//
//  MapViewModel.swift
//  TestGeoJSON
//
//  Created by Alin Fusaru on 02.03.2022.
//

import SwiftUI
import MapKit

// All Map Data Goes here...

class MapViewModel: NSObject, ObservableObject {
    
    @Published var mapView = MKMapView()
    
    
  
    func restrictionsInfo(completion: @escaping ([RestrictionInfo]) -> ()) {
        guard let url = URL(string: "https://flightplan.romatsa.ro/init/static/zone_restrictionate_uav.json") else {
            fatalError("Unable to get geoJSON") }
        
        downloadData(fromURL: url) { (returnedData) in
            if let data = returnedData {
                var geoJson = [MKGeoJSONObject]()
                do {
                    geoJson = try MKGeoJSONDecoder().decode(data)
                } catch {
                    fatalError("Unable to decode GeoJSON")
                }
                
                
                var restrictionsInfo = [RestrictionInfo]()
                for item in geoJson {
                    if let feature = item as? MKGeoJSONFeature {
                        let propData = feature.properties!
                        for geo in feature.geometry {
                            if geo is MKPolygon {
                                let polygonInfo = try? JSONDecoder.init().decode(RestrictionInfo.self, from: propData)
                                restrictionsInfo.append(polygonInfo!)
                            }
                        }
                    }
                }
                DispatchQueue.main.async {
                    completion(restrictionsInfo)
                }
            }
        }
    }
    
    
    // Decode GeoJSON from the server
    func showRestrictedZones(completion: @escaping ([MKOverlay]) -> ()) {
        guard let url = URL(string: "https://flightplan.romatsa.ro/init/static/zone_restrictionate_uav.json") else {
            fatalError("Unable to get geoJSON") }
        
        downloadData(fromURL: url) { (returnedData) in
            if let data = returnedData {
                var geoJson = [MKGeoJSONObject]()
                do {
                    geoJson = try MKGeoJSONDecoder().decode(data)
                } catch {
                    fatalError("Unable to decode GeoJSON")
                }

                var overlays = [MKOverlay]()
                for item in geoJson {
                    if let feature = item as? MKGeoJSONFeature {
                        let propData = feature.properties!
                        for geo in feature.geometry {
                            if let polygon = geo as? MKPolygon {
                                let polygonInfo = try? JSONDecoder.init().decode(RestrictionInfo.self, from: propData)
                                polygon.title = polygonInfo?.zone_id
                                overlays.append(polygon)
                            }
                        }
                    }
                }
                DispatchQueue.main.async {
                    completion(overlays)
                }
            }
        }
    }
    
    func downloadData( fromURL url: URL, completion: @escaping (_ data: Data?) -> ()) {
        URLSession.shared.dataTask(with: url) { (data, response, error) in
            guard
                let data = data,
                error == nil,
                let response = response as? HTTPURLResponse,
                response.statusCode >= 200 && response.statusCode < 300 else {
                print("Error downloading data.")
                completion(nil)
                return
            }
            completion(data)
        }
        .resume()
    }
}