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

import 'package:mobdr/service/shared_prefs.dart';
import 'package:mobdr/config/constant.dart';

class UpdateCheckPage extends StatefulWidget {
  @override
  _UpdateCheckPageState createState() => _UpdateCheckPageState();
}

class _UpdateCheckPageState extends State<UpdateCheckPage> {
  OtaEvent? currentEvent = null;

  String _currentVersion = SharedPrefs().appVersion;
  String _latestVersion = '';
  String _releaseDate = '';
  List<String> _releaseNotes = [];
  String _downloadLink = '';
  String _checksum = '';

  @override
  void initState() {
    super.initState();
    _fetchLatestVersion();
  }

  Future<void> _fetchLatestVersion() async {
    try {
      final response = await http
          .get(Uri.parse(DOMAIN_CHECK_VERSION + '/deploy/mobdr/version.json'));
      final data = jsonDecode(response.body);

      setState(() {
        _latestVersion = data['latest_version'];
        _releaseDate = data['release_date'];
        _releaseNotes = List<String>.from(data['release_notes']);
        _downloadLink = data['download_link'];
        _checksum = data['checksum'];
      });
    } catch (e) {
      print('Error retrieving latest version : $e');
    }
  }

  Future<void> _doUpdate() async {
    try {
      OtaUpdate()
          .execute(
        _downloadLink,
        // OPTIONAL
        destinationFilename: 'app_release.apk',
        //OPTIONAL, ANDROID ONLY - ABILITY TO VALIDATE CHECKSUM OF FILE:
        sha256checksum: _checksum,
      )
          .listen(
        (OtaEvent event) {
          setState(() => currentEvent = event);
        },
      );
    } catch (e) {
      print('Failed to make OTA update. Details: $e');
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Checking for update'),
      ),
      body: Center(
          child: currentEvent == null
              ? Column(
                  mainAxisAlignment: MainAxisAlignment.center,
                  children: [
                    Text(
                      'Current version : ',
                      style: TextStyle(
                        fontWeight: FontWeight.bold,
                        fontSize: 16,
                      ),
                    ),
                    Text(
                      _currentVersion,
                      style: TextStyle(
                        fontWeight: FontWeight.bold,
                        fontSize: 22,
                        color: Colors.red,
                      ),
                    ),
                    SizedBox(height: 16),
                    Text(
                      'Version available : ',
                      style: TextStyle(
                        fontWeight: FontWeight.bold,
                        fontSize: 18,
                      ),
                    ),
                    Text(
                      _latestVersion,
                      style: TextStyle(
                        fontWeight: FontWeight.bold,
                        fontSize: 24,
                        color: Colors.green,
                      ),
                    ),
                    if (_currentVersion != _latestVersion) ...[
                      SizedBox(height: 16),
                      Text(
                        'Publication date : $_releaseDate',
                        style: TextStyle(fontWeight: FontWeight.bold),
                      ),
                      SizedBox(height: 8),
                      Text(
                        'Release notes :',
                        style: TextStyle(fontWeight: FontWeight.bold),
                      ),
                      for (String note in _releaseNotes) ...[
                        SizedBox(height: 4),
                        Text('- $note'),
                      ],
                      SizedBox(height: 16),
                      ElevatedButton(
                        onPressed: _doUpdate,
                        child: Text(
                          'Update',
                          style: TextStyle(
                            fontWeight: FontWeight.bold,
                            fontSize: 18,
                          ),
                        ),
                        style: ElevatedButton.styleFrom(
                          backgroundColor: Colors.blue,
                        ),
                      ),
                    ] else ...[
                      SizedBox(height: 32),
                      Text(
                        'You have the latest version',
                        style: TextStyle(
                          fontWeight: FontWeight.bold,
                          fontSize: 18,
                        ),
                      ),
                    ],
                  ],
                )
              : Column(
                  mainAxisAlignment: MainAxisAlignment.center,
                  children: [
                    Text(
                      'OTA status',
                      style: TextStyle(
                        fontWeight: FontWeight.bold,
                        fontSize: 24,
                      ),
                    ),
                    SizedBox(height: 32),
                    Text('${currentEvent!.status}'),
                    SizedBox(height: 16),
                    Text(
                      '${currentEvent!.value}',
                      style: TextStyle(
                        fontWeight: FontWeight.bold,
                        fontSize: 16,
                      ),
                    )
                  ],
                )),
    );
  }
}