/// Copyright (c) 2020 Razeware LLC
///
/// Permission is hereby granted, free of charge, to any person obtaining a copy
/// of this software and associated documentation files (the "Software"), to deal
/// in the Software without restriction, including without limitation the rights
/// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
/// copies of the Software, and to permit persons to whom the Software is
/// furnished to do so, subject to the following conditions:
///
/// The above copyright notice and this permission notice shall be included in
/// all copies or substantial portions of the Software.
///
/// Notwithstanding the foregoing, you may not use, copy, modify, merge, publish,
/// distribute, sublicense, create a derivative work, and/or sell copies of the
/// Software in any work that is designed, intended, or marketed for pedagogical or
/// instructional purposes related to programming, coding, application development,
/// or information technology.  Permission for such use, copying, modification,
/// merger, publication, distribution, sublicensing, creation of derivative works,
/// or sale is expressly withheld.
///
/// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
/// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
/// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
/// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
/// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
/// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
/// THE SOFTWARE.

import UIKit
import PromiseKit
import Kingfisher

class ImageCacheKingfisher: ImageCache {

  // MARK: - Properties
  let manager = KingfisherManager.shared

  // MARK: - Methods
  func getImagePair(at url1: URL, and url2: URL) -> Promise<(image1: UIImage, image2: UIImage)> {
    let promises = [getImage(at: url1), getImage(at: url2)]
    return when(fulfilled: promises).map { images in
      return (image1: images[0], image2: images[1])
    }
  }

  func getImage(at url: URL) -> Promise<UIImage> {
    return Promise { seal in
      let resource = ImageResource(downloadURL: url)

      manager.retrieveImage(
        with: resource,
        options: [KingfisherOptionsInfoItem.scaleFactor(UIScreen.main.scale)],
        progressBlock: nil
      ) { result in
          switch result {
          case .failure(let error):
            seal.reject(error)
            return
          case .success(let imageResult):
            seal.fulfill(imageResult.image)
            return
          }
      }
    }
  }
  
}
