/*

    Copyright (C) 2016 Apple Inc. All Rights Reserved.

    See LICENSE.txt for this sample’s licensing information

    Abstract:

                Photo represents an image that can be imported.

*/

import UIKit

class Photo: NSObject {

    // MARK: Properties

    let imageURL: URL

    /// Marked "dynamic" so it is KVO observable.

    dynamic var image: UIImage?

    /// The photoImport is KVO observable for its progress.

    dynamic var photoImport: PhotoImport?

    // MARK: Initializers

    init(URL: Foundation.URL) {

        imageURL = (URL as NSURL).copy() as! Foundation.URL

        image = UIImage(named: "PhotoPlaceholder")

    }

    /// Kick off the import

    func startImport() -> Progress {

        let newImport = PhotoImport(URL: imageURL)

        newImport.completionHandler = { image, error in

            if let image = image {

                // The import is finished. Set our image to the result

                self.image = image

            }

            else {

                self.reportError(error!)

            }

            self.photoImport = nil

        }

        newImport.start()

        photoImport = newImport

        return newImport.progress

    }

    fileprivate func reportError(_ error: NSError) {

        if error.domain != NSCocoaErrorDomain || error.code != NSUserCancelledError {

            print("Error importing photo: \(error.localizedDescription)")

        }

    }

    /// Go back to the initial state.

    func reset() {

        image = UIImage(named: "PhotoPlaceholder")

        photoImport = nil

    }

}