/*
 * Juick
 * Copyright (C) 2008-2011, Ugnich Anton
 *
 * 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.jabber.ws;

import com.juick.xmpp.JID;
import com.juick.xmpp.MessageListener;
import com.juick.xmpp.XmppConnection;
import com.juick.xmpp.XmppConnectionComponent;
import com.juick.xmpp.XmppListener;
import com.juick.xmpp.extensions.JuickMessage;
import java.io.FileInputStream;
import java.io.IOException;
import java.math.BigInteger;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.nio.charset.Charset;
import java.security.MessageDigest;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.Properties;

/**
 *
 * @author Ugnich Anton
 */
public class Main implements XmppListener, MessageListener {

    Connection sql;
    XmppConnection xmpp;
    ArrayList<SocketSubscribed> sockReplies = new ArrayList<SocketSubscribed>();
    ArrayList<SocketSubscribed> sockMessages = new ArrayList<SocketSubscribed>();
    ArrayList<SocketSubscribed> sockAll = new ArrayList<SocketSubscribed>();
    Selector sel;

    public static void main(String[] args) {
        new Main().start();
    }

    public void start() {
        try {
            Properties conf = new Properties();
            conf.load(new FileInputStream("/etc/juick/ws.conf"));

            setupSql(conf.getProperty("mysql_username", ""), conf.getProperty("mysql_password", ""));
            setupXmppComponent(conf.getProperty("xmpp_password", ""));
            setupWsServer();
        } catch (Exception e) {
            System.err.println(e);
        }
    }

    public void setupSql(String username, String password) {
        try {
            sql = DriverManager.getConnection("jdbc:mysql://localhost/juick?autoReconnect=true&user=" + username + "&password=" + password);
        } catch (SQLException e) {
            System.err.println(e);
        }
    }

    public void setupXmppComponent(String password) {
        xmpp = new XmppConnectionComponent(new JID("", "ws.juick.com", ""), password, "127.0.0.1", 5347, false);
        xmpp.addListener((XmppListener) this);
        xmpp.addListener((MessageListener) this);
        xmpp.start();
    }

    @Override
    public void onConnectionFailed(String msg) {
        System.err.println("XMPP onConnFailed " + msg);
    }

    @Override
    public void onAuth(String resource) {
        System.err.println("XMPP onAuth " + resource);
    }

    @Override
    public void onAuthFailed(String message) {
        System.err.println("XMPP onAuthFailed " + message);
    }

    public void setupWsServer() {
        try {
            sel = Selector.open();
            ServerSocketChannel listensock = ServerSocketChannel.open();
            listensock.configureBlocking(false);
            listensock.socket().bind(new InetSocketAddress(8080));
            listensock.register(sel, SelectionKey.OP_ACCEPT);

            while (true) {
                sel.select();
//                System.out.println("ONE");
                Iterator it = sel.selectedKeys().iterator();
                while (it.hasNext()) {
//                    System.out.println("TWO");
                    SelectionKey selKey = (SelectionKey) it.next();
                    it.remove();
                    if (selKey.isAcceptable()) {
                        ServerSocketChannel ssChannel = (ServerSocketChannel) selKey.channel();
                        SocketChannel sChannel = ssChannel.accept();
                        System.out.println(sChannel.socket().getRemoteSocketAddress().toString() + " ACCEPTED");
                        sChannel.configureBlocking(false);
                        sChannel.register(sel, SelectionKey.OP_READ);
                    } else if (selKey.isReadable()) {
//                        System.out.println("THREE");
                        SocketChannel sChannel = (SocketChannel) selKey.channel();
                        ByteBuffer buf = ByteBuffer.allocate(10240);
                        try {
                            if (sChannel.read(buf) > 0) {
                                buf.flip();
                                CharBuffer charbuf = Charset.forName("ISO-8859-1").decode(buf);
                                if (charbuf.charAt(0) == 0 && charbuf.charAt(charbuf.length() - 1) == 0xFF) {
                                    wsTextFrame(sChannel, charbuf.subSequence(1, charbuf.length() - 2));
                                } else if (charbuf.charAt(0) == 'G' && charbuf.charAt(1) == 'E' && charbuf.charAt(2) == 'T' && charbuf.charAt(3) == ' ') {
                                    wsHandshake(sChannel, buf);
                                } else {
                                    System.out.println(sChannel.socket().getRemoteSocketAddress().toString() + " INVALID FRAME");
//                                    System.out.println("FOUR");
                                    sChannel.close();
                                    selKey.cancel();
                                }
                            } else {
                                sChannel.close();
                                selKey.cancel();
//                                System.out.println("SIX");
                            }
                        } catch (IOException e) {
                            System.err.println(e);
                            sChannel.close();
//                            System.out.println("FIVE");
                            selKey.cancel();
                        }
                    }
                }
            }
        } catch (Exception e) {
            System.err.println(e);
        }
    }

    public void wsHandshake(SocketChannel sock, ByteBuffer buf) throws Exception {
        String hOrigin = null;
        String hHost = null;
        String hLocation = null;
        String hSecWebSocketKey1 = null;
        String hSecWebSocketKey2 = null;
        String hCookie = null;

        buf.rewind();
        CharBuffer charbuf = Charset.forName("ISO-8859-1").decode(buf);
        String headers[] = charbuf.toString().split("\r\n");
        for (int i = 0; i < headers.length; i++) {
            String h[] = headers[i].split(" ", 2);
            if (h.length == 2) {
                if (h[0].equals("GET")) {
                    hLocation = headers[i].split(" ", 3)[1];
                } else if (h[0].equals("Origin:")) {
                    hOrigin = h[1];
                } else if (h[0].equals("Host:")) {
                    hHost = h[1];
                } else if (h[0].equals("Sec-WebSocket-Key1:")) {
                    hSecWebSocketKey1 = h[1];
                } else if (h[0].equals("Sec-WebSocket-Key2:")) {
                    hSecWebSocketKey2 = h[1];
                } else if (h[0].equals("Cookie:")) {
                    hCookie = h[1];
                }
            }
        }

        if (hOrigin == null || hHost == null || hLocation == null || hSecWebSocketKey1 == null || hSecWebSocketKey2 == null) {
            System.err.println(sock.socket().getRemoteSocketAddress().toString() + " Invalid headers");
            sock.close();
            return;
        }

        // Cookies
        int UID = 0;
        String hash = null;
        if (hCookie != null) {
            String cookies[] = hCookie.split("; ");
            for (int i = 0; i < cookies.length; i++) {
                String cookie[] = cookies[i].split("=", 2);
                if (cookie[0].equals("hash")) {
                    hash = cookie[1];
                    break;
                }
            }
            if (hash != null) {
                UID = com.juick.server.UserQueries.getUIDbyHash(sql, hash);
            }
        }

        // URL
        String loc[] = hLocation.split("/");
        int MID = 0;
        if (hLocation.equals("/my") && UID > 0) {
            sockMessages.add(new SocketSubscribed(sock, UID, 0));
        } else if (hLocation.equals("/all")) {
            sockAll.add(new SocketSubscribed(sock, UID, 0));
        } else if ((loc.length == 2 || loc.length == 3) && loc[1].equals("replies")) {
            if (loc.length == 2) {
                sockReplies.add(new SocketSubscribed(sock, UID, 0));
            } else {
                try {
                    MID = Integer.parseInt(loc[2]);
                } catch (Exception e) {
                }
                if (MID > 0) {
                    sockReplies.add(new SocketSubscribed(sock, UID, MID));
                } else {
                    System.err.println(sock.socket().getRemoteSocketAddress().toString() + " Invalid MID");
                    sock.close();
                    return;
                }
            }
        } else {
            System.err.println(sock.socket().getRemoteSocketAddress().toString() + " Invalid location");
            sock.close();
            return;
        }

        System.out.println(sock.socket().getRemoteSocketAddress().toString() + " HANDSHAKE (Hash=" + hash + "; UID = " + UID + "; MID = " + MID + ")");

        Long lSecNum1 = calcSecKeyNum(hSecWebSocketKey1);
        Long lSecNum2 = calcSecKeyNum(hSecWebSocketKey2);

        BigInteger sec1 = new BigInteger(lSecNum1.toString());
        BigInteger sec2 = new BigInteger(lSecNum2.toString());

        // concatenate 3 parts secNum1 + secNum2 + secKey (16 Bytes)
        byte[] l128Bit = new byte[]{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
        byte[] lTmp;

        lTmp = sec1.toByteArray();
        int lIdx = lTmp.length;
        int lCnt = 0;
        while (lIdx > 0 && lCnt < 4) {
            lIdx--;
            lCnt++;
            l128Bit[4 - lCnt] = lTmp[lIdx];
        }

        lTmp = sec2.toByteArray();
        lIdx = lTmp.length;
        lCnt = 0;
        while (lIdx > 0 && lCnt < 4) {
            lIdx--;
            lCnt++;
            l128Bit[8 - lCnt] = lTmp[lIdx];
        }

        buf.rewind();
        for (int i = 0; i < 8; i++) {
            l128Bit[8 + i] = buf.get(buf.limit() - 8 + i);
        }

        String outstr = "HTTP/1.1 101 Web Socket Protocol Handshake\r\n"
                + "Upgrade: WebSocket\r\n"
                + "Connection: Upgrade\r\n"
                + "Sec-WebSocket-Origin: " + hOrigin + "\r\n"
                + "Sec-WebSocket-Location: ws://" + hHost + hLocation + "\r\n"
                + "Sec-WebSocket-Protocol: sample\r\n"
                + "\r\n";
        ByteBuffer out = ByteBuffer.allocate(4096);
        out.put(Charset.forName("ISO-8859-1").encode(outstr));
        out.put(MessageDigest.getInstance("MD5").digest(l128Bit));
        out.flip();

        sock.write(out);
    }

    private static long calcSecKeyNum(String aKey) {
        StringBuilder lSB = new StringBuilder();
        // StringBuuffer lSB = new StringBuuffer();
        int lSpaces = 0;
        for (int i = 0; i < aKey.length(); i++) {
            char lC = aKey.charAt(i);
            if (lC == ' ') {
                lSpaces++;
            } else if (lC >= '0' && lC <= '9') {
                lSB.append(lC);
            }
        }
        long lRes = -1;
        if (lSpaces > 0) {
            try {
                lRes = Long.parseLong(lSB.toString()) / lSpaces;
                // log.debug("Key: " + aKey + ", Numbers: " + lSB.toString() +
                // ", Spaces: " + lSpaces + ", Result: " + lRes);
            } catch (NumberFormatException ex) {
                // use default result
            }
        }
        return lRes;
    }

    public void wsTextFrame(SocketChannel sock, CharSequence csbuf) {
        String buf = csbuf.toString();
        if (buf.equals(" ")) {
            ByteBuffer out = ByteBuffer.allocate(4);
            out.put((byte) 0x00);
            out.put((byte) 0x20);
            out.put((byte) 0xFF);
            out.flip();
            out.rewind();
            try {
                sock.write(out);
            } catch (IOException e) {
            }
        } else {
            System.out.println(sock.socket().getRemoteSocketAddress().toString() + " DATA '" + buf + "'");
        }
    }

    @Override
    public void onMessage(com.juick.xmpp.Message msg) {
        JuickMessage jmsg = (JuickMessage) msg.getChild(JuickMessage.XMLNS);
        if (jmsg != null) {
            System.err.println("MID=" + jmsg.MID + "; RID=" + jmsg.RID);
            if (jmsg.RID == 0) {
                onJuickMessagePost(jmsg);
            } else {
                onJuickMessageReply(jmsg);
            }
        }
    }

    private void onJuickMessagePost(com.juick.Message jmsg) {
        String json = "{"
                + "\"mid\":" + jmsg.MID + ","
                + "\"user\":{" + "\"uid\":" + jmsg.User.UID + "," + "\"uname\":\"" + encloseJSON(jmsg.User.UName) + "\"},"
                + "\"timestamp\":\"" + jmsg.TimestampString + "\","
                + "\"body\":\"" + encloseJSON(jmsg.Text) + "\"";
        if (jmsg.Tags.size() > 0) {
            json += ",\"tags\":[";
            for (int i = 0; i < jmsg.Tags.size(); i++) {
                if (i > 0) {
                    json += ",";
                }
                json += "\"" + encloseJSON((String) jmsg.Tags.get(i)) + "\"";
            }
            json += "]";
        }
        json += "}";

        ByteBuffer out = ByteBuffer.allocate(10240);
        out.put((byte) 0x00);
        out.put(Charset.forName("UTF-8").encode(json));
        out.put((byte) 0xFF);
        out.flip();


        String query = "SELECT suser_id FROM subscr_users WHERE user_id=" + jmsg.User.UID + " AND suser_id NOT IN (SELECT user_id FROM bl_tags INNER JOIN messages_tags USING(tag_id) WHERE message_id=" + jmsg.MID + ")";
        if (jmsg.Privacy < 0) {
            query += " AND suser_id IN (SELECT wl_user_id FROM wl_users WHERE user_id=" + jmsg.User.UID + ")";
        }

        Statement stmt = null;
        ResultSet rs = null;
        try {
            stmt = sql.createStatement();
            rs = stmt.executeQuery(query);
            rs.beforeFirst();
            while (rs.next()) {
                int UID = rs.getInt(1);

                for (int i = sockMessages.size() - 1; i >= 0; i--) {
                    SocketSubscribed ss = sockMessages.get(i);
                    if (ss.UID == UID) {
                        try {
                            out.rewind();
                            ss.sock.write(out);
                        } catch (IOException e) {
                            sockMessages.remove(i);
                            try {
                                ss.sock.close();
                            } catch (IOException ex) {
                            }
                        }
                    }
                }

                if (jmsg.Privacy <= 0) {
                    for (int i = sockAll.size() - 1; i >= 0; i--) {
                        SocketSubscribed ss = sockAll.get(i);
                        if (ss.UID == UID) {
                            try {
                                out.rewind();
                                ss.sock.write(out);
                            } catch (IOException e) {
                                sockAll.remove(i);
                                try {
                                    ss.sock.close();
                                } catch (IOException ex) {
                                }
                            }
                        }
                    }
                }

            }
        } catch (SQLException e) {
            System.err.println(e);
        } finally {
            if (rs != null) {
                try {
                    rs.close();
                } catch (SQLException e) {
                }
            }
            if (stmt != null) {
                try {
                    stmt.close();
                } catch (SQLException e) {
                }
            }
        }

        // Send to all
        if (jmsg.Privacy > 0) {
            for (int i = sockAll.size() - 1; i >= 0; i--) {
                SocketSubscribed ss = sockAll.get(i);
                try {
                    out.rewind();
                    ss.sock.write(out);
                    System.err.println("  --->" + ss.sock.socket().getRemoteSocketAddress());
                } catch (IOException e) {
                    sockAll.remove(i);
                    try {
                        ss.sock.close();
                    } catch (IOException ex) {
                    }
                }
            }
        }

    }

    private void onJuickMessageReply(com.juick.Message jmsg) {
        String json = "{"
                + "\"mid\":" + jmsg.MID + ","
                + "\"rid\":" + jmsg.RID + ","
                + "\"replyto\":" + jmsg.ReplyTo + ","
                + "\"user\":{" + "\"uid\":" + jmsg.User.UID + "," + "\"uname\":\"" + encloseJSON(jmsg.User.UName) + "\"},"
                + "\"timestamp\":\"" + jmsg.TimestampString + "\","
                + "\"body\":\"" + encloseJSON(jmsg.Text) + "\""
                + "}";

        ByteBuffer out = ByteBuffer.allocate(10240);
        out.put((byte) 0x00);
        out.put(Charset.forName("UTF-8").encode(json));
        out.put((byte) 0xFF);
        out.flip();

        for (int i = sockReplies.size() - 1; i >= 0; i--) {
            SocketSubscribed ss = sockReplies.get(i);
            if (ss.MID == 0 || ss.MID == jmsg.MID) {
                try {
                    out.rewind();
                    ss.sock.write(out);
                    System.err.println("  --->" + ss.sock.socket().getRemoteSocketAddress());
                } catch (IOException e) {
                    sockReplies.remove(i);
                    try {
                        ss.sock.close();
                    } catch (IOException ex) {
                    }
                }
            }
        }
    }

    public static String encloseJSON(String str) {
        return str.replace("\"", "&quot;").replace("\\", "\\\\").replace("\n", "\\n");
    }
}

class SocketSubscribed {

    public SocketChannel sock;
    public int UID;
    public int MID;

    public SocketSubscribed(SocketChannel sock, int UID, int MID) {
        this.sock = sock;
        this.UID = UID;
        this.MID = MID;
    }
}