/*
 *
 * Copyright 2015, Google Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#include "src/core/iomgr/tcp_client.h"

#include <errno.h>
#include <netinet/in.h>
#include <string.h>
#include <sys/socket.h>
#include <unistd.h>

#include <grpc/grpc.h>
#include <grpc/support/log.h>
#include <grpc/support/time.h>

#include "src/core/iomgr/iomgr.h"
#include "src/core/iomgr/socket_utils_posix.h"
#include "test/core/util/test_config.h"

static grpc_pollset_set g_pollset_set;
static grpc_pollset g_pollset;
static int g_connections_complete = 0;
static grpc_endpoint *g_connecting = NULL;

static gpr_timespec
test_deadline (void)
{
  return GRPC_TIMEOUT_SECONDS_TO_DEADLINE (10);
}

static void
finish_connection ()
{
  gpr_mu_lock (GRPC_POLLSET_MU (&g_pollset));
  g_connections_complete++;
  grpc_pollset_kick (&g_pollset, NULL);
  gpr_mu_unlock (GRPC_POLLSET_MU (&g_pollset));
}

static void
must_succeed (grpc_exec_ctx * exec_ctx, void *arg, int success)
{
  GPR_ASSERT (g_connecting != NULL);
  GPR_ASSERT (success);
  grpc_endpoint_shutdown (exec_ctx, g_connecting);
  grpc_endpoint_destroy (exec_ctx, g_connecting);
  g_connecting = NULL;
  finish_connection ();
}

static void
must_fail (grpc_exec_ctx * exec_ctx, void *arg, int success)
{
  GPR_ASSERT (g_connecting == NULL);
  GPR_ASSERT (!success);
  finish_connection ();
}

void
test_succeeds (void)
{
  struct sockaddr_in addr;
  socklen_t addr_len = sizeof (addr);
  int svr_fd;
  int r;
  int connections_complete_before;
  grpc_closure done;
  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;

  gpr_log (GPR_DEBUG, "test_succeeds");

  memset (&addr, 0, sizeof (addr));
  addr.sin_family = AF_INET;

  /* create a dummy server */
  svr_fd = socket (AF_INET, SOCK_STREAM, 0);
  GPR_ASSERT (svr_fd >= 0);
  GPR_ASSERT (0 == bind (svr_fd, (struct sockaddr *) &addr, addr_len));
  GPR_ASSERT (0 == listen (svr_fd, 1));

  gpr_mu_lock (GRPC_POLLSET_MU (&g_pollset));
  connections_complete_before = g_connections_complete;
  gpr_mu_unlock (GRPC_POLLSET_MU (&g_pollset));

  /* connect to it */
  GPR_ASSERT (getsockname (svr_fd, (struct sockaddr *) &addr, &addr_len) == 0);
  grpc_closure_init (&done, must_succeed, NULL);
  grpc_tcp_client_connect (&done, &g_connecting, &g_pollset_set, (struct sockaddr *) &addr, addr_len, gpr_inf_future (GPR_CLOCK_REALTIME), &closure_list);

  /* await the connection */
  do
    {
      addr_len = sizeof (addr);
      r = accept (svr_fd, (struct sockaddr *) &addr, &addr_len);
    }
  while (r == -1 && errno == EINTR);
  GPR_ASSERT (r >= 0);
  close (r);

  gpr_mu_lock (GRPC_POLLSET_MU (&g_pollset));

  while (g_connections_complete == connections_complete_before)
    {
      grpc_pollset_worker worker;
      grpc_pollset_work (&g_pollset, &worker, gpr_now (GPR_CLOCK_MONOTONIC), GRPC_TIMEOUT_SECONDS_TO_DEADLINE (5), &closure_list);
      gpr_mu_unlock (GRPC_POLLSET_MU (&g_pollset));
      grpc_exec_ctx_finish (&exec_ctx);
      gpr_mu_lock (GRPC_POLLSET_MU (&g_pollset));
    }

  gpr_mu_unlock (GRPC_POLLSET_MU (&g_pollset));
}

void
test_fails (void)
{
  struct sockaddr_in addr;
  socklen_t addr_len = sizeof (addr);
  int connections_complete_before;
  grpc_closure done;
  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;

  gpr_log (GPR_DEBUG, "test_fails");

  memset (&addr, 0, sizeof (addr));
  addr.sin_family = AF_INET;

  gpr_mu_lock (GRPC_POLLSET_MU (&g_pollset));
  connections_complete_before = g_connections_complete;
  gpr_mu_unlock (GRPC_POLLSET_MU (&g_pollset));

  /* connect to a broken address */
  grpc_closure_init (&done, must_fail, NULL);
  grpc_tcp_client_connect (&done, &g_connecting, &g_pollset_set, (struct sockaddr *) &addr, addr_len, gpr_inf_future (GPR_CLOCK_REALTIME), &closure_list);

  gpr_mu_lock (GRPC_POLLSET_MU (&g_pollset));

  /* wait for the connection callback to finish */
  while (g_connections_complete == connections_complete_before)
    {
      grpc_pollset_worker worker;
      grpc_pollset_work (&g_pollset, &worker, gpr_now (GPR_CLOCK_MONOTONIC), test_deadline (), &closure_list);
      gpr_mu_unlock (GRPC_POLLSET_MU (&g_pollset));
      grpc_exec_ctx_finish (&exec_ctx);
      gpr_mu_lock (GRPC_POLLSET_MU (&g_pollset));
    }

  gpr_mu_unlock (GRPC_POLLSET_MU (&g_pollset));
}

void
test_times_out (void)
{
  struct sockaddr_in addr;
  socklen_t addr_len = sizeof (addr);
  int svr_fd;
#define NUM_CLIENT_CONNECTS 100
  int client_fd[NUM_CLIENT_CONNECTS];
  int i;
  int r;
  int connections_complete_before;
  gpr_timespec connect_deadline;
  grpc_closure done;
  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;

  gpr_log (GPR_DEBUG, "test_times_out");

  memset (&addr, 0, sizeof (addr));
  addr.sin_family = AF_INET;

  /* create a dummy server */
  svr_fd = socket (AF_INET, SOCK_STREAM, 0);
  GPR_ASSERT (svr_fd >= 0);
  GPR_ASSERT (0 == bind (svr_fd, (struct sockaddr *) &addr, addr_len));
  GPR_ASSERT (0 == listen (svr_fd, 1));
  /* Get its address */
  GPR_ASSERT (getsockname (svr_fd, (struct sockaddr *) &addr, &addr_len) == 0);

  /* tie up the listen buffer, which is somewhat arbitrarily sized. */
  for (i = 0; i < NUM_CLIENT_CONNECTS; ++i)
    {
      client_fd[i] = socket (AF_INET, SOCK_STREAM, 0);
      grpc_set_socket_nonblocking (client_fd[i], 1);
      do
	{
	  r = connect (client_fd[i], (struct sockaddr *) &addr, addr_len);
	}
      while (r == -1 && errno == EINTR);
      GPR_ASSERT (r < 0);
      GPR_ASSERT (errno == EWOULDBLOCK || errno == EINPROGRESS);
    }

  /* connect to dummy server address */

  connect_deadline = GRPC_TIMEOUT_SECONDS_TO_DEADLINE (1);

  gpr_mu_lock (GRPC_POLLSET_MU (&g_pollset));
  connections_complete_before = g_connections_complete;
  gpr_mu_unlock (GRPC_POLLSET_MU (&g_pollset));

  grpc_closure_init (&done, must_fail, NULL);
  grpc_tcp_client_connect (&done, &g_connecting, &g_pollset_set, (struct sockaddr *) &addr, addr_len, connect_deadline, &closure_list);

  /* Make sure the event doesn't trigger early */
  gpr_mu_lock (GRPC_POLLSET_MU (&g_pollset));
  for (;;)
    {
      grpc_pollset_worker worker;
      gpr_timespec now = gpr_now (connect_deadline.clock_type);
      gpr_timespec continue_verifying_time = gpr_time_from_seconds (5, GPR_TIMESPAN);
      gpr_timespec grace_time = gpr_time_from_seconds (3, GPR_TIMESPAN);
      gpr_timespec finish_time = gpr_time_add (connect_deadline, continue_verifying_time);
      gpr_timespec restart_verifying_time = gpr_time_add (connect_deadline, grace_time);
      int is_after_deadline = gpr_time_cmp (now, connect_deadline) > 0;
      if (gpr_time_cmp (now, finish_time) > 0)
	{
	  break;
	}
      gpr_log (GPR_DEBUG, "now=%d.%09d connect_deadline=%d.%09d", now.tv_sec, now.tv_nsec, connect_deadline.tv_sec, connect_deadline.tv_nsec);
      if (is_after_deadline && gpr_time_cmp (now, restart_verifying_time) <= 0)
	{
	  /* allow some slack before insisting that things be done */
	}
      else
	{
	  GPR_ASSERT (g_connections_complete == connections_complete_before + is_after_deadline);
	}
      grpc_pollset_work (&g_pollset, &worker, gpr_now (GPR_CLOCK_MONOTONIC), GRPC_TIMEOUT_MILLIS_TO_DEADLINE (10), &closure_list);
      gpr_mu_unlock (GRPC_POLLSET_MU (&g_pollset));
      grpc_exec_ctx_finish (&exec_ctx);
      gpr_mu_lock (GRPC_POLLSET_MU (&g_pollset));
    }
  gpr_mu_unlock (GRPC_POLLSET_MU (&g_pollset));

  close (svr_fd);
  for (i = 0; i < NUM_CLIENT_CONNECTS; ++i)
    {
      close (client_fd[i]);
    }
}

static void
destroy_pollset (grpc_exec_ctx * exec_ctx, void *p, int success)
{
  grpc_pollset_destroy (p);
}

int
main (int argc, char **argv)
{
  grpc_closure destroyed;
  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
  grpc_test_init (argc, argv);
  grpc_init ();
  grpc_pollset_set_init (&g_pollset_set);
  grpc_pollset_init (&g_pollset);
  grpc_pollset_set_add_pollset (&g_pollset_set, &g_pollset, &closure_list);
  grpc_exec_ctx_finish (&exec_ctx);
  test_succeeds ();
  gpr_log (GPR_ERROR, "End of first test");
  test_fails ();
  test_times_out ();
  grpc_pollset_set_destroy (&g_pollset_set);
  grpc_closure_init (&destroyed, destroy_pollset, &g_pollset);
  grpc_pollset_shutdown (&g_pollset, &destroyed, &closure_list);
  grpc_exec_ctx_finish (&exec_ctx);
  grpc_shutdown ();
  return 0;
}