watchdog/src/main/java/cz/senslog/watchdog/messagebroker/email/EmailMessageBroker.java

package cz.senslog.watchdog.messagebroker.email;

import cz.senslog.watchdog.config.EmailMessageBrokerConfig;
import cz.senslog.watchdog.config.MessageBrokerType;
import cz.senslog.watchdog.domain.*;
import cz.senslog.watchdog.messagebroker.MessageBroker;
import cz.senslog.watchdog.messagebroker.MessageBrokerHandler;
import cz.senslog.watchdog.messagebroker.MessageStatus;
import cz.senslog.watchdog.messagebroker.writer.HtmlTableWriter;
import cz.senslog.watchdog.messagebroker.writer.TableWriter;
import cz.senslog.watchdog.provider.Record;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

import javax.mail.*;
import javax.mail.internet.*;
import java.time.Instant;
import java.time.format.DateTimeFormatter;
import java.util.*;

import static cz.senslog.watchdog.util.TimeConverter.dayToSec;
import static java.time.format.DateTimeFormatter.ofPattern;
import static javax.mail.Message.RecipientType.TO;

public class EmailMessageBroker implements MessageBroker {

    private static final String BREAK_LINE = "<br />";

    private static final Logger logger = LogManager.getLogger(EmailMessageBroker.class);

    private final EmailMessageBrokerConfig config;
    private final Session session;


    public EmailMessageBroker(EmailMessageBrokerConfig config) {
        this.config = config;
        this.session = openSession(config);
    }

    private Session openSession(EmailMessageBrokerConfig config) {
        Properties props = new Properties();
        props.put("mail.smtp.host", config.getHost());
        props.put("mail.smtp.port", config.getPort());
        props.put("mail.smtp.auth", "true");
        props.put("mail.smtp.starttls.enable", "true");
        props.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");

        Authenticator auth = new Authenticator() {
            protected PasswordAuthentication getPasswordAuthentication() {
                return new PasswordAuthentication(config.getUsername(), config.getPass());
            }
        };
        return Session.getInstance(props, auth);
    }

    private Message createMessage(Report report) throws MessagingException {
        Message message = new MimeMessage(session);
        message.setFrom(new InternetAddress(config.getSender()));
        message.setRecipients(TO, InternetAddress.parse(config.getRecipient()));
        message.setSubject(config.getSubject());

        MimeBodyPart mimeBodyPart = new MimeBodyPart();
        StringBuilder content = new StringBuilder();

        TableWriter tableWriter = HtmlTableWriter.createWithHeader("width: 100%;", "background-color: #dddddd")
                .cell("unitName (unitId)").cell("sensorName (sensorId)").cell("timestamp").cell("reported").cell("status").end();

        String reportedTime = report.getCreated().format(ofPattern("yyyy-MM-dd HH:mm:ss"));
        final String rowStyle = "border: 1px solid #dddddd; text-align: left; padding: 8px;";
        for (SimpleReport simpleReport : report.getReports()) {
            if (simpleReport.getRecord() instanceof ObservationInfo) {
                ObservationInfo observation = (ObservationInfo)simpleReport.getRecord();
                Source source = observation.getSource();

                boolean isOk = simpleReport.getStatus().equals(StatusReport.OK);
                String unitCell = String.format("%s (%s)", source.getUnit().getName(), source.getUnit().getId());
                String sensorCell = String.format("%s (%s)", source.getSensor().getName(), source.getSensor().getId());

                tableWriter.row(rowStyle + (isOk ? "background-color: #CCFFCC" : "background-color: #FFCCCC"))
                            .cell(unitCell, rowStyle)
                            .cell(sensorCell, rowStyle)
                            .cell(observation.getTimestamp().toString(), rowStyle)
                            .cell(reportedTime, rowStyle)
                            .cell(simpleReport.getStatus().name(), rowStyle)
                        .end();
            }
        }

        content.append(tableWriter.table()).append(BREAK_LINE);
        mimeBodyPart.setContent(content.toString(), "text/html");

        Multipart multipart = new MimeMultipart();
        multipart.addBodyPart(mimeBodyPart);
        message.setContent(multipart);

        return message;
    }

    @Override
    public void send(Report report, MessageBrokerHandler status) {
        if (report == null) {
            logger.info("Nothing to send. The receive report is null.");
            status.handle(new MessageStatus(null, "No report to send.")); return;
        }

        try {
            Message message = createMessage(report);
            logger.info("Sending a message via email.");
            Transport.send(message);
            logger.info("The message was send successfully.");
            status.handle(new MessageStatus(report));
        } catch (MessagingException e) {
            logger.catching(e);
            status.handle(new MessageStatus(report, e.getMessage()));
        }

      //  vanish();
    }

    @Override
    public MessageBrokerType getType() {
        return MessageBrokerType.EMAIL;
    }

    public Record[] vanish() {
        Instant deadline = Instant.now().minusSeconds(dayToSec(config.getVanishPeriodDays()));
        List<Record> deletedRecords = new ArrayList<>();
        Iterator<Record> iterator = Collections.emptyListIterator();
        while(iterator.hasNext()) {
            Record record = iterator.next();
            if (record.getTimestamp().isBefore(deadline)) {
                deletedRecords.add(record);
                iterator.remove();
            }
        }
        return deletedRecords.toArray(new Record[0]);
    }
}