//
//  WelcomeController.swift
//  Messenger
//
//  Created by Orkhan Alizade on 03.08.15.
//  Copyright (c) 2015 Orkhan Alizade. All rights reserved.
//

import UIKit

class WelcomeController: UIViewController, UIPageViewControllerDataSource {
    @IBOutlet var signUp: UIButton!
    @IBOutlet var logIn: UIButton!

    var pageViewController: UIPageViewController!
    var pageImages: NSArray!

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

        let screen = UIScreen.mainScreen().bounds

        let widthConstraint = NSLayoutConstraint (item: signUp, attribute: NSLayoutAttribute.Width, relatedBy: NSLayoutRelation.Equal, toItem: nil, attribute: NSLayoutAttribute.NotAnAttribute, multiplier: 1, constant: screen.width/2 + 12)
        self.view.addConstraint(widthConstraint)

        let widthConstraint2 = NSLayoutConstraint (item: logIn, attribute: NSLayoutAttribute.Width, relatedBy: NSLayoutRelation.Equal, toItem: nil, attribute: NSLayoutAttribute.NotAnAttribute, multiplier: 1, constant: screen.width/2 + 12)
        self.view.addConstraint(widthConstraint2)

        self.pageImages = NSArray(objects: "1.jpg", "1.jpg", "1.jpg", "1.jpg")

        self.pageViewController = self.storyboard?.instantiateViewControllerWithIdentifier("PageViewController") as! UIPageViewController

        self.pageViewController.dataSource = self

        var startVC = self.viewControllerAtIndex(0) as ContentViewController
        var viewControllers = NSArray(object: startVC)

        self.pageViewController.setViewControllers(viewControllers as [AnyObject], direction: .Forward, animated: true, completion: nil)
        self.pageViewController.view.frame = CGRectMake(0, 0, self.view.frame.width, self.view.frame.size.height - 50)

        self.addChildViewController(self.pageViewController)
        self.view.addSubview(self.pageViewController.view)
        self.pageViewController.didMoveToParentViewController(self)
    }

    func viewControllerAtIndex(index: Int) -> ContentViewController {
        if ((self.pageImages.count == 0) || (index >= self.pageImages.count)) {
            return ContentViewController()
        }

        var vc: ContentViewController = self.storyboard?.instantiateViewControllerWithIdentifier("ContentViewController") as! ContentViewController

        vc.imageFile = self.pageImages[index] as! String
        vc.pageIndex = index

        return vc
    }

    func pageViewController(pageViewController: UIPageViewController, viewControllerBeforeViewController viewController: UIViewController) -> UIViewController? {

        var vc = viewController as! ContentViewController
        var index = vc.pageIndex as Int

        if (index == 0 || index == NSNotFound) {
            return nil
        }

        index--

        return self.viewControllerAtIndex(index)
    }

    func pageViewController(pageViewController: UIPageViewController, viewControllerAfterViewController viewController: UIViewController) -> UIViewController? {

        var vc = viewController as! ContentViewController
        var index = vc.pageIndex as Int

        if (index == NSNotFound) {
            return nil
        }

        index++

        if (index == self.pageImages.count) {
            return nil
        }

        return self.viewControllerAtIndex(index)
    }

    func presentationCountForPageViewController(pageViewController: UIPageViewController) -> Int {
        return self.pageImages.count
    }

    func presentationIndexForPageViewController(pageViewController: UIPageViewController) -> Int {
        return 0
    }

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