Add CLI account check mode

backend/07-migrate.go

@@ -124,6 +124,29 @@ func migrateAccount(a Account) error {
 	return nil
 }
 
+func CheckAccount(name string) error {
+	a, err := GetAccount(name)
+	if err != nil {
+		return err
+	}
+	src, err := OpenIMAPSource(a)
+	if err != nil {
+		return fmt.Errorf("open source %s: %w", a.Name, err)
+	}
+	defer src.Close()
+	msgs, err := src.Fetch("INBOX")
+	if err != nil {
+		return fmt.Errorf("fetch source INBOX %s: %w", a.Name, err)
+	}
+	dst, err := OpenIMAPTarget(a)
+	if err != nil {
+		return fmt.Errorf("open target %s: %w", a.Name, err)
+	}
+	defer dst.Close()
+	log.Printf("account %s ok: source INBOX messages=%d, target login ok", a.Name, len(msgs))
+	return nil
+}
+
 func startJob(accountID int64) (int64, error) {
 	res, err := DB.Exec(`INSERT INTO jobs(account_id,state) VALUES(?, 'running')`, accountID)
 	if err != nil {