PhysiGo/app/lib/challenges/challenges_utils.dart

import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'package:geoflutterfire/geoflutterfire.dart';
import 'dart:math';

import '../Services/AuthService.dart';
import '../Services/logged_in_user.dart';

class ChallengesUtils {
  static final geo = Geoflutterfire();
  static final _firestore = FirebaseFirestore.instance;

  static generateChallengeIfNeeded() async {
    if (await shouldGenerateChallenge()) {
      generateChallenge();
    }
  }

  static Future<bool> shouldGenerateChallenge() async {
    LoggedInUser? user = await AuthenticationServices.getCurrentUser();
    DateTime now = DateTime.now();
    DateTime today = DateTime(now.year, now.month, now.day);
    DateTime lastMonday = today.subtract(Duration(days: today.weekday - 1));
    int secondsSinceEpoch = lastMonday.millisecondsSinceEpoch ~/ 1000;
    final dif = secondsSinceEpoch - user!.lastChallengeDate.seconds;
    return Future.value(dif / 3600 / 24 > 7);
  }

  static void generateChallenge() async {
    LoggedInUser? user = await AuthenticationServices.getCurrentUser();
    Query<Map<String, dynamic>> places = _firestore.collection('Places');
    double innerRadius = 1;
    double outerRadius = 2.5;
    String randomPlaceID = '';

    Stream<List<DocumentSnapshot>> possiblePlaces = geo.collection(collectionRef: places).within(
        center: geo.point(latitude: user!.address.latitude, longitude: user.address.longitude),
        radius: outerRadius,
        field: 'location',
        strictMode: true);

    Stream<List<DocumentSnapshot>> placesTooClose = geo.collection(collectionRef: places).within(
        center: geo.point(latitude: user.address.latitude, longitude: user.address.longitude),
        radius: innerRadius,
        field: 'location',
        strictMode: true);

    List<DocumentSnapshot<Object?>> possiblePlacesList = await possiblePlaces.first;
    List<DocumentSnapshot<Object?>> placesTooCloseList = await placesTooClose.first;
    final ids = <String>{};
    for (DocumentSnapshot<Object?> element in placesTooCloseList) {
      ids.add(element.id);
    }
    possiblePlacesList.retainWhere((element) => !ids.contains(element.id));
    int numOfPlaces = possiblePlacesList.length;
    randomPlaceID = possiblePlacesList[Random().nextInt(numOfPlaces)].id;
    AuthenticationServices.user!.weeklyPlace = _firestore.collection('Places').doc(randomPlaceID);
    _firestore.collection("profileInfo").doc(FirebaseAuth.instance.currentUser?.uid).update({
      'weekly_place': _firestore.collection('Places').doc(randomPlaceID),
      'last_challenge_date': Timestamp.now(),
    });
  }
}