/*
 * Copyright (C) 2021 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_0523;

import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.provider.Settings;
import androidx.test.runner.AndroidJUnit4;
import androidx.test.uiautomator.By;
import androidx.test.uiautomator.BySelector;
import androidx.test.uiautomator.UiDevice;
import androidx.test.uiautomator.Until;
import java.io.IOException;
import java.util.regex.Pattern;
import org.junit.Before;
import org.junit.runner.RunWith;
import org.junit.Test;

import static androidx.test.core.app.ApplicationProvider.getApplicationContext;
import static androidx.test.platform.app.InstrumentationRegistry.getInstrumentation;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertNull;

@RunWith(AndroidJUnit4.class)
public class DeviceTest {
    private static final String TEST_PKG = "android.security.cts.cve_2021_0523";
    private static final String TEST_PKG_WIFI = "com.android.settings";
    private static final int LAUNCH_TIMEOUT_MS = 20000;
    private UiDevice mDevice;
    String activityDump = "";

    private void startOverlayService() {
        Context context = getApplicationContext();
        if (Settings.canDrawOverlays(getApplicationContext())) {
            Intent intent = new Intent(getApplicationContext(), PocService.class);
            context.startService(intent);
        } else {
            try {
                Intent intent = new Intent(Settings.ACTION_MANAGE_OVERLAY_PERMISSION);
                intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                context.startActivity(intent);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

    @Before
    public void startMainActivityFromHomeScreen() {
        mDevice = UiDevice.getInstance(getInstrumentation());
        Context context = getApplicationContext();
        assertNotNull(context);
        PackageManager packageManager = context.getPackageManager();
        assertNotNull(packageManager);
        final Intent intent = packageManager.getLaunchIntentForPackage(TEST_PKG);
        assertNotNull(intent);
        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
        /* Start the launcher activity */
        context.startActivity(intent);
        /* Wait for the WifiScanModeActivity */
        if (!mDevice.wait(Until.hasObject(By.pkg(TEST_PKG_WIFI).depth(0)), LAUNCH_TIMEOUT_MS)) {
            return;
        }
        /* Start the overlay service */
        startOverlayService();
    }

    @Test
    public void testOverlayButtonPresence() {
        Pattern pattern = Pattern.compile(
                getApplicationContext().getResources().getString(R.string.overlay_button),
                Pattern.CASE_INSENSITIVE);
        BySelector selector = By.text(pattern);
        /* Wait for an object of the overlay window */
        if (!mDevice.wait(Until.hasObject(selector.depth(0)), LAUNCH_TIMEOUT_MS)) {
            return;
        }
        /* Check if the currently running activity is WifiScanModeActivity */
        try {
            activityDump = mDevice.executeShellCommand("dumpsys activity");
        } catch (IOException e) {
            throw new RuntimeException("Could not execute dumpsys activity command");
        }
        Pattern activityPattern = Pattern.compile("mResumedActivity.*WifiScanModeActivity.*\n");
        if (!activityPattern.matcher(activityDump).find()) {
            return;
        }
        String message = "Device is vulnerable to b/174047492 hence any app with "
                + "SYSTEM_ALERT_WINDOW can overlay the WifiScanModeActivity screen";
        assertNull(message, mDevice.findObject(selector));
    }
}