Use base32 encoded UUID to reduce address size

internal/api/handlers.go

@@ -22,8 +22,10 @@
 package api
 
 import (
+	"encoding/base32"
 	"fmt"
 	"net/http"
+	"strings"
 	"time"
 
 	"github.com/gin-gonic/gin"
@@ -50,16 +52,36 @@ func NewAPIHandler(store storage.Storage, cfg *config.Config) *APIHandler {
 	}
 }
 
+// uuidToBase32 converts a UUID to a URL-safe Base32 string (without padding)
+// with hyphens every 7 characters for better readability
+func uuidToBase32(id uuid.UUID) string {
+	// Use RFC 4648 Base32 encoding (URL-safe)
+	encoded := base32.StdEncoding.WithPadding(base32.NoPadding).EncodeToString(id[:])
+	// Convert to lowercase for better readability
+	encoded = strings.ToLower(encoded)
+
+	// Insert hyphens every 7 characters
+	var result strings.Builder
+	for i, char := range encoded {
+		if i > 0 && i%7 == 0 {
+			result.WriteRune('-')
+		}
+		result.WriteRune(char)
+	}
+
+	return result.String()
+}
+
 // CreateTest creates a new deliverability test
 // (POST /test)
 func (h *APIHandler) CreateTest(c *gin.Context) {
 	// Generate a unique test ID (no database record created)
 	testID := uuid.New()
 
-	// Generate test email address
+	// Generate test email address using Base32-encoded UUID
 	email := fmt.Sprintf("%s%s@%s",
 		h.config.Email.TestAddressPrefix,
-		testID.String(),
+		uuidToBase32(testID),
 		h.config.Email.Domain,
 	)
 
@@ -94,10 +116,10 @@ func (h *APIHandler) GetTest(c *gin.Context, id openapi_types.UUID) {
 		apiStatus = TestStatusPending
 	}
 
-	// Generate test email address
+	// Generate test email address using Base32-encoded UUID
 	email := fmt.Sprintf("%s%s@%s",
 		h.config.Email.TestAddressPrefix,
-		id.String(),
+		uuidToBase32(id),
 		h.config.Email.Domain,
 	)