import SwiftUI
import Combine
import AlamofireImage

let imageDownloader = ImageDownloader(
    configuration: ImageDownloader.defaultURLSessionConfiguration(),
    downloadPrioritization: .fifo,
    maximumActiveDownloads: 4,
    imageCache: AutoPurgingImageCache()
)

extension ImageDownloader {
    func image(for url: URL) -> AnyPublisher<UIImage?, Never> {
        return Publishers.Future { subscriber in
                let urlRequest = URLRequest(url: url)
                imageDownloader.download(urlRequest) { response in
                    if let image = response.result.value {
                        subscriber(.success(image))
                    }
                }
            }
            .eraseToAnyPublisher()
    }
}

struct RemoteImage: View {
    //    let placeholder = UIImage(named: "placeholder.jpg")!
    let url: URL
    init(url: URL) {
        print("RemoteImage created \(url)")
        self.url = url
    }

    @State private var image: UIImage? = nil

    var body: some View {
        Group {
            if image != nil {
                Image(uiImage: image!)
            } else {
                Image(systemName: "person.crop.circle")
            }
        }
        .bind(imageDownloader.image(for: url), to: $image)
    }
}

//#if DEBUG
//struct RemoteImage_Previews : PreviewProvider {
//    static var previews: some View {
//        RemoteImage()
//    }
//}
//#endif