/*
**
** 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.view.WindowManager.LayoutParams.SYSTEM_FLAG_HIDE_NON_SYSTEM_OVERLAY_WINDOWS;

import android.Manifest;
import android.annotation.NonNull;
import android.annotation.StringRes;
import android.app.AlertDialog;
import android.app.AppGlobals;
import android.app.AppOpsManager;
import android.app.Dialog;
import android.app.DialogFragment;
import android.content.ActivityNotFoundException;
import android.content.ContentResolver;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.ApplicationInfo;
import android.content.pm.IPackageManager;
import android.content.pm.PackageInfo;
import android.content.pm.PackageInstaller;
import android.content.pm.PackageManager;
import android.content.pm.PackageManager.NameNotFoundException;
import android.content.pm.PackageParser;
import android.content.pm.PackageUserState;
import android.net.Uri;
import android.os.Bundle;
import android.os.Process;
import android.os.RemoteException;
import android.os.UserManager;
import android.provider.Settings;
import android.util.Log;
import android.view.View;
import android.widget.Button;

import com.android.internal.app.AlertActivity;

import java.io.File;

/**
 * This activity is launched when a new application is installed via side loading
 * The package is first parsed and the user is notified of parse errors via a dialog.
 * If the package is successfully parsed, the user is notified to turn on the install unknown
 * applications setting. A memory check is made at this point and the user is notified of out
 * of memory conditions if any. If the package is already existing on the device,
 * a confirmation dialog (to replace the existing package) is presented to the user.
 * Based on the user response the package is then installed by launching InstallAppConfirm
 * sub activity. All state transitions are handled in this activity
 */
public class PackageInstallerActivity extends AlertActivity {
    private static final String TAG = "PackageInstaller";

    private static final int REQUEST_TRUST_EXTERNAL_SOURCE = 1;

    static final String SCHEME_PACKAGE = "package";

    static final String EXTRA_CALLING_PACKAGE = "EXTRA_CALLING_PACKAGE";
    static final String EXTRA_ORIGINAL_SOURCE_INFO = "EXTRA_ORIGINAL_SOURCE_INFO";
    private static final String ALLOW_UNKNOWN_SOURCES_KEY =
            PackageInstallerActivity.class.getName() + "ALLOW_UNKNOWN_SOURCES_KEY";

    private int mSessionId = -1;
    private Uri mPackageURI;
    private Uri mOriginatingURI;
    private Uri mReferrerURI;
    private int mOriginatingUid = PackageInstaller.SessionParams.UID_UNKNOWN;
    private String mOriginatingPackage; // The package name corresponding to #mOriginatingUid

    private boolean localLOGV = false;
    PackageManager mPm;
    IPackageManager mIpm;
    AppOpsManager mAppOpsManager;
    UserManager mUserManager;
    PackageInstaller mInstaller;
    PackageInfo mPkgInfo;
    String mCallingPackage;
    ApplicationInfo mSourceInfo;

    // ApplicationInfo object primarily used for already existing applications
    private ApplicationInfo mAppInfo = null;

    // Buttons to indicate user acceptance
    private Button mOk;

    private PackageUtil.AppSnippet mAppSnippet;

    static final String PREFS_ALLOWED_SOURCES = "allowed_sources";

    // Dialog identifiers used in showDialog
    private static final int DLG_BASE = 0;
    private static final int DLG_PACKAGE_ERROR = DLG_BASE + 2;
    private static final int DLG_OUT_OF_SPACE = DLG_BASE + 3;
    private static final int DLG_INSTALL_ERROR = DLG_BASE + 4;
    private static final int DLG_UNKNOWN_SOURCES_RESTRICTED_FOR_USER = DLG_BASE + 5;
    private static final int DLG_ANONYMOUS_SOURCE = DLG_BASE + 6;
    private static final int DLG_NOT_SUPPORTED_ON_WEAR = DLG_BASE + 7;
    private static final int DLG_EXTERNAL_SOURCE_BLOCKED = DLG_BASE + 8;
    private static final int DLG_INSTALL_APPS_RESTRICTED_FOR_USER = DLG_BASE + 9;

    // If unknown sources are temporary allowed
    private boolean mAllowUnknownSources;

    // Would the mOk button be enabled if this activity would be resumed
    private boolean mEnableOk = false;

    private void startInstallConfirm() {
        View viewToEnable;

        if (mAppInfo != null) {
            viewToEnable = (mAppInfo.flags & ApplicationInfo.FLAG_SYSTEM) != 0
                    ? requireViewById(R.id.install_confirm_question_update_system)
                    : requireViewById(R.id.install_confirm_question_update);
        } else {
            // This is a new application with no permissions.
            viewToEnable = requireViewById(R.id.install_confirm_question);
        }

        viewToEnable.setVisibility(View.VISIBLE);

        mEnableOk = true;
        mOk.setEnabled(true);
    }

    /**
     * Replace any dialog shown by the dialog with the one for the given {@link #createDialog id}.
     *
     * @param id The dialog type to add
     */
    private void showDialogInner(int id) {
        DialogFragment currentDialog =
                (DialogFragment) getFragmentManager().findFragmentByTag("dialog");
        if (currentDialog != null) {
            currentDialog.dismissAllowingStateLoss();
        }

        DialogFragment newDialog = createDialog(id);
        if (newDialog != null) {
            newDialog.showAllowingStateLoss(getFragmentManager(), "dialog");
        }
    }

    /**
     * Create a new dialog.
     *
     * @param id The id of the dialog (determines dialog type)
     *
     * @return The dialog
     */
    private DialogFragment createDialog(int id) {
        switch (id) {
            case DLG_PACKAGE_ERROR:
                return SimpleErrorDialog.newInstance(R.string.Parse_error_dlg_text);
            case DLG_OUT_OF_SPACE:
                return OutOfSpaceDialog.newInstance(
                        mPm.getApplicationLabel(mPkgInfo.applicationInfo));
            case DLG_INSTALL_ERROR:
                return InstallErrorDialog.newInstance(
                        mPm.getApplicationLabel(mPkgInfo.applicationInfo));
            case DLG_NOT_SUPPORTED_ON_WEAR:
                return NotSupportedOnWearDialog.newInstance();
            case DLG_INSTALL_APPS_RESTRICTED_FOR_USER:
                return SimpleErrorDialog.newInstance(
                        R.string.install_apps_user_restriction_dlg_text);
            case DLG_UNKNOWN_SOURCES_RESTRICTED_FOR_USER:
                return SimpleErrorDialog.newInstance(
                        R.string.unknown_apps_user_restriction_dlg_text);
            case DLG_EXTERNAL_SOURCE_BLOCKED:
                return ExternalSourcesBlockedDialog.newInstance(mOriginatingPackage);
            case DLG_ANONYMOUS_SOURCE:
                return AnonymousSourceDialog.newInstance();
        }
        return null;
    }

    @Override
    public void onActivityResult(int request, int result, Intent data) {
        if (request == REQUEST_TRUST_EXTERNAL_SOURCE && result == RESULT_OK) {
            // The user has just allowed this package to install other packages (via Settings).
            mAllowUnknownSources = true;

            // Log the fact that the app is requesting an install, and is now allowed to do it
            // (before this point we could only log that it's requesting an install, but isn't
            // allowed to do it yet).
            int appOpCode =
                    AppOpsManager.permissionToOpCode(Manifest.permission.REQUEST_INSTALL_PACKAGES);
            mAppOpsManager.noteOpNoThrow(appOpCode, mOriginatingUid, mOriginatingPackage);

            DialogFragment currentDialog =
                    (DialogFragment) getFragmentManager().findFragmentByTag("dialog");
            if (currentDialog != null) {
                currentDialog.dismissAllowingStateLoss();
            }

            initiateInstall();
        } else {
            finish();
        }
    }

    private String getPackageNameForUid(int sourceUid) {
        String[] packagesForUid = mPm.getPackagesForUid(sourceUid);
        if (packagesForUid == null) {
            return null;
        }
        if (packagesForUid.length > 1) {
            if (mCallingPackage != null) {
                for (String packageName : packagesForUid) {
                    if (packageName.equals(mCallingPackage)) {
                        return packageName;
                    }
                }
            }
            Log.i(TAG, "Multiple packages found for source uid " + sourceUid);
        }
        return packagesForUid[0];
    }

    private boolean isInstallRequestFromUnknownSource(Intent intent) {
        if (mCallingPackage != null && intent.getBooleanExtra(
                Intent.EXTRA_NOT_UNKNOWN_SOURCE, false)) {
            if (mSourceInfo != null) {
                if ((mSourceInfo.privateFlags & ApplicationInfo.PRIVATE_FLAG_PRIVILEGED)
                        != 0) {
                    // Privileged apps can bypass unknown sources check if they want.
                    return false;
                }
            }
        }
        return true;
    }

    private void initiateInstall() {
        String pkgName = mPkgInfo.packageName;
        // Check if there is already a package on the device with this name
        // but it has been renamed to something else.
        String[] oldName = mPm.canonicalToCurrentPackageNames(new String[] { pkgName });
        if (oldName != null && oldName.length > 0 && oldName[0] != null) {
            pkgName = oldName[0];
            mPkgInfo.packageName = pkgName;
            mPkgInfo.applicationInfo.packageName = pkgName;
        }
        // Check if package is already installed. display confirmation dialog if replacing pkg
        try {
            // This is a little convoluted because we want to get all uninstalled
            // apps, but this may include apps with just data, and if it is just
            // data we still want to count it as "installed".
            mAppInfo = mPm.getApplicationInfo(pkgName,
                    PackageManager.MATCH_UNINSTALLED_PACKAGES);
            if ((mAppInfo.flags&ApplicationInfo.FLAG_INSTALLED) == 0) {
                mAppInfo = null;
            }
        } catch (NameNotFoundException e) {
            mAppInfo = null;
        }

        startInstallConfirm();
    }

    void setPmResult(int pmResult) {
        Intent result = new Intent();
        result.putExtra(Intent.EXTRA_INSTALL_RESULT, pmResult);
        setResult(pmResult == PackageManager.INSTALL_SUCCEEDED
                ? RESULT_OK : RESULT_FIRST_USER, result);
    }

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

        super.onCreate(null);

        if (icicle != null) {
            mAllowUnknownSources = icicle.getBoolean(ALLOW_UNKNOWN_SOURCES_KEY);
        }

        mPm = getPackageManager();
        mIpm = AppGlobals.getPackageManager();
        mAppOpsManager = (AppOpsManager) getSystemService(Context.APP_OPS_SERVICE);
        mInstaller = mPm.getPackageInstaller();
        mUserManager = (UserManager) getSystemService(Context.USER_SERVICE);

        final Intent intent = getIntent();

        mCallingPackage = intent.getStringExtra(EXTRA_CALLING_PACKAGE);
        mSourceInfo = intent.getParcelableExtra(EXTRA_ORIGINAL_SOURCE_INFO);
        mOriginatingUid = intent.getIntExtra(Intent.EXTRA_ORIGINATING_UID,
                PackageInstaller.SessionParams.UID_UNKNOWN);
        mOriginatingPackage = (mOriginatingUid != PackageInstaller.SessionParams.UID_UNKNOWN)
                ? getPackageNameForUid(mOriginatingUid) : null;


        final Uri packageUri;

        if (PackageInstaller.ACTION_CONFIRM_INSTALL.equals(intent.getAction())) {
            final int sessionId = intent.getIntExtra(PackageInstaller.EXTRA_SESSION_ID, -1);
            final PackageInstaller.SessionInfo info = mInstaller.getSessionInfo(sessionId);
            if (info == null || !info.sealed || info.resolvedBaseCodePath == null) {
                Log.w(TAG, "Session " + mSessionId + " in funky state; ignoring");
                finish();
                return;
            }

            mSessionId = sessionId;
            packageUri = Uri.fromFile(new File(info.resolvedBaseCodePath));
            mOriginatingURI = null;
            mReferrerURI = null;
        } else {
            mSessionId = -1;
            packageUri = intent.getData();
            mOriginatingURI = intent.getParcelableExtra(Intent.EXTRA_ORIGINATING_URI);
            mReferrerURI = intent.getParcelableExtra(Intent.EXTRA_REFERRER);
        }

        // if there's nothing to do, quietly slip into the ether
        if (packageUri == null) {
            Log.w(TAG, "Unspecified source");
            setPmResult(PackageManager.INSTALL_FAILED_INVALID_URI);
            finish();
            return;
        }

        if (DeviceUtils.isWear(this)) {
            showDialogInner(DLG_NOT_SUPPORTED_ON_WEAR);
            return;
        }

        boolean wasSetUp = processPackageUri(packageUri);
        if (!wasSetUp) {
            return;
        }

        // load dummy layout with OK button disabled until we override this layout in
        // startInstallConfirm
        bindUi();
        checkIfAllowedAndInitiateInstall();
    }

    @Override
    protected void onResume() {
        super.onResume();

        if (mOk != null) {
            mOk.setEnabled(mEnableOk);
        }
    }

    @Override
    protected void onPause() {
        super.onPause();

        if (mOk != null) {
            // Don't allow the install button to be clicked as there might be overlays
            mOk.setEnabled(false);
        }
    }

    @Override
    protected void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);

        outState.putBoolean(ALLOW_UNKNOWN_SOURCES_KEY, mAllowUnknownSources);
    }

    private void bindUi() {
        mAlert.setIcon(mAppSnippet.icon);
        mAlert.setTitle(mAppSnippet.label);
        mAlert.setView(R.layout.install_content_view);
        mAlert.setButton(DialogInterface.BUTTON_POSITIVE, getString(R.string.install),
                (ignored, ignored2) -> {
                    if (mOk.isEnabled()) {
                        if (mSessionId != -1) {
                            mInstaller.setPermissionsResult(mSessionId, true);
                            finish();
                        } else {
                            startInstall();
                        }
                    }
                }, null);
        mAlert.setButton(DialogInterface.BUTTON_NEGATIVE, getString(R.string.cancel),
                (ignored, ignored2) -> {
                    // Cancel and finish
                    setResult(RESULT_CANCELED);
                    if (mSessionId != -1) {
                        mInstaller.setPermissionsResult(mSessionId, false);
                    }
                    finish();
                }, null);
        setupAlert();

        mOk = mAlert.getButton(DialogInterface.BUTTON_POSITIVE);
        mOk.setEnabled(false);
    }

    /**
     * Check if it is allowed to install the package and initiate install if allowed. If not allowed
     * show the appropriate dialog.
     */
    private void checkIfAllowedAndInitiateInstall() {
        // Check for install apps user restriction first.
        final int installAppsRestrictionSource = mUserManager.getUserRestrictionSource(
                UserManager.DISALLOW_INSTALL_APPS, Process.myUserHandle());
        if ((installAppsRestrictionSource & UserManager.RESTRICTION_SOURCE_SYSTEM) != 0) {
            showDialogInner(DLG_INSTALL_APPS_RESTRICTED_FOR_USER);
            return;
        } else if (installAppsRestrictionSource != UserManager.RESTRICTION_NOT_SET) {
            startActivity(new Intent(Settings.ACTION_SHOW_ADMIN_SUPPORT_DETAILS));
            finish();
            return;
        }

        if (mAllowUnknownSources || !isInstallRequestFromUnknownSource(getIntent())) {
            initiateInstall();
        } else {
            // Check for unknown sources restriction
            final int unknownSourcesRestrictionSource = mUserManager.getUserRestrictionSource(
                    UserManager.DISALLOW_INSTALL_UNKNOWN_SOURCES, Process.myUserHandle());
            final int unknownSourcesGlobalRestrictionSource = mUserManager.getUserRestrictionSource(
                    UserManager.DISALLOW_INSTALL_UNKNOWN_SOURCES_GLOBALLY, Process.myUserHandle());
            final int systemRestriction = UserManager.RESTRICTION_SOURCE_SYSTEM
                    & (unknownSourcesRestrictionSource | unknownSourcesGlobalRestrictionSource);
            if (systemRestriction != 0) {
                showDialogInner(DLG_UNKNOWN_SOURCES_RESTRICTED_FOR_USER);
            } else if (unknownSourcesRestrictionSource != UserManager.RESTRICTION_NOT_SET
                    || unknownSourcesGlobalRestrictionSource != UserManager.RESTRICTION_NOT_SET) {
                startActivity(new Intent(Settings.ACTION_SHOW_ADMIN_SUPPORT_DETAILS));
                finish();
            } else {
                handleUnknownSources();
            }
        }
    }

    private void handleUnknownSources() {
        if (mOriginatingPackage == null) {
            Log.i(TAG, "No source found for package " + mPkgInfo.packageName);
            showDialogInner(DLG_ANONYMOUS_SOURCE);
            return;
        }
        // Shouldn't use static constant directly, see b/65534401.
        final int appOpCode =
                AppOpsManager.permissionToOpCode(Manifest.permission.REQUEST_INSTALL_PACKAGES);
        final int appOpMode = mAppOpsManager.noteOpNoThrow(appOpCode,
                mOriginatingUid, mOriginatingPackage);
        switch (appOpMode) {
            case AppOpsManager.MODE_DEFAULT:
                try {
                    int result = mIpm.checkUidPermission(
                            Manifest.permission.REQUEST_INSTALL_PACKAGES, mOriginatingUid);
                    if (result == PackageManager.PERMISSION_GRANTED) {
                        initiateInstall();
                        break;
                    }
                } catch (RemoteException exc) {
                    Log.e(TAG, "Unable to talk to package manager");
                }
                mAppOpsManager.setMode(appOpCode, mOriginatingUid,
                        mOriginatingPackage, AppOpsManager.MODE_ERRORED);
                // fall through
            case AppOpsManager.MODE_ERRORED:
                showDialogInner(DLG_EXTERNAL_SOURCE_BLOCKED);
                break;
            case AppOpsManager.MODE_ALLOWED:
                initiateInstall();
                break;
            default:
                Log.e(TAG, "Invalid app op mode " + appOpMode
                        + " for OP_REQUEST_INSTALL_PACKAGES found for uid " + mOriginatingUid);
                finish();
                break;
        }
    }

    /**
     * Parse the Uri and set up the installer for this package.
     *
     * @param packageUri The URI to parse
     *
     * @return {@code true} iff the installer could be set up
     */
    private boolean processPackageUri(final Uri packageUri) {
        mPackageURI = packageUri;

        final String scheme = packageUri.getScheme();

        switch (scheme) {
            case SCHEME_PACKAGE: {
                try {
                    mPkgInfo = mPm.getPackageInfo(packageUri.getSchemeSpecificPart(),
                            PackageManager.GET_PERMISSIONS
                                    | PackageManager.MATCH_UNINSTALLED_PACKAGES);
                } catch (NameNotFoundException e) {
                }
                if (mPkgInfo == null) {
                    Log.w(TAG, "Requested package " + packageUri.getScheme()
                            + " not available. Discontinuing installation");
                    showDialogInner(DLG_PACKAGE_ERROR);
                    setPmResult(PackageManager.INSTALL_FAILED_INVALID_APK);
                    return false;
                }
                mAppSnippet = new PackageUtil.AppSnippet(mPm.getApplicationLabel(mPkgInfo.applicationInfo),
                        mPm.getApplicationIcon(mPkgInfo.applicationInfo));
            } break;

            case ContentResolver.SCHEME_FILE: {
                File sourceFile = new File(packageUri.getPath());
                PackageParser.Package parsed = PackageUtil.getPackageInfo(this, sourceFile);

                // Check for parse errors
                if (parsed == null) {
                    Log.w(TAG, "Parse error when parsing manifest. Discontinuing installation");
                    showDialogInner(DLG_PACKAGE_ERROR);
                    setPmResult(PackageManager.INSTALL_FAILED_INVALID_APK);
                    return false;
                }
                mPkgInfo = PackageParser.generatePackageInfo(parsed, null,
                        PackageManager.GET_PERMISSIONS, 0, 0, null,
                        new PackageUserState());
                mAppSnippet = PackageUtil.getAppSnippet(this, mPkgInfo.applicationInfo, sourceFile);
            } break;

            default: {
                throw new IllegalArgumentException("Unexpected URI scheme " + packageUri);
            }
        }

        return true;
    }

    @Override
    public void onBackPressed() {
        if (mSessionId != -1) {
            mInstaller.setPermissionsResult(mSessionId, false);
        }
        super.onBackPressed();
    }

    private void startInstall() {
        // Start subactivity to actually install the application
        Intent newIntent = new Intent();
        newIntent.putExtra(PackageUtil.INTENT_ATTR_APPLICATION_INFO,
                mPkgInfo.applicationInfo);
        newIntent.setData(mPackageURI);
        newIntent.setClass(this, InstallInstalling.class);
        String installerPackageName = getIntent().getStringExtra(
                Intent.EXTRA_INSTALLER_PACKAGE_NAME);
        if (mOriginatingURI != null) {
            newIntent.putExtra(Intent.EXTRA_ORIGINATING_URI, mOriginatingURI);
        }
        if (mReferrerURI != null) {
            newIntent.putExtra(Intent.EXTRA_REFERRER, mReferrerURI);
        }
        if (mOriginatingUid != PackageInstaller.SessionParams.UID_UNKNOWN) {
            newIntent.putExtra(Intent.EXTRA_ORIGINATING_UID, mOriginatingUid);
        }
        if (installerPackageName != null) {
            newIntent.putExtra(Intent.EXTRA_INSTALLER_PACKAGE_NAME,
                    installerPackageName);
        }
        if (getIntent().getBooleanExtra(Intent.EXTRA_RETURN_RESULT, false)) {
            newIntent.putExtra(Intent.EXTRA_RETURN_RESULT, true);
        }
        newIntent.addFlags(Intent.FLAG_ACTIVITY_FORWARD_RESULT);
        if(localLOGV) Log.i(TAG, "downloaded app uri="+mPackageURI);
        startActivity(newIntent);
        finish();
    }

    /**
     * A simple error dialog showing a message
     */
    public static class SimpleErrorDialog extends DialogFragment {
        private static final String MESSAGE_KEY =
                SimpleErrorDialog.class.getName() + "MESSAGE_KEY";

        static SimpleErrorDialog newInstance(@StringRes int message) {
            SimpleErrorDialog dialog = new SimpleErrorDialog();

            Bundle args = new Bundle();
            args.putInt(MESSAGE_KEY, message);
            dialog.setArguments(args);

            return dialog;
        }

        @Override
        public Dialog onCreateDialog(Bundle savedInstanceState) {
            return new AlertDialog.Builder(getActivity())
                    .setMessage(getArguments().getInt(MESSAGE_KEY))
                    .setPositiveButton(R.string.ok, (dialog, which) -> getActivity().finish())
                    .create();
        }
    }

    /**
     * Dialog to show when the source of apk can not be identified
     */
    public static class AnonymousSourceDialog extends DialogFragment {
        static AnonymousSourceDialog newInstance() {
            return new AnonymousSourceDialog();
        }

        @Override
        public Dialog onCreateDialog(Bundle savedInstanceState) {
            return new AlertDialog.Builder(getActivity())
                    .setMessage(R.string.anonymous_source_warning)
                    .setPositiveButton(R.string.anonymous_source_continue,
                            ((dialog, which) -> {
                                PackageInstallerActivity activity = ((PackageInstallerActivity)
                                        getActivity());

                                activity.mAllowUnknownSources = true;
                                activity.initiateInstall();
                            }))
                    .setNegativeButton(R.string.cancel, ((dialog, which) -> getActivity().finish()))
                    .create();
        }

        @Override
        public void onCancel(DialogInterface dialog) {
            getActivity().finish();
        }
    }

    /**
     * An error dialog shown when the app is not supported on wear
     */
    public static class NotSupportedOnWearDialog extends SimpleErrorDialog {
        static SimpleErrorDialog newInstance() {
            return SimpleErrorDialog.newInstance(R.string.wear_not_allowed_dlg_text);
        }

        @Override
        public void onCancel(DialogInterface dialog) {
            getActivity().setResult(RESULT_OK);
            getActivity().finish();
        }
    }

    /**
     * An error dialog shown when the device is out of space
     */
    public static class OutOfSpaceDialog extends AppErrorDialog {
        static AppErrorDialog newInstance(@NonNull CharSequence applicationLabel) {
            OutOfSpaceDialog dialog = new OutOfSpaceDialog();
            dialog.setArgument(applicationLabel);
            return dialog;
        }

        @Override
        protected Dialog createDialog(@NonNull CharSequence argument) {
            String dlgText = getString(R.string.out_of_space_dlg_text, argument);
            return new AlertDialog.Builder(getActivity())
                    .setMessage(dlgText)
                    .setPositiveButton(R.string.manage_applications, (dialog, which) -> {
                        // launch manage applications
                        Intent intent = new Intent("android.intent.action.MANAGE_PACKAGE_STORAGE");
                        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                        startActivity(intent);
                        getActivity().finish();
                    })
                    .setNegativeButton(R.string.cancel, (dialog, which) -> getActivity().finish())
                    .create();
        }
    }

    /**
     * A generic install-error dialog
     */
    public static class InstallErrorDialog extends AppErrorDialog {
        static AppErrorDialog newInstance(@NonNull CharSequence applicationLabel) {
            InstallErrorDialog dialog = new InstallErrorDialog();
            dialog.setArgument(applicationLabel);
            return dialog;
        }

        @Override
        protected Dialog createDialog(@NonNull CharSequence argument) {
            return new AlertDialog.Builder(getActivity())
                    .setNeutralButton(R.string.ok, (dialog, which) -> getActivity().finish())
                    .setMessage(getString(R.string.install_failed_msg, argument))
                    .create();
        }
    }

    /**
     * An error dialog shown when external sources are not allowed
     */
    public static class ExternalSourcesBlockedDialog extends AppErrorDialog {
        static AppErrorDialog newInstance(@NonNull String originationPkg) {
            ExternalSourcesBlockedDialog dialog = new ExternalSourcesBlockedDialog();
            dialog.setArgument(originationPkg);
            return dialog;
        }

        @Override
        protected Dialog createDialog(@NonNull CharSequence argument) {
            try {
                PackageManager pm = getActivity().getPackageManager();

                ApplicationInfo sourceInfo = pm.getApplicationInfo(argument.toString(), 0);

                return new AlertDialog.Builder(getActivity())
                        .setTitle(pm.getApplicationLabel(sourceInfo))
                        .setIcon(pm.getApplicationIcon(sourceInfo))
                        .setMessage(R.string.untrusted_external_source_warning)
                        .setPositiveButton(R.string.external_sources_settings,
                                (dialog, which) -> {
                                    Intent settingsIntent = new Intent();
                                    settingsIntent.setAction(
                                            Settings.ACTION_MANAGE_UNKNOWN_APP_SOURCES);
                                    final Uri packageUri = Uri.parse("package:" + argument);
                                    settingsIntent.setData(packageUri);
                                    try {
                                        getActivity().startActivityForResult(settingsIntent,
                                                REQUEST_TRUST_EXTERNAL_SOURCE);
                                    } catch (ActivityNotFoundException exc) {
                                        Log.e(TAG, "Settings activity not found for action: "
                                                + Settings.ACTION_MANAGE_UNKNOWN_APP_SOURCES);
                                    }
                                })
                        .setNegativeButton(R.string.cancel,
                                (dialog, which) -> getActivity().finish())
                        .create();
            } catch (NameNotFoundException e) {
                Log.e(TAG, "Did not find app info for " + argument);
                getActivity().finish();
                return null;
            }
        }
    }

    /**
     * Superclass for all error dialogs. Stores a single CharSequence argument
     */
    public abstract static class AppErrorDialog extends DialogFragment {
        private static final String ARGUMENT_KEY = AppErrorDialog.class.getName() + "ARGUMENT_KEY";

        protected void setArgument(@NonNull CharSequence argument) {
            Bundle args = new Bundle();
            args.putCharSequence(ARGUMENT_KEY, argument);
            setArguments(args);
        }

        protected abstract Dialog createDialog(@NonNull CharSequence argument);

        @Override
        public Dialog onCreateDialog(Bundle savedInstanceState) {
            return createDialog(getArguments().getString(ARGUMENT_KEY));
        }

        @Override
        public void onCancel(DialogInterface dialog) {
            getActivity().finish();
        }
    }
}
