import { NotificationCenter} from 'Foundation';
import { UIApplication } from "UIKit"

/**
 * 定义监听截屏事件工具类
 */
class CaptureScreenTool {
	static listener?: UTSCallback;
	
	// 监听截屏
	static listenCaptureScreen(callback?: UTSCallback) {
		this.listener = callback
		
		// 注册监听截屏事件及回调方法
		// target-action 回调方法需要通过 Selector("方法名") 构建
		const method = Selector("userDidTakeScreenshot")
		NotificationCenter.default.addObserver(this, selector = method, name = UIApplication.userDidTakeScreenshotNotification, object = null)
	}
	
	// 捕获截屏回调的方法
	// target-action 的方法前需要添加 @objc 前缀
	@objc static userDidTakeScreenshot() {
		const obj = new UTSJSONObject()
		// 回调
		this.listener?.(obj)
	}
	
	// 移除监听事件
	static removeListen(callback?: UTSCallback) {
		this.listener = null
		NotificationCenter.default.removeObserver(this)
		const obj = new UTSJSONObject()
		callback?.(obj)
	}
}

/**
 * 开启截图监听
 */
export function onUserCaptureScreen(callback?: UTSCallback) {
	CaptureScreenTool.listenCaptureScreen(callback)
}

/**
 * 关闭截屏监听
 */
export function offUserCaptureScreen(callback?: UTSCallback) {
	CaptureScreenTool.removeListen(callback)
}