import 'package:flutter/material.dart';
import 'package:url_launcher/url_launcher.dart';

/// User-facing app name. Platform launcher labels (AndroidManifest, Info.plist,
/// web/manifest.json, windows/runner) are set separately.
const appName = 'Tagesbyte';

String timeAgo(DateTime? date) {
  if (date == null) return '';
  final diff = DateTime.now().difference(date.toLocal());
  if (diff.inMinutes < 1) return 'just now';
  if (diff.inMinutes < 60) return '${diff.inMinutes} min ago';
  if (diff.inHours < 24) return '${diff.inHours} h ago';
  if (diff.inDays == 1) return 'yesterday';
  return '${diff.inDays} days ago';
}

String formatDateTime(DateTime date) {
  final d = date.toLocal();
  String two(int n) => n.toString().padLeft(2, '0');
  return '${two(d.day)}.${two(d.month)}.${d.year} ${two(d.hour)}:${two(d.minute)}';
}

const weekdayNames = [
  'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday',
];

const monthNames = [
  'January', 'February', 'March', 'April', 'May', 'June',
  'July', 'August', 'September', 'October', 'November', 'December',
];

bool isSameDay(DateTime a, DateTime b) =>
    a.year == b.year && a.month == b.month && a.day == b.day;

Future<void> openUrl(BuildContext context, String url) async {
  final ok = await launchUrl(Uri.parse(url), mode: LaunchMode.externalApplication);
  if (!ok && context.mounted) {
    ScaffoldMessenger.of(context)
        .showSnackBar(SnackBar(content: Text('Could not open $url')));
  }
}

/// Centered icon + text + optional action, used for empty and error states.
class EmptyState extends StatelessWidget {
  const EmptyState({
    super.key,
    required this.icon,
    required this.title,
    this.message,
    this.action,
  });

  final IconData icon;
  final String title;
  final String? message;
  final Widget? action;

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    return Center(
      child: Padding(
        padding: const EdgeInsets.all(32),
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            Icon(icon, size: 56, color: theme.colorScheme.primary),
            const SizedBox(height: 16),
            Text(title, style: theme.textTheme.titleMedium, textAlign: TextAlign.center),
            if (message != null) ...[
              const SizedBox(height: 8),
              Text(
                message!,
                style: theme.textTheme.bodyMedium
                    ?.copyWith(color: theme.colorScheme.onSurfaceVariant),
                textAlign: TextAlign.center,
              ),
            ],
            if (action != null) ...[const SizedBox(height: 20), action!],
          ],
        ),
      ),
    );
  }
}