import 'dart:convert';

import 'dart:io' show Platform;

import 'package:badge/device.dart';
import 'package:flutter/material.dart';

import 'package:permission_handler/permission_handler.dart';
import 'package:flutter_blue_plus/flutter_blue_plus.dart';
import 'package:logger/logger.dart';

var logger = Logger(printer: PrettyPrinter());

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

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Scanner',
      theme: ThemeData(
        // This is the theme of your application.
        //
        // TRY THIS: Try running your application with "flutter run". You'll see
        // the application has a purple toolbar. Then, without quitting the app,
        // try changing the seedColor in the colorScheme below to Colors.green
        // and then invoke "hot reload" (save your changes or press the "hot
        // reload" button in a Flutter-supported IDE, or press "r" if you used
        // the command line to start the app).
        //
        // Notice that the counter didn't reset back to zero; the application
        // state is not lost during the reload. To reset the state, use hot
        // restart instead.
        //
        // This works for code too, not just values: Most code changes can be
        // tested with just a hot reload.
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
      ),
      home: const MyHomePage(title: 'Badge Scanner'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});

  // This widget is the home page of your application. It is stateful, meaning
  // that it has a State object (defined below) that contains fields that affect
  // how it looks.

  // This class is the configuration for the state. It holds the values (in this
  // case the title) provided by the parent (in this case the App widget) and
  // used by the build method of the State. Fields in a Widget subclass are
  // always marked "final".

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  final List<ScanResult> scanResults = [];
  bool isScanning = false;
  static const int noItemSelected = -1;
  int selectedResult = noItemSelected;

  void _doConnect() async {
    var dev = scanResults[selectedResult].device;
    //???
    Navigator.push(
      context,
      MaterialPageRoute(builder: (context) => DeviceScreen(btDevice: dev)),
    );
  }

  void _doScan() async {
    var system = await FlutterBluePlus.systemDevices([]);
    for (var d in system) {
      logger.i('${d.platformName} already connected to! ${d.remoteId}');
      // if (d.platformName == "myBleDevice") {
      //   await r.connect(); // must connect our app
      // }
    }

    setState(() {
      scanResults.clear();
      isScanning = true;
      selectedResult = noItemSelected;
    });
    var subscription = FlutterBluePlus.onScanResults.listen(
      onScanResult,
      onError: (e) => logger.e(e),
    );

    // Ehhhh... can't have both
    try {
      if (Platform.isAndroid) {
        await FlutterBluePlus.startScan(
          withKeywords: ["NimBLE"],
          timeout: Duration(seconds: 5),
        );
      } else {
        // for Linux, which can't do advNames
        // msd doesn't work, either????
        await FlutterBluePlus.startScan(
          //withMsd: [MsdFilter(0xffff, data: ascii.encode("uvok"))],
          timeout: Duration(seconds: 5),
        );
      }

      // wait for scanning to stop
      await FlutterBluePlus.isScanning.where((val) => val == false).first;
    } finally {
      subscription.cancel();
      setState(() {
        isScanning = false;
      });
    }
  }

  void onScanResult(List<ScanResult> results) {
    if (results.isNotEmpty) {
      //ScanResult r = results.last; // the most recently found device
      for (var r in results.where((d) => d.rssi > -90)) {
        logger.i(
          '${r.device.remoteId}: "${r.device.platformName}" / "${r.device.advName}" / "${r.advertisementData.advName}" found!',
        );
        scanResults.add(r);
      }
      setState(() {});
    }
  }

  Future getPermissions() async {
    try {
      await Permission.bluetooth.request();
    } catch (e) {
      logger.e(e.toString());
    }
  }

  void btHandler(BluetoothAdapterState event) {
    logger.i(event);
    switch (event) {
      case BluetoothAdapterState.on:
        break;
      default:
        break;
    }
  }

  @override
  void initState() {
    super.initState();
    getPermissions();
    FlutterBluePlus.adapterState.listen(btHandler);
  }

  @override
  Widget build(BuildContext context) {
    // This method is rerun every time setState is called, for instance as done
    // by the _incrementCounter method above.
    //
    // The Flutter framework has been optimized to make rerunning build methods
    // fast, so that you can just rebuild anything that needs updating rather
    // than having to individually change instances of widgets.
    return Scaffold(
      appBar: AppBar(
        // TRY THIS: Try changing the color here to a specific color (to
        // Colors.amber, perhaps?) and trigger a hot reload to see the AppBar
        // change color while the other colors stay the same.
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
        // Here we take the value from the MyHomePage object that was created by
        // the App.build method, and use it to set our appbar title.
        title: Text(widget.title),
      ),
      body: Center(
        // Center is a layout widget. It takes a single child and positions it
        // in the middle of the parent.
        child: Column(
          // Column is also a layout widget. It takes a list of children and
          // arranges them vertically. By default, it sizes itself to fit its
          // children horizontally, and tries to be as tall as its parent.
          //
          // Column has various properties to control how it sizes itself and
          // how it positions its children. Here we use mainAxisAlignment to
          // center the children vertically; the main axis here is the vertical
          // axis because Columns are vertical (the cross axis would be
          // horizontal).
          //
          // TRY THIS: Invoke "debug painting" (choose the "Toggle Debug Paint"
          // action in the IDE, or press "p" in the console), to see the
          // wireframe for each widget.
          mainAxisAlignment: MainAxisAlignment.center,
          spacing: 24,
          children: <Widget>[
            SizedBox(height: 15),
            Row(
              mainAxisAlignment: MainAxisAlignment.center,
              spacing: 15.0,
              children: [
                ElevatedButton(
                  onPressed: isScanning ? null : _doScan,
                  child: isScanning ? Text("Scanning...") : Text("Start scan"),
                ),
                ElevatedButton(
                  onPressed: (selectedResult == noItemSelected || isScanning)
                      ? null
                      : _doConnect,
                  child: Text("Connect"),
                ),
              ],
            ),
            Expanded(
              child: ListView.separated(
                //itemCount: scanResults.length,
                itemBuilder: (context, index) {
                  if (index >= scanResults.length) return null;
                  final ScanResult result = scanResults[index];
                  final String name = firstGiven([
                    result.device.advName,
                    result.device.platformName,
                    "<Unknown>",
                  ]);

                  return ListTile(
                    title: Text(name),
                    subtitle: Text(result.device.remoteId.str),
                    trailing: Text('RSSI: ${result.rssi}'),
                    selectedTileColor: Colors.amber,
                    selectedColor: Colors.black,
                    onTap: () {
                      setState(() {
                        selectedResult = index;
                      });
                    },
                    selected: selectedResult == index,
                  );
                },
                separatorBuilder: (BuildContext context, int index) {
                  return Divider();
                },
                itemCount: scanResults.length,
              ),
            ),
          ],
        ),
      ),
    );
  }
}

String firstGiven(List<String> list) {
  return list.firstWhere((s) => s.isNotEmpty, orElse: () => "");
}