package io.gitlab.jfronny.gitea.helpdesk.mail;

import com.sun.mail.pop3.POP3Store;
import io.gitlab.jfronny.gitea.helpdesk.Config;
import jakarta.mail.*;
import jakarta.mail.internet.*;
import org.jsoup.Jsoup;

import java.util.*;
import java.util.stream.Collectors;

public class MailInterface implements AutoCloseable {
    private final Config.EMail config;
    private final Session pop3;
    private final Session smtp;
    private POP3Store lastPop3;

    public MailInterface(Config.EMail config) {
        this.config = config;
        {
            Properties properties = new Properties();
            String[] splitHost = config.pop3.host.split(":");
            if (splitHost.length == 1) {
                properties.put("mail.pop3.host", config.pop3.host);
            } else {
                properties.put("mail.pop3.host", splitHost[0]);
                properties.put("mail.pop3.port", Integer.parseInt(splitHost[1]));
            }
            if (config.pop3.ssl) properties.put("mail.pop3.ssl.enable", true);
            this.pop3 = Session.getInstance(properties);
        }
        {
            Properties properties = new Properties();
            String[] splitHost = config.smtp.host.split(":");
            if (splitHost.length == 1) {
                properties.put("mail.smtp.host", config.smtp.host);
            } else {
                properties.put("mail.smtp.host", splitHost[0]);
                properties.put("mail.smtp.port", Integer.parseInt(splitHost[1]));
            }
            if (config.smtp.ssl) properties.put("mail.smtp.ssl.enable", true);
            properties.put("mail.smtp.auth", true);
            this.smtp = Session.getInstance(properties);
        }
    }

    private POP3Store getStore() throws MessagingException {
        boolean reopen = lastPop3 == null;
        if (lastPop3 != null && !lastPop3.isConnected()) {
            lastPop3.close();
            reopen = true;
        }
        if (reopen) {
            lastPop3 = (POP3Store) pop3.getStore("pop3");
            lastPop3.connect(config.address, config.pop3.password);
        }
        return lastPop3;
    }

    public Set<WrappedMessage> getInbox() throws MessagingException {
        try (Folder inbox = getStore().getFolder("INBOX")) {
            inbox.open(Folder.READ_ONLY);
            return Arrays.stream(inbox.getMessages())
                    .map(s -> new WrappedMessage((MimeMessage) s, config.address, this))
                    .collect(Collectors.toSet());
        }
    }

    public void reply(String from, String to, String content, String subject, String previousMessageId, String previousReferences, String previousInReplyTo) throws MessagingException {
        MimeMessage reply = new MimeMessage(smtp);
        reply.setFrom(from);
        reply.addRecipients(Message.RecipientType.TO, to);
        reply.setSubject(subject.startsWith("Re: ") ? subject : "Re: " + subject);

        final MimeBodyPart textPart = new MimeBodyPart();
        textPart.setContent(Jsoup.parse(content).text(), "text/plain");
        final MimeBodyPart htmlPart = new MimeBodyPart();
        htmlPart.setContent(content, "text/html");
        final MimeMultipart mp = new MimeMultipart("alternative");
        mp.addBodyPart(textPart);
        mp.addBodyPart(htmlPart);
        reply.setContent(mp);

        if (previousMessageId != null) reply.setHeader("In-Reply-To", previousMessageId);

        if (previousReferences == null) previousReferences = previousInReplyTo;
        if (previousMessageId != null) {
            if (previousReferences != null) previousReferences = MimeUtility.unfold(previousReferences) + " " + previousMessageId;
            else previousReferences = previousMessageId;
        }
        if (previousReferences != null) reply.setHeader("References", MimeUtility.fold(12, previousReferences));
        send(reply);
    }

    public void send(Message message) throws MessagingException {
        Address[] recipients = message.getAllRecipients();
        if (recipients.length != 1) throw new MessagingException("Unexpected number of recipients: " + recipients.length);
        try (Transport transport = smtp.getTransport(recipients[0])) {
            transport.connect(config.address, config.smtp.password);
            transport.sendMessage(message, recipients);
        }
    }

    public String getAddress() {
        return config.address;
    }

    @Override
    public void close() throws MessagingException {
        if (lastPop3 != null) lastPop3.close();
    }
}