background download Alamofire swift

//
//  ViewController.swift
//  project

import UIKit
import Alamofire
import SwiftyJSON
import Haneke

class magazineViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegate, NSURLSessionDelegate, UIDocumentInteractionControllerDelegate, NSURLSessionTaskDelegate {

    @IBOutlet weak var collectionView: UICollectionView!
    
    @IBOutlet weak var progressLoading: UIActivityIndicatorView!
    
    @IBOutlet weak var searchBar: UISearchBar!

    var listMagazine = [String]()
    var titleMagazine = [String]()
    var imageMagazine = [String]()
    
    var downloadDirectory: String = ""
    
    var downloadTask: NSURLSessionDownloadTask!
    var backgroundSession: NSURLSession!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // Do any additional setup after loading the view, typically from a nib.
        getData()
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
    
    func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return listMagazine.count
    }

    func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
    
        let cell: magazineCell = self.collectionView.dequeueReusableCellWithReuseIdentifier("Cell", forIndexPath: indexPath) as! magazineCell
        
        cell.progressDownload.hidden = true
        cell.progressLabel.hidden = true
        cell.progressDownload.setProgress(0, animated: true)
        
        let imageUrl:NSURL = NSURL(string: imageMagazine[indexPath.row])!
        
        cell.displayImage.hnk_setImageFromURL(imageUrl, placeholder: nil, success: { (image) -> Void in
            cell.displayImage.image = image
            cell.activityIndicator.hidden = true
            cell.activityIndicator.stopAnimating()
            //self.imagePlaceholder.hidden = true
            }, failure: { (error) -> Void in
                // when error
        })
        
        cell.displayTitle.text = titleMagazine[indexPath.row]
        
        return cell
    }
    
    func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
        let cell = collectionView.cellForItemAtIndexPath(indexPath) as! magazineCell
        var localPath: NSURL?

        let destination = Alamofire.Request.suggestedDownloadDestination(directory: .DocumentDirectory, domain: .UserDomainMask)
        Alamofire.download(.GET, listMagazine[indexPath.row], destination: { (temporaryURL, response) in
            
            print("ITEM IS DOWNLOADING")
            print(self.listMagazine[indexPath.item])
            let directoryURL = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)[0]
            let pathComponent = response.suggestedFilename
            
            localPath = directoryURL.URLByAppendingPathComponent(pathComponent!)
            return localPath!
        })
            .response { (request, response, _, error) in
//                print("this is response \(response)")
                print("Downloaded file to \(localPath!)")
                self.downloadDirectory = "\(localPath)"
        }
        
        let backgroundSessionConfiguration = NSURLSessionConfiguration.backgroundSessionConfigurationWithIdentifier("backgroundSession")
        backgroundSession = NSURLSession(configuration: backgroundSessionConfiguration, delegate: self, delegateQueue: NSOperationQueue.mainQueue())
        
//        var counter:Int = 0 {
//            didSet {
//                let fractionalProgress = Float(counter) / 100.0
//                let animated = counter != 0
//                
//                print(counter)
//                print("THE PROGRESS")
//                
//                cell.progressDownload.setProgress(fractionalProgress, animated: animated)
//                cell.progressLabel.text = ("\(counter)%")
//            }
//        }
        
        let url = NSURL(string: "\(localPath)")!
        downloadTask = backgroundSession.downloadTaskWithURL(url)
        downloadTask.resume()
        
        cell.progressDownload.hidden = false
        cell.progressLabel.hidden = false
        
        print(localPath)
    }
    
//    func showFileWithPath(path: String){
//        let isFileFound:Bool? = NSFileManager.defaultManager().fileExistsAtPath(path)
//        if isFileFound == true{
//            let viewer = UIDocumentInteractionController(URL: NSURL(fileURLWithPath: path))
//            viewer.delegate = self
//            viewer.presentPreviewAnimated(true)
//        }
//    }
//    
//    func URLSession(session: NSURLSession, downloadTask: NSURLSessionDownloadTask, didFinishDownloadingToURL location: NSURL){
//        
//        let path = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.DocumentDirectory, NSSearchPathDomainMask.UserDomainMask, true)
//        let documentDirectoryPath:String = path[0]
//        let fileManager = NSFileManager()
//        let destinationURLForFile = NSURL(fileURLWithPath: documentDirectoryPath.stringByAppendingString("/file.pdf"))
//        
//        if fileManager.fileExistsAtPath(destinationURLForFile.path!){
//            showFileWithPath(destinationURLForFile.path!)
//        }
//        else{
//            do {
//                try fileManager.moveItemAtURL(location, toURL: destinationURLForFile)
//                // show file
//                showFileWithPath(destinationURLForFile.path!)
//            }catch{
//                print("An error occurred while moving file to destination url")
//            }
//        }
//    }
    // 2
    func URLSession(session: NSURLSession,
                    downloadTask: NSURLSessionDownloadTask,
                    didWriteData bytesWritten: Int64,
                                 totalBytesWritten: Int64,
                                 totalBytesExpectedToWrite: Int64,
                                    cell: magazineCell){
        cell.progressDownload.setProgress(Float(totalBytesWritten)/Float(totalBytesExpectedToWrite), animated: true)
        
    }
    
    
    func URLSession(session: NSURLSession,
                    task: NSURLSessionTask,
                    didCompleteWithError error: NSError?,
                        cell: magazineCell){
        downloadTask = nil
        cell.progressDownload.setProgress(0.0, animated: true)
        
        if (error != nil) {
            print(error?.description)
        }else{
            print("The task finished transferring data successfully")
        }
    }
    
    func documentInteractionControllerViewControllerForPreview(controller: UIDocumentInteractionController) -> UIViewController{
        return self
    }
    
    func getData() {
        self.progressLoading.startAnimating()
        self.progressLoading.hidden = false
        let config = Config()
        let url = NSURL(string: config.BASE_URL + config.LIST_MAGAZINE + config.SecretKey())!
        
        Alamofire.request(.GET, url).responseJSON {
            (response) -> Void in
            
            self.progressLoading.stopAnimating()
            self.progressLoading.hidden = true
            
            if response.result.isSuccess {
                if let value = response.result.value {
                    
                    let json = JSON(value)
                    let datas = json["items"].arrayValue
                    
                    for data in datas {
                        self.listMagazine.append(data["magazine"].stringValue)
                        self.titleMagazine.append(data["title"].stringValue)
                        self.imageMagazine.append(data["image"].stringValue)
                    }
                }
                self.collectionView.reloadData()
            }
        }
    }
}