/*
**
** Copyright 2007, 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 com.android.packageinstaller;

import static android.app.AppOpsManager.MODE_ALLOWED;
import static android.content.pm.Flags.usePiaV2;
import static android.view.WindowManager.LayoutParams.SYSTEM_FLAG_HIDE_NON_SYSTEM_OVERLAY_WINDOWS;

import static com.android.packageinstaller.PackageUtil.getMaxTargetSdkVersionForUid;

import android.Manifest;
import android.app.Activity;
import android.app.AppOpsManager;
import android.app.DialogFragment;
import android.app.Fragment;
import android.app.FragmentTransaction;
import android.app.Notification;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.ComponentName;
import android.content.Intent;
import android.content.pm.ActivityInfo;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageInstaller;
import android.content.pm.PackageManager;
import android.content.pm.VersionedPackage;
import android.content.res.Configuration;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.os.Process;
import android.os.UserHandle;
import android.os.UserManager;
import android.util.Log;
import androidx.annotation.NonNull;
import androidx.annotation.StringRes;
import com.android.packageinstaller.handheld.ErrorDialogFragment;
import com.android.packageinstaller.handheld.UninstallAlertDialogFragment;
import com.android.packageinstaller.television.ErrorFragment;
import com.android.packageinstaller.television.UninstallAlertFragment;
import com.android.packageinstaller.television.UninstallAppProgress;
import com.android.packageinstaller.common.EventResultPersister;
import com.android.packageinstaller.common.UninstallEventReceiver;
import com.android.packageinstaller.v2.ui.UninstallLaunch;

import java.util.List;

/*
 * This activity presents UI to uninstall an application. Usually launched with intent
 * Intent.ACTION_UNINSTALL_PKG_COMMAND and attribute
 * com.android.packageinstaller.PackageName set to the application package name
 */
public class UninstallerActivity extends Activity {
    private static final String TAG = "UninstallerActivity";

    private static final String UNINSTALLING_CHANNEL = "uninstalling";
    private boolean mIsClonedApp;

    public static class DialogInfo {
        public ApplicationInfo appInfo;
        public ActivityInfo activityInfo;
        public boolean allUsers;
        public UserHandle user;
        public PackageManager.UninstallCompleteCallback callback;
        public int deleteFlags;
    }

    private String mPackageName;
    private DialogInfo mDialogInfo;

    @Override
    public void onCreate(Bundle icicle) {
        getWindow().addSystemFlags(SYSTEM_FLAG_HIDE_NON_SYSTEM_OVERLAY_WINDOWS);

        // Never restore any state, esp. never create any fragments. The data in the fragment might
        // be stale, if e.g. the app was uninstalled while the activity was destroyed.
        super.onCreate(null);

        // TODO(b/318521110) Enable PIA v2 for archive dialog.
        if (usePiaV2() && !isTv() && !isArchiveDialog(getIntent())) {
            Log.i(TAG, "Using Pia V2");

            boolean returnResult = getIntent().getBooleanExtra(Intent.EXTRA_RETURN_RESULT, false);
            Intent piaV2 = new Intent(getIntent());
            piaV2.putExtra(UninstallLaunch.EXTRA_CALLING_PKG_UID, getLaunchedFromUid());
            piaV2.putExtra(UninstallLaunch.EXTRA_CALLING_ACTIVITY_NAME, getCallingActivity());
            if (returnResult) {
                piaV2.addFlags(Intent.FLAG_ACTIVITY_FORWARD_RESULT);
            }
            piaV2.setClass(this, UninstallLaunch.class);
            startActivity(piaV2);
            finish();
            return;
        }

        int callingUid = getLaunchedFromUid();
        if (callingUid == Process.INVALID_UID) {
            // Cannot reach Package/ActivityManager. Aborting uninstall.
            Log.e(TAG, "Could not determine the launching uid.");

            setResult(Activity.RESULT_FIRST_USER);
            finish();
            return;
        }

        String callingPackage = getPackageNameForUid(callingUid);
        if (callingPackage == null) {
            Log.e(TAG, "Package not found for originating uid " + callingUid);
            setResult(Activity.RESULT_FIRST_USER);
            finish();
            return;
        } else {
            AppOpsManager appOpsManager = getSystemService(AppOpsManager.class);
            if (appOpsManager.noteOpNoThrow(
                    AppOpsManager.OPSTR_REQUEST_DELETE_PACKAGES, callingUid, callingPackage)
                    != MODE_ALLOWED) {
                Log.e(TAG, "Install from uid " + callingUid + " disallowed by AppOps");
                setResult(Activity.RESULT_FIRST_USER);
                finish();
                return;
            }
        }

        if (getMaxTargetSdkVersionForUid(this, callingUid) >= Build.VERSION_CODES.P
                && getBaseContext().checkPermission(Manifest.permission.REQUEST_DELETE_PACKAGES,
                0 /* random value for pid */, callingUid) != PackageManager.PERMISSION_GRANTED
                && getBaseContext().checkPermission(Manifest.permission.DELETE_PACKAGES,
                0 /* random value for pid */, callingUid) != PackageManager.PERMISSION_GRANTED) {
            Log.e(TAG, "Uid " + callingUid + " does not have "
                    + Manifest.permission.REQUEST_DELETE_PACKAGES + " or "
                    + Manifest.permission.DELETE_PACKAGES);

            setResult(Activity.RESULT_FIRST_USER);
            finish();
            return;
        }

        // Get intent information.
        // We expect an intent with URI of the form package://<packageName>#<className>
        // className is optional; if specified, it is the activity the user chose to uninstall
        final Intent intent = getIntent();
        final Uri packageUri = intent.getData();
        if (packageUri == null) {
            Log.e(TAG, "No package URI in intent");
            showAppNotFound();
            return;
        }
        mPackageName = packageUri.getEncodedSchemeSpecificPart();
        if (mPackageName == null) {
            Log.e(TAG, "Invalid package name in URI: " + packageUri);
            showAppNotFound();
            return;
        }

        PackageManager pm = getPackageManager();
        UserManager userManager = getBaseContext().getSystemService(UserManager.class);

        mDialogInfo = new DialogInfo();

        mDialogInfo.allUsers = intent.getBooleanExtra(Intent.EXTRA_UNINSTALL_ALL_USERS, false);
        if (mDialogInfo.allUsers && !userManager.isAdminUser()) {
            Log.e(TAG, "Only admin user can request uninstall for all users");
            showUserIsNotAllowed();
            return;
        }
        mDialogInfo.user = intent.getParcelableExtra(Intent.EXTRA_USER);
        if (mDialogInfo.user == null) {
            mDialogInfo.user = Process.myUserHandle();
        } else {
            List<UserHandle> profiles = userManager.getUserProfiles();
            if (!profiles.contains(mDialogInfo.user)) {
                Log.e(TAG, "User " + Process.myUserHandle() + " can't request uninstall "
                        + "for user " + mDialogInfo.user);
                showUserIsNotAllowed();
                return;
            }
        }

        mDialogInfo.callback = intent.getParcelableExtra(PackageInstaller.EXTRA_CALLBACK,
                                            PackageManager.UninstallCompleteCallback.class);

        try {
            mDialogInfo.appInfo = pm.getApplicationInfo(mPackageName,
                    PackageManager.ApplicationInfoFlags.of(PackageManager.MATCH_ANY_USER
                            | PackageManager.MATCH_ARCHIVED_PACKAGES));
        } catch (PackageManager.NameNotFoundException e) {
            Log.e(TAG, "Unable to get packageName. Package manager is dead?");
        }

        if (mDialogInfo.appInfo == null) {
            Log.e(TAG, "Invalid packageName: " + mPackageName);
            showAppNotFound();
            return;
        }

        // The class name may have been specified (e.g. when deleting an app from all apps)
        final String className = packageUri.getFragment();
        if (className != null) {
            try {
                mDialogInfo.activityInfo = pm.getActivityInfo(
                        new ComponentName(mPackageName, className),
                        PackageManager.ComponentInfoFlags.of(0));
            } catch (PackageManager.NameNotFoundException e) {
                Log.e(TAG, "Unable to get className. Package manager is dead?");
                // Continue as the ActivityInfo isn't critical.
            }
        }
        parseDeleteFlags(intent);

        showConfirmationDialog();
    }

    private boolean isArchiveDialog(Intent intent) {
        return (intent.getIntExtra(PackageInstaller.EXTRA_DELETE_FLAGS, 0)
                & PackageManager.DELETE_ARCHIVE) != 0;
    }

    /**
     * Parses specific {@link android.content.pm.PackageManager.DeleteFlags} from {@link Intent}
     * to archive an app if requested.
     *
     * Do not parse any flags because developers might pass here any flags which might cause
     * unintended behaviour.
     * For more context {@link com.android.server.pm.PackageArchiver#requestArchive}.
     */
    private void parseDeleteFlags(Intent intent) {
        int deleteFlags = intent.getIntExtra(PackageInstaller.EXTRA_DELETE_FLAGS, 0);
        int archive = deleteFlags & PackageManager.DELETE_ARCHIVE;
        int keepData = deleteFlags & PackageManager.DELETE_KEEP_DATA;
        mDialogInfo.deleteFlags = archive | keepData;
    }

    public DialogInfo getDialogInfo() {
        return mDialogInfo;
    }

    private void showConfirmationDialog() {
        if (isTv()) {
            showContentFragment(new UninstallAlertFragment(), 0, 0);
        } else {
            showDialogFragment(new UninstallAlertDialogFragment(), 0, 0);
        }
    }

    private void showAppNotFound() {
        if (isTv()) {
            showContentFragment(new ErrorFragment(), R.string.app_not_found_dlg_title,
                    R.string.app_not_found_dlg_text);
        } else {
            showDialogFragment(new ErrorDialogFragment(), R.string.app_not_found_dlg_title,
                    R.string.app_not_found_dlg_text);
        }
    }

    private void showUserIsNotAllowed() {
        if (isTv()) {
            showContentFragment(new ErrorFragment(),
                    R.string.user_is_not_allowed_dlg_title, R.string.user_is_not_allowed_dlg_text);
        } else {
            showDialogFragment(new ErrorDialogFragment(), 0, R.string.user_is_not_allowed_dlg_text);
        }
    }

    private void showGenericError() {
        if (isTv()) {
            showContentFragment(new ErrorFragment(),
                    R.string.generic_error_dlg_title, R.string.generic_error_dlg_text);
        } else {
            showDialogFragment(new ErrorDialogFragment(), 0, R.string.generic_error_dlg_text);
        }
    }

    private boolean isTv() {
        return (getResources().getConfiguration().uiMode & Configuration.UI_MODE_TYPE_MASK)
                == Configuration.UI_MODE_TYPE_TELEVISION;
    }

    private void showContentFragment(@NonNull Fragment fragment, @StringRes int title,
            @StringRes int text) {
        Bundle args = new Bundle();
        args.putInt(ErrorFragment.TITLE, title);
        args.putInt(ErrorFragment.TEXT, text);
        fragment.setArguments(args);

        getFragmentManager().beginTransaction()
                .replace(android.R.id.content, fragment)
                .commit();
    }

    private void showDialogFragment(@NonNull DialogFragment fragment,
            @StringRes int title, @StringRes int text) {
        FragmentTransaction ft = getFragmentManager().beginTransaction();
        Fragment prev = getFragmentManager().findFragmentByTag("dialog");
        if (prev != null) {
            ft.remove(prev);
        }

        Bundle args = new Bundle();
        if (title != 0) {
            args.putInt(ErrorDialogFragment.TITLE, title);
        }
        args.putInt(ErrorDialogFragment.TEXT, text);

        fragment.setArguments(args);
        fragment.show(ft, "dialog");
    }

    /**
     * Starts uninstall of app.
     */
    public void startUninstallProgress(boolean keepData, boolean isClonedApp) {
        mIsClonedApp = isClonedApp;
        startUninstallProgress(keepData);
    }

    public void startUninstallProgress(boolean keepData) {
        boolean returnResult = getIntent().getBooleanExtra(Intent.EXTRA_RETURN_RESULT, false);
        CharSequence label = mDialogInfo.appInfo.loadSafeLabel(getPackageManager());

        if (isTv()) {
            Intent newIntent = new Intent(Intent.ACTION_VIEW);
            newIntent.putExtra(Intent.EXTRA_USER, mDialogInfo.user);
            newIntent.putExtra(Intent.EXTRA_UNINSTALL_ALL_USERS, mDialogInfo.allUsers);
            newIntent.putExtra(PackageInstaller.EXTRA_CALLBACK, mDialogInfo.callback);
            newIntent.putExtra(PackageUtil.INTENT_ATTR_APPLICATION_INFO, mDialogInfo.appInfo);

            if (returnResult) {
                newIntent.putExtra(Intent.EXTRA_RETURN_RESULT, true);
                newIntent.addFlags(Intent.FLAG_ACTIVITY_FORWARD_RESULT);
            }

            newIntent.setClass(this, UninstallAppProgress.class);
            startActivity(newIntent);
        } else if (returnResult || mDialogInfo.callback != null || getCallingActivity() != null) {
            Intent newIntent = new Intent(this, UninstallUninstalling.class);

            newIntent.putExtra(Intent.EXTRA_USER, mDialogInfo.user);
            newIntent.putExtra(Intent.EXTRA_UNINSTALL_ALL_USERS, mDialogInfo.allUsers);
            newIntent.putExtra(PackageUtil.INTENT_ATTR_APPLICATION_INFO, mDialogInfo.appInfo);
            newIntent.putExtra(UninstallUninstalling.EXTRA_APP_LABEL, label);
            newIntent.putExtra(UninstallUninstalling.EXTRA_KEEP_DATA, keepData);
            newIntent.putExtra(PackageInstaller.EXTRA_CALLBACK, mDialogInfo.callback);
            if (returnResult) {
                newIntent.putExtra(Intent.EXTRA_RETURN_RESULT, true);
            }

            if (returnResult || getCallingActivity() != null) {
                newIntent.addFlags(Intent.FLAG_ACTIVITY_FORWARD_RESULT);
            }
            if (mDialogInfo.deleteFlags != 0) {
                newIntent.putExtra(PackageInstaller.EXTRA_DELETE_FLAGS,
                        mDialogInfo.deleteFlags);
            }
            startActivity(newIntent);
        } else {
            int uninstallId;
            try {
                uninstallId = UninstallEventReceiver.getNewId(this);
            } catch (EventResultPersister.OutOfIdsException e) {
                showGenericError();
                return;
            }

            Intent broadcastIntent = new Intent(this, UninstallFinish.class);

            broadcastIntent.setFlags(Intent.FLAG_RECEIVER_FOREGROUND);
            broadcastIntent.putExtra(Intent.EXTRA_UNINSTALL_ALL_USERS, mDialogInfo.allUsers);
            broadcastIntent.putExtra(PackageUtil.INTENT_ATTR_APPLICATION_INFO, mDialogInfo.appInfo);
            broadcastIntent.putExtra(UninstallFinish.EXTRA_APP_LABEL, label);
            broadcastIntent.putExtra(UninstallFinish.EXTRA_UNINSTALL_ID, uninstallId);
            broadcastIntent.putExtra(UninstallFinish.EXTRA_IS_CLONE_APP, mIsClonedApp);

            PendingIntent pendingIntent =
                    PendingIntent.getBroadcast(this, uninstallId, broadcastIntent,
                            PendingIntent.FLAG_MUTABLE | PendingIntent.FLAG_UPDATE_CURRENT);

            NotificationManager notificationManager = getSystemService(NotificationManager.class);
            NotificationChannel uninstallingChannel = new NotificationChannel(UNINSTALLING_CHANNEL,
                    getString(R.string.uninstalling_notification_channel),
                    NotificationManager.IMPORTANCE_MIN);
            notificationManager.createNotificationChannel(uninstallingChannel);

            Notification uninstallingNotification =
                    (new Notification.Builder(this, UNINSTALLING_CHANNEL))
                    .setSmallIcon(R.drawable.ic_remove).setProgress(0, 1, true)
                    .setContentTitle(mIsClonedApp
                            ? getString(R.string.uninstalling_cloned_app, label)
                            : getString(R.string.uninstalling_app, label))
                            .setOngoing(true)
                    .build();

            notificationManager.notify(uninstallId, uninstallingNotification);

            try {
                Log.i(TAG, "Uninstalling extras=" + broadcastIntent.getExtras());

                int flags = mDialogInfo.allUsers ? PackageManager.DELETE_ALL_USERS : 0;
                flags |= keepData ? PackageManager.DELETE_KEEP_DATA : 0;
                flags |= mDialogInfo.deleteFlags;

                createContextAsUser(mDialogInfo.user, 0).getPackageManager().getPackageInstaller()
                        .uninstall(new VersionedPackage(mDialogInfo.appInfo.packageName,
                                PackageManager.VERSION_CODE_HIGHEST), flags,
                                pendingIntent.getIntentSender());
            } catch (Exception e) {
                notificationManager.cancel(uninstallId);

                Log.e(TAG, "Cannot start uninstall", e);
                showGenericError();
            }
        }
    }

    public void dispatchAborted() {
        if (mDialogInfo != null && mDialogInfo.callback != null) {
            mDialogInfo.callback.onUninstallComplete(mPackageName,
                    PackageManager.DELETE_FAILED_ABORTED, "Cancelled by user");
        }
    }

    private String getPackageNameForUid(int sourceUid) {
        String[] packagesForUid = getPackageManager().getPackagesForUid(sourceUid);
        if (packagesForUid == null) {
            return null;
        }
        return packagesForUid[0];
    }
}