package jp.ac.u_ryukyu.treevnc;

import java.io.IOException;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.net.BindException;
import java.net.NetworkInterface;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.UnknownHostException;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.zip.DataFormatException;
import java.util.zip.Deflater;
import java.util.zip.Inflater;

import com.glavsoft.exceptions.TransportException;
import com.glavsoft.rfb.client.ClientToServerMessage;
import com.glavsoft.rfb.encoding.EncodingType;
import com.glavsoft.rfb.protocol.Protocol;
import com.glavsoft.rfb.protocol.ProtocolContext;
import com.glavsoft.transport.Reader;
import com.glavsoft.transport.Writer;
import com.glavsoft.viewer.ViewerInterface;
import com.glavsoft.viewer.swing.ConnectionParams;


public class TreeRFBProto {

    final static int FramebufferUpdateRequest = 3;
    final static int CheckDelay = 11;
    protected final static int FramebufferUpdate = 0;
    protected ProtocolContext context;
    private int clients = 0;
    public MulticastQueue<LinkedList<ByteBuffer>> multicastqueue = new MulticastQueue<LinkedList<ByteBuffer>>();
    private RequestScreenThread rThread;
    public int acceptPort = 0;
    private String myAddress;
    protected boolean readyReconnect = false;
    private boolean cuiVersion;
    private long counter = 0; // packet serial number
    public ServerSocket servSock;
    private boolean permitChangeScreen = true;
    private static final int INFLATE_BUFSIZE = 1024 * 100;
    private Inflater inflater = new Inflater();
    private Deflater deflater = new Deflater();
    ViewerInterface viewer;
    private short id;  // my tree node id ( = 0 in root )
    private boolean leader;
    private TreeVncCommandChannelListener acceptThread;
    private boolean firstTime = true;
    private TreeRootFinderListener getCast;
    private CreateConnectionParam cp;
    private boolean hasViewer = false;
    public boolean showTreeNode = false;
    private boolean reconnecting;
    private short reconnectingId;  // Change Server Request to id's node VNC server
    private TreeVNCNetwork nets = new TreeVNCNetwork();
    private boolean normalTermination;
    private TreeVncRootSelectionPanel rootSelectionPanel;
    private boolean isTreeManager;
    private String vncInterface;
    public LinkedList<TreeVNCNode> nodeList;
    public boolean checkDelay = false;
    public boolean addSerialNum = false;


    public TreeRFBProto(boolean isTreeManager) {
        rThread = new RequestScreenThread(this);
        nets.setMyRfb(this);
        this.isTreeManager = isTreeManager;
    }

    public boolean isTreeManager() {
        return isTreeManager;
    }

    public ProtocolContext getContext() {
        return context;
    }

    /**
     * handle new client accept 
     *     it also handle TreeVNC Command
     * @param acceptThread
     * @param newCli
     * @param os
     * @param is
     * @throws IOException
     * @throws TransportException
     */
    public void newClient(final Socket newCli,final Writer os, final Reader is) { 

        final int myId = clients;
        final MulticastQueue.Client<LinkedList<ByteBuffer>> c = multicastqueue.newClient();
        final AtomicInteger writerRunning = new AtomicInteger();
        writerRunning.set(1);
        /**
         * Timeout thread. If a client is suspended, it has top of queue
         * indefinitely, which caused memory overflow. After the timeout, we
         * poll the queue and discard it. Start long wait if writer is running.
         */
        final Runnable timer = new Runnable() {
            public void run() {
                int count = 0;
                for (;;) {
                    long timeout = 50000 / 8;
                    try {
                        synchronized (this) {
                            int state, flag;
                            writerRunning.set(0);
                            wait(timeout);
                            flag = 0;
                            while ((state = writerRunning.get()) == 0) {
                                c.poll(); // discard, should be timeout
                                count++;
                                if (flag == 0) {
                                    System.out.println("Discarding " + myId
                                            + " count=" + count);
                                    flag = 1;
                                }
                                wait(10); // if this is too short, writer cannot
                                // take the poll, if this is too
                                // long, memory will overflow...
                            }
                            if (flag == 1)
                                System.out.println("Resuming " + myId
                                        + " count=" + count);
                            if (state != 1) {
                                System.out.println("Client died " + myId);
                                break;
                            }
                        }
                    } catch (InterruptedException e) {
                    }
                }
            }
        };
        new Thread(timer, "timer-discard-multicastqueue").start();
        /**
         * handle command from lower node
         */
        final Runnable reader = new Runnable() {
            public void run() {
                for (;;) {
                    try {
                        final byte b[] = new byte[4096];
                        final int c = is.readByte(b);
                        if (c <= 0)
                            throw new IOException();
                        if (isTreeManager()) {
                            if (b[0] == ClientToServerMessage.SERVER_CHANGE_REQUEST) {
                                if (permitChangeScreen()) {
                                    ByteBuffer buf = ByteBuffer.wrap(b);
                                    buf.order(ByteOrder.BIG_ENDIAN);
                                    short id = buf.getShort(2);
                                    int length = buf.getInt(4);
                                    if (length == 0) 
                                        continue;
                                    String newHostName = new String(b, 8, length);
                                    System.out.println("Root server change request :" + newHostName);
                                    // please remove these numbers.
                                    if (viewer != null) {
                                        changeVNCServer(viewer, newHostName, 3200, 1980, id);
                                    }
                                } else {
                                    continue;
                                }
                            } else if (b[0] == ClientToServerMessage.CHECK_DELAY_REPLY) {
                                ByteBuffer buf = ByteBuffer.wrap(b);
                                buf.order(ByteOrder.BIG_ENDIAN);
                                //                                getNodeNum(port, hostname, localhostname);
                                buf.getShort();
                                Long time = buf.getLong();
                                int port = buf.getInt();
                                int addressLength = buf.getInt();
                                byte[] byteAddress = new byte[addressLength];
                                buf.get(byteAddress);
                                String address = new String(byteAddress, "UTF-8");
                                int nodeNum = getNodeNum(port, address);
                                Long delay = System.currentTimeMillis() - time;
                                double halfDelay = (double) delay / 2;
                                System.out.println("nodeNum" + nodeNum + ", port = " + port + ", address = " + address + ", delay = " + halfDelay);
                                
                                // checkNodeNum();
                                // readSendData(check);
                                
                            }
                        } else if (b[0] == ClientToServerMessage.SERVER_CHANGE_REQUEST) {
                            ClientToServerMessage sc = new ClientToServerMessage() {
                                @Override
                                public void send(Writer writer)
                                        throws TransportException {
                                    writer.write(b,0,c);
                                }
                            };
                            context.sendMessage(sc);
                        } else if (b[0] == ClientToServerMessage.CHECK_DELAY_REPLY) {
                            ClientToServerMessage checkDelayReply = new ClientToServerMessage() {
                                @Override
                                public void send(Writer writer)
                                        throws TransportException {
                                    writer.write(b,0,c);
                                }
                            };
                            context.sendMessage(checkDelayReply);
                        }
                    } catch (Exception e) {
                        try {
                            writerRunning.set(2);
                            os.close();
                            is.close();
                            break;
                        } catch (IOException e1) {
                        } catch (TransportException e1) {
                            e1.printStackTrace();
                        }
                        return;
                    }
                }
            }

        };
        /**
         * send packets to a client (one thread for each client )
         */
        Runnable sender = new Runnable() {
            public void run() {
                writerRunning.set(1);
                try {
                    requestThreadNotify();
                    
                    // after this, we discard upward packet.
                    new Thread(reader, "upward-packet-processing").start();
                    
                    for (;;) {
                        LinkedList<ByteBuffer> bufs = c.poll();
                        
                        int inputIndex = 0;
                        ByteBuffer header = bufs.get(inputIndex);
                        if (header == null)
                            continue;
                        writeToClient(os, bufs, inputIndex);
                        writerRunning.set(1); // yes my client is awaking.
                    }
                } catch (Exception e) {
                    try {
                        writerRunning.set(2);
                        os.close();
                    } catch (IOException e1) {
                        System.out.println("root writer close faild :" + e1);
                    }
                    System.out.println("root writer faild :" + e);
                    /* if socket closed cliList.remove(newCli); */
                }
            }

            public void writeToClient(final Writer os,
                    LinkedList<ByteBuffer> bufs, int inputIndex)
                            throws TransportException {
                while (inputIndex < bufs.size()) {
                    ByteBuffer b = bufs.get(inputIndex++);
                    os.write(b.array(), b.position(), b.limit());
                }
                os.flush();
                bufs = null;
                multicastqueue.heapAvailable();
            }
        };
        clients++;
        new Thread(sender, "writer-to-lower-node").start();

    }



    public boolean permitChangeScreen() {
        return permitChangeScreen;
    }


    public void setPermitChangeScreen(boolean v) {
        permitChangeScreen = v;
    }

    public void requestThreadNotify() {
        rThread.reStart();
    }


    public void setProtocolContext(Protocol workingProtocol) {
        context = workingProtocol;
    }

    public Socket accept() throws IOException {
        return servSock.accept();
    }

    public int selectPort(int p) {
        int port = p;
        while (true) {
            try {
                servSock = new ServerSocket(port);
                acceptPort = port;
                myAddress = "127.0.0.1";
                nets.getNetworkInterfaces();
                break;
            } catch (BindException e) {
                port++;
                continue;
            } catch (IOException e) {

            }
        }
        System.out.println("accept port = " + port);
        return port;
    }



    public void writeFramebufferUpdateRequest(int x, int y, int w, int h,
            boolean incremental) throws TransportException {
        byte[] b = new byte[10];

        b[0] = (byte) FramebufferUpdateRequest; // 3 is FrameBufferUpdateRequest
        b[1] = (byte) (incremental ? 1 : 0);
        b[2] = (byte) ((x >> 8) & 0xff);
        b[3] = (byte) (x & 0xff);
        b[4] = (byte) ((y >> 8) & 0xff);
        b[5] = (byte) (y & 0xff);
        b[6] = (byte) ((w >> 8) & 0xff);
        b[7] = (byte) (w & 0xff);
        b[8] = (byte) ((h >> 8) & 0xff);
        b[9] = (byte) (h & 0xff);
    }

    public void setViewer(ViewerInterface v) {
        viewer = v;
    }

    public ViewerInterface getViewer() {
        return viewer;
    }


    void sendInitData(OutputStream os) throws IOException {
        os.write(context.getInitData());
    }


    public void setTerminationType(boolean setType) {
        normalTermination = setType;
    }

    public boolean getTerminationType() {
        return normalTermination;
    }


    public void addHostToSelectionPanel(int port, String hostname,String myHostName) {
        if (rootSelectionPanel != null) {
            rootSelectionPanel.checkBox(Integer.toString(port) + ":" + hostname + ":" + myHostName);
            rootSelectionPanel.setButton();
            rootSelectionPanel.visible();			
        }
    }

    public void createRootSelectionPanel(CreateConnectionParam cp) {
        rootSelectionPanel = new TreeVncRootSelectionPanel();
        rootSelectionPanel.setCp(cp);
    }

    public void close() {
        // none
    }

    public int getAcceptPort() {
        return acceptPort;
    }

    public boolean getReadyReconnect() {
        return readyReconnect;
    }


    public boolean getCuiVersion() {
        return cuiVersion;
    } 

    public void  setCuiVersion(boolean flag) {
        cuiVersion = flag;
    }

    public void readCheckDelay(Reader reader) throws TransportException {

    }

    public synchronized void vncConnected(boolean ready) {
        if (ready && reconnecting) {
            Socket vncSocket = viewer.getVNCSocket();
            NetworkInterface ni = nets.getInterface(vncSocket);
            if (ni!=null) {
                vncInterface = ni.getName();
                System.out.println("VNCNetworkInterface :" + vncInterface);
            }
            sendDesktopSizeChange(reconnectingId);
            reconnecting = false;
            if (reconnectingId == 0) {
                viewer.setVisible(false);
            }
        } 
        if (reconnectingId!=0) {
            readyReconnect = ready;
            if (ready) {
                notifyAll();
            }
        }
    }	


    public synchronized void waitForVNCConnection() throws InterruptedException {
        if (reconnectingId!=0) {
            while (!readyReconnect) {
                wait();
            }
        }
    }


    public void sendDesktopSizeChange(short id) {
        LinkedList<ByteBuffer> desktopSize = new LinkedList<ByteBuffer>();
        int width = context.getFbWidth();
        int height = context.getFbHeight();
        desktopSize.add(new UpdateRectangleMessage(width, height, EncodingType.INIT_DATA, context.getInitData(),id).getMessage());
        addSerialNumber(desktopSize);
        multicastqueue.put(desktopSize);
    }


    public void addSerialNumber(LinkedList<ByteBuffer> bufs) {
        ByteBuffer serialNum = multicastqueue.allocate(4+8); // addSerialNum flag + SerialNum
        if (this.addSerialNum) {
            serialNum.putInt(1);
        } else {
            serialNum.putInt(0);
        }
        serialNum.putLong(counter++);
        serialNum.flip();
        bufs.addFirst(serialNum);
    }


    public void resetDecoder() {
        context.resetDecoder();
    }

    public void stopReceiverTask() {
        if (context!=null)
            context.cleanUpSession(null);
        // cleanup zlib decoder for new VNCServer
        if (isTreeManager())
            inflater = new Inflater();
    }

    public String getMyAddress() {
        return myAddress;
    }

    /**
     * gzip byte arrays
     * 
     * @param deflater
     * @param inputs
     *            byte data[]
     * @param inputIndex
     * @param outputs
     *            byte data[]
     * @return byte length in last byte array
     * @throws IOException
     */
    public int zip(Deflater deflater, LinkedList<ByteBuffer> inputs,
            int inputIndex, LinkedList<ByteBuffer> outputs) throws IOException {
        int len = 0;
        ByteBuffer c1 = multicastqueue.allocate(INFLATE_BUFSIZE);
        while (inputIndex < inputs.size()) {
            ByteBuffer b1 = inputs.get(inputIndex++);
            deflater.setInput(b1.array(), b1.position(), b1.remaining());
            /**
             * If we finish() stream and reset() it, Deflater start new gzip
             * stream, this makes continuous zlib reader unhappy. if we remove
             * finish(), Deflater.deflate() never flushes its output. The
             * original zlib deflate has flush flag. I'm pretty sure this a kind
             * of bug of Java library.
             */
            if (inputIndex == inputs.size())
                deflater.finish();
            int len1 = 0;
            do {
                len1 = deflater.deflate(c1.array(), c1.position(),
                        c1.remaining());
                if (len1 > 0) {
                    len += len1;
                    c1.position(c1.position() + len1);
                    if (c1.remaining() == 0) {
                        c1.flip();
                        outputs.addLast(c1);
                        c1 = multicastqueue.allocate(INFLATE_BUFSIZE);
                    }
                }
            } while (len1 > 0 || !deflater.needsInput()); // &&!deflater.finished());
        }
        if (c1.position() != 0) {
            c1.flip();
            outputs.addLast(c1);
        }
        deflater.reset();
        return len;
    }

    /**
     * gunzip byte arrays
     * 
     * @param inflater
     * @param inputs
     *            byte data[]
     * @param bytes
     *            byte data[]
     * @return number of total bytes
     * @throws IOException
     */
    public int unzip(Inflater inflater, LinkedList<ByteBuffer> inputs,
            int inputIndex, byte[] bytes, int bufSize)
                    throws DataFormatException {
        int position = 0;
        int limit = bytes.length;
        while (inputIndex < inputs.size()) {
            ByteBuffer input = inputs.get(inputIndex++);
            inflater.setInput(input.array(), input.position(), input.limit());
            // if (inputIndex==inputs.size()) if inflater/deflater has symmetry,
            // we need this
            // inflater.end(); but this won't work
            do {
                int len0 = inflater.inflate(bytes, position,
                        limit-position);
                if (len0 > 0) {
                    position += len0;
                    if (position > limit) {
                        throw new DataFormatException();
                    }
                }
            } while (!inflater.needsInput());
        }
        return position;
    }

    /**
     * read FrameBuffferUpdate. If it is ZLE, make it ZLEE which is self contained compressed packet.
     * put the packet to the multicastqueue. Then normal rendering engine read the same stream using is.reset().
     * @param dataLen
     * @param reader
     * @throws TransportException
     * @throws UnsupportedEncodingException 
     */
    public void readSendData(int dataLen, Reader reader, byte[] bytes)
            throws TransportException, UnsupportedEncodingException {
        LinkedList<ByteBuffer> bufs = new LinkedList<ByteBuffer>();
        ByteBuffer header = multicastqueue.allocate(16);
        ByteBuffer serial = multicastqueue.allocate(4+8);
        if (!isTreeManager()) {
            reader.readBytes(serial.array(),0,4+8);
            serial.limit(4+8);
        }
        reader.mark(dataLen);
        reader.readBytes(header.array(), 0, 16);
        header.limit(16);
        if (header.get(0) == FramebufferUpdate) {
            int encoding = header.getInt(12);
            
            if (encoding == EncodingType.ZRLE.getId()
                    || encoding == EncodingType.ZLIB.getId()) {
                // recompress into ZREE
                // uncompressed result is remain in bytes
                ByteBuffer len = multicastqueue.allocate(4);
                reader.readBytes(len.array(), 0, 4);
                len.limit(4);
                ByteBuffer inputData = multicastqueue.allocate(dataLen - 20);
                reader.readBytes(inputData.array(), 0, inputData.capacity());
                inputData.limit(dataLen - 20);
                LinkedList<ByteBuffer> inputs = new LinkedList<ByteBuffer>();
                inputs.add(inputData);
                header.putInt(12, EncodingType.ZRLEE.getId()); // means
                // recompress
                // every time
                // using new Deflecter every time is incompatible with the
                // protocol, clients have to be modified.
                Deflater nDeflater = deflater; // new Deflater();
                LinkedList<ByteBuffer> out = new LinkedList<ByteBuffer>();
                try {
                    unzip(inflater, inputs, 0, bytes, INFLATE_BUFSIZE);
                    // dump32(inputs);
                    out.add(ByteBuffer.wrap(bytes));
                    int len2 = zip(nDeflater, out, 0, bufs);
                    ByteBuffer blen = multicastqueue.allocate(4);
                    blen.putInt(len2);
                    blen.flip();
                    bufs.addFirst(blen);
                    bufs.addFirst(header);
                    addSerialNumber(bufs);
                    multicastqueue.put(bufs);
                } catch (DataFormatException e) {
                    throw new TransportException(e);
                } catch (IOException e) {
                    throw new TransportException(e);
                }
                return;
            }

            //    ZRLEE is already compressed
            bufs.add(header);
            if (dataLen > 16) {
                ByteBuffer b = multicastqueue.allocate(dataLen - 16);
                reader.readBytes(b.array(), 0, dataLen - 16);
                b.limit(dataLen - 16);
                bufs.add(b);
            }
            this.addSerialNumber(bufs);
            multicastqueue.put(bufs);

            return;
        }
        // It may be compressed. We can inflate here to avoid repeating clients
        // decompressing here,
        // but it may generate too many large data. It is better to do it in
        // each client.
        // But we have do inflation for all input data, so we have to do it
        // here.
    }

    public void setId(short id) {
        this.id = id;
    }

    public short getId() {
        return id;
    }

    public void setMyAddress(String myHostName) {
        this.myAddress = myHostName;

    }

    public void setLeader(boolean leader) {
        this.leader = leader;
    }

    public boolean isLeader() {
        return leader;
    }

    public void setTreeManager(String intf, TreeManagement clients) {
        nets.setTreeManager(intf, clients);
    }

    public TreeManagement getTreeManager(String intf) {
        TreeManagement tm = nets.getTreeManager(intf);
        this.nodeList = tm.getList();
        return tm;
    }

    /**
     * chnageVNCServer is called when host change.
     * 
     * @param vncProxyService 
     * @param hostName
     *            HostAddress
     * @param width
     *            FrameWidth
     * @param height
     *            FrameHeight
     * @param id 
     * @throws InterruptedException 
     */
    public void changeVNCServer(ViewerInterface vncProxyService, String hostName, int width, int height, short id)
            throws UnknownHostException, IOException, InterruptedException {
        // stop reader stop
        stopReceiverTask();
        reconnectingId = id;
        vncProxyService.inhelitClients(vncProxyService, hostName);
        // after connecting VNC server, rfb send SEND_INIT_DATA command and wakes me up if necessary 
        reconnecting = true;
        if (reconnectingId!=0) {
            waitForVNCConnection();
        }
    }

    /**
     * start accepting children
     * run rootFinderListener if necessary
     */
    public void createConnectionAndStart(ViewerInterface v) {
        selectPort(ConnectionParams.DEFAULT_VNC_ROOT);
        startTreeVncCommandListener();
        if(isTreeManager() && firstTime) {
            getCast = new TreeRootFinderListener(v);
            Thread treeRootFindThread = new Thread(getCast, "tree-root-find-listener");
            treeRootFindThread.start();
            firstTime = false;
        }
    }

    public void startTreeVncCommandListener() {
        acceptThread = new TreeVncCommandChannelListener(this, getAcceptPort());
        Thread thread = new Thread(acceptThread, "TreeVNC-accept");
        thread.start();
    }

    public TreeVncCommandChannelListener getAcceptThread() {
        return acceptThread;
    }

    public void setConnectionParam(CreateConnectionParam createConnectionParam) {
        cp =  createConnectionParam;
    }

    public CreateConnectionParam getConnectionParam() {
        return cp;
    }

    public boolean hasViewer() {
        return hasViewer;
    }

    public void setHasViewer(boolean b) {
        hasViewer = b;
    }

    public void setReconnecting(boolean b) {
        reconnecting = b;
    }

    public int getReconnectingId() {
        return reconnectingId;
    }

    public void setShowTree(boolean showTree) {
        this.showTreeNode = showTree;
    }

    public void setCheckDelay(boolean checkDelay) {
        this.checkDelay = checkDelay;
    }

    public void setAddSerialNum(boolean addSerialNum) {
        this.addSerialNum  = addSerialNum;
    }

    public int getNodeNum(int port, String address) {
        int nodeNum = 0;
        
        for (Iterator<TreeVNCNode> i = nodeList.iterator(); i.hasNext();) {
            TreeVNCNode tvn = (TreeVNCNode)i.next();
            if (port == tvn.port && address.equals(tvn.hostname)) {
                nodeNum = tvn.treeNum;
                return nodeNum;
            }
        }
        return nodeNum;
    }

}