chore: improve error messages

internal/rlpa/conn.go

@@ -41,7 +41,7 @@ func (c *Conn) registerHandlers() {
 			conn.Send(TagMessageBox, []byte("Processing notifications..."))
 			if err := processNotification(conn); err != nil {
 				slog.Error("error processing notification", "error", err)
-				return conn.Send(TagMessageBox, []byte("Process failed \n"+err.Error()))
+				return conn.Send(TagMessageBox, []byte("Process failed \n"+ToTitle(err.Error())))
 			}
 			return conn.Send(TagMessageBox, []byte("All notifications have been processed successfully"))
 		},
@@ -50,7 +50,7 @@ func (c *Conn) registerHandlers() {
 			conn.Send(TagMessageBox, []byte("Your profile is being downloaded. \n Please wait..."))
 			if err := downloadProfile(conn, data); err != nil {
 				slog.Error("error downloading profile", "error", err)
-				return conn.Send(TagMessageBox, []byte("Download failed \n"+err.Error()))
+				return conn.Send(TagMessageBox, []byte("Download failed \n"+ToTitle(err.Error())))
 			}
 			return conn.Send(TagMessageBox, []byte("Your profile has been downloaded successfully"))
 		},

internal/rlpa/download.go

@@ -9,7 +9,7 @@ import (
 
 const (
 	ErrInvalidActivationCode   = "invalid activation code"
-	ErrRequireConfirmationCode = "replace <cc> with a confirmation code and try again\n"
+	ErrRequireConfirmationCode = "confirmation code is required\n"
 )
 
 func downloadProfile(conn *Conn, data []byte) error {
@@ -36,7 +36,7 @@ func downloadProfile(conn *Conn, data []byte) error {
 	if len(parts) == 5 {
 		confirmationCode = string(parts[4])
 		if confirmationCode == "1" {
-			parts[4] = []byte("<cc>")
+			parts[4] = bytes.Replace([]byte("<confirmation_code>"), []byte("_"), []byte{0x11}, 1)
 			return errors.New(ErrRequireConfirmationCode + string(bytes.Join(parts, []byte{0x02})))
 		}
 	}

internal/rlpa/util.go

@@ -0,0 +1,8 @@
+package rlpa
+
+import "unicode"
+
+func ToTitle(s string) string {
+	r := []rune(s)
+	return string(unicode.ToUpper(r[0])) + string(r[1:])
+}