/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

/*

 *

 *

 * Used in conjunction to EchoService to test System.inheritedChannel().

 *

 * The first test is the TCP echo test. A service is launched with a TCP

 * socket and a TCP message is sent to the service. The test checks that

 * the message is correctly echoed.

 *

 * The second test is a UDP echo test. A service is launched with a UDP

 * socket and a UDP packet is sent to the service. The test checks that

 * the packet is correctly echoed.

 *

 */

import java.io.IOException;

import java.net.DatagramPacket;

import java.nio.ByteBuffer;

import java.nio.channels.DatagramChannel;

import java.nio.channels.SelectionKey;

import java.nio.channels.Selector;

import java.nio.channels.SocketChannel;

import java.util.Random;

public class EchoTest {

    private static int failures = 0;

    private static String ECHO_SERVICE = "EchoService";

    /*

     * Sends a message with random bytes to the service, and then waits for

     * a reply (with timeout). Once the reply is received it is checked to ensure

     * that it matches the original message.

     */

    private static void TCPEchoTest() throws IOException {

        SocketChannel sc = Launcher.launchWithSocketChannel(ECHO_SERVICE, null);

        String msg = "Where's that damn torpedo?";

        int repeat = 100;

        int size = msg.length() * repeat;

        // generate bytes into a buffer and send it to the service

        ByteBuffer bb1 = ByteBuffer.allocate(size);

        Random gen = new Random();

        for (int i=0; i<repeat; i++) {

            bb1.put(msg.getBytes("UTF-8"));

        }

        bb1.flip();

        sc.write(bb1);

        // now we put the channel into non-blocking mode and we read the

        // reply from the service into a second buffer.

        ByteBuffer bb2 = ByteBuffer.allocate(size+100);

        sc.configureBlocking(false);

        Selector sel = sc.provider().openSelector();

        SelectionKey sk = sc.register(sel, SelectionKey.OP_READ);

        int nread = 0;

        while (nread < size) {

            long st = System.currentTimeMillis();

            sel.select(to);

            if (sk.isReadable()) {

                int n = sc.read(bb2);

                if (n > 0) {

                    nread += n;

                }

                if (n < 0) {

                    break;              // EOF

                }

            }

            sel.selectedKeys().remove(sk);

            to -= System.currentTimeMillis() - st;

            if (to <= 0) {

                break;

            }

        }

        sc.close();

        // and compare the response

        boolean err = false;

        if (nread != size) {

            err = true;

        } else {

            bb1.flip();

            bb2.flip();

            while (bb1.hasRemaining()) {

                if (bb1.get() != bb2.get()) {

                    err = true;

                }

            }

        }

        // if error print out the response from the service (could be a stack trace)

        if (err) {

            System.err.println("Bad response or premature EOF, bytes read: ");

            bb2.flip();

            while (bb2.hasRemaining()) {

                char c = (char)bb2.get();

                System.out.print(c);

            }

            throw new RuntimeException("Bad response or premature EOF from service");

        }

    }

    /*

     * Send a UDP packet to the service, wait for a reply (with timeout). Finally

     * check that the packet is the same length as the original.

     */

    private static void UDPEchoTest() throws IOException {

        DatagramChannel dc = Launcher.launchWithDatagramChannel(ECHO_SERVICE, null);

        String msg = "I was out saving the galaxy when your grandfather was in diapers";

        ByteBuffer bb = ByteBuffer.wrap(msg.getBytes("UTF-8"));

        dc.write(bb);

        // and receive the echo

        byte b[] = new byte[msg.length() + 100];

        DatagramPacket pkt2 = new DatagramPacket(b, b.length);

        dc.socket().receive(pkt2);

        if (pkt2.getLength() != msg.length()) {

            throw new RuntimeException("Received packet of incorrect length");

        }

        dc.close();

    }

    public static void main(String args[]) throws IOException {

        // TCP echo

        try {

            TCPEchoTest();

            System.out.println("TCP echo test passed.");

        } catch (Exception x) {

            System.err.println(x);

            failures++;

        }

        // UDP echo

        try {

            UDPEchoTest();

            System.out.println("UDP echo test passed.");

        } catch (Exception x) {

            x.printStackTrace();

            System.err.println(x);

            failures++;

        }

        if (failures > 0) {

            throw new RuntimeException("Test failed - see log for details");

        }

    }

}