iOSGiphyCodeChallenge/LiveLikeGiphyChallenge/CachedImageView.swift

//
//  CachedImageView.swift
//  LiveLikeGiphyChallenge
//
//  Created by Arbnor Tefiki on 6.2.22.
//

import UIKit

var cachedImages = NSCache<NSString, UIImage>()

class CachedImageView: UIImageView {
  private var currentURL: NSString?

  func loadAsyncImage(url: String, placeholder: UIImage?) {
    let imageURL = url as NSString
    if let cachedImage = cachedImages.object(forKey: imageURL) {
      image = cachedImage
      return
    }
    image = placeholder
    currentURL = imageURL
    guard let requestURL = URL(string: url) else { image = placeholder; return }
    URLSession.shared.dataTask(with: requestURL) { (data, response, error) in
      DispatchQueue.main.async { [weak self] in
        guard let imageData = data, error == nil else {
          self?.image = placeholder
          return
        }
        if self?.currentURL == imageURL {
          if let imageToShow = UIImage.gifImageWithData(imageData) {
            cachedImages.setObject(imageToShow, forKey: imageURL)
            self?.image = imageToShow
          } else {
            self?.image = placeholder
          }
        }
      }
    }.resume()
  }
}