/**
 * Copyright 2013, Landz and its contributors. All rights reserved.
 *
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 */

package z.znr;

import org.junit.Test;
import z.znr.event.EPollEventArray;
import z.znr.event.FileDescriptorEPollEvent;
import z.znr.socket.SocketAddressInet;
import z.znr.socket.Sockets;

import static org.hamcrest.MatcherAssert.assertThat;
import static org.hamcrest.Matchers.greaterThan;
import static org.hamcrest.Matchers.greaterThanOrEqualTo;
import static org.hamcrest.core.Is.is;
import static z.offheap.zmalloc.Allocator.allocate;
import static z.offheap.zmalloc.Allocator.free;
import static z.util.Throwables.uncheck;
import static z.util.Unsafes.UNSAFE;
import static z.znr.Syscall.*;
import static z.znr.event.EPollEvents.*;
import static z.znr.event.EPolls.*;
/**
 * this is an integration test for Syscall with EPoll
 */
public class SyscallIntegrationTestEPoll {
  static {
    System.setProperty("jnr.invoke.compile.dump", "false");
  }

  public static final String MSG = "hello";


  @Test
  public void test_syscall_socket() {
    int serverfd, suc, clientfd;
    long size;

    serverfd =
        sys_socket(
            Sockets.DomainFamily.INET,
            Sockets.SocketType.SOCK_STREAM,
            0);
    assertThat(serverfd, greaterThan(0));
//    System.out.println(sockfd);

    SocketAddressInet addr = new SocketAddressInet(SocketAddressInet.LOOPBACK_ADDRESS,12345);

    suc = Sockets.bind(serverfd,addr);
    assertThat(suc, is(0));

    suc = sys_listen(serverfd, 10);
    assertThat(suc, is(0));

    //epoll
    int epfd = sys_epoll_create1(0);
    assertThat(epfd, greaterThan(0));

    FileDescriptorEPollEvent e = new FileDescriptorEPollEvent();
    e.setEventMask(EPOLLIN);
    e.setFileDescriptor(serverfd);

    suc = epollAdd(epfd, serverfd, e);
    assertThat(suc, is(0));

    //client
    spawnClientThread(addr);
    //

    //wait on
    EPollEventArray events = new EPollEventArray();

//    for (; ; ) {
      System.out.println("wait on the epoll instance: " + epfd);
      int n = epoll_wait(epfd, events, -1);
      assertThat(suc, greaterThanOrEqualTo(0));

      System.out.println("got " + n + " ready fd now.");//TODO: sometimes n=0(signal)

      for (int i = 0; i < n; i++) {
        FileDescriptorEPollEvent fdev =
            events.getEvent(i, FileDescriptorEPollEvent.class);
        assertThat(fdev.getFileDescriptor(), is(serverfd));

        System.out.println("server thread will block on accepting...");
        clientfd = Sockets.acceptNonBlock(serverfd);
        assertThat(clientfd, greaterThan(0));
        System.out.println("server thread got a clientfd:" + clientfd);

        long sBuffer = allocate(8);//to hold "hello"
        System.out.println("server thread will block on reading...");

        size = sys_read(clientfd, sBuffer, 8);
        assertThat(size, is(5L));
        System.out.println("server thread come back.");

        StringBuilder msg = new StringBuilder(5);
        for (int j = 0; j < size; j++) {
          msg.append((char) UNSAFE.getByte(sBuffer + j));
        }

        System.out.println("and we got msg:" + msg);
        assertThat(msg.toString(), is(MSG));

        suc = sys_close(serverfd);
        assertThat(suc, is(0));
        free(sBuffer);
        System.out.println("whole test done.");
      }

//    }

  }


  private void spawnClientThread(SocketAddressInet addr) {

    //client thread
    new Thread(()->{
      uncheck(()->Thread.sleep(5_000L));

      System.out.println("client thread start to work...");
      int cfd =
          sys_socket(
              Sockets.DomainFamily.INET,
              Sockets.SocketType.SOCK_STREAM,
              0);

      System.out.println("client thread now try to connect to server...");
      int csuc = Sockets.connect(cfd,addr);
      assertThat(csuc, is(0));
      System.out.println("client thread connected.");

      long cBuffer = allocate(8);

      for (int i = 0; i < MSG.length(); i++) {
        UNSAFE.putByte(cBuffer+i, (byte)MSG.charAt(i));
      }

      System.out.println("client thread will block on writing...");
      long csize = sys_write(cfd,cBuffer,5);
      assertThat(csize,is(5L));
      System.out.println("client thread come back.");
      free(cBuffer);

      //TODO: shutdown
      csuc = sys_shutdown(cfd,Sockets.ShutDownType.SHUT_RD);
      assertThat(csuc, is(0));

      csuc = sys_shutdown(cfd,Sockets.ShutDownType.SHUT_WR);
      assertThat(csuc, is(0));

      //fail for repeating call?
      csuc = sys_shutdown(cfd,Sockets.ShutDownType.SHUT_RDWR);
      assertThat(csuc, is(0));

      csuc = sys_close(cfd);
      assertThat(csuc, is(0));
      free(cBuffer);
      //
      uncheck(()->Thread.sleep(1_000L));
      System.out.println("client thread done.");
    }).start();

  }


}