// Copyright 2017, Paul DeMarco.
// All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

import 'dart:async';

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:flutter_blue/flutter_blue.dart';
import 'package:flutter_blue_localnotify/widgets.dart';
import 'package:flutter_local_notifications/flutter_local_notifications.dart';

FlutterLocalNotificationsPlugin flutterLocalNotificationsPlugin;

void main() {
  flutterLocalNotificationsPlugin = FlutterLocalNotificationsPlugin();
  runApp(FlutterBlueApp());
}

class FlutterBlueApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      color: Colors.lightBlue,
      home: StreamBuilder<BluetoothState>(
          stream: FlutterBlue.instance.state,
          initialData: BluetoothState.unknown,
          builder: (c, snapshot) {
            final state = snapshot.data;
            if (state == BluetoothState.on) {
              return FindDevicesScreen();
            }
            return BluetoothOffScreen(state: state);
          }),
    );
  }
}

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

  final BluetoothState state;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Colors.lightBlue,
      body: Center(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: <Widget>[
            Icon(
              Icons.bluetooth_disabled,
              size: 200.0,
              color: Colors.white54,
            ),
            Text(
              'Bluetooth Adapter is ${state.toString().substring(15)}.',
              style: Theme.of(context)
                  .primaryTextTheme
                  .subhead
                  .copyWith(color: Colors.white),
            ),
          ],
        ),
      ),
    );
  }
}

class FindDevicesScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Find Devices'),
      ),
      body: RefreshIndicator(
        onRefresh: () =>
            FlutterBlue.instance.startScan(timeout: Duration(seconds: 4)),
        child: SingleChildScrollView(
          child: Column(
            children: <Widget>[
              StreamBuilder<List<BluetoothDevice>>(
                stream: Stream.periodic(Duration(seconds: 2))
                    .asyncMap((_) => FlutterBlue.instance.connectedDevices),
                initialData: [],
                builder: (c, snapshot) => Column(
                  children: snapshot.data
                      .map((d) => ListTile(
                            title: Text(d.name),
                            subtitle: Text(d.id.toString()),
                            trailing: StreamBuilder<BluetoothDeviceState>(
                              stream: d.state,
                              initialData: BluetoothDeviceState.disconnected,
                              builder: (c, snapshot) {
                                if (snapshot.data ==
                                    BluetoothDeviceState.connected) {
                                  return RaisedButton(
                                    child: Text('OPEN'),
                                    onPressed: () => Navigator.of(context).push(
                                        MaterialPageRoute(
                                            builder: (context) =>
                                                DeviceScreen(device: d))),
                                  );
                                }
                                return Text(snapshot.data.toString());
                              },
                            ),
                          ))
                      .toList(),
                ),
              ),
              StreamBuilder<List<ScanResult>>(
                stream: FlutterBlue.instance.scanResults,
                initialData: [],
                builder: (c, snapshot) => Column(
                  children: snapshot.data
                      .map(
                        (r) => ScanResultTile(
                          result: r,
                          onTap: () => Navigator.of(context)
                              .push(MaterialPageRoute(builder: (context) {
                            r.device.connect();
                            return DeviceScreen(device: r.device);
                          })),
                        ),
                      )
                      .toList(),
                ),
              ),
            ],
          ),
        ),
      ),
      floatingActionButton: StreamBuilder<bool>(
        stream: FlutterBlue.instance.isScanning,
        initialData: false,
        builder: (c, snapshot) {
          if (snapshot.data) {
            return FloatingActionButton(
              child: Icon(Icons.stop),
              onPressed: () => FlutterBlue.instance.stopScan(),
              backgroundColor: Colors.red,
            );
          } else {
            return FloatingActionButton(
                child: Icon(Icons.search),
                onPressed: () => FlutterBlue.instance
                    .startScan(timeout: Duration(seconds: 4)));
          }
        },
      ),
    );
  }
}

class DeviceScreen extends StatefulWidget {
  const DeviceScreen({Key key, this.device}) : super(key: key);

  final BluetoothDevice device;

  @override
  _DeviceScreenState createState() => _DeviceScreenState();
}

class _DeviceScreenState extends State<DeviceScreen> {
  bool isConnected = false;

  List<Widget> _buildServiceTiles(List<BluetoothService> services) {
    return services
        .map(
          (s) => ServiceTile(
            service: s,
            characteristicTiles: s.characteristics
                .map(
                  (c) => CharacteristicTile(
                    characteristic: c,
                    onReadPressed: () => c.read(),
                    onWritePressed: () => c.write([13, 24]),
                    onNotificationPressed: () =>
                        c.setNotifyValue(!c.isNotifying),
                    descriptorTiles: c.descriptors
                        .map(
                          (d) => DescriptorTile(
                            descriptor: d,
                            onReadPressed: () => d.read(),
                            onWritePressed: () => d.write([11, 12]),
                          ),
                        )
                        .toList(),
                  ),
                )
                .toList(),
          ),
        )
        .toList();
  }

  @override
  void initState() {
    super.initState();
    FlutterLocalNotificationsPlugin flutterLocalNotificationsPlugin =
        new FlutterLocalNotificationsPlugin();
// initialise the plugin. app_icon needs to be a added as a drawable resource to the Android head project
    var initializationSettingsAndroid =
        new AndroidInitializationSettings('app_icon');
    var initializationSettingsIOS = new IOSInitializationSettings(
        onDidReceiveLocalNotification: onDidReceiveLocalNotification);
    var initializationSettings = new InitializationSettings(
        initializationSettingsAndroid, initializationSettingsIOS);
    flutterLocalNotificationsPlugin.initialize(initializationSettings,
        onSelectNotification: onSelectNotification);

    Timer.periodic(new Duration(seconds: 1), (timer) {
      FlutterBlue.instance.connectedDevices.then((value) {
        if (value.length >= 1 && !isConnected) {
          _showNotificationWithNoBadge("${widget.device.name}", "Connected");
          isConnected = true;
        } else if (value.length == 0 && isConnected) {
          _showNotificationWithNoBadge("${widget.device.name}", "Disconnected");
          isConnected = false;
        }
      });
    });
  }

  Future<void> _showNotificationWithNoBadge(String title, String body) async {
    var androidPlatformChannelSpecifics = AndroidNotificationDetails(
        'no badge channel', 'no badge name', 'no badge description',
        channelShowBadge: false,
        importance: Importance.Max,
        priority: Priority.High,
        onlyAlertOnce: true);
    var iOSPlatformChannelSpecifics = IOSNotificationDetails();
    var platformChannelSpecifics = NotificationDetails(
        androidPlatformChannelSpecifics, iOSPlatformChannelSpecifics);
    await flutterLocalNotificationsPlugin
        .show(0, title, body, platformChannelSpecifics, payload: 'item x');
  }

  Future<void> onDidReceiveLocalNotification(
      int id, String title, String body, String payload) async {
    // display a dialog with the notification details, tap ok to go to another page
    await showDialog(
      context: context,
      builder: (BuildContext context) => CupertinoAlertDialog(
        title: Text(title),
        content: Text(body),
        actions: [
          CupertinoDialogAction(
            isDefaultAction: true,
            child: Text('Ok'),
            onPressed: () async {
              Navigator.of(context, rootNavigator: true).pop();
            },
          )
        ],
      ),
    );
  }

  Future<void> onSelectNotification(String payload) async {
    if (payload != null) {
      debugPrint('notification payload: ' + payload);
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.device.name),
        actions: <Widget>[
          StreamBuilder<BluetoothDeviceState>(
            stream: widget.device.state,
            initialData: BluetoothDeviceState.connecting,
            builder: (c, snapshot) {
              VoidCallback onPressed;
              String text;
              switch (snapshot.data) {
                case BluetoothDeviceState.connected:
                  onPressed = () => widget.device.disconnect();
                  text = 'DISCONNECT';
                  break;
                case BluetoothDeviceState.disconnected:
                  onPressed = () => widget.device.connect();
                  text = 'CONNECT';
                  break;
                default:
                  onPressed = null;
                  text = snapshot.data.toString().substring(21).toUpperCase();
                  break;
              }
              return FlatButton(
                  onPressed: onPressed,
                  child: Text(
                    text,
                    style: Theme.of(context)
                        .primaryTextTheme
                        .button
                        .copyWith(color: Colors.white),
                  ));
            },
          )
        ],
      ),
      body: SingleChildScrollView(
        child: Column(
          children: <Widget>[
            StreamBuilder<BluetoothDeviceState>(
              stream: widget.device.state,
              initialData: BluetoothDeviceState.connecting,
              builder: (c, snapshot) => ListTile(
                leading: (snapshot.data == BluetoothDeviceState.connected)
                    ? Icon(Icons.bluetooth_connected)
                    : Icon(Icons.bluetooth_disabled),
                title: Text(
                    'Device is ${snapshot.data.toString().split('.')[1]}.'),
                subtitle: Text('${widget.device.id}'),
                trailing: StreamBuilder<bool>(
                  stream: widget.device.isDiscoveringServices,
                  initialData: false,
                  builder: (c, snapshot) => IndexedStack(
                    index: snapshot.data ? 1 : 0,
                    children: <Widget>[
                      IconButton(
                        icon: Icon(Icons.refresh),
                        onPressed: () => widget.device.discoverServices(),
                      ),
                      IconButton(
                        icon: SizedBox(
                          child: CircularProgressIndicator(
                            valueColor: AlwaysStoppedAnimation(Colors.grey),
                          ),
                          width: 18.0,
                          height: 18.0,
                        ),
                        onPressed: null,
                      )
                    ],
                  ),
                ),
              ),
            ),
            StreamBuilder<List<BluetoothService>>(
              stream: widget.device.services,
              initialData: [],
              builder: (c, snapshot) {
                return Column(
                  children: _buildServiceTiles(snapshot.data),
                );
              },
            ),
          ],
        ),
      ),
    );
  }
}
