import {
	getUniActivity
} from "io.dcloud.uts.android";


import ActivityCompat from "androidx.core.app.ActivityCompat";
import Manifest from "android.Manifest";
import PackageManager from "android.content.pm.PackageManager";
import Build from "android.os.Build";
import FileObserver from "android.os.FileObserver";
import File from "java.io.File";
import Environment from "android.os.Environment";
import System from 'java.lang.System';



/**
 * 文件监听器
 */
let screenOB: ScreenFileObserver | null = null;
/**
 * 记录文件监听器上次监听的时间戳，避免重复监听
 */
let lastFileObserverTime: number = 0;
/**
 * 图片被捕获的实现
 */
let imageChange: UTSCallback | null = null;




/**
 * android 文件监听实现
 */

class ScreenFileObserver extends FileObserver {

	/**
	 * 所有截屏文件的存放目录
	 */
	allScreen: File;

	
	constructor(screenFile: string) {
		super(File(allScreen))
		this.allScreen = new File(screenFile);
		
	}


	override onEvent(event: Int, path?: string): void {
		
		// 只监听文件新增事件
		if (event == FileObserver.CREATE) {
			
			let newPath: string = new File(this.allScreen, path!).getPath();
			let currentTime = System.currentTimeMillis();

			if ((currentTime - lastFileObserverTime) < 1000) {
				// 本地截屏行为比上一次超过1000ms,才认为是一个有效的时间
				return;
			}
			
			lastFileObserverTime = System.currentTimeMillis()
			let ret = {
				errCode:1,
				image:newPath
			}
			
			imageChange!(ret);
		}
	}
}








/**
 * 开启截图监听
 */
export function onUserCaptureScreen(callback: (res:UTSJSONObject) => void) {
	
	// 检查相关权限是否已经具备
	if (ActivityCompat.checkSelfPermission(getUniActivity()!, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
		// 不具备权限，申请权限，并且告知用户监听失败
		ActivityCompat.requestPermissions(getUniActivity()!, arrayOf(Manifest.permission.READ_EXTERNAL_STORAGE), 1001)
		
		// 因权限缺失导致监听失败
		let ret = {
			errCode:-1
		}
		callback(ret);
		return ;
	}
	
	imageChange = callback;

	let directory_screenshot: File;
	// 找到设备存放截屏文件的目录
	let directory_pictures = new File(Environment.getExternalStorageDirectory(), Environment.DIRECTORY_PICTURES);
	let directory_dcim = new File(Environment.getExternalStorageDirectory(), Environment.DIRECTORY_DCIM);
	
	if (Build.MANUFACTURER.lowercase() === "xiaomi") {
		directory_screenshot = new File(directory_dcim, "Screenshots");
	} else {
		directory_screenshot = new File(directory_pictures, "Screenshots");
	}
	
	if (screenOB != null) {
		screenOB!.stopWatching()
	}
	//开始监听
	screenOB = new ScreenFileObserver(directory_screenshot.path)
	screenOB!.startWatching()

	// 监听成功
	let ret = {
		errCode:0
	}
	callback(ret);
	
}


/**
 * 关闭截屏监听
 */
export function offUserCaptureScreen(success: (res: any) => void) {

	// android 10以上，关闭监听通过移除文件监听器实现
	if (screenOB != null) {
		screenOB!.stopWatching()
		screenOB = null
	}
	lastFileObserverTime = 0;
	
	success({});
}