123",
       );
       const body = await response.json();
       expect(body.warningsSent).toBe(1);
@@ -438,6 +439,7 @@ describe("POST /api/cron/garmin-sync", () => {
       expect(mockSendTokenExpirationWarning).toHaveBeenCalledWith(
         "user@example.com",
         7,
+        "user123",
       );
       const body = await response.json();
       expect(body.warningsSent).toBe(1);
@@ -493,10 +495,12 @@ describe("POST /api/cron/garmin-sync", () => {
       expect(mockSendTokenExpirationWarning).toHaveBeenCalledWith(
         "user1@example.com",
         14,
+        "user1",
       );
       expect(mockSendTokenExpirationWarning).toHaveBeenCalledWith(
         "user2@example.com",
         7,
+        "user2",
       );
       const body = await response.json();
       expect(body.warningsSent).toBe(2);

src/app/api/cron/garmin-sync/route.ts

@@ -82,7 +82,7 @@ export async function POST(request: Request) {
       const daysRemaining = daysUntilExpiry(tokens);
       if (daysRemaining === 14 || daysRemaining === 7) {
         try {
-          await sendTokenExpirationWarning(user.email, daysRemaining);
+          await sendTokenExpirationWarning(user.email, daysRemaining, user.id);
           result.warningsSent++;
         } catch {
           // Continue processing even if warning email fails

src/app/api/cron/notifications/route.ts

@@ -121,7 +121,8 @@ export async function POST(request: Request) {
       const nutrition = getNutritionGuidance(dailyLog.cycleDay);
 
       // Send email
-      await sendDailyEmail({
+      await sendDailyEmail(
+        {
           to: user.email,
           cycleDay: dailyLog.cycleDay,
           phase: dailyLog.phase,
@@ -139,7 +140,9 @@ export async function POST(request: Request) {
           seeds: nutrition.seeds,
           carbRange: nutrition.carbRange,
           ketoGuidance: nutrition.ketoGuidance,
-      });
+        },
+        user.id,
+      );
 
       // Update notificationSentAt timestamp
       await pb.collection("dailyLogs").update(dailyLog.id, {

src/lib/email.test.ts

@@ -2,8 +2,10 @@
 // ABOUTME: Tests email composition, subject lines, and Resend integration.
 import { afterEach, describe, expect, it, vi } from "vitest";
 
-const { mockSend } = vi.hoisted(() => ({
+const { mockSend, mockLoggerInfo, mockLoggerError } = vi.hoisted(() => ({
   mockSend: vi.fn().mockResolvedValue({ id: "mock-email-id" }),
+  mockLoggerInfo: vi.fn(),
+  mockLoggerError: vi.fn(),
 }));
 
 // Mock the resend module before importing email utilities
@@ -13,6 +15,14 @@ vi.mock("resend", () => ({
   },
 }));
 
+// Mock the logger
+vi.mock("@/lib/logger", () => ({
+  logger: {
+    info: mockLoggerInfo,
+    error: mockLoggerError,
+  },
+}));
+
 import type { DailyEmailData } from "./email";
 import {
   sendDailyEmail,
@@ -277,3 +287,135 @@ describe("sendTokenExpirationWarning", () => {
     });
   });
 });
+
+describe("email structured logging", () => {
+  afterEach(() => {
+    vi.clearAllMocks();
+  });
+
+  const sampleDailyEmailData: DailyEmailData = {
+    to: "user@example.com",
+    cycleDay: 15,
+    phase: "OVULATION",
+    decision: {
+      status: "TRAIN",
+      reason: "Body battery high",
+      icon: "💪",
+    },
+    bodyBatteryCurrent: 85,
+    bodyBatteryYesterdayLow: 45,
+    hrvStatus: "Balanced",
+    weekIntensity: 60,
+    phaseLimit: 80,
+    remainingMinutes: 20,
+    seeds: "Sesame",
+    carbRange: "100-150g",
+    ketoGuidance: "No",
+  };
+
+  describe("sendDailyEmail logging", () => {
+    it("logs email sent with info level on success", async () => {
+      await sendDailyEmail(sampleDailyEmailData, "user-123");
+      expect(mockLoggerInfo).toHaveBeenCalledWith(
+        expect.objectContaining({
+          userId: "user-123",
+          type: "daily",
+          recipient: "user@example.com",
+        }),
+        "Email sent",
+      );
+    });
+
+    it("logs email failed with error level on failure", async () => {
+      const error = new Error("Resend API failed");
+      mockSend.mockRejectedValueOnce(error);
+
+      await expect(
+        sendDailyEmail(sampleDailyEmailData, "user-123"),
+      ).rejects.toThrow("Resend API failed");
+
+      expect(mockLoggerError).toHaveBeenCalledWith(
+        expect.objectContaining({
+          userId: "user-123",
+          type: "daily",
+          err: error,
+        }),
+        "Email failed",
+      );
+    });
+  });
+
+  describe("sendPeriodConfirmationEmail logging", () => {
+    it("logs email sent with info level on success", async () => {
+      await sendPeriodConfirmationEmail(
+        "user@example.com",
+        new Date("2025-01-15"),
+        31,
+        "user-456",
+      );
+      expect(mockLoggerInfo).toHaveBeenCalledWith(
+        expect.objectContaining({
+          userId: "user-456",
+          type: "period_confirmation",
+          recipient: "user@example.com",
+        }),
+        "Email sent",
+      );
+    });
+
+    it("logs email failed with error level on failure", async () => {
+      const error = new Error("Resend API failed");
+      mockSend.mockRejectedValueOnce(error);
+
+      await expect(
+        sendPeriodConfirmationEmail(
+          "user@example.com",
+          new Date("2025-01-15"),
+          31,
+          "user-456",
+        ),
+      ).rejects.toThrow("Resend API failed");
+
+      expect(mockLoggerError).toHaveBeenCalledWith(
+        expect.objectContaining({
+          userId: "user-456",
+          type: "period_confirmation",
+          err: error,
+        }),
+        "Email failed",
+      );
+    });
+  });
+
+  describe("sendTokenExpirationWarning logging", () => {
+    it("logs email sent with info level on success", async () => {
+      await sendTokenExpirationWarning("user@example.com", 14, "user-789");
+      expect(mockLoggerInfo).toHaveBeenCalledWith(
+        expect.objectContaining({
+          userId: "user-789",
+          type: "warning",
+          recipient: "user@example.com",
+        }),
+        "Email sent",
+      );
+    });
+
+    it("logs email failed with error level on failure", async () => {
+      const error = new Error("Resend API failed");
+      mockSend.mockRejectedValueOnce(error);
+
+      await expect(
+        sendTokenExpirationWarning("user@example.com", 14, "user-789"),
+      ).rejects.toThrow("Resend API failed");
+
+      expect(mockLoggerError).toHaveBeenCalledWith(
+        expect.objectContaining({
+          userId: "user-789",
+          type: "warning",
+          err: error,
+        }),
+        "Email failed",
+      );
+    });
+  });
+});

src/lib/email.ts

@@ -2,6 +2,7 @@
 // ABOUTME: Sends daily training notifications and period confirmation emails.
 import { Resend } from "resend";
 
+import { logger } from "@/lib/logger";
 import { emailSentTotal } from "@/lib/metrics";
 
 const resend = new Resend(process.env.RESEND_API_KEY);
@@ -28,7 +29,10 @@ export interface DailyEmailData {
   ketoGuidance: string;
 }
 
-export async function sendDailyEmail(data: DailyEmailData): Promise<void> {
+export async function sendDailyEmail(
+  data: DailyEmailData,
+  userId?: string,
+): Promise<void> {
   const subject = `Today's Training: ${data.decision.icon} ${data.decision.status}`;
 
   const body = `Good morning!
@@ -53,6 +57,7 @@ ${data.decision.icon} ${data.decision.reason}
 ---
 Auto-generated by PhaseFlow`;
 
+  try {
     await resend.emails.send({
       from: EMAIL_FROM,
       to: data.to,
@@ -60,13 +65,19 @@ Auto-generated by PhaseFlow`;
       text: body,
     });
 
+    logger.info({ userId, type: "daily", recipient: data.to }, "Email sent");
     emailSentTotal.inc({ type: "daily" });
+  } catch (err) {
+    logger.error({ userId, type: "daily", err }, "Email failed");
+    throw err;
+  }
 }
 
 export async function sendPeriodConfirmationEmail(
   to: string,
   lastPeriodDate: Date,
   cycleLength: number,
+  userId?: string,
 ): Promise<void> {
   const subject = "🔵 Period Tracking Updated";
 
@@ -78,17 +89,28 @@ Your calendar will update automatically within 24 hours.
 ---
 Auto-generated by PhaseFlow`;
 
+  try {
     await resend.emails.send({
       from: EMAIL_FROM,
       to,
       subject,
       text: body,
     });
+
+    logger.info(
+      { userId, type: "period_confirmation", recipient: to },
+      "Email sent",
+    );
+  } catch (err) {
+    logger.error({ userId, type: "period_confirmation", err }, "Email failed");
+    throw err;
+  }
 }
 
 export async function sendTokenExpirationWarning(
   to: string,
   daysUntilExpiry: number,
+  userId?: string,
 ): Promise<void> {
   const isUrgent = daysUntilExpiry <= 7;
 
@@ -112,6 +134,7 @@ This will ensure your training recommendations continue to use fresh Garmin data
 ---
 Auto-generated by PhaseFlow`;
 
+  try {
     await resend.emails.send({
       from: EMAIL_FROM,
       to,
@@ -119,5 +142,10 @@ Auto-generated by PhaseFlow`;
       text: body,
     });
 
+    logger.info({ userId, type: "warning", recipient: to }, "Email sent");
     emailSentTotal.inc({ type: "warning" });
+  } catch (err) {
+    logger.error({ userId, type: "warning", err }, "Email failed");
+    throw err;
+  }
 }