package com.juick.components.s2s;

import com.juick.components.XMPPServer;
import com.juick.xmpp.Iq;
import com.juick.xmpp.JID;
import com.juick.xmpp.Message;
import com.juick.xmpp.Presence;
import com.juick.xmpp.utils.XmlUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.xmlpull.v1.XmlPullParser;

import javax.net.ssl.SSLException;
import javax.net.ssl.SSLSocket;
import java.io.EOFException;
import java.io.IOException;
import java.net.Socket;
import java.net.SocketException;
import java.util.ArrayList;
import java.util.List;
import java.util.UUID;

/**
 * @author ugnich
 */
public class ConnectionIn extends Connection implements Runnable {

    private static final Logger LOGGER = LoggerFactory.getLogger(ConnectionIn.class);

    final public List<String> from = new ArrayList<>();
    public long tsRemoteData = 0;
    public long packetsRemote = 0;
    JuickBot bot;

    public ConnectionIn(XMPPServer xmpp, JuickBot bot, Socket socket) throws Exception {
        super(xmpp);
        this.bot = bot;
        this.socket = socket;
        streamID = UUID.randomUUID().toString();
        restartParser();
    }

    @Override
    public void run() {
        LOGGER.info("STREAM FROM ? {} START", streamID);
        try {
            parser.next(); // stream:stream
            updateTsRemoteData();
            if (!parser.getName().equals("stream")
                    || !parser.getNamespace("stream").equals(NS_STREAM)) {
//                    || !parser.getAttributeValue(null, "version").equals("1.0")
//                    || !parser.getAttributeValue(null, "to").equals(Main.HOSTNAME)) {
                throw new Exception("STREAM FROM ? " + streamID + " INVALID FIRST PACKET");
            }
            boolean xmppversionnew = parser.getAttributeValue(null, "version") != null;
            String from = parser.getAttributeValue(null, "from");

            if (xmpp.bannedHosts.contains(from)) {
                closeConnection();
                return;
            }
            sendOpenStream(from, xmppversionnew);

            while (parser.next() != XmlPullParser.END_DOCUMENT) {
                updateTsRemoteData();
                if (parser.getEventType() != XmlPullParser.START_TAG) {
                    continue;
                }
                logParser();

                packetsRemote++;

                String tag = parser.getName();
                if (tag.equals("result") && parser.getNamespace().equals(NS_DB)) {
                    String dfrom = parser.getAttributeValue(null, "from");
                    String to = parser.getAttributeValue(null, "to");
                    LOGGER.info("STREAM FROM {} TO {} {} ASKING FOR DIALBACK", dfrom, to, streamID);
                    if (dfrom.endsWith(xmpp.HOSTNAME) && (dfrom.equals(xmpp.HOSTNAME) || dfrom.endsWith("." + xmpp.HOSTNAME))) {
                        break;
                    }
                    if (to != null && to.equals(xmpp.HOSTNAME)) {
                        String dbKey = XmlUtils.getTagText(parser);
                        updateTsRemoteData();

                        ConnectionOut c = xmpp.getConnectionOut(dfrom, false);
                        if (c != null) {
                            c.sendDialbackVerify(streamID, dbKey);
                        } else {
                            c = new ConnectionOut(xmpp, dfrom, streamID, dbKey);
                            xmpp.service.submit(c);
                        }
                    } else {
                        throw new HostUnknownException("STREAM FROM " + dfrom + " " + streamID + " INVALID TO " + to);
                    }
                } else if (tag.equals("verify") && parser.getNamespace().equals(NS_DB)) {
                    String vfrom = parser.getAttributeValue(null, "from");
                    String vto = parser.getAttributeValue(null, "to");
                    String vid = parser.getAttributeValue(null, "id");
                    String vkey = XmlUtils.getTagText(parser);
                    updateTsRemoteData();
                    boolean valid = false;
                    if (vfrom != null && vto != null && vid != null && vkey != null) {
                        String vkey2 = generateDialbackKey(vfrom, vto, vid);
                        valid = vkey.equals(vkey2);
                    }
                    if (valid) {
                        sendStanza("<db:verify from='" + vto + "' to='" + vfrom + "' id='" + vid + "' type='valid'/>");
                        LOGGER.info("STREAM FROM {} {} DIALBACK VERIFY VALID", vfrom, streamID);
                    } else {
                        sendStanza("<db:verify from='" + vto + "' to='" + vfrom + "' id='" + vid + "' type='invalid'/>");
                        LOGGER.warn("STREAM FROM {} {} DIALBACK VERIFY INVALID", vfrom, streamID);
                    }
                } else if (tag.equals("presence") && checkFromTo(parser)) {
                    Presence p = Presence.parse(parser, null);
                    if (p != null && (p.type == null || !p.type.equals(Presence.Type.error))) {
                        bot.incomingPresence(p);
                    }
                } else if (tag.equals("message") && checkFromTo(parser)) {
                    updateTsRemoteData();
                    Message msg = Message.parse(parser, xmpp.childParsers);
                    if (msg != null && (msg.type == null || !msg.type.equals(Message.Type.error))) {
                        LOGGER.info("STREAM {}: {}", streamID, msg);
                        if (!bot.incomingMessage(msg)) {
                            xmpp.getRouter().sendStanza(msg.toString());
                        }
                    }
                } else if (tag.equals("iq") && checkFromTo(parser)) {
                    updateTsRemoteData();
                    String type = parser.getAttributeValue(null, "type");
                    String xml = XmlUtils.parseToString(parser, true);
                    if (type == null || !type.equals(Iq.Type.error)) {
                        LOGGER.info("STREAM {}: {}", streamID, xml);
                        xmpp.getRouter().sendStanza(xml);
                    }
                } else if (sc != null && !isSecured() && tag.equals("starttls")) {
                    LOGGER.info("STREAM {} SECURING", streamID);
                    sendStanza("<proceed xmlns=\"" + NS_TLS + "\" />");
                    try {
                        socket = sc.getSocketFactory().createSocket(socket, socket.getInetAddress().getHostAddress(),
                                socket.getPort(), true);
                        ((SSLSocket) socket).setUseClientMode(false);
                        ((SSLSocket) socket).startHandshake();
                        setSecured(true);
                        LOGGER.info("STREAM {} SECURED", streamID);
                        restartParser();
                    } catch (SSLException sex) {
                        LOGGER.warn("STREAM {} SSL ERROR {}", streamID, sex);
                        sendStanza("<failed xmlns\"" + NS_TLS + "\" />");
                        xmpp.removeConnectionIn(this);
                        closeConnection();
                    }
                } else if (isSecured() && tag.equals("stream") && parser.getNamespace().equals(NS_STREAM)) {
                    sendOpenStream(null, true);
                } else {
                    if (LOGGER.isInfoEnabled()) // prevent call parseToString if logger disabled
                        LOGGER.info("STREAM {}: {}", streamID, XmlUtils.parseToString(parser, true));
                }
            }
            LOGGER.warn("STREAM {} FINISHED", streamID);
            xmpp.removeConnectionIn(this);
            closeConnection();
        } catch (EOFException | SocketException ex) {
            LOGGER.info("STREAM {} CLOSED (dirty)", streamID);
            xmpp.removeConnectionIn(this);
            closeConnection();
        } catch (HostUnknownException e) {
            LOGGER.warn(e.getMessage());
        } catch (Exception e) {
            LOGGER.warn("STREAM {} ERROR {}", streamID, e);
            xmpp.removeConnectionIn(this);
            closeConnection();
        }
    }

    void updateTsRemoteData() {
        tsRemoteData = System.currentTimeMillis();
    }

    void sendOpenStream(String from, boolean xmppversionnew) throws IOException {
        String openStream = "<?xml version='1.0'?><stream:stream xmlns='jabber:server' " +
                "xmlns:stream='http://etherx.jabber.org/streams' xmlns:db='jabber:server:dialback' from='" +
                xmpp.HOSTNAME + "' id='" + streamID + "' version='1.0'>";
        if (xmppversionnew) {
            openStream += "<stream:features>";
            if (sc != null && !isSecured() && !xmpp.brokenSSLhosts.contains(from)) {
                openStream += "<starttls xmlns=\"" + NS_TLS + "\"><optional/></starttls>";
            }
            openStream += "</stream:features>";
        }
        sendStanza(openStream);
    }

    public void sendDialbackResult(String sfrom, String type) {
        try {
            sendStanza("<db:result from='" + xmpp.HOSTNAME + "' to='" + sfrom + "' type='" + type + "'/>");
            if (type.equals("valid")) {
                from.add(sfrom);
                LOGGER.info("STREAM FROM {} {} READY", sfrom, streamID);
            }
        } catch (IOException e) {
            LOGGER.warn("STREAM FROM {} {} ERROR: {}", sfrom, streamID, e);
        }
    }

    boolean checkFromTo(XmlPullParser parser) throws Exception {
        String cfrom = parser.getAttributeValue(null, "from");
        String cto = parser.getAttributeValue(null, "to");
        if (cfrom != null && cto != null && !cfrom.isEmpty() && !cto.isEmpty()) {
            JID jidto = new JID(cto);
            if (jidto.Host != null && jidto.Username != null && jidto.Host.equals(xmpp.HOSTNAME) && jidto.Username.matches("^[a-zA-Z0-9\\-]{2,16}$")) {
                JID jidfrom = new JID(cfrom);
                int size = from.size();
                for (int i = 0; i < size; i++) {
                    if (from.get(i).equals(jidfrom.Host)) {
                        return true;
                    }
                }
            }
        }
        return false;
    }

    class HostUnknownException extends Exception {
        public HostUnknownException(String message) {
            super(message);
        }
    }
}