package com.juick.jabber.ws;

import java.io.IOException;
import java.math.BigInteger;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.SocketChannel;
import java.nio.charset.Charset;
import java.security.MessageDigest;
import java.sql.Connection;
import java.util.Iterator;

/**
 *
 * @author ugnich
 */
public class WSData implements Runnable {

    Connection sql;
    public static Selector sel;

    public WSData(Connection sql) {
        this.sql = sql;
    }

    @Override
    public void run() {
        try {
            sel = Selector.open();
            while (true) {
                sel.select();
                Iterator<SelectionKey> it = sel.selectedKeys().iterator();
                while (it.hasNext()) {
                    SelectionKey selKey = it.next();
                    it.remove();

                    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 {
                                throw new IOException(sChannel.socket().getRemoteSocketAddress().toString() + " INVALID FRAME");
                            }
                        } else {
                            throw new IOException(sChannel.socket().getRemoteSocketAddress().toString()+ " NO DATA");
                        }
                    } catch (IOException e) {
                        System.err.println("WSData: " + e);
                        sChannel.socket().close();
                        sChannel.close();
                        selKey.cancel();
                    }
                }
            }
        } catch (Exception e) {
            System.err.println("WSData: " + 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) {
            throw new IOException(sock.socket().getRemoteSocketAddress().toString() + " Invalid headers");
        }

        // 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) {
            Main.sockMessages.add(new SocketSubscribed(sock, UID, 0));
        } else if (hLocation.equals("/all")) {
            Main.sockAll.add(new SocketSubscribed(sock, UID, 0));
        } else if ((loc.length == 2 || loc.length == 3) && loc[1].equals("replies")) {
            if (loc.length == 2) {
                Main.sockReplies.add(new SocketSubscribed(sock, UID, 0));
            } else {
                try {
                    MID = Integer.parseInt(loc[2]);
                } catch (Exception e) {
                }
                if (MID > 0) {
                    Main.sockReplies.add(new SocketSubscribed(sock, UID, MID));
                } else {
                    throw new IOException(sock.socket().getRemoteSocketAddress().toString() + " Invalid MID");
                }
            }
        } else {
            throw new IOException(sock.socket().getRemoteSocketAddress().toString() + " Invalid location");
        }

        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();
        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;
            } 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 + "'");
        }
    }
}