fix: while connected to MySQL if internet was lost no qso would be logged anymore

internal/qso/qso.go

@@ -1011,6 +1011,32 @@ func FilterableFields() []string {
 }
 
 // columnExpr resolves a filter field to a safe SQL expression — either a
+// OfflineQueueKey is the ADIF extras key stamped on a QSO that was parked in the
+// offline safety file. It survives the ADIF round-trip and makes the replay
+// IDEMPOTENT: if the app dies between "inserted into the DB" and "removed from
+// the file", the next replay sees the id already in the log and skips it instead
+// of creating a duplicate.
+const OfflineQueueKey = "APP_OPSLOG_QUEUEID"
+
+// ExistsByQueueID reports whether a QSO carrying this offline-queue id is already
+// in the logbook — the guard that makes replaying the safety file safe to repeat.
+func (r *Repo) ExistsByQueueID(ctx context.Context, qid string) (bool, error) {
+	qid = strings.TrimSpace(qid)
+	if qid == "" {
+		return false, nil
+	}
+	expr := "json_extract(extras_json, '$." + OfflineQueueKey + "')"
+	if db.IsMySQL() {
+		expr = "JSON_UNQUOTE(JSON_EXTRACT(NULLIF(extras_json,''), '$." + OfflineQueueKey + "'))"
+	}
+	var n int
+	if err := r.db.QueryRowContext(ctx,
+		`SELECT COUNT(*) FROM qso WHERE `+expr+` = ?`, qid).Scan(&n); err != nil {
+		return false, err
+	}
+	return n > 0, nil
+}
+
 // whitelisted column name or a json_extract over extras_json.
 func columnExpr(field string) (string, bool) {
 	f := strings.ToLower(strings.TrimSpace(field))