import 'dart:async';

import 'package:flutter/material.dart';
import 'package:flutter_activity_recognition/flutter_activity_recognition.dart';
import 'package:geolocator/geolocator.dart';

class WalkingPage extends StatefulWidget {
  WalkingPage({Key? key}) : super(key: key);

  @override
  State<WalkingPage> createState() => _WalkingPageState();
}

class _WalkingPageState extends State<WalkingPage> {
  final FlutterActivityRecognition activityRecognition = FlutterActivityRecognition.instance;
  final StreamController<Position> _streamController = StreamController.broadcast();
  num distance = 0;
  Position? lastPosition;
  @override
  void dispose() {
    _streamController.close();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    Geolocator.getPositionStream(locationSettings: LocationSettings(distanceFilter: 1)).listen((position) {
      _streamController.add(position);
      print(position);
    });
    return Scaffold(
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            FutureBuilder<bool>(
              future: isPermissionGrants(),
              builder: (context, snapshot) {
                if (snapshot.hasData && snapshot.data!) {
                  return StreamBuilder<Activity>(
                    stream: activityRecognition.activityStream,
                    builder: (context, snapshot) {
                      if (snapshot.hasData) {
                        return Text("${snapshot.data!.type}, ${snapshot.data!.confidence}");
                      } else {
                        return CircularProgressIndicator();
                      }
                    },
                  );
                } else {
                  return CircularProgressIndicator();
                }
              },
            ),
            StreamBuilder<Position>(
              stream: _streamController.stream,
              builder: (context, snapshot) {
                if (snapshot.hasData) {
                  final position = snapshot.data!;
                  final latitude = position.latitude;
                  final longitude = position.longitude;
                  final currentActivity = activityRecognition.activityStream.last;
                  if (lastPosition != null) {
                    distance += Geolocator.distanceBetween(
                        lastPosition!.latitude, lastPosition!.longitude, position.latitude, position.longitude);
                  }
                  lastPosition = position;
                  return Text("${latitude}, ${longitude}, DISTANCE: ${distance.round()}");
                } else {
                  return CircularProgressIndicator();
                }
              },
            ),
          ],
        ),
      ),
    );
  }

  Future<bool> isPermissionGrants() async {
    // Check if the user has granted permission. If not, request permission.
    PermissionRequestResult reqResult;
    reqResult = await activityRecognition.checkPermission();
    if (reqResult == PermissionRequestResult.PERMANENTLY_DENIED) {
      print('Permission is permanently denied.');
      return false;
    } else if (reqResult == PermissionRequestResult.DENIED) {
      reqResult = await activityRecognition.requestPermission();
      if (reqResult != PermissionRequestResult.GRANTED) {
        print('Permission is denied.');
        return false;
      }
    }

    return true;
  }

  Future<void> _getPermissions() async {
    bool serviceEnabled;
    LocationPermission permission;

    // Test if location services are enabled.
    serviceEnabled = await Geolocator.isLocationServiceEnabled();
    if (!serviceEnabled) {
      // Location services are not enabled don't continue
      // accessing the position and request users of the
      // App to enable the location services.
      return Future.error('Location services are disabled.');
    }

    permission = await Geolocator.checkPermission();
    if (permission == LocationPermission.denied) {
      permission = await Geolocator.requestPermission();
      if (permission == LocationPermission.denied) {
        // Permissions are denied, next time you could try
        // requesting permissions again (this is also where
        // Android's shouldShowRequestPermissionRationale
        // returned true. According to Android guidelines
        // your App should show an explanatory UI now.
        return Future.error('Location permissions are denied');
      }
    }

    if (permission == LocationPermission.deniedForever) {
      // Permissions are denied forever, handle appropriately.
      return Future.error('Location permissions are permanently denied, we cannot request permissions.');
    }
  }
}