import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.InetAddress;
import java.net.Socket;
import java.net.SocketAddress;
import java.net.SocketException;
import java.nio.channels.SocketChannel;
import java.util.ArrayList;
import java.util.List;

public class MultiSocket extends Socket {
    public static class Destination {
        private final String    host;
        private final int           port;

        public Destination(final String host, final int port) {
            this.host = host;
            this.port = port;
        }

        public String getHost() {
            return host;
        }

        public int getPort() {
            return port;
        }
    }

    private final List<Socket>  alls;
    private List<InputStream>       allis;
    private List<OutputStream>  allos;
    private int                                 lastwrite;
    private final byte[]                buf;
    private int                                 buflen;

    private class MultiInputStream extends InputStream {
        @Override
        public int read() throws IOException {
            if (lastwrite < 0)
                throw new IllegalStateException("MultiSocket is only for request-response");
            while (alls.size() > 0) {
                try {
                    final int b = allis.get(lastwrite).read();
                    buflen = 0;
                    return b;
                } catch (final Exception e) {
                    remove(lastwrite);
                    allos.get(0).write(buf, 0, buflen); // additional code is necessary final to handle if this call throws an exception
                    lastwrite = 0;
                }
            }
            throw new IOException("No working sockets");
        }
    }

    private class MultiOutputStream extends OutputStream {
        @Override
        public void write(final int b) throws IOException {
            while (alls.size() > 0) {
                try {
                    buf[buflen] = (byte) b;
                    buflen++;
                    allos.get(0).write(b);
                    lastwrite = 0;
                    return;
                } catch (final Exception e) {
                    remove(0);
                    allos.get(0).write(buf, 0, buflen); // additional code is necessary final to handle if this call throws an exception
                    lastwrite = 0;
                }
            }
            throw new IOException("No working sockets");
        }
    }

    private void remove(final int ix) {
        final OutputStream os = allos.remove(ix);
        try {
            os.close();
        } catch (final Exception ex) {
            // nothing to do
        }
        final InputStream is = allis.remove(ix);
        try {
            is.close();
        } catch (final Exception ex) {
            // nothing to do
        }
        final Socket s = alls.remove(ix);
        try {
            s.close();
        } catch (final Exception ex) {
            // nothing to do
        }
    }

    public MultiSocket(final List<Destination> dest) throws IOException {
        alls = new ArrayList<Socket>();
        for (final Destination d : dest) {
            alls.add(new Socket(d.getHost(), d.getPort()));
        }
        lastwrite = -1;
        buf = new byte[102400];
        buflen = 0;
    }

    @Override
    public InputStream getInputStream() throws IOException {
        allis = new ArrayList<InputStream>();
        for (final Socket s : alls) {
            allis.add(s.getInputStream());
        }
        return new MultiInputStream();
    }

    @Override
    public OutputStream getOutputStream() throws IOException {
        allos = new ArrayList<OutputStream>();
        for (final Socket s : alls) {
            allos.add(s.getOutputStream());
        }
        return new MultiOutputStream();
    }

    @Override
    public synchronized void close() throws IOException {
        while (alls.size() > 0) {
            remove(0);
        }
    }

    // move exception throwing stubs up as they get an implementation that makes sense
    @Override
    public void connect(final SocketAddress endpoint) throws IOException {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public void connect(final SocketAddress endpoint, final int timeout) throws IOException {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public void bind(final SocketAddress bindpoint) throws IOException {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public InetAddress getInetAddress() {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public InetAddress getLocalAddress() {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public int getPort() {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public int getLocalPort() {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public SocketAddress getRemoteSocketAddress() {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public SocketAddress getLocalSocketAddress() {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public SocketChannel getChannel() {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public void setTcpNoDelay(final boolean on) throws SocketException {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public boolean getTcpNoDelay() throws SocketException {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public void setSoLinger(final boolean on, final int linger) throws SocketException {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public int getSoLinger() throws SocketException {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public void sendUrgentData(final int data) throws IOException {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public void setOOBInline(final boolean on) throws SocketException {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public boolean getOOBInline() throws SocketException {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public synchronized void setSoTimeout(final int timeout) throws SocketException {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public synchronized int getSoTimeout() throws SocketException {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public synchronized void setSendBufferSize(final int size) throws SocketException {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public synchronized int getSendBufferSize() throws SocketException {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public synchronized void setReceiveBufferSize(final int size) throws SocketException {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public synchronized int getReceiveBufferSize() throws SocketException {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public void setKeepAlive(final boolean on) throws SocketException {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public boolean getKeepAlive() throws SocketException {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public void setTrafficClass(final int tc) throws SocketException {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public int getTrafficClass() throws SocketException {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public void setReuseAddress(final boolean on) throws SocketException {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public boolean getReuseAddress() throws SocketException {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public void shutdownInput() throws IOException {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public void shutdownOutput() throws IOException {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public String toString() {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public boolean isConnected() {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public boolean isBound() {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public boolean isClosed() {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public boolean isInputShutdown() {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public boolean isOutputShutdown() {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public void setPerformancePreferences(final int connectionTime, final int latency,
            final int bandwidth) {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public int hashCode() {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    public boolean equals(final Object obj) {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    protected Object clone() throws CloneNotSupportedException {
        throw new RuntimeException("Not supported by MultiSocket");
    }

    @Override
    protected void finalize() throws Throwable {
        throw new RuntimeException("Not supported by MultiSocket");
    }
}