//
//  ImageViewController.swift
//  TableView
//
//  Created by Neil Quinn on 23/06/2014.
//  Copyright (c) 2014 Neil Quinn. All rights reserved.
//

import UIKit

class ImageViewController: UIViewController, UIScrollViewDelegate {

    var imageURL : NSURL = NSURL() {
        didSet {
            self.startDownloadingImage()
        }
    }

    @lazy var imageView = UIImageView()
    @IBOutlet var spinner : UIActivityIndicatorView
    @IBOutlet var scrollView : UIScrollView

    var image : UIImage? {
        set{
            self.scrollView.zoomScale = 1.0
            self.scrollView.contentSize = self.image ? self.image!.size : CGSizeZero
            self.spinner.stopAnimating()
            self.imageView.frame = CGRectMake(0, 0, image!.size.width, image!.size.height)
            self.imageView.image = image
        }

        get{
            return self.imageView.image
        }
    }

    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
        self.scrollView.addSubview(self.imageView)
        self.scrollView.minimumZoomScale = 0.2
        self.scrollView.maximumZoomScale = 2.0
        self.scrollView.delegate = self;
    }

    func viewForZoomingInScrollView(scrollView: UIScrollView) -> UIView
    {
        return self.imageView
    }

    func startDownloadingImage()
    {
        self.image = nil

        if self.imageURL != nil {
        //   self.spinner.startAnimating()
            var request : NSURLRequest = NSURLRequest(URL: self.imageURL)

            //another configuration option is the backgroundSessionConfiguration (multitasking API required though)
            var configuration : NSURLSessionConfiguration = NSURLSessionConfiguration.ephemeralSessionConfiguration()
            // create the session without specifying a queue to run completion handler on (thus not main queue
            // we also don't specify a delegate (since completion handler is all we need)
            var session : NSURLSession = NSURLSession(configuration: configuration)
            var task = session.dataTaskWithRequest(request, completionHandler: { localdatafile, response, error in
                if !error {
                    if request.URL.isEqual(self.imageURL) {
                        var localString : NSString = NSString(data: localdatafile, encoding:NSUTF8StringEncoding)
                        var localfile : NSURL = NSURL(string: localString)

                        var image : UIImage = UIImage(data: NSData(contentsOfURL: localfile))
                        dispatch_async(dispatch_get_main_queue(), {self.image = image})
                    }
                }
            })

            task.resume()

        }
    }


    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }


    /*
    // #pragma mark - Navigation

    // In a storyboard-based application, you will often want to do a little preparation before navigation
    override func prepareForSegue(segue: UIStoryboardSegue?, sender: AnyObject?) {
        // Get the new view controller using [segue destinationViewController].
        // Pass the selected object to the new view controller.
    }
    */

}