// turn on bluetooth and location
// allow app location in settings
// change android/app/build.gradle
//        minSdkVersion 19
//
// add to pubspec.yaml
//       flutter_ble_lib:
//
// troubleshooting: turn on/off bluetooth on phone/tablet
// use nordic nrfconnect to find out
//     1) device name
//     2) service
//     3) characteristic

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

class MyApp extends StatelessWidget {
  final BleManager ble = BleManager();
  Peripheral peri;
  final List writeValue = [0x41,0x42,0x43,0x30,0x31,0x32]; // ABC123

  @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 {

BleManager ble;
Peripheral peri;
List writeValue = [0x41,0x42,0x43,0x30,0x31,0x32]; // ABC123

connectToBle() {
  ble.startPeripheralScan(
  ).listen((scanResult) async {
    if (scanResult.peripheral.name == "Adafruit Bluefruit LE") { // device name
      peri = scanResult.peripheral;
      ble.stopPeripheralScan();
      bool c = await peri.isConnected();
      if (!c) { await peri.connect(); await peri.isConnected();}  //test if connected otherwise getting error connected already
      await peri.discoverAllServicesAndCharacteristics();
      peri.writeCharacteristic(
        "6e400001-b5a3-f393-e0a9-e50e24dcca9e", // service
        "6e400002-b5a3-f393-e0a9-e50e24dcca9e", // tx characteristic
         Uint8List.fromList(writeValue),
         false);}});}

@override  
void initState() {
  super.initState();
  ble = BleManager();
  ble.createClient();
  connectToBle();}

  @override
  Widget build(BuildContext context) {return Scaffold(body: Center(child:Text('hello')),);}}