비밀번호 재설정 중복 완료 요청 문제 수정

backend/internal/service/sms_service.go

@@ -17,6 +17,8 @@ import (
 	"time"
 )
 
+const naverSMSMaxBytes = 90
+
 type SmsServiceImpl struct {
 	accessKey   string
 	secretKey   string
@@ -46,17 +48,11 @@ func (s *SmsServiceImpl) SendSms(to, content string) error {
 	// Naver SENS API requires phone number without '+'
 	sanitizedTo := strings.Replace(to, "+", "", 1)
 
-	reqBody := domain.NaverSmsRequest{
-		Type:        "SMS",
-		ContentType: "COMM",
-		CountryCode: "82",
-		From:        s.senderPhone,
-		Content:     content,
-		Messages: []domain.SmsMessage{
-			{
-				To: sanitizedTo,
-			},
-		},
+	reqBody := buildNaverSmsRequest(s.senderPhone, sanitizedTo, content)
+	if reqBody.Type == "LMS" {
+		slog.Info("[SmsService] Upgrading message type to LMS due to content length",
+			"bytes", len([]byte(content)),
+		)
 	}
 
 	jsonBody, err := json.Marshal(reqBody)
@@ -100,6 +96,29 @@ func (s *SmsServiceImpl) SendSms(to, content string) error {
 	return nil
 }
 
+func buildNaverSmsRequest(senderPhone, sanitizedTo, content string) domain.NaverSmsRequest {
+	requestType := "SMS"
+	subject := ""
+	if len([]byte(content)) > naverSMSMaxBytes {
+		requestType = "LMS"
+		subject = "[Baron 로그인]"
+	}
+
+	return domain.NaverSmsRequest{
+		Type:        requestType,
+		ContentType: "COMM",
+		CountryCode: "82",
+		From:        senderPhone,
+		Subject:     subject,
+		Content:     content,
+		Messages: []domain.SmsMessage{
+			{
+				To: sanitizedTo,
+			},
+		},
+	}
+}
+
 func (s *SmsServiceImpl) makeSignature(method, url, timestamp string) (string, error) {
 	space := " "
 	newLine := "\n"

backend/internal/service/sms_service_test.go

@@ -0,0 +1,26 @@
+package service
+
+import "testing"
+
+func TestBuildNaverSmsRequest_UsesSMSForShortContent(t *testing.T) {
+	req := buildNaverSmsRequest("0262857755", "821012345678", "123456")
+
+	if req.Type != "SMS" {
+		t.Fatalf("expected SMS, got %s", req.Type)
+	}
+	if req.Subject != "" {
+		t.Fatalf("expected empty subject for SMS, got %q", req.Subject)
+	}
+}
+
+func TestBuildNaverSmsRequest_UsesLMSForLongContent(t *testing.T) {
+	content := "[Baron 로그인] 비밀번호 재설정 링크: http://sso-test.hmac.kr/api/v1/auth/password/reset/v/1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef"
+	req := buildNaverSmsRequest("0262857755", "821012345678", content)
+
+	if req.Type != "LMS" {
+		t.Fatalf("expected LMS, got %s", req.Type)
+	}
+	if req.Subject == "" {
+		t.Fatal("expected LMS subject to be set")
+	}
+}