/* ====================================================================
 * Trove - Copyright (c) 1997-2000 Walt Disney Internet Group
 * ====================================================================
 * The Tea Software License, Version 1.1
 *
 * Copyright (c) 2000 Walt Disney Internet Group. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Walt Disney Internet Group (http://opensource.go.com/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Tea", "TeaServlet", "Kettle", "Trove" and "BeanDoc" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact opensource@dig.com.
 *
 * 5. Products derived from this software may not be called "Tea",
 *    "TeaServlet", "Kettle" or "Trove", nor may "Tea", "TeaServlet",
 *    "Kettle", "Trove" or "BeanDoc" appear in their name, without prior
 *    written permission of the Walt Disney Internet Group.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE WALT DISNEY INTERNET GROUP OR ITS
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * For more information about Tea, please see http://opensource.go.com/.
 */

package com.go.trove.net;

import java.net.*;
import java.io.*;

/******************************************************************************
 * A socket implementation that lazily establishs a connection. It only
 * connects when actually needed. Setting options and getting I/O streams will
 * not force a connection to be established. As soon as a read or write
 * operation is performed, a connection is established.
 * <p>
 * If the first write operation requires a connection to be established, then a
 * recycled connection is requested. The connection is tested by writing the
 * data to it. If this fails, a new connection is requested and the operation
 * is tried again.
 *
 * @author Brian S O'Neill
 * @version
 * <!--$$Revision: 1.1 $-->, <!--$$JustDate:--> 00/12/05 <!-- $-->
 */
class LazySocket extends Socket {
    private final Impl mImpl;

    public LazySocket(SocketFactory factory) throws SocketException {
        this(factory, null, factory.getDefaultTimeout());
    }

    public LazySocket(SocketFactory factory, Object session)
        throws SocketException
    {
        this(factory, session, factory.getDefaultTimeout());
    }

    public LazySocket(SocketFactory factory, long timeout)
        throws SocketException
    {
        this(factory, null, timeout);
    }

    public LazySocket(SocketFactory factory, Object session, long timeout)
        throws SocketException
    {
        this(new Impl(factory, session, timeout));
    }

    private LazySocket(Impl impl) throws SocketException {
        super(impl);
        mImpl = impl;
    }

    /**
     * Returns the internal wrapped socket or null if not connected. After
     * calling recycle, this LazySocket instance is closed.
     */
    CheckedSocket recycle() {
        CheckedSocket s;
        if (mImpl.mClosed) {
            s = null;
        }
        else {
            s = mImpl.mSocket;
            mImpl.mSocket = null;
            try {
                mImpl.close();
            }
            catch (IOException e) {
            }
        }
        return s;
    }

    private static class Impl extends SocketImpl {
        private final SocketFactory mFactory;
        private final Object mSession;
        private final long mTimeout;

        private boolean mClosed;
        private CheckedSocket mSocket;

        private Object[] mOptions;

        private InputStream mIn;
        private OutputStream mOut;

        public Impl(SocketFactory factory, Object session, long timeout) {
            mFactory = factory;
            mSession = session;
            mTimeout = timeout;
        }

        public void setOption(int optId, Object value) throws SocketException {
            int optionIndex;

            switch (optId) {
            case TCP_NODELAY:
                optionIndex = 0;
                break;
            case SO_LINGER:
                optionIndex = 1;
                break;
            case SO_TIMEOUT:
                optionIndex = 2;
                break;
            case SO_SNDBUF:
                optionIndex = 3;
                break;
            case SO_RCVBUF:
                optionIndex = 4;
                break;
            case SO_BINDADDR:
            case SO_REUSEADDR:
            case IP_MULTICAST_IF:
            default:
                throw new SocketException("Invalid option: " + optId);
            }

            if (mOptions == null) {
                mOptions = new Object[5];
            }

            mOptions[optionIndex] = value;

            if (mSocket == null) {
                return;
            }

            switch (optId) {
            case TCP_NODELAY:
                mSocket.setTcpNoDelay(((Boolean)value).booleanValue());
                break;
            case SO_LINGER:
                if (value instanceof Boolean) {
                    mSocket.setSoLinger(((Boolean)value).booleanValue(), 0);
                }
                else {
                    mSocket.setSoLinger(true, ((Integer)value).intValue());
                }
                break;
            case SO_TIMEOUT:
                mSocket.setSoTimeout(((Integer)value).intValue());
                break;
            case SO_SNDBUF:
                mSocket.setSendBufferSize(((Integer)value).intValue());
                break;
            case SO_RCVBUF:
                mSocket.setReceiveBufferSize(((Integer)value).intValue());
                break;
            }
        }

        public Object getOption(int optId) throws SocketException {
            Socket socket = createSocket();

            switch (optId) {
            case TCP_NODELAY:
                return socket.getTcpNoDelay() ? Boolean.TRUE : Boolean.FALSE;
            case SO_BINDADDR:
                return socket.getLocalAddress();
            case SO_LINGER:
                return new Integer(socket.getSoLinger());
            case SO_TIMEOUT:
                return new Integer(socket.getSoTimeout());
            case SO_SNDBUF:
                return new Integer(socket.getSendBufferSize());
            case SO_RCVBUF:
                return new Integer(socket.getReceiveBufferSize());
            case SO_REUSEADDR:
            case IP_MULTICAST_IF:
            default:
                throw new SocketException("Invalid option: " + optId);
            }
        }

        protected InputStream getInputStream() throws IOException {
            if (mIn == null) {
                mIn = new In();
            }
            return mIn;
        }

        protected OutputStream getOutputStream() throws IOException {
            if (mOut == null) {
                mOut = new Out();
            }
            return mOut;
        }

        protected int available() throws IOException {
            return getInputStream().available();
        }

        protected void close() throws IOException {
            if (!mClosed) {
                mClosed = true;
                if (mSocket != null) {
                    mSocket.close();
                }
            }
        }

        protected InetAddress getInetAddress() {
            if (mSocket != null) {
                return mSocket.getInetAddress();
            }
            else {
                return mFactory.getInetAddressAndPort(mSession).getInetAddress();
            }
        }

        protected int getPort() {
            if (mSocket != null) {
                return mSocket.getPort();
            }
            else {
                return mFactory.getInetAddressAndPort(mSession).getPort();
            }
        }

        protected int getLocalPort() {
            if (mSocket != null) {
                return mSocket.getLocalPort();
            }
            else {
                return -1;
            }
        }

        Socket createSocket() throws SocketException {
            if (mSocket != null) {
                return mSocket;
            }

            if (mClosed) {
                throw new SocketException("Socket is closed");
            }

            mSocket = mFactory.createSocket(mSession, mTimeout);
            applyOptions();

            return mSocket;
        }

        Socket getSocket(byte[] data, int off, int len)
            throws SocketException
        {
            if (mSocket != null) {
                return mSocket;
            }

            if (mClosed) {
                throw new SocketException("Socket is closed");
            }

            long timeout = mTimeout;
            long start;
            if (timeout > 0) {
                start = System.currentTimeMillis();
            }
            else {
                start = 0;
            }

            try {
                mSocket = mFactory.getSocket(mSession, timeout);
                applyOptions();
                OutputStream out = mSocket.getOutputStream();
                out.write(data, off, len);
                out.flush();
            }
            catch (Exception e) {
                if (mSocket != null) {
                    try {
                        mSocket.close();
                    }
                    catch (Exception e2) {
                    }
                }

                if (timeout > 0) {
                    timeout = timeout - (System.currentTimeMillis() - start);
                    if (timeout < 0) {
                        timeout = 0;
                    }
                }

                mSocket = mFactory.createSocket(mSession, timeout);
                applyOptions();
                try {
                    OutputStream out = mSocket.getOutputStream();
                    out.write(data, off, len);
                    out.flush();
                }
                catch (IOException e2) {
                    throw new SocketException(e2.getMessage());
                }
            }

            return mSocket;
        }

        private void applyOptions() throws SocketException {
            if (mOptions == null || mSocket == null) {
                return;
            }

            Object[] options = mOptions;
            Object value;

            if ((value = options[0]) != null) {
                mSocket.setTcpNoDelay(((Boolean)value).booleanValue());
            }
            if ((value = options[1]) != null) {
                if (value instanceof Boolean) {
                    mSocket.setSoLinger(((Boolean)value).booleanValue(), 0);
                }
                else {
                    mSocket.setSoLinger(true, ((Integer)value).intValue());
                }
            }
            if ((value = options[2]) != null) {
                mSocket.setSoTimeout(((Integer)value).intValue());
            }
            if ((value = options[3]) != null) {
                mSocket.setSendBufferSize(((Integer)value).intValue());
            }
            if ((value = options[4]) != null) {
                mSocket.setReceiveBufferSize(((Integer)value).intValue());
            }
        }

        protected void create(boolean stream) throws IOException {
            error();
        }

        protected void connect(String host, int port) throws IOException {
            error();
        }

        protected void connect(InetAddress host, int port) throws IOException {
            error();
        }

        protected void connect(SocketAddress host,
                               int port) throws IOException {
            error();
        }

        protected void bind(InetAddress host, int port) throws IOException {
            error();
        }

        protected void listen(int backlog) throws IOException {
            error();
        }

        protected void accept(SocketImpl s) throws IOException {
            error();
        }

        protected void sendUrgentData(int aByte) throws IOException {
            throw new UnsupportedOperationException();
        }

        private void error() throws IOException {
            throw new IOException("Unsupported operation");
        }

        private class In extends InputStream {
            private InputStream mStream;

            public int read() throws IOException {
                return getStream().read();
            }

            public int read(byte[] b) throws IOException {
                return getStream().read(b);
            }

            public int read(byte[] b, int off, int len) throws IOException {
                return getStream().read(b, off, len);
            }

            public long skip(long n) throws IOException {
                return getStream().skip(n);
            }

            public int available() throws IOException {
                return getStream().available();
            }
            
            public void close() throws IOException {
                if (mStream != null) {
                    mStream.close();
                }
                Impl.this.close();
            }

            public void mark(int readlimit) {
                try {
                    getStream().mark(readlimit);
                }
                catch (IOException e) {
                }
            }

            public void reset() throws IOException {
                if (mStream == null) {
                    throw new IOException("Stream not marked");
                }
                else {
                    mStream.reset();
                }
            }

            public boolean markSupported() {
                try {
                    return getStream().markSupported();
                }
                catch (IOException e) {
                    return false;
                }
            }
            
            private InputStream getStream() throws IOException {
                if (mStream == null) {
                    mStream = createSocket().getInputStream();
                }
                return mStream;
            }
        }

        private class Out extends OutputStream {
            private OutputStream mStream;

            public void write(int b) throws IOException {
                write(new byte[] {(byte)b}, 0, 1);
            }

            public void write(byte[] b) throws IOException {
                write(b, 0, b.length);
            }

            public void write(byte[] b, int off, int len) throws IOException {
                if (mStream == null) {
                    mStream = getSocket(b, off, len).getOutputStream();
                }
                else {
                    mStream.write(b, off, len);
                }
            }

            public void flush() throws IOException {
                if (mStream != null) {
                    mStream.flush();
                }
            }

            public void close() throws IOException {
                if (mStream != null) {
                    mStream.close();
                }
                Impl.this.close();
            }
        }
    }
}