//
// Copyright (c) ZeroC, Inc. All rights reserved.
//

package IceInternal;

public class StreamSocket
{
    public StreamSocket(ProtocolInstance instance,
                        NetworkProxy proxy,
                        java.net.InetSocketAddress addr,
                        java.net.InetSocketAddress sourceAddr)
    {
        _instance = instance;
        _proxy = proxy;
        _addr = addr;
        _fd = Network.createTcpSocket();
        _state = StateNeedConnect;

        try
        {
            init();
            if(Network.doConnect(_fd, _proxy != null ? _proxy.getAddress() : _addr, sourceAddr))
            {
                _state = _proxy != null ? StateProxyWrite : StateConnected;
            }
        }
        catch(Ice.LocalException ex)
        {
            assert(!_fd.isOpen());
            _fd = null; // Necessary for the finalizer
            throw ex;
        }

        _desc = Network.fdToString(_fd, _proxy, _addr);
    }

    public StreamSocket(ProtocolInstance instance, java.nio.channels.SocketChannel fd)
    {
        _instance = instance;
        _proxy = null;
        _addr = null;
        _fd = fd;
        _state = StateConnected;

        try
        {
            init();
        }
        catch(Ice.LocalException ex)
        {
            assert(!_fd.isOpen());
            _fd = null; // Necessary for the finalizer
            throw ex;
        }

        _desc = Network.fdToString(_fd);
    }

    @SuppressWarnings("deprecation")
    @Override
    protected synchronized void finalize()
        throws Throwable
    {
        try
        {
            IceUtilInternal.Assert.FinalizerAssert(_fd == null);
        }
        catch(java.lang.Exception ex)
        {
        }
        finally
        {
            super.finalize();
        }
    }

    public void setBufferSize(int rcvSize, int sndSize)
    {
        Network.setTcpBufSize(_fd, rcvSize, sndSize, _instance);
    }

    public int connect(Buffer readBuffer, Buffer writeBuffer)
    {
        if(_state == StateNeedConnect)
        {
            _state = StateConnectPending;
            return SocketOperation.Connect;
        }
        else if(_state <= StateConnectPending)
        {
            Network.doFinishConnect(_fd);
            _desc = Network.fdToString(_fd, _proxy, _addr);
            _state = _proxy != null ? StateProxyWrite : StateConnected;
        }

        if(_state == StateProxyWrite)
        {
            _proxy.beginWrite(_addr, writeBuffer);
            return SocketOperation.Write;
        }
        else if(_state == StateProxyRead)
        {
            _proxy.beginRead(readBuffer);
            return SocketOperation.Read;
        }
        else if(_state == StateProxyConnected)
        {
            _proxy.finish(readBuffer, writeBuffer);

            readBuffer.clear();
            writeBuffer.clear();

            _state = StateConnected;
        }

        assert(_state == StateConnected);
        return SocketOperation.None;
    }

    public boolean isConnected()
    {
        return _state == StateConnected;
    }

    public java.nio.channels.SocketChannel fd()
    {
        return _fd;
    }

    public int read(Buffer buf)
    {
        if(_state == StateProxyRead)
        {
            while(true)
            {
                int ret = read(buf.b);
                if(ret == 0)
                {
                    return SocketOperation.Read;
                }
                _state = toState(_proxy.endRead(buf));
                if(_state != StateProxyRead)
                {
                    return SocketOperation.None;
                }
            }
        }
        read(buf.b);
        return buf.b.hasRemaining() ? SocketOperation.Read : SocketOperation.None;
    }

    public int write(Buffer buf)
    {
        if(_state == StateProxyWrite)
        {
            while(true)
            {
                int ret = write(buf.b);
                if(ret == 0)
                {
                    return SocketOperation.Write;
                }
                _state = toState(_proxy.endWrite(buf));
                if(_state != StateProxyWrite)
                {
                    return SocketOperation.None;
                }
            }
        }
        write(buf.b);
        return buf.b.hasRemaining() ? SocketOperation.Write : SocketOperation.None;
    }

    public int read(java.nio.ByteBuffer buf)
    {
        assert(_fd != null);

        int read = 0;

        while(buf.hasRemaining())
        {
            try
            {
                int ret = _fd.read(buf);
                if(ret == -1)
                {
                    throw new Ice.ConnectionLostException();
                }
                else if(ret == 0)
                {
                    return read;
                }

                read += ret;
            }
            catch(java.io.InterruptedIOException ex)
            {
                continue;
            }
            catch(java.io.IOException ex)
            {
                throw new Ice.ConnectionLostException(ex);
            }
        }
        return read;
    }

    public int write(java.nio.ByteBuffer buf)
    {
        assert(_fd != null);

        int sent = 0;
        while(buf.hasRemaining())
        {
            try
            {
                int ret;
                if(_maxSendPacketSize > 0 && buf.remaining() > _maxSendPacketSize)
                {
                    int previous = buf.limit();
                    // Cast to java.nio.Buffer to avoid incompatible covariant
                    // return type used in Java 9 java.nio.ByteBuffer
                    ((java.nio.Buffer)buf).limit(buf.position() + _maxSendPacketSize);
                    ret = _fd.write(buf);
                    ((java.nio.Buffer)buf).limit(previous);
                }
                else
                {
                    ret = _fd.write(buf);
                }

                if(ret == -1)
                {
                    throw new Ice.ConnectionLostException();
                }
                else if(ret == 0)
                {
                    return sent;
                }
                sent += ret;
            }
            catch(java.io.InterruptedIOException ex)
            {
                continue;
            }
            catch(java.io.IOException ex)
            {
                throw new Ice.SocketException(ex);
            }
        }
        return sent;
    }

    public void close()
    {
        assert(_fd != null);
        try
        {
            _fd.close();
        }
        catch(java.io.IOException ex)
        {
            throw new Ice.SocketException(ex);
        }
        finally
        {
            _fd = null;
        }
    }

    @Override
    public String toString()
    {
        return _desc;
    }

    private void init()
    {
        Network.setBlock(_fd, false);
        Network.setTcpBufSize(_fd, _instance);

        if(System.getProperty("os.name").startsWith("Windows"))
        {
            //
            // On Windows, limiting the buffer size is important to prevent
            // poor throughput performances when sending large amount of
            // data. See Microsoft KB article KB823764.
            //
            _maxSendPacketSize = java.lang.Math.max(512, Network.getSendBufferSize(_fd) / 2);
        }
        else
        {
            _maxSendPacketSize = 0;
        }
    }

    private int toState(int operation)
    {
        switch(operation)
        {
        case SocketOperation.Read:
            return StateProxyRead;
        case SocketOperation.Write:
            return StateProxyWrite;
        default:
            return StateProxyConnected;
        }
    }

    private final ProtocolInstance _instance;

    final private NetworkProxy _proxy;
    final private java.net.InetSocketAddress _addr;

    private java.nio.channels.SocketChannel _fd;
    private int _maxSendPacketSize;
    private int _state;
    private String _desc;

    private static final int StateNeedConnect = 0;
    private static final int StateConnectPending = 1;
    private static final int StateProxyRead = 2;
    private static final int StateProxyWrite = 3;
    private static final int StateProxyConnected = 4;
    private static final int StateConnected = 5;
}
