//
// flutter bluetooth notify with stream example
// 
// change android/app/build.gradle
//    line 42 minSDKVersion to at least 19
//
// pubspec yaml:   flutter_ble_lib: ^2.2.4
//
// make sure bluetooth and location is turned on
//   on the phone/tablet
//
// also if you're having problem
//   goto phone settings
//   find this app
//   allow permission for location
// 

import 'package:flutter/material.dart';
import 'dart:typed_data';
import 'package:flutter_ble_lib/flutter_ble_lib.dart';
void main() {runApp(MyApp());}

class MyApp extends StatelessWidget {
 
  @override
  Widget build(BuildContext context) {
    return MaterialApp(title: 'Flutter Demo', home: Home());}}

class Home extends StatefulWidget {
  Home({Key key, this.title}) : super(key: key);
  final String title;
  @override
  _HomeState createState() => _HomeState();}

class _HomeState extends State<Home> {

BleManager ble = BleManager();
Peripheral peri;
List<Service> servs;
Service serv;
List<Characteristic> chars;
Characteristic char;
Stream<Uint8List> stream;

String data = "init data";

connectToBle() async {
  await ble.createClient();
  print("************************connecttoble func");
  ble.startPeripheralScan()
  .listen((scanResult) async {
    print("*******************scanresult");
    if (scanResult.peripheral.name == "Adafruit Bluefruit LE") {
      print("**************found adafruit");
      peri = scanResult.peripheral;
      ble.stopPeripheralScan();
      //await peri.disconnectOrCancelConnection();
      bool c = await peri.isConnected();
      if (!c) { await peri.connect(); await peri.isConnected();}  //test if connected otherwise getting error connected already
      print("*****************connected");
      await peri.discoverAllServicesAndCharacteristics();
      servs = await peri.services();
      serv = servs.singleWhere((s) => s.uuid == "6e400001-b5a3-f393-e0a9-e50e24dcca9e");
      char = (await serv.characteristics()).singleWhere((c) => c.uuid == "6e400003-b5a3-f393-e0a9-e50e24dcca9e");
    }
  });
}

Stream<Uint8List> startNotify(){
  stream = char.monitor().asBroadcastStream();
  return stream;
}

listen() {
  startNotify().listen((d){
    setState((){ data = String.fromCharCodes(d); });
  });
}

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

  @override
  Widget build(BuildContext context){
    return Scaffold(
      body: Column(children:[
        SizedBox(height: 100),
        Text("data received: $data"),  
        RaisedButton(  
          onPressed:() => listen(),
          child: Text('connect'),
        ),
      ]),
    );
  }}