TailboneApp.swift

import SwiftUI
import WebKit

struct ContentView: View {
    var webview = Webview.init(url: Bundle.main.url(
        forResource: "index",
        withExtension: "html"
    )!)
    var body: some View {
        ZStack {
            Color.black.edgesIgnoringSafeArea(.all)
            webview
        }
    }
}

class ViewController: UIViewController, WKScriptMessageHandler {
    func userContentController(
        _ userContentController: WKUserContentController,
        didReceive message: WKScriptMessage
    ) {
        // Do nothing. This is only here to give the JS something to detect
        // so that it can skip the web version's start menu.
    }
}

struct Webview: UIViewRepresentable {
    let url: URL

    func makeUIView(
        context: UIViewRepresentableContext<Webview>
    ) -> WKWebView {
        let config = WKWebViewConfiguration()

        // enable audio playback to begin immediately
        config.mediaTypesRequiringUserActionForPlayback = []

        // ensure window.webkit.messageHandlers is present for index.html to
        // detect the platform correctly and skip the web-only menu screen
        let contentController = WKUserContentController()
        contentController.add(
            ViewController.init(),
            name: "placeholder"
        )
        config.userContentController = contentController

        let webview = WKWebView(
            frame: .zero,
            configuration: config
        )

        // prevent white flash during load
        webview.isOpaque = false
        webview.backgroundColor = UIColor.clear

        let request = URLRequest(
            url: self.url,
            cachePolicy: .returnCacheDataElseLoad
        )
        webview.load(request)
        return webview
    }

    func updateUIView(
        _ webview: WKWebView,
        context: UIViewRepresentableContext<Webview>
    ) {
        let request = URLRequest(
            url: self.url,
            cachePolicy: .returnCacheDataElseLoad
        )
        webview.load(request)
    }
}


@main
struct TailboneApp: App {
    var body: some Scene {
        WindowGroup {
            ContentView()
        }
    }
}