@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

        var window: UIWindow?

        var currentUser: SYUser?

        override init() {
                super.init()

                FIRApp.configure()
        }

        func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {

                if window == nil {
                        let bounds = UIScreen.mainScreen().bounds
                        let window = UIWindow(frame: bounds)
                        self.window = window
                }

                if let userId = FIRAuth.auth()?.currentUser?.uid {
                        let ref = FIRDatabase.database().reference().child("users").child(userId)
                        ref.observeSingleEventOfType(.Value, withBlock: { snapshot in
                                self.currentUser = SYUser(snapshot: snapshot)
                                self.window?.rootViewController = UIStoryboard(name: "Main", bundle: NSBundle.mainBundle()).instantiateInitialViewController()
                                self.window?.makeKeyAndVisible()
                        })
                } else {
                        let rootViewController = UIStoryboard(name: "Main", bundle: NSBundle.mainBundle()).instantiateViewControllerWithIdentifier("LoginViewController")
                        self.window?.rootViewController = rootViewController
                        self.window?.makeKeyAndVisible()
                }

                return true
        }
}

class SignUpViewController: UIViewController {

        @IBOutlet weak var firstName: UITextField!
        @IBOutlet weak var firstNameLine: UIView!
        @IBOutlet weak var lastName: UITextField!
        @IBOutlet weak var lastNameLine: UIView!
        @IBOutlet weak var email: UITextField!
        @IBOutlet weak var emailLine: UIView!
        @IBOutlet weak var password: UITextField!
        @IBOutlet weak var passwordLine: UIView!
        @IBOutlet weak var confirmPassword: UITextField!
        @IBOutlet weak var confirmPasswordLine: UIView!
        @IBOutlet weak var device: UITextField!
        @IBOutlet weak var deviceLine: UIView!
        @IBOutlet weak var scrollView: UIScrollView!

        let appDelegate = UIApplication.sharedApplication().delegate! as! AppDelegate

        override func viewWillAppear(animated: Bool) {
                super.viewWillAppear(animated)

                registerForKeyboardNotifications()
        }

        override func viewDidLayoutSubviews() {
                super.viewDidLayoutSubviews()

                // Center scrollview for 5/5s screen size
                let offsetY = ((scrollView.contentSize.height - scrollView.bounds.height) / 2) + 10
                scrollView.contentOffset = CGPointMake(0, offsetY)
        }

        override func viewWillDisappear(animated: Bool) {
                super.viewWillDisappear(animated)

                NSNotificationCenter.defaultCenter().removeObserver(self)
        }

        @IBAction func signUpPressed(sender: AnyObject) {

                print("Sign up button pressed: (mach_absolute_time())")

                guard registrationFormIsValid() else { return }

                var user = [String: String]()
                user["firstName"] = firstName.text!
                user["lastName"] = lastName.text!
                user["email"] = email.text!
                user["password"] = password.text!
                user["device"] = device.text!

                print("Start creating Account: (mach_absolute_time())")

                SYAuthService.createAccount(user) { [unowned self] (error) in
                        if error == nil {
                                SYUserService.currentUser({ (user, error) in
                                        if error == nil {
                                                print("Sign up completed successfully: (mach_absolute_time())")
                                                self.appDelegate.currentUser = user
                                                self.appDelegate.window?.rootViewController = UIStoryboard(name: "Main", bundle: NSBundle.mainBundle()).instantiateInitialViewController()
                                        } else {
                                                print("Sign up error: (error!.message) (mach_absolute_time())")
                                                self.displayFormError(message: error!.message)
                                        }
                                })
                        } else {
                                print("Sign up error: (error!.message) (mach_absolute_time())")
                                self.displayFormError(message: error!.message)
                        }
                }

                print("Waiting for completion: (mach_absolute_time())")

        }

        override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
                view.endEditing(true)
        }

        func registerForKeyboardNotifications() {
                let notificationCenter = NSNotificationCenter.defaultCenter()
                notificationCenter.addObserver(self, selector: #selector(adjustForKeyboard), name: UIKeyboardWillHideNotification, object: nil)
                notificationCenter.addObserver(self, selector: #selector(adjustForKeyboard), name: UIKeyboardWillChangeFrameNotification, object: nil)
        }

        func adjustForKeyboard(notification: NSNotification) {
                guard let userInfo = notification.userInfo else { return }

                let keyboardScreenEndFrame = (userInfo[UIKeyboardFrameEndUserInfoKey] as! NSValue).CGRectValue()
                let keyboardViewEndFrame = view.convertRect(keyboardScreenEndFrame, fromView: view.window)

                if notification.name == UIKeyboardWillHideNotification {
                        scrollView.contentInset = UIEdgeInsetsZero
                } else {
                        scrollView.contentInset = UIEdgeInsets(top: 0, left: 0, bottom: keyboardViewEndFrame.height, right: 0)
                }

                scrollView.scrollIndicatorInsets = scrollView.contentInset
        }

        func registrationFormIsValid() -> Bool {
                guard SYFormValidationHelper.fieldIsValid(firstName.text) else { displayFormError(line: firstNameLine); return false }
                guard SYFormValidationHelper.fieldIsValid(lastName.text) else { displayFormError(line: lastNameLine); return false }
                guard SYFormValidationHelper.emailIsValid(email.text) else { displayFormError(line: emailLine); return false }
                guard SYFormValidationHelper.passwordIsValid(password.text) else { displayFormError(line: passwordLine); return false }
                guard SYFormValidationHelper.passwordsMatch(password.text, password2: confirmPassword.text) else {
                        displayFormError(line: passwordLine)
                        displayFormError(line: confirmPasswordLine)
                        return false
                }
                guard SYFormValidationHelper.fieldIsValid(device.text) else { displayFormError(line: deviceLine); return false }
                return true
        }

        func displayFormError(message message: String) {
                let alert = UIAlertController(title: "Sign up error", message: message, preferredStyle: .Alert)
                alert.addAction(UIAlertAction(title: "OK", style: .Default, handler: nil))
                self.presentViewController(alert, animated: true, completion: nil)
        }

        func displayFormError(line line: UIView) {
                UIView.animateWithDuration(0.5) {
                        line.backgroundColor = UIColor.redColor()
                        line.alpha = 1.0
                }

                let seconds = 1.0
                let delay = seconds * Double(NSEC_PER_SEC)  // nanoseconds per seconds
                let dispatchTime = dispatch_time(DISPATCH_TIME_NOW, Int64(delay))

                dispatch_after(dispatchTime, dispatch_get_main_queue(), {
                        UIView.animateWithDuration(0.5) {
                                line.backgroundColor = UIColor.whiteColor()
                                line.alpha = 0.34
                        }
                })
        }

}

extension SignUpViewController: UITextFieldDelegate {

        func textFieldDidBeginEditing(textField: UITextField) {
                scrollView.scrollRectToVisible(textField.frame, animated: true)
        }

        func textFieldShouldReturn(textField: UITextField) -> Bool {
                switch textField {
                case firstName:
                        lastName.becomeFirstResponder()
                        break
                case lastName:
                        email.becomeFirstResponder()
                        break
                case email:
                        password.becomeFirstResponder()
                        break
                case password:
                        confirmPassword.becomeFirstResponder()
                        break
                case confirmPassword:
                        device.becomeFirstResponder()
                        break
                case device:
                        device.resignFirstResponder()
                        break
                default:
                        break
                }
                return true
        }

}