import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;
import java.util.ArrayList;
import java.util.List;

import lombok.AutoGenMethodStub;
import lombok.Cleanup;
import lombok.Data;

@AutoGenMethodStub (throwException = true)
public class MultiSocketLomboked extends Socket {
    @Data
    public static class Destination {
        private final String    host;
        private final int           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) {
        try {
            @Cleanup final OutputStream os = allos.remove(ix);
            @Cleanup final InputStream is = allis.remove(ix);
            @Cleanup final Socket s = alls.remove(ix);
        } catch (final IOException ignored) {}
    }

    public MultiSocketLomboked(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);
        }
    }
}