connectionStatus.dart

// ignore_for_file: avoid_print

import 'dart:convert';
import 'dart:io'; //InternetAddress utility
import 'dart:async'; //For StreamController/Stream

import 'package:connectivity/connectivity.dart';
import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;
import 'appConstant.dart';

class ConnectionStatusSingleton {
  //This creates the single instance by calling the `_internal` constructor specified below
  static final ConnectionStatusSingleton _singleton =
      ConnectionStatusSingleton._internal();

  ConnectionStatusSingleton._internal();

  factory ConnectionStatusSingleton() {
    return _singleton;
  }

  //This is how we'll allow subscribing to connection changes
  StreamController connectionChangeController = StreamController.broadcast();

  StreamController notificationCountController = StreamController.broadcast();

  //flutter_connectivity
  final Connectivity _connectivity = Connectivity();

  //Hook into flutter_connectivity's Stream to listen for changes
  //And check the connection status out of the gate
  void initialize() {
    _connectivity.onConnectivityChanged.listen(_connectionChange);
    checkConnection();
  }

  Stream get connectionChange => connectionChangeController.stream;

  Stream get bildirimSayisiChange => notificationCountController.stream;

  //A clean up method to close our StreamController
  //   Because this is meant to exist through the entire application life cycle this isn't
  //   really an issue
  void dispose() {
    connectionChangeController.close();
    notificationCountController.close();
  }

  void _connectionChange(ConnectivityResult result) async {
    print("_connectivity connection changed: $result");
    //if ConnectivityResult.none, there's no need to "check"
    if (result != ConnectivityResult.none) {
      await checkConnection();
    } else {
      hasConnection = false;
    }
  }

  //The test to actually see if there is a connection
  Future<bool> checkConnection() async {
    bool previousConnection = hasConnection;

    List userData = await dbHelper.getUserTable();
    String requestUser = userData.isNotEmpty ? userData[0]['email'] : "";

    //I need Current Route and I need it to be  not null..
    String currentRoute = navigatorKey.currentState != null
        ? ModalRoute.of(navigatorKey.currentState!.context) != null
            ? ModalRoute.of(navigatorKey.currentState!.context)!.settings.name!
            : ""
        : "";

    /// <summary>
    /// this method checks if our API is up and returns notification-count.
    /// By calling this method, we get answers to;
    ///     - do I have connection?
    ///     - is my API up & running?
    ///     - do I have any unread notification?
    ///     - logs: deviceID, IP address and active on which page(app)
    /// </summary>
    ///
    String requestURL =
        "${apiURL}GetNotificationCount?dID=$deviceId&rU=$requestUser&p=$currentRoute";

    try {
      final response = await http
          .get(Uri.parse(requestURL))
          .timeout(const Duration(seconds: 3));

      if (response.statusCode == 200) {
        var responseDecode = json.decode(response.body);
        bildirimSayisi = int.parse(responseDecode.toString());

        notificationCountController.add(bildirimSayisi);

        print("Current notification count: $bildirimSayisi");
        hasConnection = true;
      } else {
        await dbHelper.insertLogBase(
            "No Internet", "checkConnection", "Connectivity");
        hasConnection = false;
      }
    } on TimeoutException catch (_) {
      await dbHelper.insertLogBase(
          "No Internet - TimeOut", "checkConnection", "Connectivity");
      hasConnection = false;
    } on SocketException catch (_) {
      await dbHelper.insertLogBase(
          "No Internet", "checkConnection", "Connectivity");
      hasConnection = false;
    }

    //The connection status changed send out an update to all listeners
    if (previousConnection != hasConnection) {
      connectionChangeController.add(hasConnection);
    }
    print("Am I Online? --->  $hasConnection");
    return hasConnection;
  }
}

final connectionStatus = ConnectionStatusSingleton();