/// Universal time formatting helper to format relative timestamps cleanly for UI displays.
class TimeUtils {
  /// Converts ISO-8601 or DateTime inputs to localized, readable relative time strings.
  /// 
  /// Examples:
  /// - Under 60 minutes: "Vor 15 Min.", "Vor 42 Min."
  /// - 1 hour or more: "Vor 1 Std.", "Vor 1 Std. 15 Min.", "Vor 3 Std. 45 Min."
  /// - Yesterday: "Gestern"
  /// - Older: "22.07.2026"
  static String formatRelativeTime(dynamic rawDate) {
    if (rawDate == null) return '';
    final str = rawDate.toString().trim();
    if (str.isEmpty) return '';

    DateTime dt;
    try {
      dt = DateTime.parse(str).toLocal();
    } catch (_) {
      // Return raw string if already formatted or non-date string
      return str;
    }

    final now = DateTime.now();
    final rawDiff = now.difference(dt);
    
    // If the timestamp is in the future (e.g. slight clock skew or scraper timezone issues), cap it to 0
    final duration = rawDiff.isNegative ? Duration.zero : rawDiff;
    final totalMinutes = duration.inMinutes;

    if (totalMinutes < 1) {
      return 'Vor 1 Min.';
    }

    if (totalMinutes < 60) {
      return 'Vor $totalMinutes Min.';
    }

    final hours = duration.inHours;
    if (hours < 24) {
      final remainingMinutes = totalMinutes % 60;
      if (remainingMinutes == 0) {
        return 'Vor $hours Std.';
      } else {
        return 'Vor $hours Std. $remainingMinutes Min.';
      }
    }

    final days = duration.inDays;
    if (days == 1) {
      return 'Gestern';
    } else if (days < 7) {
      return 'Vor $days Tagen';
    }

    final dayStr = dt.day.toString().padLeft(2, '0');
    final monthStr = dt.month.toString().padLeft(2, '0');
    return '$dayStr.$monthStr.${dt.year}';
  }
}