import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:http/http.dart' as http;
import 'package:url_launcher/url_launcher.dart';
import 'settings_provider.dart';

const _currentVersion = 1;

final updateCheckProvider = FutureProvider<UpdateInfo?>((ref) async {
  final settings = ref.watch(settingsProvider).valueOrNull;
  if (settings == null) return null;

  final baseUrl = settings.workoutPlayerUrl;
  // Update server runs alongside workout-player
  final host = Uri.parse(baseUrl).host;

  try {
    final response = await http.get(
      Uri.parse('http://$host:9091/api/mirror-os/version'),
    ).timeout(const Duration(seconds: 5));

    if (response.statusCode != 200) return null;

    final data = jsonDecode(response.body) as Map<String, dynamic>;
    final latestVersion = data['version'] as int? ?? 0;
    final downloadUrl = data['downloadUrl'] as String?;
    final changelog = data['changelog'] as String?;

    if (latestVersion > _currentVersion && downloadUrl != null) {
      return UpdateInfo(
        currentVersion: _currentVersion,
        latestVersion: latestVersion,
        downloadUrl: downloadUrl,
        changelog: changelog,
      );
    }
    return null;
  } catch (_) {
    return null;
  }
});

class UpdateInfo {
  final int currentVersion;
  final int latestVersion;
  final String downloadUrl;
  final String? changelog;

  const UpdateInfo({
    required this.currentVersion,
    required this.latestVersion,
    required this.downloadUrl,
    this.changelog,
  });
}

class UpdateBanner extends ConsumerWidget {
  const UpdateBanner({super.key});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final update = ref.watch(updateCheckProvider).valueOrNull;
    if (update == null) return const SizedBox.shrink();

    return Container(
      width: double.infinity,
      margin: const EdgeInsets.only(bottom: 16),
      padding: const EdgeInsets.all(16),
      decoration: BoxDecoration(
        color: const Color(0xFF1E3A5F),
        borderRadius: BorderRadius.circular(12),
        border: Border.all(color: const Color(0xFF60A5FA), width: 1),
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Row(
            children: [
              const Icon(Icons.system_update, color: Color(0xFF60A5FA), size: 20),
              const SizedBox(width: 8),
              Text(
                'Update available (v${update.latestVersion})',
                style: const TextStyle(
                  fontWeight: FontWeight.w600,
                  fontSize: 14,
                  color: Colors.white,
                ),
              ),
            ],
          ),
          if (update.changelog != null) ...[
            const SizedBox(height: 8),
            Text(
              update.changelog!,
              style: const TextStyle(fontSize: 13, color: Colors.white70),
              maxLines: 2,
              overflow: TextOverflow.ellipsis,
            ),
          ],
          const SizedBox(height: 12),
          SizedBox(
            width: double.infinity,
            child: FilledButton.icon(
              onPressed: () => _downloadUpdate(context, update.downloadUrl),
              icon: const Icon(Icons.download, size: 18),
              label: const Text('Download & Install'),
            ),
          ),
        ],
      ),
    );
  }

  void _downloadUpdate(BuildContext context, String url) async {
    final uri = Uri.parse(url);
    if (await canLaunchUrl(uri)) {
      await launchUrl(uri, mode: LaunchMode.externalApplication);
    } else {
      if (context.mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text('Open in browser: $url')),
        );
      }
    }
  }
}