import 'dart:async';
import 'dart:io';

import 'package:diplomaticquarterapp/theme/colors.dart';
import 'package:diplomaticquarterapp/uitl/ble_utils.dart';
import 'package:diplomaticquarterapp/uitl/translations_delegate_base.dart';
import 'package:diplomaticquarterapp/widgets/buttons/defaultButton.dart';
import 'package:diplomaticquarterapp/widgets/others/app_scaffold_widget.dart';
import 'package:flutter/material.dart';
import 'package:flutter_blue_plus/flutter_blue_plus.dart';
import 'package:permission_handler/permission_handler.dart';

class BloodPressureBLE extends StatefulWidget {
  @override
  State<BloodPressureBLE> createState() => _BloodPressureBLEState();
}

class _BloodPressureBLEState extends State<BloodPressureBLE> {
  String connectionStatus = "disconnected";
  String currentBPmmHG = "0/0 mmHG";
  String currentPulse = "0 PPM";

  BluetoothDevice currentConnectedDevice;

  StreamSubscription bloodPressureReadingStream;

  Timer _timer;

  @override
  void dispose() {
    super.dispose();
    if (bloodPressureReadingStream != null) bloodPressureReadingStream.cancel();
    if (currentConnectedDevice != null) currentConnectedDevice.disconnect();
    if (_timer != null && _timer.isActive) _timer.cancel();
  }

  @override
  Widget build(BuildContext context) {
    return AppScaffold(
      appBarTitle: TranslationBase.of(context).bloodPressure,
      showNewAppBar: true,
      isShowDecPage: true,
      showNewAppBarTitle: true,
      backgroundColor: Color(0xffF8F8F8),
      body: SingleChildScrollView(
        child: StreamBuilder<BluetoothAdapterState>(
            stream: FlutterBluePlus.adapterState,
            initialData: BluetoothAdapterState.unknown,
            builder: (c, snapshot) {
              final adapterState = snapshot.data;
              if (adapterState == BluetoothAdapterState.on) {
                return Container(
                  margin: EdgeInsets.only(top: 200.0, left: 50.0, right: 50.0),
                  child: Column(
                    children: [
                      Center(
                        child: DefaultButton(
                          TranslationBase.of(context).start.toUpperCase(),
                          () {
                            checkBLEPermissions();
                          },
                          color: CustomColors.green,
                        ),
                      ),
                      SizedBox(
                        height: 50.0,
                      ),
                      Text("Connection state: $connectionStatus"),
                      SizedBox(
                        height: 50.0,
                      ),
                      Text("Current BP Level: $currentBPmmHG"),
                      SizedBox(
                        height: 20.0,
                      ),
                      Text("Current Pulse: $currentPulse"),
                    ],
                  ),
                );
              } else {
                FlutterBluePlus.stopScan();
                return SizedBox(height: 300.0, child: BluetoothOffScreen(adapterState: adapterState));
              }
            }),
      ),
    );
  }

  void checkBLEPermissions() {
    [Permission.location, Permission.storage, Permission.bluetooth, Permission.bluetoothConnect, Permission.bluetoothScan].request().then((status) {
      startBLEConnection();
    });
  }

  void startBLEConnection() {
    if (FlutterBluePlus.isScanningNow == false) {
      setState(() {
        connectionStatus = "Connecting...";
      });

      FlutterBluePlus.startScan(timeout: const Duration(seconds: 5), androidUsesFineLocation: false).then((value) {
        // List<ScanResult> blueToothDevices = value;
        List<ScanResult> blueToothDevices = [];
        blueToothDevices.forEach((element) async {
          if (element.device.localName.isNotEmpty) {
            if (element.device.localName.toLowerCase() == "bpm") {
              element.device.connectionState.listen((BluetoothConnectionState state) async {
                setState(() {
                  connectionStatus = state.toString();
                });
                if (state == BluetoothConnectionState.disconnected) {
                  // typically, start a periodic timer that tries to periodically reconnect.
                  // Note: you must always re-discover services after disconnection!

                  // _timer = Timer.periodic(Duration(seconds: 2), (Timer timer) {
                  //   startBLEConnection();
                  // });
                }
                if (state == BluetoothConnectionState.connected) {
                  currentConnectedDevice = element.device;
                  // _timer.cancel();
                  List<BluetoothService> services = await element.device.discoverServices();
                  services.forEach((service) {
                    if (service.serviceUuid.toString().toLowerCase() == BLEUtils.BLOOD_PRESSURE_SERVICE) {
                      print(service.serviceUuid);
                      service.characteristics.forEach((characteristic) async {
                        if (characteristic.characteristicUuid.toString().toLowerCase() == BLEUtils.BLOOD_PRESSURE_CHARACTERISTIC) {
                          print(characteristic.characteristicUuid);
                          bloodPressureReadingStream = characteristic.onValueReceived.listen((event) {
                            print("onValueReceived Stream");
                            print(event);
                            setState(() {
                              if (event.length < 12) {
                                currentBPmmHG = "Measuring...";
                              } else {
                                currentBPmmHG = "Measurement complete!";
                                Map<String, dynamic> results = handleBPResult(event, characteristic);
                                currentBPmmHG = results["systolic"] + "/" + results["diastolic"] + " - " + (results["isBPHigh"] == "true" ? "High BP" : "Normal BP");
                                currentPulse = results["pulse"] + " - " + (results["isPulseHigh"] == "true" ? "High pulse" : "Normal Pulse");
                              }
                            });
                          });
                          await characteristic.setNotifyValue(true);
                        }
                      });
                      return true;
                    }
                  });
                }
              });
              await element.device.connect(timeout: Duration(seconds: 35));
              return true;
            }
          }
        });
      });
    }
  }
}

Map<String, dynamic> handleBPResult(List<int> byteArray, BluetoothCharacteristic characteristic) {
  // [28, 0, 148, 0, 118, 0, 0, 0, 106, 0, 0, 0]

  // {isBPHigh: true, systolic: 145, diastolic: 111, pulse: 109, isPulseHigh: true}

  Map<String, dynamic> results = Map();

  if (byteArray[1] != 0 && byteArray[3] != 0) {
    results["isBPHigh"] = "false";
    results["systolic"] = byteArray[1].toString();
    results["diastolic"] = byteArray[3].toString();
  } else {
    results["isBPHigh"] = "true";
    results["systolic"] = byteArray[2].toString();
    results["diastolic"] = byteArray[4].toString();
  }

  if (byteArray[8] != 0) {
    results["pulse"] = byteArray[8].toString();
    results["isPulseHigh"] = "true";
  } else {
    results["pulse"] = byteArray[9].toString();
    results["isPulseHigh"] = "false";
  }

  if (characteristic.isNotifying) characteristic.setNotifyValue(false);

  print(results);

  return results;
}

class BluetoothOffScreen extends StatelessWidget {
  const BluetoothOffScreen({Key key, this.adapterState}) : super(key: key);

  final BluetoothAdapterState adapterState;

  @override
  Widget build(BuildContext context) {
    return ScaffoldMessenger(
      child: Scaffold(
        backgroundColor: Colors.lightBlue,
        body: Center(
          child: Column(
            mainAxisSize: MainAxisSize.min,
            children: <Widget>[
              const Icon(
                Icons.bluetooth_disabled,
                size: 200.0,
                color: Colors.white54,
              ),
              Text(
                'Bluetooth Adapter is ${adapterState != null ? adapterState.toString().split(".").last + ", Please turn on your bluetooth to continue." : 'not available'}.',
                textAlign: TextAlign.center,
                style: Theme.of(context).primaryTextTheme.titleSmall?.copyWith(color: Colors.white),
              ),
              if (Platform.isAndroid)
                ElevatedButton(
                  child: const Text('TURN ON'),
                  onPressed: () async {
                    try {
                      if (Platform.isAndroid) {
                        await FlutterBluePlus.turnOn();
                      }
                    } catch (e) {}
                  },
                ),
            ],
          ),
        ),
      ),
    );
  }
}