Write data to Firebase not working - Caot convert value of type 'user' to expected argument type 'AnyObject?'

I am trying to save my registered data to Firebase but get a "Caot convert value of type 'user' to expected argument type 'AnyObject?'" error. I tried many things but I can't seem to figure it out...can someone help me please? how do it save it?

import UIKit

import Firebase import FirebaseDatabaseUI

class EventViewController: UIViewController, UIImagePickerControllerDelegate, UINavigationControllerDelegate {

//outlets for text & image
@IBOutlet weak var photoImageView: UIImageView!

@IBOutlet weak var eventName: UITextField!
@IBOutlet weak var eventDate: UITextField!
@IBOutlet weak var eventDes: UITextView!



//Database coection
let rootref = FIRDatabase().reference()
var imagePicker: UIImagePickerController = UIImagePickerController()



override func viewDidLoad() {
    super.viewDidLoad()
}

override func didReceiveMemoryWaing() {
    super.didReceiveMemoryWaing()
}

@IBAction func submitEvent(sender: AnyObject) {

    let name = eventName.text
    let date = eventDate.text
    let text = eventDes.text
    var data: NSData = NSData()

    if let image = photoImageView.image {
        data = UIImageJPEGRepresentation(image,0.1)!
    }

     let base64String = data.base64EncodedStringWithOptions(NSDataBase64EncodingOptions.Encoding64CharacterLineLength)

    if let unwrappedName = name , unwrappedDate = date, unwrappedText = text{
        let user: NSDictionary = ["name":unwrappedName, "date":unwrappedDate, "text":unwrappedText, "photoBase64":base64String]
    }

    //Add firebase child node
    let event = FIRDatabase().reference().child(name!)

    // Write data to Firebase

    event.setValue(user.init())

    navigationController?.popViewControllerAnimated(true)
}

override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
    view.endEditing(true)
    super.touchesBegan(touches, withEvent: event)
}

    //UIImagePickerControllerDelegate methods

    func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : AnyObject]) {
        imagePicker.dismissViewControllerAnimated(true, completion: nil)
        photoImageView.image = info[UIImagePickerControllerOriginalImage] as? UIImage
    }

    func imagePickerControllerDidCancel(picker: UIImagePickerController) {
        dismissViewControllerAnimated(true, completion: nil)
    }

@IBAction func addPicture(sender: AnyObject) {
    if(UIImagePickerController.isSourceTypeAvailable(UIImagePickerControllerSourceType.Camera)) {
        imagePicker =  UIImagePickerController()
        imagePicker.delegate = self
        imagePicker.sourceType = .Camera

        presentViewController(imagePicker, animated: true, completion: nil)
    } else {
        imagePicker.allowsEditing = false
        imagePicker.sourceType = .PhotoLibrary
        imagePicker.delegate = self
        presentViewController(imagePicker, animated: true, completion:nil)
    }
}

}