Proyectos de Subversion Iphone Microlearning - Nuevo Interface

//

//  ImageLoader.swift

//  twogetskills

//

//  Created by Efrain Yanez Recanatini on 3/9/22.

//

import Combine

import UIKit

import var CommonCrypto.CC_MD5_DIGEST_LENGTH

import func CommonCrypto.CC_MD5

import typealias CommonCrypto.CC_LONG

class ImageLoader: ObservableObject {

    @Published var image: UIImage?

    private(set) var isLoading = false

    private let url: URL

    private var cache: ImageCache?

    private var appData = AppData.sharedInstance

    init(url: URL, cache: ImageCache? = nil) {

        self.url = url

        self.cache = cache

    }

    /*

    deinit {

        cancel()

    }

 */

    func load() {

        let urlString : String = url.absoluteString

        //print("ImageLoader URL : \(urlString) ")

        //guard !isLoading else { return }

        let md5Data = MD5(string: urlString)

        let key =  md5Data.map {

            String(format: "%02hhx", $0)

        }.joined()

        if let image = cache?[key as NSString] {

            //print("ImageLoader in Cache")

            self.image = image

            return

        }

        //print("ImageLoader not in Cache")

        var request = URLRequest(url: url)

        let headerSecurity = HeaderSecurity()

        request.httpMethod = "GET"

        request.addValue(appData.deviceUuid, forHTTPHeaderField: Constants.HTTP_HEADER_SECURITY_TOKEN)

        request.addValue(headerSecurity.secret, forHTTPHeaderField: Constants.HTTP_HEADER_SECURITY_SECRET)

        request.addValue(String(headerSecurity.created), forHTTPHeaderField: Constants.HTTP_HEADER_SECURITY_CREATED)

        request.addValue(String(headerSecurity.rand), forHTTPHeaderField: Constants.HTTP_HEADER_SECURITY_RAND)

        //print("ImageLoader Header \(Constants.HTTP_HEADER_SECURITY_TOKEN) =  \(appData.deviceUuid) ")

        //print("ImageLoader Header \( Constants.HTTP_HEADER_SECURITY_SECRET) =  \(headerSecurity.secret) ")

        //print("ImageLoader Header \(Constants.HTTP_HEADER_SECURITY_CREATED) =  \(headerSecurity.created) ")

        //print("ImageLoader Header \(Constants.HTTP_HEADER_SECURITY_RAND) =  \(headerSecurity.rand) ")

        /*

        cancellable = URLSession.shared.dataTaskPublisher(for: request)

            .map { UIImage(data: $0.data) }

            .replaceError(with: nil)

            .handleEvents(receiveSubscription: { [weak self] _ in self?.onStart() },

                          receiveOutput: { [weak self] in self?.cache($0) },

                          receiveCompletion: { [weak self] _ in self?.onFinish() },

                          receiveCancel: { [weak self] in self?.onFinish() })

            .subscribe(on: Self.imageProcessingQueue)

            .receive(on: DispatchQueue.main)

            .sink { [weak self] in self?.image = $0 }*/

        let task = URLSession.shared.dataTask(with: request, completionHandler: setImageFromData)

        task.resume()

    }

    private func setImageFromData(data: Data?, urlResponse: URLResponse?, error: Error?) {

            guard error == nil else {

               // print("\(error!)")

                return

            }

            guard let content = data else {

               // print("No data")

                return

            }

            DispatchQueue.main.async {

                self.image = UIImage(data: content)

               // self.dataHasLoaded = true

            }

        }

    /*

    func cancel() {

        cancellable?.cancel()

    }

    private func onStart() {

        isLoading = true

    }

    private func onFinish() {

        isLoading = false

    }*/

    private func cache(_ image: UIImage?) {

        let urlString : String = url.absoluteString

        //print("ImageLoader URL : \(urlString) ")

        //guard !isLoading else { return }

        let md5Data = MD5(string: urlString)

        let key =  md5Data.map {

            String(format: "%02hhx", $0)

        }.joined()

        image.map { cache?[key as NSString] = $0 }

    }

    private func MD5(string: String) -> Data {

        let length = Int(CC_MD5_DIGEST_LENGTH)

        let messageData = string.data(using:.utf8)!

        var digestData = Data(count: length)

        _ = digestData.withUnsafeMutableBytes { digestBytes -> UInt8 in

        messageData.withUnsafeBytes { messageBytes -> UInt8 in

        if let messageBytesBaseAddress = messageBytes.baseAddress, let digestBytesBlindMemory = digestBytes.bindMemory(to: UInt8.self).baseAddress {

                let messageLength = CC_LONG(messageData.count)

                    CC_MD5(messageBytesBaseAddress, messageLength, digestBytesBlindMemory)

                }

            return 0

            }

        }

        return digestData

    }

}