/*
 * 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.components;

import com.juick.User;
import com.juick.components.s2s.StanzaListener;
import com.juick.formatters.PlainTextFormatter;
import com.juick.service.*;
import org.apache.commons.lang3.StringUtils;
import org.ocpsoft.prettytime.PrettyTime;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
import rocks.xmpp.addr.Jid;
import rocks.xmpp.core.stanza.model.*;
import rocks.xmpp.core.stanza.model.client.ClientMessage;
import rocks.xmpp.core.stanza.model.client.ClientPresence;
import rocks.xmpp.core.stanza.model.errors.Condition;

import javax.annotation.PostConstruct;
import javax.inject.Inject;
import java.util.Collections;
import java.util.List;
import java.util.Locale;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.stream.Collectors;

/**
 *
 * @author ugnich
 */
@Component
public class JuickBot implements StanzaListener, AutoCloseable {

    private static final Logger logger = LoggerFactory.getLogger(JuickBot.class);

    @Inject
    private XMPPServer xmpp;
    @Inject
    private XMPPConnection router;
    @Value("${xmppbot_jid}")
    private String xmppbotJidStr;

    private Jid jid;

    private PrettyTime pt;

    @Inject
    public MessagesService messagesService;
    @Inject
    public UserService userService;
    @Inject
    public TagService tagService;
    @Inject
    public PMQueriesService pmQueriesService;
    @Inject
    public ShowQueriesService showQueriesService;

    @PostConstruct
    public void init() {
        xmpp.addStanzaListener(this);
        jid = Jid.of(xmppbotJidStr);
        broadcastPresence(null);
        pt = new PrettyTime(new Locale("ru"));
    }

    public Jid getJid() {
        return jid;
    }

    private static final String HELPTEXT =
            "@username text - Send private message\n"
            + "*tagname Blah-blah-blah - Post a message with tag 'tagname'\n"
            + "#1234 Blah-blah-blah - Answer to message #1234\n"
            + "#1234/5 Blah - Answer to reply #1234/5\n"
            + "! #1234 - Recommend post\n"
            + "\n"
            + "# - Show last messages from your feed (## - second page, ...)\n"
            + "@ - Show recomendations and popular personal blogs\n"
            + "* - Show your tags\n"
            + "#1234 - Show message\n"
            + "#1234+ - Show message with replies\n"
            + "@username - Show user's info\n"
            + "@username+ - Show user's info and last 10 messages\n"
            + "@username *tag - User's messages with this tag\n"
            + "*tag - Show last 10 messages with this tag\n"
            + "? blah - Search posts for 'blah'\n"
            + "? @username blah - Searching among user\'s posts for 'blah'\n"
            + "D #123 - Delete message\n"
            + "D #123/45 - Delete reply\n"
            + "DL - Delete last message/reply\n"
            + "S - Show your subscriptions\n"
            + "S #123 - Subscribe to message replies\n"
            + "S @username - Subscribe to user's blog\n"
            + "U #123 - Unsubscribe from comments\n"
            + "U @username - Unsubscribe from user's blog\n"
            + "BL - Show your blacklist\n"
            + "BL @username - Add/delete user to/from your blacklist\n"
            + "BL *tag - Add/delete tag to/from your blacklist\n"
            + "ON / OFF - Enable/disable subscriptions delivery\n"
            + "PING - Pong\n"
            + "\n"
            + "Read more: http://juick.com/help/";

    public boolean incomingPresence(Presence p) {
        final String username = p.getTo().getLocal();
        final boolean toJuick = username.equals(jid.getLocal());

        if (p.getType() == null) {
            Presence reply = new Presence();
            reply.setFrom(p.getTo().asBareJid());
            reply.setTo(p.getFrom().asBareJid());
            reply.setType(Presence.Type.UNSUBSCRIBE);
            xmpp.sendOut(ClientPresence.from(reply));
            return true;
        } else if (p.getType().equals(Presence.Type.PROBE)) {
            int uid_to = 0;
            if (!toJuick) {
                uid_to = userService.getUIDbyName(username);
            }

            if (toJuick || uid_to > 0) {
                Presence reply = new Presence();
                reply.setFrom(p.getTo().withResource(jid.getResource()));
                reply.setTo(p.getFrom());
                reply.setPriority((byte)10);
                xmpp.sendOut(ClientPresence.from(reply));
            } else {
                Presence reply = new Presence();
                reply.setFrom(p.getTo());
                reply.setTo(p.getFrom());
                reply.setType(Presence.Type.ERROR);
                reply.setId(p.getId());
                reply.setError(new StanzaError(StanzaError.Type.CANCEL, Condition.ITEM_NOT_FOUND));
                xmpp.sendOut(ClientPresence.from(reply));
                return true;
            }
            return true;
        } else if (p.getType().equals(Presence.Type.SUBSCRIBE)) {
            boolean canSubscribe = false;
            if (toJuick) {
                canSubscribe = true;
            } else {
                int uid_to = userService.getUIDbyName(username);
                if (uid_to > 0) {
                    pmQueriesService.addPMinRoster(uid_to, p.getFrom().asBareJid().toEscapedString());
                    canSubscribe = true;
                }
            }

            if (canSubscribe) {
                Presence reply = new Presence();
                reply.setFrom(p.getTo());
                reply.setTo(p.getFrom());
                reply.setType(Presence.Type.SUBSCRIBED);
                xmpp.sendOut(ClientPresence.from(reply));

                reply.setFrom(reply.getFrom().withResource(jid.getResource()));
                reply.setPriority((byte) 10);
                reply.setType(null);
                xmpp.sendOut(ClientPresence.from(reply));

                return true;
            } else {
                Presence reply = new Presence();
                reply.setFrom(p.getTo());
                reply.setTo(p.getFrom());
                reply.setType(Presence.Type.ERROR);
                reply.setId(p.getId());
                reply.setError(new StanzaError(StanzaError.Type.CANCEL, Condition.ITEM_NOT_FOUND));
                xmpp.sendOut(ClientPresence.from(reply));
                return true;
            }
        } else if (p.getType().equals(Presence.Type.UNSUBSCRIBE)) {
            if (!toJuick) {
                int uid_to = userService.getUIDbyName(username);
                if (uid_to > 0) {
                    pmQueriesService.removePMinRoster(uid_to, p.getFrom().asBareJid().toEscapedString());
                }
            }

            Presence reply = new Presence();
            reply.setFrom(p.getTo());
            reply.setTo(p.getFrom());
            reply.setType(Presence.Type.UNSUBSCRIBED);
            xmpp.sendOut(ClientPresence.from(reply));
        }

        return false;
    }

    public boolean incomingMessage(Message msg) {
        if (StringUtils.isBlank(msg.getBody()) || (msg.getType() != null && msg.getType().equals(Message.Type.ERROR))) {
            return false;
        }

        String username = msg.getTo().getLocal();

        User user_from;
        String signuphash = StringUtils.EMPTY;
        user_from = userService.getUserByJID(msg.getFrom().asBareJid().toEscapedString());
        if (user_from == null) {
            signuphash = userService.getSignUpHashByJID(msg.getFrom().asBareJid().toEscapedString());
        }

        if (user_from == null) {
            Message reply = new Message();
            reply.setFrom(msg.getTo());
            reply.setTo(msg.getFrom());
            reply.setType(Message.Type.CHAT);
            if (username.equals(jid.getLocal())) {
                reply.setBody("Для того, чтобы начать пользоваться сервисом, пожалуйста пройдите быструю регистрацию: http://juick.com/signup?type=xmpp&hash=" + signuphash + "\nЕсли у вас уже есть учетная запись на Juick, вы сможете присоединить этот JabberID к ней.\n\nTo start using Juick, please sign up: http://juick.com/signup?type=xmpp&hash=" + signuphash + "\nIf you already have an account on Juick, you will be proposed to attach this JabberID to your existing account.");
            } else {
                reply.setBody("Внимание, системное сообщение!\nВаш JabberID не обнаружен в списке доверенных. Для того, чтобы отправить сообщение пользователю " + username + "@juick.com, пожалуйста зарегистрируйте свой JabberID в системе: http://juick.com/signup?type=xmpp&hash=" + signuphash + "\nЕсли у вас уже есть учетная запись на Juick, вы сможете присоединить этот JabberID к ней.\n\nWarning, system message!\nYour JabberID is not found in our server's white list. To send a message to " + username + "@juick.com, please sign up: http://juick.com/signup?type=xmpp&hash=" + signuphash + "\nIf you already have an account on Juick, you will be proposed to attach this JabberID to your existing account.");
            }
            xmpp.sendOut(ClientMessage.from(reply));
            return true;
        }

        if (username.equals(jid.getLocal())) {
            return incomingMessageJuick(user_from, msg);
        }

        int uid_to = userService.getUIDbyName(username);

        if (uid_to == 0) {
            Message reply = new Message();
            reply.setFrom(msg.getTo());
            reply.setTo(msg.getFrom());
            reply.setType(Message.Type.ERROR);
            reply.setId(msg.getId());
            reply.setError(new StanzaError(StanzaError.Type.CANCEL, Condition.ITEM_NOT_FOUND));
            xmpp.sendOut(ClientMessage.from(reply));
            return true;
        }

        boolean success = false;
        if (!userService.isInBLAny(uid_to, user_from.getUid())) {
            success = pmQueriesService.createPM(user_from.getUid(), uid_to, msg.getBody());
        }

        if (success) {
            Message m = new Message();
            m.setFrom(jid.asBareJid());
            m.setTo(Jid.of(Integer.toString(uid_to), "push.juick.com", null));
            com.juick.Message jmsg = new com.juick.Message();
            jmsg.setUser(user_from);
            jmsg.setText(msg.getBody());
            m.addExtension(jmsg);
            router.sendStanza(m);

            m.setTo(Jid.of(Integer.toString(uid_to), "ws.juick.com", null));
            router.sendStanza(m);

            List<String> jids;
            boolean inroster = false;
            jids = userService.getJIDsbyUID(uid_to);
            for (String userJid : jids) {
                Message mm = new Message();
                mm.setTo(Jid.of(userJid));
                mm.setType(Message.Type.CHAT);
                inroster = pmQueriesService.havePMinRoster(user_from.getUid(), userJid);
                if (inroster) {
                    mm.setFrom(Jid.of(jmsg.getUser().getName(), "juick.com", "Juick"));
                    mm.setBody(msg.getBody());
                } else {
                    mm.setFrom(jid);
                    mm.setBody("Private message from @" + jmsg.getUser().getName() + ":\n" + msg.getBody());
                }
                xmpp.sendOut(ClientMessage.from(mm));
            }
        } else {
            Message reply = new Message();
            reply.setFrom(msg.getTo());
            reply.setTo(msg.getFrom());
            reply.setType(Message.Type.ERROR);
            reply.setId(msg.getId());
            reply.setError(new StanzaError(StanzaError.Type.CANCEL, Condition.NOT_ALLOWED));
            xmpp.sendOut(ClientMessage.from(reply));
        }

        return false;
    }
    private static Pattern regexPM = Pattern.compile("^\\@(\\S+)\\s+([\\s\\S]+)$");

    public boolean incomingMessageJuick(User user_from, Message msg) {
        String command = msg.getBody().trim();
        int commandlen = command.length();

        // COMPATIBILITY
        if (commandlen > 7 && command.substring(0, 3).equalsIgnoreCase("PM ")) {
            command = command.substring(3).trim();
            commandlen = command.length();
        }

        if (commandlen == 4) {
            if (command.equalsIgnoreCase("PING")) {
                commandPing(msg);
                return true;
            } else if (command.equalsIgnoreCase("HELP")) {
                commandHelp(msg);
                return true;
            }
        } else if (commandlen == 5 && command.equalsIgnoreCase("LOGIN")) {
            commandLogin(msg, user_from);
            return true;
        } else if (command.charAt(0) == '@') {
            Matcher matchPM = regexPM.matcher(command);
            if (matchPM.find()) {
                String user_to = matchPM.group(1);
                String msgtxt = matchPM.group(2);
                commandPM(msg, user_from, user_to, msgtxt);
                return true;
            }
        } else if (commandlen == 2 && command.equalsIgnoreCase("BL")) {
            commandBLShow(msg, user_from);
            return true;
        } else if (commandlen == 2 && command.equalsIgnoreCase("#+")) {
            return commandLast(msg.getFrom());
        } else if (command.equalsIgnoreCase("@")) {
            return commandUsers(msg.getFrom());
        }

        return false;
    }

    private void commandPing(Message m) {
        Presence p = new Presence(m.getFrom());
        p.setFrom(jid);
        p.setPriority((byte) 10);
        xmpp.sendOut(ClientPresence.from(p));

        sendReply(m.getFrom(), "PONG");
    }

    private void commandHelp(Message m) {
        sendReply(m.getFrom(), HELPTEXT);
    }

    private void commandLogin(Message m, User user_from) {
        sendReply(m.getFrom(), "http://juick.com/login?hash=" + userService.getHashByUID(user_from.getUid()));
    }

    private void commandPM(Message m, User user_from, String user_to, String body) {
        int ret = 0;

        int uid_to = 0;
        List<String> jids_to = null;
        boolean haveInRoster = false;

        if (user_to.indexOf('@') > 0) {
            uid_to = userService.getUIDbyJID(user_to);
        } else {
            uid_to = userService.getUIDbyName(user_to);
        }

        if (uid_to > 0) {
            if (!userService.isInBLAny(uid_to, user_from.getUid())) {
                if (pmQueriesService.createPM(user_from.getUid(), uid_to, body)) {
                    jids_to = userService.getJIDsbyUID(uid_to);
                    ret = 200;
                } else {
                    ret = 500;
                }
            } else {
                ret = 403;
            }
        } else {
            ret = 404;
        }

        if (ret == 200) {
            Message msg = new Message();
            msg.setFrom(jid.asBareJid());
            msg.setTo(Jid.of(Integer.toString(uid_to), "push.juick.com", null));
            com.juick.Message jmsg = new com.juick.Message();
            jmsg.setUser(user_from);
            jmsg.setText(body);
            msg.addExtension(jmsg);
            router.sendStanza(msg);

            msg.setTo(Jid.of(Integer.toString(uid_to), "ws.juick.com", null));
            router.sendStanza(msg);

            for (String userJid : jids_to) {
                Message mm = new Message();
                mm.setTo(Jid.of(userJid));
                mm.setType(Message.Type.CHAT);
                haveInRoster = pmQueriesService.havePMinRoster(user_from.getUid(), userJid);
                if (haveInRoster) {
                    mm.setFrom(Jid.of(user_from.getName(), "juick.com", "Juick"));
                    mm.setBody(body);
                } else {
                    mm.setFrom(jid);
                    mm.setBody("Private message from @" + user_from.getName() + ":\n" + body);
                }
                xmpp.sendOut(ClientMessage.from(mm));
            }
        }

        Message reply = new Message();
        reply.setFrom(m.getTo());
        reply.setTo(m.getFrom());
        if (ret == 200) {
            reply.setType(m.getType());
            reply.setBody("Private message sent");
        } else {
            reply.setType(Message.Type.ERROR);
            reply.setBody("Error " + ret);
        }
        xmpp.sendOut(ClientMessage.from(reply));
    }

    private void commandBLShow(Message m, User user_from) {
        List<User> blusers = userService.getUserBLUsers(user_from.getUid());
        List<String> bltags = tagService.getUserBLTags(user_from.getUid());

        String txt = StringUtils.EMPTY;
        if (bltags.size() > 0) {
            for (String bltag : bltags) {
                txt += "*" + bltag + "\n";
            }

            if (blusers.size() > 0) {
                txt += "\n";
            }
        }
        if (blusers.size() > 0) {
            for (User bluser : blusers) {
                txt += "@" + bluser.getName() + "\n";
            }
        }
        if (txt.isEmpty()) {
            txt = "You don't have any users or tags in your blacklist.";
        }

        sendReply(m.getFrom(), txt);
    }

    boolean commandLast(Jid jidFrom) {
        User user = userService.getUserByJID(jidFrom.asBareJid().toEscapedString());
        sendReply(jidFrom, "Last messages:\n"
                + printMessages(messagesService.getAll(user.getUid(), 0), true));
        return true;
    }

    boolean commandUsers(Jid jidFrom) {
        StringBuilder msg = new StringBuilder();
        msg.append("Recommended blogs");
        User currentUser = userService.getUserByJID(jidFrom.asBareJid().toEscapedString());
        List<String> recommendedUsers = showQueriesService.getRecommendedUsers(currentUser);
        if (recommendedUsers.size() > 0) {
            for (String user : recommendedUsers) {
                msg.append("\n@").append(user);
            }
        } else {
            msg.append("\nNo recommendations now. Subscribe to more blogs. ;)");
        }
        msg.append("\n\nTop 10 personal blogs:");
        List<String> topUsers = showQueriesService.getTopUsers();
        if (topUsers.size() > 0) {
            for (String user : topUsers) {
                msg.append("\n@").append(user);
            }
        } else {
            msg.append("\nNo top users. Empty DB? ;)");
        }
        sendReply(jidFrom, msg.toString());
        return true;
    }

    void sendReply(Jid jidTo, String txt) {
        Message reply = new Message();
        reply.setFrom(jid);
        reply.setTo(jidTo);
        reply.setType(Message.Type.CHAT);
        reply.setBody(txt);
        xmpp.sendOut(ClientMessage.from(reply));
    }

    void sendNotification(Stanza stanza) {
        xmpp.sendOut(stanza);
    }

    @Override
    public void stanzaReceived(Stanza xmlValue) {
        if (xmlValue instanceof Presence) {
            Presence p = (Presence) xmlValue;
            if (p.getType() == null || !p.getType().equals(Presence.Type.ERROR)) {
                incomingPresence(p);
            }
        } else if (xmlValue instanceof Message) {
            Message msg = (Message) xmlValue;
            if (!incomingMessage(msg)) {
                router.sendStanza(msg);
            }
        } else if (xmlValue instanceof IQ) {
            IQ iq = (IQ) xmlValue;
            router.sendStanza(iq);
        }
    }

    String printMessages(List<Integer> mids, boolean crop) {
        return messagesService.getMessages(mids).stream()
                .sorted(Collections.reverseOrder())
                .map(PlainTextFormatter::formatPostSummary).collect(Collectors.joining("\n\n"));
    }

    void broadcastPresence(Presence.Type type) {
        Presence presence = new Presence();
        presence.setFrom(jid);
        if (type != null) {
            presence.setType(type);
        }
        userService.getActiveJIDs().forEach(j -> {
            try {
                presence.setTo(Jid.of(j));
                xmpp.sendOut(ClientPresence.from(presence));
            } catch (IllegalArgumentException ex) {
                logger.warn("Invalid jid: {}", j, ex);
            }
        });
    }

    @Override
    public void close() throws Exception {
        broadcastPresence(Presence.Type.UNAVAILABLE);
    }
}