I need to fetch all users within x radius that match the preferences of the current user.

So I started implementing geohash from Firebase, the documentation was great, my problem might be silly but I don't know when to use all my compound queries...(whereField) I'm specifying them in the "for query in queries" below but I have the feeling It's not the right spot. how do you use compound queries when using geohash?

    //MARK: - GET MATCHES WITH GEOHASH
    func getMatchesNearMe(radius: Double) {
        // Find matches within 50km of my location
        let user = UserService.shared.user
        let center = CLLocationCoordinate2D(latitude: user.latitude ?? 0, longitude: user.longitude ?? 0)
        let radiusInKilometers: Double = radius

        // Each item in 'bounds' represents a startAt/endAt pair. We have to issue
        // a separate query for each pair. There can be up to 9 pairs of bounds
        // depending on overlap, but in most cases there are 4.
        let queryBounds = GFUtils.queryBounds(forLocation: center,
                                              withRadius: radiusInKilometers)
        let queries = queryBounds.compactMap { (any) -> Query? in
            guard let bound = any as? GFGeoQueryBounds else { return nil }
            return db.collection("users")
                .order(by: "geohash")
                .start(at: [bound.startValue])
                .end(at: [bound.endValue])
        }

        var matchingDocs = [Matches]()
        // Collect all the query results together into a single list
        func getDocumentsCompletion(snapshot: QuerySnapshot?, error: Error?) -> () {
            guard let documents = snapshot?.documents else {
                print("Unable to fetch snapshot data. \(String(describing: error))")
                return
            }
            
            print("\nDocs: Count \(documents.count)")
            for doc in snapshot!.documents {
                var m = Matches()
                m.latitude = doc.data()["latitude"] as? Double ?? 0
                m.longitude = doc.data()["longitude"] as? Double ?? 0
                let coordinates = CLLocation(latitude: m.latitude ?? 0, longitude: m.longitude ?? 0)
                let centerPoint = CLLocation(latitude: center.latitude, longitude: center.longitude)
                
                m.id = doc.data()["id"] as? String ?? ""
                m.name = doc.data()["name"] as? String ?? ""
                m.birthdate = doc.data()["birthdate"] as? Date ?? Date()
                m.gender = doc.data()["gender"] as? String ?? ""
                m.datingPreferences = doc.data()["datingPreferences"] as? String ?? ""
                m.height = doc.data()["height"] as? Int ?? 0
                
                m.imageUrl1 = doc.data()["photo1"] as? String ?? ""
                m.imageUrl2 = doc.data()["photo2"] as? String ?? ""
                m.imageUrl3 = doc.data()["photo3"] as? String ?? ""
                m.imageUrl4 = doc.data()["photo4"] as? String ?? ""
                m.imageUrl5 = doc.data()["photo5"] as? String ?? ""
                m.imageUrl6 = doc.data()["photo6"] as? String ?? ""
                
                m.Q1day2live = doc.data()["Q1day2live"] as? String ?? ""
                m.QlotteryWin = doc.data()["QlotteryWin"] as? String ?? ""
                m.QmoneynotanIssue = doc.data()["QmoneynotanIssue"] as? String ?? ""
                m.bucketList = doc.data()["bucketList"] as? String ?? ""
                m.jokes = doc.data()["jokes"] as? String ?? ""

                // We have to filter out a few false positives due to GeoHash accuracy, but
                // most will match
                let distance = GFUtils.distance(from: centerPoint, to: coordinates)
                print("MatchName: \(m.name), distance: \(distance) \tlat: \(m.latitude), \(m.longitude)")
                if distance <= radiusInKilometers {
                    matchingDocs.append(m)
                }
            } //end for loop
            
            self.matches = matchingDocs
            self.usersLoaded = true
        }

        // After all callbacks have executed, matchingDocs contains the result. Note that this
        // sample does not demonstrate how to wait on all callbacks to complete.
        for query in queries {
            query
                .whereField("gender", in: ["Women", "men"])
                .whereField("conversations", notIn: [user.name])
                //.getDocuments(completion: getDocumentsCompletion)
                .addSnapshotListener(getDocumentsCompletion)
        }
        print("Docs: \(matchingDocs.count)")

    }

CodePudding user response：

If you want to add additional conditions to the query you got from GeoFire, you can do so here:

return db.collection("users")
    .order(by: "geohash")
    .start(at: [bound.startValue])
    .end(at: [bound.endValue])
    .whereField("gender", isEqualTo: "female")

You may need to add an index for this, so be sure to check the log output for error messages around that (and a link to the Firebase console to quickly create the index).