import { NotificationCenter} from 'Foundation';
import { UIApplication } from "UIKit"
import { OnUserCaptureScreen, OffUserCaptureScreen, UserCaptureScreenCallback, OnUserCaptureScreenResult } from "../interface.uts"


/**
 * 定义监听截屏事件工具类
 */
class CaptureScreenTool {
	static listener: UserCaptureScreenCallback | null;
	
	// 监听截屏
	static listenCaptureScreen(callback: UserCaptureScreenCallback | null) {
		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() {
		// 回调
		const res: OnUserCaptureScreenResult = {
			errCode: 0,
			errSubject: "uni-usercapturescreen",
			errMsg: "onUserCaptureScreen:ok",
			path: null
		}
		this.listener?.(res)
	}
	
	// 移除监听事件
	static removeListen(callback: UserCaptureScreenCallback | null) {
		this.listener = null
		NotificationCenter.default.removeObserver(this)
	}
}

/**
	* 开启截图监听
	*/
export const onUserCaptureScreen : OnUserCaptureScreen = function (callback : UserCaptureScreenCallback | null) {
	CaptureScreenTool.listenCaptureScreen(callback)
}

/**
	* 关闭截屏监听
	*/
export const offUserCaptureScreen : OffUserCaptureScreen = function (callback : UserCaptureScreenCallback | null) {
	CaptureScreenTool.removeListen(callback)
}