//
// demo of flutter_blue_plus plugin
//
// micropython code
/*
from machine import UART, Pin
import time
u=UART(0,baudrate=9600,tx=Pin(0),rx=Pin(1))
buf=bytearray(2)
while 1:
    time.sleep_ms(50)
    buf=u.read(2)
    if buf is not None:
        print(buf)
        time.sleep_ms(50)
*/

import 'package:flutter/material.dart';
import 'dart:async';
import 'package:flutter_blue_plus/flutter_blue_plus.dart';

void main() {runApp(MyApp());}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: BleScanner());}}

class BleScanner extends StatefulWidget {
@override _BleScannerState createState() => _BleScannerState();}

class _BleScannerState extends State<BleScanner> {
List<BluetoothDevice> devices=[];
List<ScanResult> results=[];
late StreamSubscription<List<ScanResult>> scanResult;
late BluetoothService bs;
late BluetoothCharacteristic ch;
String? message='finding ble device';

Future<void> connectDevice(BluetoothDevice d) async {
  setState((){message='scanning...';});
  await d.connect();
  List<BluetoothService> services = await d.discoverServices();
  services.forEach((s){
    if (s.serviceUuid.toString() == "ffe0") bs = s;});
  for(BluetoothCharacteristic c in bs.characteristics) {
    if (c.characteristicUuid.toString() == "ffe1") ch = c;}
  setState((){message='ble ready';});}

void send_data() async { await ch.write([0x43,0x44]);}

  @override
  void initState() {
    super.initState();
    scanResult=FlutterBluePlus.scanResults.listen((r){
      results = r;
      for(int i=0; i<results.length; i++){
        if (results[i].device.remoteId.toString() == "CC:33:31:CF:74:72") {
          FlutterBluePlus.stopScan();
          connectDevice(results[i].device);}}});}

  void startScanning() async {
    try{
      await FlutterBluePlus.startScan(timeout:Duration(seconds:10));
    } catch (e){print(e);}}

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('BLE Scanner')),
      body: Column(children:[
      SizedBox(height:30),
        ElevatedButton(child:Text('scan and connect'),
          onPressed:startScanning),
          
        SizedBox(height:30),
        Text('status: ${message}'),
        
        SizedBox(height:30),
        ElevatedButton(child:Text('send'),
          onPressed:send_data)]));}}