Alamofire.download() method: Where is the file and did it save successfully?

The example on the Alamofire readme file actually has the file path in it, so I grab it with a separate variable to use elsewhere in my code. It is not very elegant and I am hoping there is a way to get that info in the response, but for now, this is getting the job done:

var fileName: String?
var finalPath: NSURL?

Alamofire.download(.GET, urlToCall, { (temporaryURL, response) in

    if let directoryURL = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)[0] as? NSURL {    

        fileName = response.suggestedFilename!
        finalPath = directoryURL.URLByAppendingPathComponent(fileName!)
        return finalPath!
    }

    return temporaryURL
})
    .response { (request, response, data, error) in

        if error != nil {
            println("REQUEST: \(request)")
            println("RESPONSE: \(response)")
        } 

        if finalPath != nil {
            doSomethingWithTheFile(finalPath!, fileName: fileName!)
        }
 }

I spent about 8 hours looking for an answer to this one. The solution below works for me, and basically I chain to the download method to display the image. In the example below, I'm downloading the profile image of a user knowing his Facebook ID:

    let imageURL = "http://graph.facebook.com/\(FBId!)/picture?type=large"

    let destination: (NSURL, NSHTTPURLResponse) -> (NSURL) = {
        (temporaryURL, response) in

        if let directoryURL = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)[0] as? NSURL {
            var localImageURL = directoryURL.URLByAppendingPathComponent("\(self.FBId!).\(response.suggestedFilename!)")
            return localImageURL
        }
        return temporaryURL
    }

    Alamofire.download(.GET, imageURL, destination).response(){
        (_, _, data, _) in
            if let directoryURL = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)[0] as? NSURL {
                var error: NSError?
                let urls = NSFileManager.defaultManager().contentsOfDirectoryAtURL(directoryURL, includingPropertiesForKeys: nil, options: nil, error: &error)

                if error == nil {
                    let downloadedPhotoURLs = urls as! [NSURL]
                    let imagePath = downloadedPhotoURLs[0] // assuming it's the first file
                    let data = NSData(contentsOfURL: imagePath)
                    self.viewProfileImage?.image = UIImage(data: data!)
                }
            }
    }

Swift 2.1 and a little simpler:

var localPath: NSURL?
Alamofire.download(.GET,
    "http://jplayer.org/video/m4v/Big_Buck_Bunny_Trailer.m4v",
    destination: { (temporaryURL, response) in
    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(response)
        print("Downloaded file to \(localPath!)")
    }
)

Still hard to understand why they are using closures to set the destination path...