add cache to UrlImages

@@ -130,24 +130,20 @@ extension CouponView {
     }
     
     struct ImageView: View {
-        @ObservedObject var imageLoader:ImageLoaderGifts
-        @State var image:UIImage = UIImage()
+        @ObservedObject var imageLoader:UrlImageModel
         
         var uiscreen = UIScreen.main.bounds
 
         init(withURL url:String) {
-            imageLoader = ImageLoaderGifts(urlString:url)
+            imageLoader = UrlImageModel(urlString:url)
         }
 
         var body: some View {
             
-            Image(uiImage: image)
+            Image(uiImage: imageLoader.image ?? UIImage())
                 .resizable()
                 .aspectRatio(contentMode: .fill)
                 .frame(width: self.uiscreen.width, height: self.uiscreen.height * 0.25)
-                .onReceive(imageLoader.didChange) { data in
-                    self.image = UIImage(data: data) ?? UIImage()
-                }
         }
     }
     

@@ -179,24 +179,88 @@ struct RoundedCorner: Shape {
     }
 }
 
-class ImageLoaderGifts: ObservableObject {
-    var didChange = PassthroughSubject<Data, Never>()
-    var data = Data() {
-        didSet {
-            didChange.send(data)
+class UrlImageModel: ObservableObject {
+    @Published var image: UIImage?
+    var urlString: String?
+    var imageCache = ImageCache.getImageCache()
+    
+    
+    func loadImage() {
+        if loadImageFromCache() {
+            print("Cache hit")
+            return
         }
+        
+        print("Cache miss, loading from url")
+        loadImageFromUrl()
     }
     
-    init(urlString:String) {
-        guard let url = URL(string: urlString) else { return }
-        let task = URLSession.shared.dataTask(with: url) { data, response, error in
-            guard let data = data else { return }
-            DispatchQueue.main.async {
-                self.data = data
+    func loadImageFromCache() -> Bool {
+        guard let urlString = urlString else {
+            return false
         }
+        
+        guard let cacheImage = imageCache.get(forKey: urlString) else {
+            return false
+        }
+        
+        image = cacheImage
+        return true
     }
+    
+    func loadImageFromUrl() {
+        guard let urlString = urlString else {
+            return
+        }
+        
+        let url = URL(string: urlString)!
+        let task = URLSession.shared.dataTask(with: url, completionHandler: getImageFromResponse(data:response:error:))
         task.resume()
     }
+    
+    func getImageFromResponse(data: Data?, response: URLResponse?, error: Error?) {
+        guard error == nil else {
+            print("Error: \(error!)")
+            return
+        }
+        guard let data = data else {
+            print("No data found")
+            return
+        }
+        
+        DispatchQueue.main.async {
+            guard let loadedImage = UIImage(data: data) else {
+                return
+            }
+            
+            self.imageCache.set(forKey: self.urlString!, image: loadedImage)
+            self.image = loadedImage
+        }
+    }
+
+    init(urlString:String) {
+        self.urlString = urlString
+        loadImage()
+    }
+}
+
+class ImageCache {
+    var cache = NSCache<NSString, UIImage>()
+    
+    func get(forKey: String) -> UIImage? {
+        return cache.object(forKey: NSString(string: forKey))
+    }
+    
+    func set(forKey: String, image: UIImage) {
+        cache.setObject(image, forKey: NSString(string: forKey))
+    }
+}
+
+extension ImageCache {
+    private static var imageCache = ImageCache()
+    static func getImageCache() -> ImageCache {
+        return imageCache
+    }
 }
 
 
@@ -286,29 +350,25 @@ extension GiftsView {
     }
     
     struct ImageView: View {
-        @ObservedObject var imageLoader:ImageLoaderGifts
-        @State var image:UIImage = UIImage()
+        @ObservedObject var imageLoader:UrlImageModel
         @State var width:CGFloat
         @State var isFill:Bool
         
         var uiscreen = UIScreen.main.bounds
 
         init(withURL url:String , width:CGFloat, isFill:Bool) {
-            imageLoader = ImageLoaderGifts(urlString:url)
+            imageLoader = UrlImageModel(urlString:url)
             self.width = width
             self.isFill = isFill
         }
 
         var body: some View {
             
-                Image(uiImage: image)
+            Image(uiImage: imageLoader.image ?? UIImage())
                 .resizable()
                 .aspectRatio(contentMode: isFill ? .fill : .fit)
                 .frame(width: self.width)
                 .frame(maxHeight: .infinity)
-                    .onReceive(imageLoader.didChange) { data in
-                        self.image = UIImage(data: data) ?? UIImage()
-                    }
         }
     }