WebView

//
//  WebViewExample.swift
//  CombineApp
//
//  Created by Abdullah Kardas on 29.06.2022.
//

import SwiftUI
import UIKit
import WebKit

struct WebViewExample: View {
    
    @ObservedObject var webViewModel = WebViewModel(url: "https://fit-meapp.web.app/")
    var body: some View {
        NavigationView {
                   VStack {
                       ScrollView {
                           Text("This is is a text").font(.title)
                           WebViewContainer(webViewModel: webViewModel).frame(height: webViewModel.containerHeight)
                           
                           
                           Button {
                               
                           } label: {
                               Text("Custom Button").foregroundColor(.white).padding(.vertical,16).frame(width: 200).background(Color.red.cornerRadius(12))
                           }
                           
                           Image(systemName: "heart").font(.largeTitle).foregroundColor(.blue)

                       }.listStyle(.plain)
                       if webViewModel.isLoading {
                           ProgressView()
                               .frame(height: 30)
                           
                       }
                   }
                   .navigationBarHidden(true)

               }
    }
}

struct WebViewExample_Previews: PreviewProvider {
    static var previews: some View {
        WebViewExample()
    }
}


class WebViewModel: ObservableObject {
    @Published var isLoading: Bool = false
    @Published var canGoBack: Bool = true
    @Published var shouldGoBack: Bool = false
    @Published var title: String = ""
    
    @Published var containerHeight:CGFloat = 100
    
    var url: String
    
    init(url: String) {
        self.url = url
    }
}

struct WebViewContainer: UIViewRepresentable {
    @ObservedObject var webViewModel: WebViewModel
  
    
    func makeCoordinator() -> WebViewContainer.Coordinator {
        Coordinator(self, webViewModel)
    }
    
    func makeUIView(context: Context) -> WKWebView {
        guard let url = URL(string: self.webViewModel.url) else {
            return WKWebView()
        }
        
        let request = URLRequest(url: url)
        let webView = WKWebView()
        webView.navigationDelegate = context.coordinator
        webView.load(request)
      
        webView.scrollView.isScrollEnabled = false
        
        return webView
    }
    
    func updateUIView(_ uiView: WKWebView, context: Context) {
        if webViewModel.shouldGoBack {
            uiView.goBack()
            webViewModel.shouldGoBack = false
        }
    }
   
}
extension WebViewContainer {
    class Coordinator: NSObject, WKNavigationDelegate {
        @ObservedObject private var webViewModel: WebViewModel
        private let parent: WebViewContainer
        
        init(_ parent: WebViewContainer, _ webViewModel: WebViewModel) {
            self.parent = parent
            self.webViewModel = webViewModel
        }
        
        func webView(_ webView: WKWebView, didStartProvisionalNavigation navigation: WKNavigation!) {
            webViewModel.isLoading = true
        }
        
        func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
            webViewModel.isLoading = false
            webViewModel.title = webView.title ?? ""
            webViewModel.canGoBack = webView.canGoBack
            print("*****\(webView.scrollView.contentSize.height)")
           // height = webView.scrollView.contentSize.height
            webViewModel.containerHeight = webView.scrollView.contentSize.height
        }
        
        func webView(_ webView: WKWebView, didFail navigation: WKNavigation!, withError error: Error) {
            webViewModel.isLoading = false
        }
    }
}