import ClawdisKit
import Observation
import SwiftUI
import WebKit
@MainActor
@Observable
final class ScreenController {
let webView: WKWebView
private let navigationDelegate: ScreenNavigationDelegate
var mode: ClawdisCanvasMode = .canvas
var urlString: String = ""
var errorText: String?
/// Callback invoked when a clawdis:// deep link is tapped in the canvas
var onDeepLink: ((URL) -> Void)?
init() {
let config = WKWebViewConfiguration()
config.websiteDataStore = .nonPersistent()
self.navigationDelegate = ScreenNavigationDelegate()
self.webView = WKWebView(frame: .zero, configuration: config)
self.webView.isOpaque = false
self.webView.backgroundColor = .clear
self.webView.scrollView.backgroundColor = .clear
self.webView.scrollView.contentInsetAdjustmentBehavior = .never
self.webView.scrollView.contentInset = .zero
self.webView.scrollView.scrollIndicatorInsets = .zero
self.webView.scrollView.automaticallyAdjustsScrollIndicatorInsets = false
// Disable scroll to allow touch events to pass through to canvas
self.webView.scrollView.isScrollEnabled = false
self.webView.scrollView.bounces = false
self.webView.navigationDelegate = self.navigationDelegate
self.navigationDelegate.controller = self
self.reload()
}
func setMode(_ mode: ClawdisCanvasMode) {
self.mode = mode
self.reload()
}
func navigate(to urlString: String) {
self.urlString = urlString
self.reload()
}
func reload() {
switch self.mode {
case .web:
guard let url = URL(string: self.urlString.trimmingCharacters(in: .whitespacesAndNewlines)) else { return }
self.webView.load(URLRequest(url: url))
case .canvas:
self.webView.loadHTMLString(Self.canvasScaffoldHTML, baseURL: nil)
}
}
func eval(javaScript: String) async throws -> String {
try await withCheckedThrowingContinuation { cont in
self.webView.evaluateJavaScript(javaScript) { result, error in
if let error {
cont.resume(throwing: error)
return
}
if let result {
cont.resume(returning: String(describing: result))
} else {
cont.resume(returning: "")
}
}
}
}
func snapshotPNGBase64(maxWidth: CGFloat? = nil) async throws -> String {
let config = WKSnapshotConfiguration()
if let maxWidth {
config.snapshotWidth = NSNumber(value: Double(maxWidth))
}
let image: UIImage = try await withCheckedThrowingContinuation { cont in
self.webView.takeSnapshot(with: config) { image, error in
if let error {
cont.resume(throwing: error)
return
}
guard let image else {
cont.resume(throwing: NSError(domain: "Screen", code: 2, userInfo: [
NSLocalizedDescriptionKey: "snapshot failed",
]))
return
}
cont.resume(returning: image)
}
}
guard let data = image.pngData() else {
throw NSError(domain: "Screen", code: 1, userInfo: [
NSLocalizedDescriptionKey: "snapshot encode failed",
])
}
return data.base64EncodedString()
}
private static let canvasScaffoldHTML = """
Canvas
"""
}
// MARK: - Navigation Delegate
/// Handles navigation policy to intercept clawdis:// deep links from canvas
private final class ScreenNavigationDelegate: NSObject, WKNavigationDelegate {
weak var controller: ScreenController?
func webView(
_ webView: WKWebView,
decidePolicyFor navigationAction: WKNavigationAction,
decisionHandler: @escaping (WKNavigationActionPolicy) -> Void)
{
guard let url = navigationAction.request.url else {
decisionHandler(.allow)
return
}
// Intercept clawdis:// deep links
if url.scheme == "clawdis" {
decisionHandler(.cancel)
Task { @MainActor in
self.controller?.onDeepLink?(url)
}
return
}
decisionHandler(.allow)
}
}