AutoCat/AutoCat/Controllers/Location/LocationPickerController.swift

import Foundation
import MapKit
import Eureka
import RxSwift
import Intents

public struct Placemark: Equatable {
    var latitude: Double
    var longitude: Double
    var address: String?
}

public class LocationPickerController : UIViewController, TypedRowControllerType, MKMapViewDelegate {

    public var row: RowOf<Placemark>!
    public var onDismissCallback: ((UIViewController) -> ())?
    
    private let bag = DisposeBag()
    private var geocodingDisposable: Disposable?
    private var address: String?

    lazy var mapView : MKMapView = { [unowned self] in
        let v = MKMapView(frame: self.view.bounds)
        v.autoresizingMask = [.flexibleWidth, .flexibleHeight]
        return v
        }()

    lazy var pinView: UIImageView = { [unowned self] in
        let v = UIImageView(frame: CGRect(x: 0, y: 0, width: 50, height: 50))
        v.image = UIImage(named: "MapPin", in: Bundle(for: LocationPickerController.self), compatibleWith: nil)
        v.image = v.image?.withRenderingMode(.alwaysTemplate)
        v.tintColor = self.view.tintColor
        v.backgroundColor = .clear
        v.clipsToBounds = true
        v.contentMode = .scaleAspectFit
        v.isUserInteractionEnabled = false
        return v
        }()

    let width: CGFloat = 10.0
    let height: CGFloat = 5.0

    lazy var ellipse: UIBezierPath = { [unowned self] in
        let ellipse = UIBezierPath(ovalIn: CGRect(x: 0, y: 0, width: self.width, height: self.height))
        return ellipse
        }()


    lazy var ellipsisLayer: CAShapeLayer = { [unowned self] in
        let layer = CAShapeLayer()
        layer.bounds = CGRect(x: 0, y: 0, width: self.width, height: self.height)
        layer.path = self.ellipse.cgPath
        layer.fillColor = UIColor.gray.cgColor
        layer.fillRule = .nonZero
        layer.lineCap = .butt
        layer.lineDashPattern = nil
        layer.lineDashPhase = 0.0
        layer.lineJoin = .miter
        layer.lineWidth = 1.0
        layer.miterLimit = 10.0
        layer.strokeColor = UIColor.gray.cgColor
        return layer
        }()


    required public init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
    }

    public override init(nibName nibNameOrNil: String?, bundle nibBundleOrNil: Bundle?) {
        super.init(nibName: nil, bundle: nil)
    }

    convenience public init(_ callback: ((UIViewController) -> ())?){
        self.init(nibName: nil, bundle: nil)
        onDismissCallback = callback
    }

    public override func viewDidLoad() {
        super.viewDidLoad()
        view.addSubview(mapView)

        mapView.delegate = self
        mapView.addSubview(pinView)
        mapView.layer.insertSublayer(ellipsisLayer, below: pinView.layer)

        let button = UIBarButtonItem(barButtonSystemItem: .done, target: self, action: #selector(LocationPickerController.tappedDone(_:)))
        button.title = "Done"
        navigationItem.rightBarButtonItem = button

        if let value = row.value {
            let region = MKCoordinateRegion(center: CLLocationCoordinate2D(latitude: value.latitude, longitude: value.longitude), latitudinalMeters: 1000, longitudinalMeters: 1000)
            mapView.setRegion(region, animated: true)
        }
        else{
            mapView.showsUserLocation = true
        }
        updateTitle()

    }

    public override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)

        let center = mapView.convert(mapView.centerCoordinate, toPointTo: pinView)
        pinView.center = CGPoint(x: center.x, y: center.y - (pinView.bounds.height/2))
        ellipsisLayer.position = center
    }


    @objc func tappedDone(_ sender: UIBarButtonItem){
        let target = mapView.convert(ellipsisLayer.position, toCoordinateFrom: mapView)
        row.value = Placemark(latitude: target.latitude, longitude: target.longitude, address: self.address)
        onDismissCallback?(self)
    }

    func updateTitle(){
        let fmt = NumberFormatter()
        fmt.maximumFractionDigits = 4
        fmt.minimumFractionDigits = 4
        let latitude = fmt.string(from: NSNumber(value: mapView.centerCoordinate.latitude))!
        let longitude = fmt.string(from: NSNumber(value: mapView.centerCoordinate.longitude))!
        title = "\(latitude), \(longitude)"
        
        self.address = nil
        self.geocodingDisposable?.dispose()
        self.geocodingDisposable = LocationManager
            .getAddressForLocation(latitude: mapView.centerCoordinate.latitude, longitude: mapView.centerCoordinate.longitude)
            .observeOn(MainScheduler.instance)
            .subscribe(onSuccess: { address in
                self.title = address
                self.address = address
            })
    }

    public func mapView(_ mapView: MKMapView, regionWillChangeAnimated animated: Bool) {
        ellipsisLayer.transform = CATransform3DMakeScale(0.5, 0.5, 1)
        UIView.animate(withDuration: 0.2, animations: { [weak self] in
            self?.pinView.center = CGPoint(x: self!.pinView.center.x, y: self!.pinView.center.y - 10)
            })
    }

    public func mapView(_ mapView: MKMapView, regionDidChangeAnimated animated: Bool) {
        ellipsisLayer.transform = CATransform3DIdentity
        UIView.animate(withDuration: 0.2, animations: { [weak self] in
            self?.pinView.center = CGPoint(x: self!.pinView.center.x, y: self!.pinView.center.y + 10)
            })
        updateTitle()
    }
    
    public func mapView(_ mapView: MKMapView, didUpdate userLocation: MKUserLocation) {
        let region = MKCoordinateRegion(center: userLocation.coordinate, latitudinalMeters: 1000, longitudinalMeters: 1000)
        mapView.setRegion(region, animated: true)
        mapView.showsUserLocation = false
    }
    
    public func mapView(_ mapView: MKMapView, didFailToLocateUserWithError error: Error) {
        print(error)
    }
}