import 'dart:async';
import 'package:flutter/material.dart';
import 'package:flutter_activity_recognition/flutter_activity_recognition.dart';
import 'package:geolocator/geolocator.dart' hide ActivityType;
import 'package:rxdart/rxdart.dart';
import '../models/score.dart';
import '../services/walking_services.dart';

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

  @override
  State<Walking> createState() => _WalkingState();
}

class _WalkingState extends State<Walking> {
  final FlutterActivityRecognition activityRecognition = FlutterActivityRecognition.instance;
  final StreamController<Position> _streamController = StreamController.broadcast();
  late Stream<dynamic> _activityPositionStream;

  num distance = 0;
  Position? lastPosition;
  num points = 0;
  int totalPoints = 0;
  num totalDistance = 0;

  @override
  void initState() {
    _activityPositionStream = CombineLatestStream.combine2(
      activityRecognition.activityStream,
      Geolocator.getPositionStream(locationSettings: LocationSettings(distanceFilter: 0)),
      (Activity a, Position b) => [a, b],
    );
    _activityPositionStream.listen(_calculatePoints);
    super.initState();
  }

  @override
  void dispose() {
    _streamController.close();
    super.dispose();
  }

  void _updatePoints(num newPoints) {
    setState(() {
      final currentPoints = points + newPoints;
      totalPoints += currentPoints.floor();
      points += currentPoints;
    });
  }

  void _updateDistance(num newDistance) {
    setState(() {
      totalDistance += newDistance;
    });
  }

  void _calculatePoints(dynamic activityPosition) {
    var activity = activityPosition[0] as Activity;
    var position = activityPosition[1];
    if (activity.type == ActivityType.WALKING || activity.type == ActivityType.RUNNING) {
      if (lastPosition != null) {
        distance = Geolocator.distanceBetween(
            lastPosition!.latitude, lastPosition!.longitude, position.latitude, position.longitude);
        _updateDistance(distance);
      }
    }
    if (distance > 0 && activity.type == ActivityType.WALKING) {
      _updatePoints(distance / 10);
    } else if (distance > 0 && activity.type == ActivityType.RUNNING) {
      _updatePoints(distance / 8);
    }
    if (activity.type != ActivityType.WALKING && activity.type != ActivityType.RUNNING && points.floor() > 0) {
      WalkingServices.addScore(Score(points: points.floor(), distance: 0));
      setState(() {
        points = 0;
      });
    }
    lastPosition = position;
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Text(
              "Walked distance since start:\n${totalDistance.round()} m",
              textAlign: TextAlign.center,
              style: const TextStyle(fontSize: 24),
            ),
            const SizedBox(height: 32),
            Text(
              "Earned points since start:\n$totalPoints pts",
              textAlign: TextAlign.center,
              style: const TextStyle(fontSize: 24),
            ),
          ],
        ),
      ),
    );
  }
}