Widerhall/src/main/java/de/srsoftware/widerhall/mail/SmtpClient.java

package de.srsoftware.widerhall.mail;

import com.sun.mail.imap.protocol.ENVELOPE;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.mail.*;
import javax.mail.internet.*;
import java.io.UnsupportedEncodingException;
import java.util.Date;
import java.util.List;
import java.util.Properties;

import static de.srsoftware.widerhall.Util.t;

public class SmtpClient {
    private static final Logger LOG = LoggerFactory.getLogger(SmtpClient.class);
    private static final String HOST = "mail.smtp.host";
    private static final String PORT = "mail.smtp.port";
    private static final String AUTH = "mail.smtp.auth";
    private static final String ENVELOPE_FROM = "mail.smtp.from";
    private static final String SSL = "mail.smtp.ssl.enable";
    private static final String UTF8 = "UTF-8";
    private final String host,password,username,from;
    private final int port;
    private boolean forwardUsingListAddress = true;

    private Session session;

    public SmtpClient(String host, int port, String username, String password, String envelopeFrom){
        this.username = username;
        this.password = password;
        this.host = host;
        this.port = port;
        this.from = envelopeFrom;
    }



    public void forward(String newSender, List<String> receivers, Message message, String subject, boolean forwardAsAttachment, boolean bcc, String replyTo) throws MessagingException {
        if (session == null) login();
        MimeMessage forward = new MimeMessage(session);
        var oldSender = message.getFrom()[0].toString();
        { // drop old (von ... comment)
            var pos = subject.indexOf(" (von ");
            while (pos > 0){
                var end = subject.indexOf(')',pos);
                if (end < pos) break;
                subject = (subject.substring(0,pos)+subject.substring(end+1)).trim();
                pos = subject.indexOf(" (von ");
            }
        }
        if (newSender != null){
            forward.setFrom(newSender);
            forward.setSubject(subject+" (von "+oldSender+")");
        } else {
            forward.setFrom(oldSender);
            forward.setSubject(subject);
        }
        if (replyTo != null) forward.setReplyTo(InternetAddress.parse(replyTo));
        var recipientType = bcc ? Message.RecipientType.BCC : Message.RecipientType.TO;
        forward.setRecipients(recipientType,InternetAddress.parse(String.join(", ",receivers)));

        MimeMultipart multipart = new MimeMultipart();
        if (forwardAsAttachment){
            MimeBodyPart bodyPart = new MimeBodyPart();
            bodyPart.setText(t("Find the forwarded message in the attachment(s)!\n"));
            multipart.addBodyPart(bodyPart);

            // create another body part to contain the message to be forwarded
            bodyPart = new MimeBodyPart();
            // forwardedMsg is the MimeMessage object you want to forward as an attachment
            bodyPart.setContent(message, "message/rfc822");
            bodyPart.setDisposition(Part.ATTACHMENT);
            multipart.addBodyPart(bodyPart);
        } else {
            MimeBodyPart bodyPart = new MimeBodyPart();

            bodyPart.setDataHandler(message.getDataHandler());
            multipart.addBodyPart(bodyPart);
        }
        forward.setContent(multipart);
        send(forward);
    }

    public String host() {
        return host;
    }

    public SmtpClient login(){
        if (session == null) {
            Properties props = new Properties();
            props.put(HOST, host);
            props.put(PORT, port);
            props.put(AUTH, true);
            props.put(SSL, true);
            props.put(ENVELOPE_FROM,from);

            session = Session.getInstance(props);
            LOG.debug("Created new session: {}", session);
        }
        return this;
    }

    public String password() {
        return password;
    }

    public int port() {
        return port;
    }

    public void send(Message message) throws MessagingException {
        LOG.debug("sending mail…");
        Transport.send(message,username,password);
        LOG.debug("…sent");
    }

    public void send(String senderAdress, String senderName, String receivers, String subject, String content) throws MessagingException, UnsupportedEncodingException {
        login();
        MimeMessage message = new MimeMessage(session);
        message.addHeader("Content-Type","text/plain; charset="+UTF8);
        message.addHeader("format","flowed");
        message.addHeader("Content-Transfer-Encoding","8bit");

        message.setFrom(new InternetAddress(senderAdress,senderName));
        message.setReplyTo(InternetAddress.parse(senderAdress,false));
        message.setSubject(subject,UTF8);
        message.setText(content,UTF8);
        message.setSentDate(new Date());
        message.setRecipients(Message.RecipientType.TO,InternetAddress.parse(receivers,false));
        send(message);
    }

    public String username() {
        return username;
    }
}