/*
 *
 * Copyright 2016, 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 <memory.h>
#include <stdio.h>

#include <grpc/grpc.h>
#include <grpc/support/alloc.h>
#include <grpc/support/log.h>
#include <grpc/support/string_util.h>
#include <grpc/support/thd.h>

#include "src/core/lib/iomgr/exec_ctx.h"
#include "src/core/lib/iomgr/iomgr.h"
#include "src/core/lib/iomgr/sockaddr_utils.h"
#include "src/core/lib/iomgr/tcp_server.h"

#include "test/core/util/port.h"
#include "test/core/util/test_config.h"

#define NUM_THREADS 100
#define NUM_OUTER_LOOPS 10
#define NUM_INNER_LOOPS 10
#define DELAY_MILLIS 10
#define POLL_MILLIS 3000

static void *tag(int n) { return (void *)(uintptr_t)n; }
static int detag(void *p) { return (int)(uintptr_t)p; }

void create_loop_destroy(void *addr) {
  for (int i = 0; i < NUM_OUTER_LOOPS; ++i) {
    grpc_completion_queue *cq = grpc_completion_queue_create(NULL);
    grpc_channel *chan = grpc_insecure_channel_create((char *)addr, NULL, NULL);

    for (int j = 0; j < NUM_INNER_LOOPS; ++j) {
      gpr_timespec later_time = GRPC_TIMEOUT_MILLIS_TO_DEADLINE(DELAY_MILLIS);
      grpc_connectivity_state state =
          grpc_channel_check_connectivity_state(chan, 1);
      grpc_channel_watch_connectivity_state(chan, state, later_time, cq, NULL);
      gpr_timespec poll_time = GRPC_TIMEOUT_MILLIS_TO_DEADLINE(POLL_MILLIS);
      GPR_ASSERT(grpc_completion_queue_next(cq, poll_time, NULL).type ==
                 GRPC_OP_COMPLETE);
    }
    grpc_channel_destroy(chan);
    grpc_completion_queue_destroy(cq);
  }
}

struct server_thread_args {
  char *addr;
  grpc_server *server;
  grpc_completion_queue *cq;
  grpc_pollset *pollset;
  gpr_mu *mu;
  gpr_event ready;
  gpr_atm stop;
};

void server_thread(void *vargs) {
  struct server_thread_args *args = (struct server_thread_args *)vargs;
  grpc_event ev;
  gpr_timespec deadline = gpr_inf_future(GPR_CLOCK_MONOTONIC);
  ev = grpc_completion_queue_next(args->cq, deadline, NULL);
  GPR_ASSERT(ev.type == GRPC_OP_COMPLETE);
  GPR_ASSERT(detag(ev.tag) == 0xd1e);
}

static void on_connect(grpc_exec_ctx *exec_ctx, void *vargs, grpc_endpoint *tcp,
                       grpc_pollset *accepting_pollset,
                       grpc_tcp_server_acceptor *acceptor) {
  struct server_thread_args *args = (struct server_thread_args *)vargs;
  (void)acceptor;
  grpc_endpoint_shutdown(exec_ctx, tcp);
  grpc_endpoint_destroy(exec_ctx, tcp);
  GRPC_LOG_IF_ERROR("pollset_kick", grpc_pollset_kick(args->pollset, NULL));
}

void bad_server_thread(void *vargs) {
  struct server_thread_args *args = (struct server_thread_args *)vargs;

  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
  struct sockaddr_storage addr;
  socklen_t addr_len = sizeof(addr);
  int port;
  grpc_tcp_server *s;
  grpc_error *error = grpc_tcp_server_create(NULL, &s);
  GPR_ASSERT(error == GRPC_ERROR_NONE);
  memset(&addr, 0, sizeof(addr));
  addr.ss_family = AF_INET;
  error =
      grpc_tcp_server_add_port(s, (struct sockaddr *)&addr, addr_len, &port);
  GPR_ASSERT(GRPC_LOG_IF_ERROR("grpc_tcp_server_add_port", error));
  GPR_ASSERT(port > 0);
  gpr_asprintf(&args->addr, "localhost:%d", port);

  grpc_tcp_server_start(&exec_ctx, s, &args->pollset, 1, on_connect, args);
  gpr_event_set(&args->ready, (void *)1);

  gpr_mu_lock(args->mu);
  while (gpr_atm_acq_load(&args->stop) == 0) {
    gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
    gpr_timespec deadline =
        gpr_time_add(now, gpr_time_from_millis(100, GPR_TIMESPAN));

    grpc_pollset_worker *worker = NULL;
    if (!GRPC_LOG_IF_ERROR("pollset_work",
                           grpc_pollset_work(&exec_ctx, args->pollset, &worker,
                                             now, deadline))) {
      gpr_atm_rel_store(&args->stop, 1);
    }
    gpr_mu_unlock(args->mu);
    grpc_exec_ctx_finish(&exec_ctx);
    gpr_mu_lock(args->mu);
  }
  gpr_mu_unlock(args->mu);

  grpc_tcp_server_unref(&exec_ctx, s);

  grpc_exec_ctx_finish(&exec_ctx);

  gpr_free(args->addr);
}

static void done_pollset_shutdown(grpc_exec_ctx *exec_ctx, void *pollset,
                                  grpc_error *error) {
  grpc_pollset_destroy(pollset);
  gpr_free(pollset);
}

int main(int argc, char **argv) {
  struct server_thread_args args;
  memset(&args, 0, sizeof(args));

  grpc_test_init(argc, argv);
  grpc_init();

  gpr_thd_id threads[NUM_THREADS];
  gpr_thd_id server;

  char *localhost = gpr_strdup("localhost:54321");
  gpr_thd_options options = gpr_thd_options_default();
  gpr_thd_options_set_joinable(&options);

  /* First round, no server */
  gpr_log(GPR_DEBUG, "Wave 1");
  for (size_t i = 0; i < NUM_THREADS; ++i) {
    gpr_thd_new(&threads[i], create_loop_destroy, localhost, &options);
  }
  for (size_t i = 0; i < NUM_THREADS; ++i) {
    gpr_thd_join(threads[i]);
  }
  gpr_free(localhost);

  /* Second round, actual grpc server */
  gpr_log(GPR_DEBUG, "Wave 2");
  int port = grpc_pick_unused_port_or_die();
  gpr_asprintf(&args.addr, "localhost:%d", port);
  args.server = grpc_server_create(NULL, NULL);
  grpc_server_add_insecure_http2_port(args.server, args.addr);
  args.cq = grpc_completion_queue_create(NULL);
  grpc_server_register_completion_queue(args.server, args.cq, NULL);
  grpc_server_start(args.server);
  gpr_thd_new(&server, server_thread, &args, &options);

  for (size_t i = 0; i < NUM_THREADS; ++i) {
    gpr_thd_new(&threads[i], create_loop_destroy, args.addr, &options);
  }
  for (size_t i = 0; i < NUM_THREADS; ++i) {
    gpr_thd_join(threads[i]);
  }
  grpc_server_shutdown_and_notify(args.server, args.cq, tag(0xd1e));

  gpr_thd_join(server);
  grpc_server_destroy(args.server);
  grpc_completion_queue_destroy(args.cq);
  gpr_free(args.addr);

  /* Third round, bogus tcp server */
  gpr_log(GPR_DEBUG, "Wave 3");
  args.pollset = gpr_malloc(grpc_pollset_size());
  grpc_pollset_init(args.pollset, &args.mu);
  gpr_event_init(&args.ready);
  gpr_thd_new(&server, bad_server_thread, &args, &options);
  gpr_event_wait(&args.ready, gpr_inf_future(GPR_CLOCK_MONOTONIC));

  for (size_t i = 0; i < NUM_THREADS; ++i) {
    gpr_thd_new(&threads[i], create_loop_destroy, args.addr, &options);
  }
  for (size_t i = 0; i < NUM_THREADS; ++i) {
    gpr_thd_join(threads[i]);
  }

  gpr_atm_rel_store(&args.stop, 1);
  gpr_thd_join(server);
  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
  grpc_pollset_shutdown(
      &exec_ctx, args.pollset,
      grpc_closure_create(done_pollset_shutdown, args.pollset));
  grpc_exec_ctx_finish(&exec_ctx);

  grpc_shutdown();
  return 0;
}