feat: mail service

authsession/internal/ports/mail_sender.go

@@ -24,8 +24,16 @@ type SendLoginCodeInput struct {
 	// Email identifies the normalized target e-mail address.
 	Email common.Email
 
+	// IdempotencyKey stores the raw challenge_id value sent to Mail Service as
+	// the required Idempotency-Key header.
+	IdempotencyKey string
+
 	// Code stores the cleartext login code that should be delivered to Email.
 	Code string
+
+	// Locale stores the canonical BCP 47 language tag that selects the auth
+	// mail template locale.
+	Locale string
 }
 
 // Validate reports whether SendLoginCodeInput contains a complete delivery
@@ -35,10 +43,18 @@ func (i SendLoginCodeInput) Validate() error {
 		return fmt.Errorf("send login code input email: %w", err)
 	}
 	switch {
+	case strings.TrimSpace(i.IdempotencyKey) == "":
+		return errors.New("send login code input idempotency key must not be empty")
+	case strings.TrimSpace(i.IdempotencyKey) != i.IdempotencyKey:
+		return errors.New("send login code input idempotency key must not contain surrounding whitespace")
 	case strings.TrimSpace(i.Code) == "":
 		return errors.New("send login code input code must not be empty")
 	case strings.TrimSpace(i.Code) != i.Code:
 		return errors.New("send login code input code must not contain surrounding whitespace")
+	case strings.TrimSpace(i.Locale) == "":
+		return errors.New("send login code input locale must not be empty")
+	case strings.TrimSpace(i.Locale) != i.Locale:
+		return errors.New("send login code input locale must not contain surrounding whitespace")
 	default:
 		return nil
 	}

authsession/internal/ports/ports_test.go

@@ -310,8 +310,10 @@ func TestSendLoginCodeInputAndResultValidate(t *testing.T) {
 	t.Parallel()
 
 	input := SendLoginCodeInput{
-		Email: common.Email("pilot@example.com"),
-		Code:  "654321",
+		Email:          common.Email("pilot@example.com"),
+		IdempotencyKey: "challenge-1",
+		Code:           "654321",
+		Locale:         "en",
 	}
 	if err := input.Validate(); err != nil {
 		require.Failf(t, "test failed", "SendLoginCodeInput.Validate() returned error: %v", err)
@@ -339,13 +341,14 @@ func TestValidateComparableChallenges(t *testing.T) {
 func challengeFixture() challenge.Challenge {
 	timestamp := time.Unix(10, 0).UTC()
 	return challenge.Challenge{
-		ID:            common.ChallengeID("challenge-1"),
-		Email:         common.Email("pilot@example.com"),
-		CodeHash:      []byte("hash"),
-		Status:        challenge.StatusPendingSend,
-		DeliveryState: challenge.DeliveryPending,
-		CreatedAt:     timestamp,
-		ExpiresAt:     timestamp.Add(5 * time.Minute),
+		ID:                common.ChallengeID("challenge-1"),
+		Email:             common.Email("pilot@example.com"),
+		CodeHash:          []byte("hash"),
+		PreferredLanguage: "en",
+		Status:            challenge.StatusPendingSend,
+		DeliveryState:     challenge.DeliveryPending,
+		CreatedAt:         timestamp,
+		ExpiresAt:         timestamp.Add(5 * time.Minute),
 	}
 }