import SwiftUI
import WebKit

struct AuthenticationView: View {
    let destination: URL
    @ObservedObject var model: BrowserModel
    var body: some View {
        NavigationStack {
            IsolatedAuthentication(url: destination, model: model)
                .navigationTitle(model.authenticationHost)
                .navigationBarTitleDisplayMode(.inline)
                .toolbar { Button("Close") { model.authentication = nil } }
        }
    }
}

struct IsolatedAuthentication: UIViewRepresentable {
    let url: URL
    let model: BrowserModel
    func makeCoordinator() -> Coordinator { Coordinator(model) }
    func makeUIView(context: Context) -> WKWebView {
        let configuration = WKWebViewConfiguration()
        // Same cookie store as the initiating Yuvomi handshake; no manual cookie export.
        configuration.websiteDataStore = model.web.configuration.websiteDataStore
        configuration.preferences.javaScriptCanOpenWindowsAutomatically = false
        configuration.mediaTypesRequiringUserActionForPlayback = .all
        let view = WKWebView(frame: .zero, configuration: configuration)
        view.navigationDelegate = context.coordinator
        view.uiDelegate = context.coordinator
        if #available(iOS 16.4, *) { view.isInspectable = false }
        view.load(URLRequest(url: url))
        return view
    }
    func updateUIView(_ uiView: WKWebView, context: Context) {}
    static func dismantleUIView(_ uiView: WKWebView, coordinator: Coordinator) {
        uiView.stopLoading()
        uiView.navigationDelegate = nil
        uiView.uiDelegate = nil
    }
    final class Coordinator: NSObject, WKNavigationDelegate, WKUIDelegate {
        let model: BrowserModel
        init(_ model: BrowserModel) { self.model = model }
        func webView(_ webView: WKWebView, didStartProvisionalNavigation navigation: WKNavigation!) {
            model.authenticationHost = webView.url?.host ?? "Sign in"
        }
        func webView(
            _ webView: WKWebView, decidePolicyFor navigationAction: WKNavigationAction,
            decisionHandler: @escaping (WKNavigationActionPolicy) -> Void
        ) {
            guard let url = navigationAction.request.url, url.scheme == "https",
                url.user == nil, url.password == nil
            else {
                decisionHandler(.cancel)
                return
            }
            decisionHandler(.allow)
        }
        func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
            if let url = webView.url, model.server?.owns(url) == true, !url.path.hasPrefix("/api/") {
                model.authentication = nil
                model.web.load(URLRequest(url: url))
            }
        }
        func webView(
            _ webView: WKWebView, requestMediaCapturePermissionFor origin: WKSecurityOrigin,
            initiatedByFrame frame: WKFrameInfo, type: WKMediaCaptureType,
            decisionHandler: @escaping (WKPermissionDecision) -> Void
        ) { decisionHandler(.deny) }
        func webView(
            _ webView: WKWebView, runOpenPanelWith parameters: WKOpenPanelParameters,
            initiatedByFrame frame: WKFrameInfo,
            completionHandler: @escaping @MainActor @Sendable ([URL]?) -> Void
        ) {
            completionHandler(nil)
        }
    }
}