/*
 * Copyright (C) 2008-2017, Juick
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package com.juick.ws;

import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.juick.User;
import com.juick.service.MessagesService;
import com.juick.service.SubscriptionService;
import org.apache.commons.lang3.math.NumberUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.core.env.Environment;
import org.springframework.util.Assert;
import org.springframework.web.socket.TextMessage;
import rocks.xmpp.core.XmppException;
import rocks.xmpp.core.session.Extension;
import rocks.xmpp.core.session.XmppSession;
import rocks.xmpp.core.session.XmppSessionConfiguration;
import rocks.xmpp.core.session.debug.LogbackDebugger;
import rocks.xmpp.core.stanza.model.Message;
import rocks.xmpp.extensions.component.accept.ExternalComponent;
import rocks.xmpp.util.XmppUtils;

import javax.inject.Inject;
import javax.xml.bind.JAXBException;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamWriter;
import java.io.IOException;
import java.io.StringWriter;
import java.util.List;
import java.util.stream.Collectors;

/**
 * @author ugnich
 */
public class XMPPConnection implements AutoCloseable {
    private static final Logger logger = LoggerFactory.getLogger(XMPPConnection.class);

    private final WebsocketComponent wsHandler;
    private final String xmppPassword;
    private final ObjectMapper ms;
    private final int xmppPort;
    private final String wsJid;

    private XmppSession xmpp;

    @Inject
    MessagesService messagesService;
    @Inject
    SubscriptionService subscriptionService;


    public XMPPConnection(
            final Environment env, final WebsocketComponent wsHandler) {
        Assert.notNull(env, "Environment must be initialized");
        Assert.notNull(wsHandler, "WebsocketComponent must be initialized");

        this.wsHandler = wsHandler;

        xmppPassword = env.getProperty("xmpp_password");
        xmppPort = NumberUtils.toInt(env.getProperty("xmpp_port"), 5347);
        wsJid = env.getProperty("ws_jid", "ws.juick.local");

        ms = new ObjectMapper();
        ms.setSerializationInclusion(JsonInclude.Include.NON_EMPTY);
        ms.setSerializationInclusion(JsonInclude.Include.NON_NULL);
        ms.setSerializationInclusion(JsonInclude.Include.NON_DEFAULT);

        XmppSessionConfiguration configuration = XmppSessionConfiguration.builder()
                .extensions(Extension.of(com.juick.Message.class))
                .debugger(LogbackDebugger.class)
                .build();
        xmpp = ExternalComponent.create(wsJid, xmppPassword, configuration, "localhost", xmppPort);
        xmpp.addInboundMessageListener(e -> {
            try {
                Message msg = e.getMessage();
                com.juick.Message jmsg = msg.getExtension(com.juick.Message.class);
                if (jmsg != null) {
                    if (logger.isInfoEnabled()) { // prevent writeValueAsString execution if log is disabled
                        try {
                            StringWriter stanzaWriter = new StringWriter();
                            XMLStreamWriter xmppStreamWriter = XmppUtils.createXmppStreamWriter(
                                    xmpp.getConfiguration().getXmlOutputFactory().createXMLStreamWriter(stanzaWriter));
                            xmpp.createMarshaller().marshal(msg, xmppStreamWriter);
                            xmppStreamWriter.flush();
                            xmppStreamWriter.close();
                            logger.info("got msg: {}", stanzaWriter.toString());
                        } catch (XMLStreamException e1) {
                            logger.info("jaxb exception", e1);
                        }

                    }
                    if (jmsg.getMid() == 0) {
                        int uid_to = NumberUtils.toInt(msg.getTo().getLocal(), 0);
                        if (uid_to > 0) {
                            onJuickPM(uid_to, jmsg);
                        }
                    } else if (jmsg.getRid() == 0) {
                        // to get full message with attachment, etc.
                        onJuickMessagePost(messagesService.getMessage(jmsg.getMid()));
                    } else {
                        // to get quote and attachment
                        com.juick.Message reply = messagesService.getReply(jmsg.getMid(), jmsg.getRid());
                        onJuickMessageReply(reply);
                    }
                }
            } catch (JsonProcessingException ex) {
                logger.error("mapper exception", ex);
            } catch (JAXBException exc) {
                logger.error("jaxb exception", exc);
            }
        });
        try {
            xmpp.connect();
        } catch (XmppException e) {
            logger.warn("xmpp extension", e);
        }
    }

    @Override
    public void close() throws Exception {
        if (xmpp != null)
            xmpp.close();

        logger.info("XmppSession on WS destroyed");
    }

    private void onJuickPM(final int uid_to, final com.juick.Message jmsg) throws JsonProcessingException {
        String json = ms.writeValueAsString(jmsg);
        synchronized (wsHandler.getClients()) {
            wsHandler.getClients().stream().filter(c -> !c.legacy && c.visitor.getUid() == uid_to).forEach(c -> {
                try {
                    logger.info("sending pm to {}", c.visitor.getUid());
                    c.session.sendMessage(new TextMessage(json));
                } catch (IOException e) {
                    logger.warn("ws error", e);
                }
            });
        }
    }

    private void onJuickMessagePost(final com.juick.Message jmsg) throws JsonProcessingException {
        String json = ms.writeValueAsString(jmsg);
        List<Integer> uids = subscriptionService.getSubscribedUsers(jmsg.getUser().getUid(), jmsg.getMid())
                .stream().map(User::getUid).collect(Collectors.toList());
        synchronized (wsHandler.getClients()) {
            wsHandler.getClients().stream().filter(c ->
                    (!c.legacy && c.visitor.getUid() == 0) // anonymous users
                            || (!c.legacy && uids.contains(c.visitor.getUid()))) // subscriptions
                    .forEach(c -> {
                        try {
                            logger.info("sending message to {}", c.visitor.getUid());
                            c.session.sendMessage(new TextMessage(json));
                        } catch (IOException e) {
                            logger.warn("ws error", e);
                        }
                    });
            wsHandler.getClients().stream().filter(c ->
                    c.legacy && c.allMessages) // legacy all posts
                    .forEach(c -> {
                        try {
                            logger.info("sending message to legacy client {}", c.visitor.getUid());
                            c.session.sendMessage(new TextMessage(json));
                        } catch (IOException e) {
                            logger.warn("ws error", e);
                        }
                    });
        }
    }

    private void onJuickMessageReply(final com.juick.Message jmsg) throws JsonProcessingException {
        String json = ms.writeValueAsString(jmsg);
        List<Integer> threadUsers =
                subscriptionService.getUsersSubscribedToComments(jmsg.getMid(), jmsg.getUser().getUid())
                        .stream().map(User::getUid).collect(Collectors.toList());
        synchronized (wsHandler.getClients()) {
            wsHandler.getClients().stream().filter(c ->
                    (!c.legacy && c.visitor.getUid() == 0) // anonymous users
                            || (!c.legacy && threadUsers.contains(c.visitor.getUid()))) // subscriptions
                    .forEach(c -> {
                        try {
                            logger.info("sending reply to {}", c.visitor.getUid());
                            c.session.sendMessage(new TextMessage(json));
                        } catch (IOException e) {
                            logger.warn("ws error", e);
                        }
                    });
            wsHandler.getClients().stream().filter(c ->
                    (c.legacy && c.allReplies) || (c.legacy && c.MID == jmsg.getMid())) // legacy replies
                    .forEach(c -> {
                        try {
                            logger.info("sending reply to legacy client {}", c.visitor.getUid());
                            c.session.sendMessage(new TextMessage(json));
                        } catch (IOException e) {
                            logger.warn("ws error", e);
                        }
                    });
        }
    }
}