Util.java

/**
 * Copyright (c) 2010-2016 by the respective copyright holders.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 */
package org.openhab.io.caldav.internal;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.security.KeyManagementException;
import java.security.KeyStoreException;
import java.security.NoSuchAlgorithmException;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;

import org.apache.commons.io.FilenameUtils;
import org.apache.commons.lang.StringUtils;
import org.apache.http.conn.ssl.AllowAllHostnameVerifier;
import org.apache.http.conn.ssl.SSLContextBuilder;
import org.apache.http.conn.ssl.TrustStrategy;
import org.apache.http.impl.client.HttpClientBuilder;
import org.joda.time.DateTimeZone;
import org.openhab.io.caldav.CalDavEvent;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.github.sardine.Sardine;
import com.github.sardine.impl.SardineImpl;

import net.fortuna.ical4j.data.CalendarOutputter;
import net.fortuna.ical4j.model.Calendar;
import net.fortuna.ical4j.model.TimeZone;
import net.fortuna.ical4j.model.TimeZoneRegistry;
import net.fortuna.ical4j.model.TimeZoneRegistryFactory;
import net.fortuna.ical4j.model.ValidationException;
import net.fortuna.ical4j.model.component.VEvent;
import net.fortuna.ical4j.model.property.Clazz;
import net.fortuna.ical4j.model.property.Description;
import net.fortuna.ical4j.model.property.DtEnd;
import net.fortuna.ical4j.model.property.DtStart;
import net.fortuna.ical4j.model.property.LastModified;
import net.fortuna.ical4j.model.property.ProdId;
import net.fortuna.ical4j.model.property.Summary;
import net.fortuna.ical4j.model.property.Uid;
import net.fortuna.ical4j.model.property.Version;

public final class Util {
    private static final String HTTP_URL_PREFIX = "http://";
    private static final Logger log = LoggerFactory.getLogger(Util.class);

    private Util() {
    }

    public static Calendar createCalendar(CalDavEvent calDavEvent, DateTimeZone timeZone) {
        TimeZoneRegistry registry = TimeZoneRegistryFactory.getInstance().createRegistry();
        TimeZone timezone = registry.getTimeZone(timeZone.getID());

        Calendar calendar = new Calendar();
        calendar.getProperties().add(Version.VERSION_2_0);
        calendar.getProperties().add(new ProdId("openHAB"));
        VEvent vEvent = new VEvent();
        vEvent.getProperties().add(new Summary(calDavEvent.getName()));
        vEvent.getProperties().add(new Description(calDavEvent.getContent()));
        final DtStart dtStart = new DtStart(new net.fortuna.ical4j.model.DateTime(calDavEvent.getStart().toDate()));
        dtStart.setTimeZone(timezone);
        vEvent.getProperties().add(dtStart);
        final DtEnd dtEnd = new DtEnd(new net.fortuna.ical4j.model.DateTime(calDavEvent.getEnd().toDate()));
        dtEnd.setTimeZone(timezone);
        vEvent.getProperties().add(dtEnd);
        vEvent.getProperties().add(new Uid(calDavEvent.getId()));
        vEvent.getProperties().add(Clazz.PUBLIC);
        vEvent.getProperties()
                .add(new LastModified(new net.fortuna.ical4j.model.DateTime(calDavEvent.getLastChanged().toDate())));
        calendar.getComponents().add(vEvent);

        return calendar;
    }

    public static File getCachePath(String calendarKey) {
        return new File(CalDavLoaderImpl.CACHE_PATH + "/" + calendarKey);
    }

    public static String getFilename(String name) {
        name = FilenameUtils.getBaseName(name);
        name = name.replaceAll("[^a-zA-Z0-9-_]", "_");
        return name;
    }

    public static File getCacheFile(String calendarId, String filename) {
        return new File(getCachePath(calendarId), filename + ".ics");
    }

    public static void storeToDisk(String calendarId, String filename, Calendar calendar) {
        File cacheFile = getCacheFile(calendarId, filename);
        try {
            FileOutputStream fout = new FileOutputStream(cacheFile);
            CalendarOutputter outputter = new CalendarOutputter();
            outputter.setValidating(false);
            outputter.output(calendar, fout);
            fout.flush();
            fout.close();
        } catch (IOException e) {
            log.error("cannot store event '{}' to disk (path={}): {}", filename, cacheFile.getAbsoluteFile(),
                    e.getMessage());
        } catch (ValidationException e) {
            log.error("cannot store event '{}' to disk (path={}): {}", filename, cacheFile.getAbsoluteFile(),
                    e.getMessage());
        }
    }

    public static Sardine getConnection(CalDavConfig config) {
        if (config.isDisableCertificateVerification()) {
            if (config.getUrl().startsWith(HTTP_URL_PREFIX)) {
                log.error("do not use '{}' if no ssl is used", CalDavLoaderImpl.PROP_DISABLE_CERTIFICATE_VERIFICATION);
            }
            log.trace("connecting to caldav '{}' with disabled certificate verification (url={}, username={}, password={})", 
                    config.getKey(), config.getUrl(), config.getUsername(), config.getPassword());
            HttpClientBuilder httpClientBuilder = HttpClientBuilder.create().setHostnameVerifier(new AllowAllHostnameVerifier());
            try {
                httpClientBuilder.setSslcontext(new SSLContextBuilder().loadTrustMaterial(null, new TrustStrategy() {
                    @Override
                    public boolean isTrusted(X509Certificate[] arg0, String arg1) throws CertificateException {
                        return true;
                    }
                }).build());
            } catch (KeyManagementException e) {
                log.error("error verifying certificate", e);
            } catch (NoSuchAlgorithmException e) {
                log.error("error verifying certificate", e);
            } catch (KeyStoreException e) {
                log.error("error verifying certificate", e);
            }
            if (StringUtils.isEmpty(config.getUsername()) && StringUtils.isEmpty(config.getPassword())) {
                log.trace("connecting without credentials for '{}'", config.getKey());
                return new SardineImpl(httpClientBuilder);
            } else {
                return new SardineImpl(httpClientBuilder, config.getUsername(), config.getPassword());
            }
        } else {
            log.trace("connecting to caldav '{}' (url={}, username={}, password={})", 
                    config.getKey(), config.getUrl(), config.getUsername(), config.getPassword());
            if (StringUtils.isEmpty(config.getUsername()) && StringUtils.isEmpty(config.getPassword())) {
                log.trace("connecting without credentials for '{}'", config.getKey());
                return new SardineImpl();
            } else {
                return new SardineImpl(config.getUsername(), config.getPassword());
            }
        }
    }
}