import 'package:relationship_saver/features/ai_digest/domain/ai_digest_models.dart';
import 'package:url_launcher/url_launcher.dart';

class CalendarEventLauncher {
  const CalendarEventLauncher();

  Future<bool> addSuggestionToCalendar(AiSuggestionDraft draft) async {
    final Uri? uri = calendarUriForSuggestion(draft);
    if (uri == null) {
      return false;
    }
    if (await launchUrl(uri, mode: LaunchMode.externalApplication)) {
      return true;
    }
    return launchUrl(uri);
  }
}

Uri? calendarUriForSuggestion(AiSuggestionDraft draft) {
  final DateTime? startsAt = draft.suggestedFor;
  if (draft.kind != AiSuggestionKind.eventIdea || startsAt == null) {
    return null;
  }
  final DateTime endsAt =
      draft.eventEndsAt ?? startsAt.add(const Duration(hours: 2));
  final String details = <String>[
    draft.details,
    if (draft.reason != null && draft.reason!.trim().isNotEmpty)
      'Why: ${draft.reason!.trim()}',
    if (draft.eventUrl != null && draft.eventUrl!.trim().isNotEmpty)
      draft.eventUrl!.trim(),
    if (draft.sourceUrls.isNotEmpty) 'Sources: ${draft.sourceUrls.join(', ')}',
  ].where((String value) => value.trim().isNotEmpty).join('\n\n');

  return Uri.https('calendar.google.com', '/calendar/render', <String, String>{
    'action': 'TEMPLATE',
    'text': draft.title,
    'dates': '${_calendarTimestamp(startsAt)}/${_calendarTimestamp(endsAt)}',
    if (details.isNotEmpty) 'details': details,
    if (draft.eventLocation != null && draft.eventLocation!.trim().isNotEmpty)
      'location': draft.eventLocation!.trim(),
  });
}

String _calendarTimestamp(DateTime value) {
  final DateTime utc = value.toUtc();
  return '${utc.year.toString().padLeft(4, '0')}'
      '${utc.month.toString().padLeft(2, '0')}'
      '${utc.day.toString().padLeft(2, '0')}T'
      '${utc.hour.toString().padLeft(2, '0')}'
      '${utc.minute.toString().padLeft(2, '0')}'
      '${utc.second.toString().padLeft(2, '0')}Z';
}