import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:physigo/friends/models/challenge_location_request.dart';
import 'package:physigo/services/push_notifications_service.dart';

const userId = "tlmysIvwTBaoZKWqBofx";
const name = "John";
const surname = "Smith";

class ChallengeLocationService {
  static final _db = FirebaseFirestore.instance;
  static final _users = _db.collection("Users");
  static final _shareLocationRequests = _db.collection("ShareLocationRequests");
  static final _friends = _db.collection("Friends");

  static Future<List<ChallengeLocationRequest>> getShareChallengeLocationRequests() async {
    final requests = await _shareLocationRequests.where("user_id", isEqualTo: userId).get();
    if (requests.docs.isEmpty) {
      return [];
    }
    final requesterIdLocationId = {
      for (final request in requests.docs)
        request.data()['requester_id']: {"requestId": request.id, "locationRef": request.data()['location']}
    };
    final requesters = await _users.where(FieldPath.documentId, whereIn: requesterIdLocationId.keys.toList()).get();
    final shareChallengeLocationRequests = await Future.wait(requesters.docs.map((requester) async {
      final data = requester.data();
      final place = (await requesterIdLocationId[requester.id]!["locationRef"].get()).data();
      return ChallengeLocationRequest(
          id: requesterIdLocationId[requester.id]!["requestId"]!,
          name: data['name'],
          surname: data['surname'],
          locationName: place['name'],
          locationRef: requesterIdLocationId[requester.id]!["locationRef"]!);
    }));
    return shareChallengeLocationRequests;
  }

  static Future<void> shareChallengeLocation(String friendId) async {
    await Future.wait([_checkExistingFriendRelation(friendId), _checkExistingChallengeLocationRequest(friendId)]);
    final user = await _users.doc(userId).get();
    final shareLocationRequest = {"user_id": friendId, "requester_id": userId, "location": user['weekly_place']};
    await _shareLocationRequests.add(shareLocationRequest);
    PushNotificationsService.sendChallengeLocationRequestNotification(userId, name, surname);
  }

  static Future<void> acceptChallengeLocationRequest(ChallengeLocationRequest request) async {
    final newLocation = {"weekly_place": request.locationRef};
    await _users.doc(userId).update(newLocation);
    await _shareLocationRequests.doc(request.id).delete();
  }

  static Future<void> refuseChallengeLocationRequest(ChallengeLocationRequest request) async {
    await _shareLocationRequests.doc(request.id).delete();
  }

  static Future<void> _checkExistingFriendRelation(String friendId) async {
    if (friendId == userId) {
      return Future.error("You cannot share a location with yourself");
    }

    var friendRelationByUserId = _friends
        .where("user_id", isEqualTo: userId)
        .where("friend_id", isEqualTo: friendId)
        .where("request_status", isEqualTo: "accepted")
        .get();

    var friendRelationByFriendId = _friends
        .where("friend_id", isEqualTo: userId)
        .where("user_id", isEqualTo: friendId)
        .where("request_status", isEqualTo: "accepted")
        .get();

    final relations = await Future.wait([friendRelationByUserId, friendRelationByFriendId]);
    if (relations.expand((relation) => relation.docs).isEmpty) {
      return Future.error("You must be friend to share a location");
    }
  }

  static Future<void> _checkExistingChallengeLocationRequest(String friendId) async {
    final requests = await _shareLocationRequests
        .where("requester_id", isEqualTo: userId)
        .where("user_id", isEqualTo: friendId)
        .get();
    if (requests.docs.isNotEmpty) {
      return Future.error("You already shared your location with this person");
    }
  }
}