import BentoMap

static var sampleData: QuadTree<Int, MKMapRect, MKMapPoint> {
    var samples = QuadTree<Int, MKMapRect, MKMapPoint>(bentoBox: BentoBox(minPoint: MKMapPointForCoordinate(CLLocationCoordinate2D.minCoord), maxPoint: MKMapPointForCoordinate(CLLocationCoordinate2D.maxCoord)), bucketCapacity: 5)
    let randomData = (1...5000).map { count in
        return QuadTreeNode(originCoordinate: MKMapPointForCoordinate(CLLocationCoordinate2D.randomCoordinate()), content: count)
    }
    for node in randomData {
        samples.insertNode(node)
    }
    return samples
}

func updateAnnotations(inMapView mapView: MKMapView,
                                 forMapRect root: MKMapRect) {
    guard !mapView.frame.isEmpty && !MKMapRectIsEmpty(root) else {
        mapView.removeAnnotations(mapView.annotations)
        return
    }
    let zoomScale = Double(mapView.frame.width) / root.size.width
    let clusterResults = mapData.clusteredDataWithinMapRect(root,
                                    zoomScale: zoomScale,
                                    cellSize: Double(MapKitViewController.cellSize))
    let newAnnotations = clusterResults.map(BaseAnnotation.makeAnnotation)

    let oldAnnotations = mapView.annotations.flatMap({ $0 as? BaseAnnotation })

    let toRemove = oldAnnotations.filter { annotation in
        return !newAnnotations.contains { newAnnotation in
            return newAnnotation == annotation
        }
    }

    mapView.removeAnnotations(toRemove)

    let toAdd = newAnnotations.filter { annotation in
        return !oldAnnotations.contains { oldAnnotation in
            return oldAnnotation == annotation
        }
    }

    mapView.addAnnotations(toAdd)
}