import 'dart:io' show Platform;

import 'package:badge/device_details.dart';
import 'package:badge/device_scan_select.dart';
import 'package:flutter/material.dart';
import 'package:flutter_blue_plus/flutter_blue_plus.dart';
import 'package:logger/logger.dart';
import 'package:permission_handler/permission_handler.dart';

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

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

  // Original doc: Fields in a Widget subclass are always marked "final".

  final String title;

  @override
  State<ScanPage> createState() => _ScanPageState();
}

class _ScanPageState extends State<ScanPage> {
  List<ScanResult> scanResults = [];
  bool isScanning = false;

  ScanResult? selectedDevice;

  void _doConnect() async {
    var dev = selectedDevice?.device;
    if (dev == null) return;
    //???
    Navigator.push(
      context,
      MaterialPageRoute(
        builder: (context) => DeviceDetailsScreen(btDevice: dev),
      ),
    );
  }

  void _doScan() async {
    var system = await FlutterBluePlus.systemDevices([]);
    for (var d in system) {
      logger.i('${d.platformName} already connected to! ${d.remoteId}');
    }

    setState(() {
      selectedDevice = null;
      scanResults = [];
      isScanning = true;
    });
    var subscription = FlutterBluePlus.scanResults.listen(
      onScanResult,
      onError: (e) => logger.e(e),
    );
    // either this, or the cancel in the finally block, should do the same?
    FlutterBluePlus.cancelWhenScanComplete(subscription);

    try {
      if (Platform.isAndroid) {
        // Ehhhh... can't have both keyword/services
        await FlutterBluePlus.startScan(
          withKeywords: ["NimBLE"],
          timeout: Duration(seconds: 5),
        );
      } else {
        // for Linux, which can't do advNames (but platformname, for whatever reason)
        // 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) {
      for (var r in results.where(
        (d) => d.rssi > -90 && !_deviceInResults(d),
      )) {
        logger.i(
          '${r.device.remoteId}: "${r.device.platformName}" / "${r.device.advName}" / "${r.advertisementData.advName}" found!',
        );
        scanResults.add(r);
      }
      setState(() {});
    }
  }

  bool _deviceInResults(ScanResult incomingDev) => scanResults.any(
    (existingDev) => existingDev.device.remoteId == incomingDev.device.remoteId,
  );

  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) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          // 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: (selectedDevice == null || isScanning)
                      ? null
                      : _doConnect,
                  child: Text("Connect"),
                ),
              ],
            ),
            Expanded(
              child: DeviceScanSelection(
                items: scanResults,
                onItemSelected: (item) {
                  setState(() => selectedDevice = item);
                },
              ),
            ),
          ],
        ),
      ),
    );
  }
}