/*
 *
 * Copyright 2015 gRPC authors.
 *
 * 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.
 *
 */

#include "src/core/lib/iomgr/port.h"

// This test won't work except with posix sockets enabled
#ifdef GRPC_POSIX_SOCKET_UDP_SERVER

#include "src/core/lib/iomgr/udp_server.h"

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

#include <vector>

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

#include "src/core/lib/channel/channel_args.h"
#include "src/core/lib/gpr/useful.h"
#include "src/core/lib/gprpp/memory.h"
#include "src/core/lib/iomgr/ev_posix.h"
#include "src/core/lib/iomgr/iomgr.h"
#include "src/core/lib/iomgr/socket_factory_posix.h"
#include "src/core/lib/iomgr/socket_utils_posix.h"
#include "test/core/util/test_config.h"

#define LOG_TEST(x) gpr_log(GPR_INFO, "%s", #x)

static grpc_pollset* g_pollset;
static gpr_mu* g_mu;
static int g_number_of_reads = 0;
static int g_number_of_writes = 0;
static int g_number_of_bytes_read = 0;
static int g_number_of_orphan_calls = 0;
static int g_number_of_starts = 0;

int rcv_buf_size = 1024;
int snd_buf_size = 1024;

static int g_num_listeners = 1;

class TestGrpcUdpHandler : public GrpcUdpHandler {
 public:
  TestGrpcUdpHandler(grpc_fd* emfd, void* user_data)
      : GrpcUdpHandler(emfd, user_data), emfd_(emfd) {
    g_number_of_starts++;
  }
  ~TestGrpcUdpHandler() override {}

 protected:
  bool Read() override {
    char read_buffer[512];
    ssize_t byte_count;

    gpr_mu_lock(g_mu);
    byte_count =
        recv(grpc_fd_wrapped_fd(emfd()), read_buffer, sizeof(read_buffer), 0);

    g_number_of_reads++;
    g_number_of_bytes_read += static_cast<int>(byte_count);

    gpr_log(GPR_DEBUG, "receive %zu on handler %p", byte_count, this);
    GPR_ASSERT(GRPC_LOG_IF_ERROR("pollset_kick",
                                 grpc_pollset_kick(g_pollset, nullptr)));
    gpr_mu_unlock(g_mu);
    return false;
  }

  void OnCanWrite(void* /*user_data*/,
                  grpc_closure* /*notify_on_write_closure*/) override {
    gpr_mu_lock(g_mu);
    g_number_of_writes++;

    GPR_ASSERT(GRPC_LOG_IF_ERROR("pollset_kick",
                                 grpc_pollset_kick(g_pollset, nullptr)));
    gpr_mu_unlock(g_mu);
  }

  void OnFdAboutToOrphan(grpc_closure* orphan_fd_closure,
                         void* /*user_data*/) override {
    gpr_log(GPR_INFO, "gRPC FD about to be orphaned: %d",
            grpc_fd_wrapped_fd(emfd()));
    grpc_core::ExecCtx::Run(DEBUG_LOCATION, orphan_fd_closure, GRPC_ERROR_NONE);
    g_number_of_orphan_calls++;
  }

  grpc_fd* emfd() { return emfd_; }

 private:
  grpc_fd* emfd_;
};

class TestGrpcUdpHandlerFactory : public GrpcUdpHandlerFactory {
 public:
  GrpcUdpHandler* CreateUdpHandler(grpc_fd* emfd, void* user_data) override {
    gpr_log(GPR_INFO, "create udp handler for fd %d", grpc_fd_wrapped_fd(emfd));
    return new TestGrpcUdpHandler(emfd, user_data);
  }

  void DestroyUdpHandler(GrpcUdpHandler* handler) override {
    gpr_log(GPR_INFO, "Destroy handler");
    delete reinterpret_cast<TestGrpcUdpHandler*>(handler);
  }
};

TestGrpcUdpHandlerFactory handler_factory;

struct test_socket_factory {
  grpc_socket_factory base;
  int number_of_socket_calls;
  int number_of_bind_calls;
};
typedef struct test_socket_factory test_socket_factory;

static int test_socket_factory_socket(grpc_socket_factory* factory, int domain,
                                      int type, int protocol) {
  test_socket_factory* f = reinterpret_cast<test_socket_factory*>(factory);
  f->number_of_socket_calls++;
  return socket(domain, type, protocol);
}

static int test_socket_factory_bind(grpc_socket_factory* factory, int sockfd,
                                    const grpc_resolved_address* addr) {
  test_socket_factory* f = reinterpret_cast<test_socket_factory*>(factory);
  f->number_of_bind_calls++;
  return bind(sockfd,
              reinterpret_cast<struct sockaddr*>(const_cast<char*>(addr->addr)),
              static_cast<socklen_t>(addr->len));
}

static int test_socket_factory_compare(grpc_socket_factory* a,
                                       grpc_socket_factory* b) {
  return GPR_ICMP(a, b);
}

static void test_socket_factory_destroy(grpc_socket_factory* factory) {
  test_socket_factory* f = reinterpret_cast<test_socket_factory*>(factory);
  gpr_free(f);
}

static const grpc_socket_factory_vtable test_socket_factory_vtable = {
    test_socket_factory_socket, test_socket_factory_bind,
    test_socket_factory_compare, test_socket_factory_destroy};

static test_socket_factory* test_socket_factory_create(void) {
  test_socket_factory* factory = static_cast<test_socket_factory*>(
      gpr_malloc(sizeof(test_socket_factory)));
  grpc_socket_factory_init(&factory->base, &test_socket_factory_vtable);
  factory->number_of_socket_calls = 0;
  factory->number_of_bind_calls = 0;
  return factory;
}

static void destroy_pollset(void* p, grpc_error* /*error*/) {
  grpc_pollset_destroy(static_cast<grpc_pollset*>(p));
}

static void shutdown_and_destroy_pollset() {
  gpr_mu_lock(g_mu);
  auto closure = GRPC_CLOSURE_CREATE(destroy_pollset, g_pollset,
                                     grpc_schedule_on_exec_ctx);
  grpc_pollset_shutdown(g_pollset, closure);
  gpr_mu_unlock(g_mu);
  /* Flush exec_ctx to run |destroyed| */
  grpc_core::ExecCtx::Get()->Flush();
}

static void test_no_op(void) {
  grpc_pollset_init(g_pollset, &g_mu);
  grpc_core::ExecCtx exec_ctx;
  grpc_udp_server* s = grpc_udp_server_create(nullptr);
  LOG_TEST("test_no_op");
  grpc_udp_server_destroy(s, nullptr);
  shutdown_and_destroy_pollset();
}

static void test_no_op_with_start(void) {
  grpc_pollset_init(g_pollset, &g_mu);
  grpc_core::ExecCtx exec_ctx;
  grpc_udp_server* s = grpc_udp_server_create(nullptr);
  LOG_TEST("test_no_op_with_start");
  std::vector<grpc_pollset*> empty_pollset;
  grpc_udp_server_start(s, &empty_pollset, nullptr);
  grpc_udp_server_destroy(s, nullptr);
  shutdown_and_destroy_pollset();
}

static void test_no_op_with_port(void) {
  grpc_pollset_init(g_pollset, &g_mu);
  g_number_of_orphan_calls = 0;
  grpc_core::ExecCtx exec_ctx;
  grpc_resolved_address resolved_addr;
  struct sockaddr_in* addr =
      reinterpret_cast<struct sockaddr_in*>(resolved_addr.addr);
  grpc_udp_server* s = grpc_udp_server_create(nullptr);
  LOG_TEST("test_no_op_with_port");

  memset(&resolved_addr, 0, sizeof(resolved_addr));
  resolved_addr.len = static_cast<socklen_t>(sizeof(struct sockaddr_in));
  addr->sin_family = AF_INET;
  GPR_ASSERT(grpc_udp_server_add_port(s, &resolved_addr, rcv_buf_size,
                                      snd_buf_size, &handler_factory,
                                      g_num_listeners) > 0);

  grpc_udp_server_destroy(s, nullptr);

  /* The server haven't start listening, so no udp handler to be notified. */
  GPR_ASSERT(g_number_of_orphan_calls == 0);
  shutdown_and_destroy_pollset();
}

static void test_no_op_with_port_and_socket_factory(void) {
  grpc_pollset_init(g_pollset, &g_mu);
  g_number_of_orphan_calls = 0;
  grpc_core::ExecCtx exec_ctx;
  grpc_resolved_address resolved_addr;
  struct sockaddr_in* addr =
      reinterpret_cast<struct sockaddr_in*>(resolved_addr.addr);

  test_socket_factory* socket_factory = test_socket_factory_create();
  grpc_arg socket_factory_arg =
      grpc_socket_factory_to_arg(&socket_factory->base);
  grpc_channel_args* channel_args =
      grpc_channel_args_copy_and_add(nullptr, &socket_factory_arg, 1);
  grpc_udp_server* s = grpc_udp_server_create(channel_args);
  grpc_channel_args_destroy(channel_args);

  LOG_TEST("test_no_op_with_port_and_socket_factory");

  memset(&resolved_addr, 0, sizeof(resolved_addr));
  resolved_addr.len = static_cast<socklen_t>(sizeof(struct sockaddr_in));
  addr->sin_family = AF_INET;
  GPR_ASSERT(grpc_udp_server_add_port(s, &resolved_addr, rcv_buf_size,
                                      snd_buf_size, &handler_factory,
                                      g_num_listeners) > 0);
  GPR_ASSERT(socket_factory->number_of_socket_calls == g_num_listeners);
  GPR_ASSERT(socket_factory->number_of_bind_calls == g_num_listeners);

  grpc_udp_server_destroy(s, nullptr);

  grpc_socket_factory_unref(&socket_factory->base);

  /* The server haven't start listening, so no udp handler to be notified. */
  GPR_ASSERT(g_number_of_orphan_calls == 0);
  shutdown_and_destroy_pollset();
}

static void test_no_op_with_port_and_start(void) {
  grpc_pollset_init(g_pollset, &g_mu);
  g_number_of_orphan_calls = 0;
  grpc_core::ExecCtx exec_ctx;
  grpc_resolved_address resolved_addr;
  struct sockaddr_in* addr =
      reinterpret_cast<struct sockaddr_in*>(resolved_addr.addr);
  grpc_udp_server* s = grpc_udp_server_create(nullptr);
  LOG_TEST("test_no_op_with_port_and_start");

  memset(&resolved_addr, 0, sizeof(resolved_addr));
  resolved_addr.len = static_cast<socklen_t>(sizeof(struct sockaddr_in));
  addr->sin_family = AF_INET;
  GPR_ASSERT(grpc_udp_server_add_port(s, &resolved_addr, rcv_buf_size,
                                      snd_buf_size, &handler_factory,
                                      g_num_listeners) > 0);

  std::vector<grpc_pollset*> empty_pollset;
  grpc_udp_server_start(s, &empty_pollset, nullptr);
  GPR_ASSERT(g_number_of_starts == g_num_listeners);
  grpc_udp_server_destroy(s, nullptr);

  /* The server had a single FD, which is orphaned exactly once in *
   * grpc_udp_server_destroy. */
  GPR_ASSERT(g_number_of_orphan_calls == g_num_listeners);
  shutdown_and_destroy_pollset();
}

static void test_receive(int number_of_clients) {
  grpc_pollset_init(g_pollset, &g_mu);
  grpc_core::ExecCtx exec_ctx;
  grpc_resolved_address resolved_addr;
  struct sockaddr_storage* addr =
      reinterpret_cast<struct sockaddr_storage*>(resolved_addr.addr);
  int clifd, svrfd;
  grpc_udp_server* s = grpc_udp_server_create(nullptr);
  int i;
  grpc_millis deadline;
  LOG_TEST("test_receive");
  gpr_log(GPR_INFO, "clients=%d", number_of_clients);

  g_number_of_bytes_read = 0;
  g_number_of_orphan_calls = 0;

  memset(&resolved_addr, 0, sizeof(resolved_addr));
  resolved_addr.len = static_cast<socklen_t>(sizeof(struct sockaddr_storage));
  addr->ss_family = AF_INET;
  GPR_ASSERT(grpc_udp_server_add_port(s, &resolved_addr, rcv_buf_size,
                                      snd_buf_size, &handler_factory,
                                      g_num_listeners) > 0);

  svrfd = grpc_udp_server_get_fd(s, 0);
  GPR_ASSERT(svrfd >= 0);
  GPR_ASSERT(getsockname(svrfd, (struct sockaddr*)addr,
                         (socklen_t*)&resolved_addr.len) == 0);
  GPR_ASSERT(resolved_addr.len <= sizeof(struct sockaddr_storage));

  std::vector<grpc_pollset*> test_pollsets;
  test_pollsets.emplace_back(g_pollset);
  grpc_udp_server_start(s, &test_pollsets, nullptr);

  gpr_mu_lock(g_mu);

  for (i = 0; i < number_of_clients; i++) {
    deadline =
        grpc_timespec_to_millis_round_up(grpc_timeout_seconds_to_deadline(10));

    int number_of_bytes_read_before = g_number_of_bytes_read;
    /* Create a socket, send a packet to the UDP server. */
    clifd = socket(addr->ss_family, SOCK_DGRAM, 0);
    GPR_ASSERT(clifd >= 0);
    GPR_ASSERT(connect(clifd, (struct sockaddr*)addr,
                       (socklen_t)resolved_addr.len) == 0);
    GPR_ASSERT(5 == write(clifd, "hello", 5));
    while (g_number_of_bytes_read < (number_of_bytes_read_before + 5) &&
           deadline > grpc_core::ExecCtx::Get()->Now()) {
      grpc_pollset_worker* worker = nullptr;
      GPR_ASSERT(GRPC_LOG_IF_ERROR(
          "pollset_work", grpc_pollset_work(g_pollset, &worker, deadline)));
      gpr_mu_unlock(g_mu);
      grpc_core::ExecCtx::Get()->Flush();
      gpr_mu_lock(g_mu);
    }
    close(clifd);
  }
  GPR_ASSERT(g_number_of_bytes_read == 5 * number_of_clients);

  gpr_mu_unlock(g_mu);

  grpc_udp_server_destroy(s, nullptr);

  /* The server had a single FD, which is orphaned exactly once in *
   * grpc_udp_server_destroy. */
  GPR_ASSERT(g_number_of_orphan_calls == g_num_listeners);
  shutdown_and_destroy_pollset();
}

int main(int argc, char** argv) {
  grpc::testing::TestEnvironment env(argc, argv);
  grpc_init();
  if (grpc_is_socket_reuse_port_supported()) {
    g_num_listeners = 10;
  }
  {
    grpc_core::ExecCtx exec_ctx;
    g_pollset = static_cast<grpc_pollset*>(gpr_zalloc(grpc_pollset_size()));

    test_no_op();
    test_no_op_with_start();
    test_no_op_with_port();
    test_no_op_with_port_and_socket_factory();
    test_no_op_with_port_and_start();
    test_receive(1);
    test_receive(10);

    gpr_free(g_pollset);
  }
  grpc_shutdown();
  return 0;
}

#else /* GRPC_POSIX_SOCKET_UDP_SERVER */

int main(int argc, char** argv) { return 1; }

#endif /* GRPC_POSIX_SOCKET_UDP_SERVER */
