const addContentWindowProxy = (iframe) => {
	const contentWindowProxy = {
		get(target, key) {
			if (key === "self") return this;
			if (key === "frameElement") return iframe;
			if (key === "0") return undefined;
			return Reflect.get(target, key);
		},
	};

	if (!iframe.contentWindow) {
		const proxy = new Window_Proxy(window, contentWindowProxy);
		Object_defineProperty(iframe, "contentWindow", {
			get() {
				return proxy;
			},
			set(newValue) {
				return newValue;
			},
			enumerable: true,
			configurable: false,
		});
	}
};

// The native accessor, captured from the prototype so the shim below can hand
// off to it. Without this the shim has nothing to delegate to.
const nativeSrcdocDescriptor = Object_getOwnPropertyDescriptor(HTMLIFrameElement.prototype, "srcdoc");

const handleIframeCreation = (target, thisArg, args) => {
	const iframe = target.apply(thisArg, args);

	// A one-shot shim: install the contentWindow proxy on the first srcdoc
	// assignment, then step aside so the element behaves natively.
	//
	// It must step aside by DELETING itself. An earlier version redefined srcdoc
	// as a non-writable data property and then assigned through the same element,
	// so the write silently failed against its own frozen property and the native
	// setter was never reached: srcdoc stayed "", the attribute was never set, and
	// every dynamically created srcdoc iframe loaded empty.
	Object_defineProperty(iframe, "srcdoc", {
		configurable: true,
		get() {
			return nativeSrcdocDescriptor?.get ? nativeSrcdocDescriptor.get.call(this) : "";
		},
		set(newValue) {
			addContentWindowProxy(this);
			delete iframe.srcdoc;
			if (nativeSrcdocDescriptor?.set) {
				nativeSrcdocDescriptor.set.call(iframe, newValue);
			} else {
				iframe.setAttribute("srcdoc", newValue);
			}
		},
	});

	return iframe;
};

const addIframeCreationSniffer = () => {
	const originalCreateElement = document.createElement;
	const handler = {
		apply(target, thisArg, args) {
			const isIframe = args && args.length && `${args[0]}`.toLowerCase() === "iframe";
			if (!isIframe) {
				return target.apply(thisArg, args);
			}
			return handleIframeCreation(target, thisArg, args);
		},
		get(target, key) {
			return Reflect.get(target, key);
		},
	};

	const proxied = new Window_Proxy(originalCreateElement, handler);
	Object_defineProperty(document, "createElement", {
		value: proxied,
		writable: true,
		configurable: true,
	});
	Object_defineProperty(document.createElement, "toString", {
		value: Function_toString.bind(originalCreateElement),
		writable: false,
		configurable: true,
		enumerable: false,
	});
};

try {
	addIframeCreationSniffer();
} catch {}