import UIKit
import FBSDKCoreKit
import FBSDKLoginKit
import Firebase
import FirebaseDatabase

class TutorialViewController: UIViewController {

    @IBOutlet var containerView: UIView!
    @IBOutlet var pageControl: UIPageControl!
    @IBOutlet var facebookButton: UIButton!

    //this dict stores the facebook user object
    var dict : [String : AnyObject]!

    //firebase
    var ref: FIRDatabaseReference!

    //keys below
    struct defaultsKeys {
        static let facebookID = "facebookID"
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        facebookButton.layer.cornerRadius = 18
        pageControl.addTarget(self, action: #selector(TutorialViewController.didChangePageControlValue), for: .valueChanged)
    }

    //facebook functions below
    @IBAction func fbLoginButtonPressed(_ sender: AnyObject) {
        let fbLoginManager : FBSDKLoginManager = FBSDKLoginManager()
        fbLoginManager.logIn(withReadPermissions: ["email", "public_profile", "user_friends", "user_location"], from: self) { (result, error) in
            print("Here is the result", result)
            print("Here is the error" , error)

            // To update constraints programmatically
            //self.view.layoutIfNeeded()

            if ( error == nil ){
                print("the error is nil")
                let fbloginresult : FBSDKLoginManagerLoginResult = result!
                //commenting if statement out temporarily for debugging purposes

                if(fbloginresult.grantedPermissions.contains("email"))
                {
                    print("email is contained and printing result")
                    self.getFBUserData()
                    fbLoginManager.logOut()

//                    func instantiateFromStoryboard()
//                    func instantiateFromStoryboard(storyboardIdentifier: String!)
//                    NSStringFromClass(aClass: AnyClass)

                    //figure out to how to resolve "whose view is not in the window hierarchy!"
                    let storyBoard : UIStoryboard = UIStoryboard(name: "Main", bundle:nil)
                    let nextViewController = storyBoard.instantiateViewController(withIdentifier: "VerifyLinkedInViewController") as! UIViewController
//                    self.present(nextViewController, animated:true, completion:nil)
                    UIApplication.shared.keyWindow?.rootViewController?.present(nextViewController, animated: true, completion: nil)


                }
            }
        }
    }

    func getFBUserData(){
        if((FBSDKAccessToken.current()) != nil){
            FBSDKGraphRequest(graphPath: "me", parameters: ["fields": "id, name, first_name, last_name, picture.type(large), email"]).start(completionHandler: { (connection, result, error) -> Void in

                print("inside get FB user data")
                if (error == nil){
                    self.dict = result as! [String : AnyObject]
                    print(result!)
                    print(self.dict)

                    //firebase storing user
                    self.ref = FIRDatabase.database().reference()

                    //or
                    if let myDictionary = self.dict as? [String : AnyObject] {
                        let id = myDictionary["id"]
                        let defaults = UserDefaults.standard
                        defaults.setValue(id, forKey: defaultsKeys.facebookID)
                        defaults.synchronize()
                        self.ref.child("users").child(id as! String).setValue(self.dict)
                        self.ref.child("users").child((id as! String)+"/largePictureURL").setValue("http://graph.facebook.com/"+(id as! String)+"/picture?width=1080&height=1080")

                    }
                }
            })
        }
    }
    var tutorialPageViewController: TutorialPageViewController? {
        didSet {
            tutorialPageViewController?.tutorialDelegate = self
        }
    }

    /**
     Fired when the user taps on the pageControl to change its current page.
     */
    func didChangePageControlValue() {
        tutorialPageViewController?.scrollToViewController(index: pageControl.currentPage)
    }
}

extension TutorialViewController: TutorialPageViewControllerDelegate {

    @objc(tutorialPageViewController:didUpdatePageIndex:) func tutorialPageViewController(_ tutorialPageViewController: TutorialPageViewController,didUpdatePageIndex count: Int) {
        pageControl.numberOfPages = count
    }

    @objc(tutorialPageViewController:didUpdatePageCount:) func tutorialPageViewController(_ tutorialPageViewController: TutorialPageViewController,didUpdatePageCount index: Int) {
        pageControl.currentPage = index
    }
}