NetGuard/app/src/main/java/eu/faircode/netguard/ServiceExternal.java

package eu.faircode.netguard;

/*
    This file is part of NetGuard.

    NetGuard is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    NetGuard is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with NetGuard.  If not, see <http://www.gnu.org/licenses/>.

    Copyright 2015-2018 by Marcel Bokhorst (M66B)
*/

import android.app.IntentService;
import android.app.Notification;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.preference.PreferenceManager;
import android.util.Log;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.text.SimpleDateFormat;
import java.util.Date;

import androidx.core.app.NotificationCompat;

public class ServiceExternal extends IntentService {
    private static final String TAG = "NetGuard.External";
    private static final String ACTION_DOWNLOAD_HOSTS_FILE = "eu.faircode.netguard.DOWNLOAD_HOSTS_FILE";

    // am startservice -a eu.faircode.netguard.DOWNLOAD_HOSTS_FILE

    public ServiceExternal() {
        super(TAG);
    }

    @Override
    protected void onHandleIntent(Intent intent) {
        try {
            startForeground(ServiceSinkhole.NOTIFY_EXTERNAL, getForegroundNotification(this));

            Log.i(TAG, "Received " + intent);
            Util.logExtras(intent);

            if (ACTION_DOWNLOAD_HOSTS_FILE.equals(intent.getAction())) {
                final SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);

                String hosts_url = prefs.getString("hosts_url", null);
                File tmp = new File(getFilesDir(), "hosts.tmp");
                File hosts = new File(getFilesDir(), "hosts.txt");

                InputStream in = null;
                OutputStream out = null;
                URLConnection connection = null;
                try {
                    URL url = new URL(hosts_url);
                    connection = url.openConnection();
                    connection.connect();

                    if (connection instanceof HttpURLConnection) {
                        HttpURLConnection httpConnection = (HttpURLConnection) connection;
                        if (httpConnection.getResponseCode() != HttpURLConnection.HTTP_OK)
                            throw new IOException(httpConnection.getResponseCode() + " " + httpConnection.getResponseMessage());
                    }

                    int contentLength = connection.getContentLength();
                    Log.i(TAG, "Content length=" + contentLength);
                    in = connection.getInputStream();
                    out = new FileOutputStream(tmp);

                    long size = 0;
                    byte buffer[] = new byte[4096];
                    int bytes;
                    while ((bytes = in.read(buffer)) != -1) {
                        out.write(buffer, 0, bytes);
                        size += bytes;
                    }

                    Log.i(TAG, "Downloaded size=" + size);

                    if (hosts.exists())
                        hosts.delete();
                    tmp.renameTo(hosts);

                    String last = SimpleDateFormat.getDateTimeInstance().format(new Date().getTime());
                    prefs.edit().putString("hosts_last_download", last).apply();

                    ServiceSinkhole.reload("hosts file download", this, false);

                } catch (Throwable ex) {
                    Log.e(TAG, ex.toString() + "\n" + Log.getStackTraceString(ex));

                    if (tmp.exists())
                        tmp.delete();
                } finally {
                    try {
                        if (out != null)
                            out.close();
                    } catch (IOException ex) {
                        Log.e(TAG, ex.toString() + "\n" + Log.getStackTraceString(ex));
                    }
                    try {
                        if (in != null)
                            in.close();
                    } catch (IOException ex) {
                        Log.e(TAG, ex.toString() + "\n" + Log.getStackTraceString(ex));
                    }

                    if (connection instanceof HttpURLConnection)
                        ((HttpURLConnection) connection).disconnect();
                }
            }
        } finally {
            stopForeground(true);
        }
    }

    private static Notification getForegroundNotification(Context context) {
        NotificationCompat.Builder builder = new NotificationCompat.Builder(context, "foreground");
        builder.setSmallIcon(R.drawable.ic_hourglass_empty_white_24dp);
        builder.setPriority(NotificationCompat.PRIORITY_MIN);
        builder.setCategory(NotificationCompat.CATEGORY_STATUS);
        builder.setVisibility(NotificationCompat.VISIBILITY_PUBLIC);
        builder.setContentTitle(context.getString(R.string.app_name));
        return builder.build();
    }
}