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//
//  ViewController.swift
//  project4
//
//  Created by VSAA on 7/16/19.
//  Copyright © 2019 VSAA. All rights reserved.
//

import UIKit
import WebKit


class ViewController: UIViewController, WKNavigationDelegate {

    var webView: WKWebView!
    var progressView: UIProgressView!
    var webSites = ["apple.com", "hackingwithswift.com"]

    override func loadView() {
        webView = WKWebView()
        webView.navigationDelegate = self
        view = webView
    }
    override func viewDidLoad() {
        super.viewDidLoad()




        let url = URL(string: "https://" + webSites[0])!
        webView.load(URLRequest(url: url))

        webView.allowsBackForwardNavigationGestures = true

        navigationItem.rightBarButtonItem = UIBarButtonItem(title: "Open", style: .plain, target: self, action: #selector(openTapped))

        progressView = UIProgressView(progressViewStyle: .default)
        progressView.sizeToFit()

        let progressButton = UIBarButtonItem(customView: progressView)

        let spacer = UIBarButtonItem(barButtonSystemItem: .flexibleSpace, target: nil, action: nil)
        let refresh = UIBarButtonItem(barButtonSystemItem: .refresh, target: webView, action: #selector(webView.reload))

        toolbarItems = [progressButton, spacer, refresh]
        navigationController?.isToolbarHidden = false

         webView.addObserver(self, forKeyPath: #keyPath(WKWebView.estimatedProgress), options: .new, context: nil)
    }

    override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {
        if keyPath == "estimatedProgress" {
            progressView.progress = Float(webView.estimatedProgress)
        }
    }



    @objc func openTapped() {
        let ac = UIAlertController(title: "Open page...", message: nil, preferredStyle: .actionSheet)
        for website in webSites {
            ac.addAction(UIAlertAction(title: website, style: .default, handler: openPage))
        }

        ac.addAction(UIAlertAction(title: "Cancel", style: .cancel))
        ac.popoverPresentationController?.barButtonItem = self.navigationItem.rightBarButtonItem
        present(ac, animated: true)
    }

    func openPage(action: UIAlertAction) {
        let url = URL(string: "https://" + action.title!)!
        webView.load(URLRequest(url: url))
    }
    func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
        title = webView.title
    }
    func webView(_ webView: WKWebView, decidePolicyFor navigationAction: WKNavigationAction, decisionHandler: @escaping (WKNavigationActionPolicy) -> Void) {
        let url  = navigationAction.request.url

        if let host = url?.host {
            for website in webSites {
                if host.contains(website) {
                    decisionHandler(.allow)
                    return
                }
            }
        }
        decisionHandler(.cancel)

/// Вот так вот сразу крашится во время загрузки(появляется Alert и все, выкидывает исключение) Без кода ниже все работает.

///     let alertController = UIAlertController(title: "Blocked", message: "The url was blocked", preferredStyle: .alert)
///     let alertAction = UIAlertAction( title : "Ok" ,
                                         style : .default, handler: nil)
///     alertController.addAction(alertAction)
///     self.present(alertController, animated: true, completion: nil)
    }

}