/*
 * Copyright (C) 2016 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 com.android.packageinstaller.PackageInstallerActivity.EXTRA_APP_SNIPPET;
import static com.android.packageinstaller.PackageInstallerActivity.EXTRA_STAGED_SESSION_ID;

import android.app.Activity;
import android.app.AlertDialog;
import android.app.PendingIntent;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageInstaller;
import android.content.pm.PackageManager;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Handler;
import android.os.Looper;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import androidx.annotation.Nullable;
import com.android.packageinstaller.common.EventResultPersister;
import com.android.packageinstaller.common.InstallEventReceiver;
import java.io.File;
import java.io.IOException;

/**
 * Send package to the package manager and handle results from package manager. Once the
 * installation succeeds, start {@link InstallSuccess} or {@link InstallFailed}.
 * <p>This has two phases: First send the data to the package manager, then wait until the package
 * manager processed the result.</p>
 */
public class InstallInstalling extends Activity {
    private static final String LOG_TAG = InstallInstalling.class.getSimpleName();

    private static final String SESSION_ID = "com.android.packageinstaller.SESSION_ID";
    private static final String INSTALL_ID = "com.android.packageinstaller.INSTALL_ID";

    private static final String BROADCAST_ACTION =
            "com.android.packageinstaller.ACTION_INSTALL_COMMIT";

    /** Task that sends the package to the package installer */
    private InstallingAsyncTask mInstallingTask;

    /** Id of the session to install the package */
    private int mSessionId;

    /** Id of the install event we wait for */
    private int mInstallId;

    /** URI of package to install */
    private Uri mPackageURI;

    /** The button that can cancel this dialog */
    private Button mCancelButton;

    private AlertDialog mDialog;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        ApplicationInfo appInfo = getIntent()
                .getParcelableExtra(PackageUtil.INTENT_ATTR_APPLICATION_INFO);
        mPackageURI = getIntent().getData();

        if (PackageInstallerActivity.SCHEME_PACKAGE.equals(mPackageURI.getScheme())) {
            try {
                getPackageManager().installExistingPackage(appInfo.packageName);
                launchSuccess();
            } catch (PackageManager.NameNotFoundException e) {
                launchFailure(PackageInstaller.STATUS_FAILURE,
                        PackageManager.INSTALL_FAILED_INTERNAL_ERROR, null);
            }
        } else {
            // ContentResolver.SCHEME_FILE
            // STAGED_SESSION_ID extra contains an ID of a previously staged install session.
            final File sourceFile = new File(mPackageURI.getPath());

            // Dialogs displayed while changing update-owner have a blank icon. To fix this,
            // fetch the appSnippet from the source file again
            PackageUtil.AppSnippet as = PackageUtil.getAppSnippet(this, appInfo, sourceFile);
            getIntent().putExtra(EXTRA_APP_SNIPPET, as);

            AlertDialog.Builder builder = new AlertDialog.Builder(this);

            builder.setIcon(as.icon);
            builder.setTitle(as.label);
            builder.setView(R.layout.install_content_view);
            builder.setNegativeButton(getString(R.string.cancel),
                    (ignored, ignored2) -> {
                        if (mInstallingTask != null) {
                            mInstallingTask.cancel(true);
                        }

                        if (mSessionId > 0) {
                            getPackageManager().getPackageInstaller().abandonSession(mSessionId);
                            mSessionId = 0;
                        }

                        setResult(RESULT_CANCELED);
                        finish();
                    });
            builder.setCancelable(false);
            mDialog = builder.create();
            mDialog.show();
            mDialog.requireViewById(R.id.installing).setVisibility(View.VISIBLE);

            if (savedInstanceState != null) {
                mSessionId = savedInstanceState.getInt(SESSION_ID);
                mInstallId = savedInstanceState.getInt(INSTALL_ID);

                // Reregister for result; might instantly call back if result was delivered while
                // activity was destroyed
                try {
                    InstallEventReceiver.addObserver(this, mInstallId,
                            this::launchFinishBasedOnResult);
                } catch (EventResultPersister.OutOfIdsException e) {
                    // Does not happen
                }
            } else {
                try {
                    mInstallId = InstallEventReceiver
                            .addObserver(this, EventResultPersister.GENERATE_NEW_ID,
                                    this::launchFinishBasedOnResult);
                } catch (EventResultPersister.OutOfIdsException e) {
                    launchFailure(PackageInstaller.STATUS_FAILURE,
                            PackageManager.INSTALL_FAILED_INTERNAL_ERROR, null);
                }

                mSessionId = getIntent().getIntExtra(EXTRA_STAGED_SESSION_ID, 0);
                // Try to open session previously staged in InstallStaging.
                try (PackageInstaller.Session ignored =
                             getPackageManager().getPackageInstaller().openSession(
                        mSessionId)) {
                    Log.d(LOG_TAG, "Staged session is valid, proceeding with the install");
                } catch (IOException | SecurityException e) {
                    Log.e(LOG_TAG, "Invalid session id passed", e);
                    launchFailure(PackageInstaller.STATUS_FAILURE,
                            PackageManager.INSTALL_FAILED_INTERNAL_ERROR, null);
                }
            }

            mCancelButton = mDialog.getButton(DialogInterface.BUTTON_NEGATIVE);
        }
    }

    /**
     * Launch the "success" version of the final package installer dialog
     */
    private void launchSuccess() {
        Intent successIntent = new Intent(getIntent());
        successIntent.setClass(this, InstallSuccess.class);
        successIntent.addFlags(Intent.FLAG_ACTIVITY_FORWARD_RESULT);

        startActivity(successIntent);
        finish();
    }

    /**
     * Launch the "failure" version of the final package installer dialog
     *
     * @param statusCode    The generic status code as returned by the package installer.
     * @param legacyStatus  The status as used internally in the package manager.
     * @param statusMessage The status description.
     */
    private void launchFailure(int statusCode, int legacyStatus, String statusMessage) {
        Intent failureIntent = new Intent(getIntent());
        failureIntent.setClass(this, InstallFailed.class);
        failureIntent.addFlags(Intent.FLAG_ACTIVITY_FORWARD_RESULT);
        failureIntent.putExtra(PackageInstaller.EXTRA_STATUS, statusCode);
        failureIntent.putExtra(PackageInstaller.EXTRA_LEGACY_STATUS, legacyStatus);
        failureIntent.putExtra(PackageInstaller.EXTRA_STATUS_MESSAGE, statusMessage);

        startActivity(failureIntent);
        finish();
    }

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

        // This is the first onResume in a single life of the activity
        if (mInstallingTask == null) {
            PackageInstaller installer = getPackageManager().getPackageInstaller();
            PackageInstaller.SessionInfo sessionInfo = installer.getSessionInfo(mSessionId);

            if (sessionInfo != null && !sessionInfo.isActive()) {
                mInstallingTask = new InstallingAsyncTask();
                mInstallingTask.execute();
            } else {
                // we will receive a broadcast when the install is finished
                mCancelButton.setEnabled(false);
                setFinishOnTouchOutside(false);
            }
        }
    }

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

        outState.putInt(SESSION_ID, mSessionId);
        outState.putInt(INSTALL_ID, mInstallId);
    }

    @Override
    public void onBackPressed() {
        if (mCancelButton.isEnabled()) {
            super.onBackPressed();
        }
    }

    @Override
    protected void onDestroy() {
        if (mInstallingTask != null) {
            mInstallingTask.cancel(true);
            synchronized (mInstallingTask) {
                while (!mInstallingTask.isDone) {
                    try {
                        mInstallingTask.wait();
                    } catch (InterruptedException e) {
                        Log.i(LOG_TAG, "Interrupted while waiting for installing task to cancel",
                                e);
                    }
                }
            }
        }

        InstallEventReceiver.removeObserver(this, mInstallId);

        super.onDestroy();
    }

    @Override
    public void finish() {
        if (mDialog != null) {
            mDialog.dismiss();
        }
        super.finish();
    }

    /**
     * Launch the appropriate finish activity (success or failed) for the installation result.
     *
     * @param statusCode    The installation result.
     * @param legacyStatus  The installation as used internally in the package manager.
     * @param statusMessage The detailed installation result.
     * @param serviceId     Id for PowerManager.WakeLock service. Used only by Wear devices
     *                      during an uninstall.
     */
    private void launchFinishBasedOnResult(int statusCode, int legacyStatus, String statusMessage,
            int serviceId /* ignore */) {
        if (statusCode == PackageInstaller.STATUS_SUCCESS) {
            launchSuccess();
        } else {
            launchFailure(statusCode, legacyStatus, statusMessage);
        }
    }

    /**
     * Send the package to the package installer and then register a event result observer that
     * will call {@link #launchFinishBasedOnResult(int, int, String, int)}
     */
    private final class InstallingAsyncTask extends AsyncTask<Void, Void,
            PackageInstaller.Session> {
        volatile boolean isDone;

        @Override
        protected PackageInstaller.Session doInBackground(Void... params) {
            try {
                return getPackageManager().getPackageInstaller().openSession(mSessionId);
            } catch (IOException e) {
                return null;
            } finally {
                synchronized (this) {
                    isDone = true;
                    notifyAll();
                }
            }
        }

        @Override
        protected void onPostExecute(PackageInstaller.Session session) {
            if (session != null) {
                Intent broadcastIntent = new Intent(BROADCAST_ACTION);
                broadcastIntent.setFlags(Intent.FLAG_RECEIVER_FOREGROUND);
                broadcastIntent.setPackage(getPackageName());
                broadcastIntent.putExtra(EventResultPersister.EXTRA_ID, mInstallId);

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

                // Delay committing the session by 100ms to fix a UI glitch while displaying the
                // Update-Owner change dialog on top of the Installing dialog
                new Handler(Looper.getMainLooper()).postDelayed(() -> {
                    try {
                        session.commit(pendingIntent.getIntentSender());
                    } catch (Exception e) {
                        Log.e(LOG_TAG, "Cannot install package: ", e);
                        launchFailure(PackageInstaller.STATUS_FAILURE,
                            PackageManager.INSTALL_FAILED_INTERNAL_ERROR, null);
                        return;
                    }
                }, 100);
                mCancelButton.setEnabled(false);
                setFinishOnTouchOutside(false);
            } else {
                getPackageManager().getPackageInstaller().abandonSession(mSessionId);

                if (!isCancelled()) {
                    launchFailure(PackageInstaller.STATUS_FAILURE,
                            PackageManager.INSTALL_FAILED_INVALID_APK, null);
                }
            }
        }
    }
}