/*
 * Copyright (C) 2022 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.security.cts.CVE_2021_39796;

import static org.junit.Assume.assumeTrue;

import android.app.Service;
import android.content.Intent;
import android.content.res.Resources;
import android.graphics.PixelFormat;
import android.os.IBinder;
import android.provider.Settings;
import android.view.Gravity;
import android.view.WindowManager;
import android.widget.Button;

public class PocService extends Service {
    public static Button mButton;
    private WindowManager mWindowManager;
    private WindowManager.LayoutParams mLayoutParams;

    private static int getScreenWidth() {
        return Resources.getSystem().getDisplayMetrics().widthPixels;
    }

    private static int getScreenHeight() {
        return Resources.getSystem().getDisplayMetrics().heightPixels;
    }

    @Override
    public void onCreate() {
        super.onCreate();
        mWindowManager = getSystemService(WindowManager.class);
        mLayoutParams = new WindowManager.LayoutParams();
        mLayoutParams.type = WindowManager.LayoutParams.TYPE_APPLICATION_OVERLAY;
        mLayoutParams.flags = WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL
                | WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE;
        mLayoutParams.format = PixelFormat.OPAQUE;
        mLayoutParams.gravity = Gravity.LEFT | Gravity.TOP;
        mLayoutParams.width = getScreenWidth();
        mLayoutParams.height = getScreenHeight();
        mLayoutParams.x = getScreenWidth() / 2;
        mLayoutParams.y = getScreenHeight() / 2;
    }

    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        showFloatingWindow();
        return super.onStartCommand(intent, flags, startId);
    }

    @Override
    public void onDestroy() {
        if (mWindowManager != null && mButton != null) {
            mWindowManager.removeView(mButton);
        }
        super.onDestroy();
    }

    private void showFloatingWindow() {
        assumeTrue("The application cannot draw overlays",
                Settings.canDrawOverlays(getApplicationContext()));
        mButton = new Button(getApplicationContext());
        mButton.setText("OverlayButton");
        mWindowManager.addView(mButton, mLayoutParams);
        mButton.setTag(mButton.getVisibility());
    }
}