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

class AboutPage extends StatefulWidget {
  const AboutPage({super.key});

  @override
  State<AboutPage> createState() => _AboutPageState();
}

class _AboutPageState extends State<AboutPage> {
  final String _currentVersion = '0.9.8-beta.2';
  bool _isChecking = false;

  Future<void> _checkUpdate() async {
    setState(() => _isChecking = true);
    try {
      final response = await http
          .get(
            Uri.parse(
              'https://api.github.com/repos/Ujwal223/FocusGram/releases/latest',
            ),
          )
          .timeout(const Duration(seconds: 10));

      if (response.statusCode == 200) {
        final data = json.decode(response.body);
        final latestVersion = data['tag_name'].toString().replaceAll('v', '');
        final downloadUrl = data['html_url'];

        if (latestVersion != _currentVersion) {
          _showUpdateDialog(latestVersion, downloadUrl);
        } else {
          _showSnackBar('You are up to date! 🎉');
        }
      } else {
        _showSnackBar('Could not check for updates.');
      }
    } catch (_) {
      _showSnackBar('Connectivity issue. Try again later.');
    } finally {
      if (mounted) setState(() => _isChecking = false);
    }
  }

  void _showUpdateDialog(String version, String url) {
    showDialog(
      context: context,
      builder: (ctx) => AlertDialog(
        backgroundColor: const Color(0xFF1A1A1A),
        title: const Text(
          'Update Available!',
          style: TextStyle(color: Colors.white),
        ),
        content: Text(
          'A new version ($version) is available on GitHub.',
          style: const TextStyle(color: Colors.white70),
        ),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(ctx),
            child: const Text('Later', style: TextStyle(color: Colors.white38)),
          ),
          ElevatedButton(
            onPressed: () {
              Navigator.pop(ctx);
              _launchURL(url);
            },
            style: ElevatedButton.styleFrom(backgroundColor: Colors.blue),
            child: const Text('Download'),
          ),
        ],
      ),
    );
  }

  void _showSnackBar(String msg) {
    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(content: Text(msg), duration: const Duration(seconds: 2)),
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Colors.black,
      appBar: AppBar(
        backgroundColor: Colors.black,
        title: const Text(
          'About FocusGram',
          style: TextStyle(fontSize: 17, fontWeight: FontWeight.bold),
        ),
        leading: IconButton(
          icon: const Icon(Icons.arrow_back_ios_new, size: 18),
          onPressed: () => Navigator.pop(context),
        ),
      ),
      body: Center(
        child: Padding(
          padding: const EdgeInsets.symmetric(horizontal: 40.0),
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              Container(
                width: 100,
                height: 100,
                decoration: BoxDecoration(
                  color: Colors.blue.withValues(alpha: 0.1),
                  shape: BoxShape.circle,
                ),
                child: ClipOval(
                  child: Image.asset(
                    'assets/images/focusgram.png',
                    width: 60,
                    height: 60,
                    fit: BoxFit.cover,
                  ),
                ),
              ),
              const SizedBox(height: 24),
              const Text(
                'FocusGram',
                style: TextStyle(
                  color: Colors.white,
                  fontSize: 24,
                  fontWeight: FontWeight.bold,
                ),
              ),
              const SizedBox(height: 8),
              Text(
                'Version $_currentVersion',
                style: const TextStyle(color: Colors.white38, fontSize: 13),
              ),
              const SizedBox(height: 40),
              const Text(
                'Developed with passion for digital discipline by',
                textAlign: TextAlign.center,
                style: TextStyle(color: Colors.white70, fontSize: 14),
              ),
              const SizedBox(height: 4),
              const Text(
                'Ujwal Chapagain',
                style: TextStyle(
                  color: Colors.white,
                  fontSize: 16,
                  fontWeight: FontWeight.w600,
                ),
              ),
              const SizedBox(height: 40),
              ElevatedButton.icon(
                onPressed: _isChecking ? null : _checkUpdate,
                icon: _isChecking
                    ? const SizedBox(
                        width: 14,
                        height: 14,
                        child: CircularProgressIndicator(
                          strokeWidth: 2,
                          color: Colors.white,
                        ),
                      )
                    : const Icon(Icons.update),
                label: Text(_isChecking ? 'Checking...' : 'Check for Update'),
                style: ElevatedButton.styleFrom(
                  backgroundColor: Colors.blueAccent.withValues(alpha: 0.2),
                  foregroundColor: Colors.white,
                  minimumSize: const Size(200, 45),
                  shape: RoundedRectangleBorder(
                    borderRadius: BorderRadius.circular(12),
                  ),
                ),
              ),
              const SizedBox(height: 16),
              ElevatedButton.icon(
                onPressed: () =>
                    _launchURL('https://github.com/Ujwal223/FocusGram'),
                icon: const Icon(Icons.code),
                label: const Text('View on GitHub'),
                style: ElevatedButton.styleFrom(
                  backgroundColor: Colors.white10,
                  foregroundColor: Colors.white,
                  minimumSize: const Size(200, 45),
                  shape: RoundedRectangleBorder(
                    borderRadius: BorderRadius.circular(12),
                  ),
                ),
              ),
              const SizedBox(height: 20),
              const Text(
                'FocusGram is not affiliated with Instagram.',
                style: TextStyle(
                  color: Color.fromARGB(48, 255, 255, 255),
                  fontSize: 10,
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }

  Future<void> _launchURL(String url) async {
    final uri = Uri.tryParse(url);
    if (uri == null) return;
    try {
      await launchUrl(uri, mode: LaunchMode.externalApplication);
    } catch (_) {}
  }
}