import CoreLocation
import MapKit
import SwiftUI
import UIKit

struct AttachmentLocationPickerView: View {
    @StateObject private var locationManager = LocationManager()
    @State private var region = MKCoordinateRegion(
        center: CLLocationCoordinate2D(latitude: 34.011_286, longitude: -116.166_868),
        span: MKCoordinateSpan(latitudeDelta: 0.2, longitudeDelta: 0.2)
    )
    @State private var showingAlert = false
    @State private var userInteraction = false

    var body: some View {
        MapView(coordinateRegion: $region, interactionState: $userInteraction)
            .onAppear {
                locationManager.start()
            }
            .onChange(of: locationManager.lastLocation) { newLocation in
                if let newLocation, !userInteraction {
                    region.center = newLocation.coordinate
                }
            }
            .onChange(of: locationManager.authorizationStatus) { newStatus in
                if newStatus == .denied {
                    showingAlert = true
                }
            }
            .alert(isPresented: $showingAlert) {
                Alert(
                    title: Text("Location Permission Denied"),
                    message: Text("Please enable location permissions in settings."),
                    dismissButton: .default(Text("OK")) {
                        openAppSettings()
                    }
                )
            }
            .overlay {
                Image(systemName: "mappin")
                    .font(.title)
                    .foregroundColor(.Material.Elements.active)
                    .padding()
                if userInteraction {
                    VStack {
                        Spacer()
                        HStack {
                            Spacer()
                            Image(systemName: "location.north.circle.fill")
                                .font(.title)
                                .foregroundColor(.Material.Elements.active)
                                .padding()
                                .tappablePadding(.symmetric(10)) {
                                    userInteraction = false
                                    region.center = locationManager.lastLocation?.coordinate ?? region.center
                                }
                        }
                    }
                }
            }
    }
}

class LocationManager: NSObject, ObservableObject, CLLocationManagerDelegate {
    private let locationManager = CLLocationManager()
    @Published var lastLocation: CLLocation?
    @Published var authorizationStatus: CLAuthorizationStatus

    override init() {
        authorizationStatus = locationManager.authorizationStatus
        super.init()
        locationManager.delegate = self
    }

    func start() {
        locationManager.requestWhenInUseAuthorization()
        locationManager.startUpdatingLocation()
    }

    func locationManager(_: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
        lastLocation = locations.first
    }

    func locationManager(_: CLLocationManager, didChangeAuthorization status: CLAuthorizationStatus) {
        authorizationStatus = status
    }
}

struct MapView: UIViewRepresentable {
    @Binding var coordinateRegion: MKCoordinateRegion
    @Binding var interactionState: Bool

    func makeUIView(context: Context) -> MKMapView {
        let mapView = MKMapView()
        mapView.delegate = context.coordinator
        mapView.addGestureRecognizer(UIPanGestureRecognizer(target: context.coordinator, action: #selector(Coordinator.mapWasDragged)))
        return mapView
    }

    func updateUIView(_ uiView: MKMapView, context _: Context) {
        uiView.setRegion(coordinateRegion, animated: true)
    }

    func makeCoordinator() -> Coordinator {
        Coordinator(self)
    }

    class Coordinator: NSObject, MKMapViewDelegate {
        var parent: MapView

        init(_ parent: MapView) {
            self.parent = parent
        }

        @objc func mapWasDragged() {
            parent.interactionState = true
        }
    }
}