/*
 *
 * 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 <stdint.h>
#include <string.h>

#include <algorithm>
#include <memory>
#include <string>

#include <grpc/grpc.h>
#include <grpc/impl/codegen/propagation_bits.h>
#include <grpc/slice.h>
#include <grpc/status.h>
#include <grpc/support/alloc.h>
#include <grpc/support/log.h>

#include "src/core/lib/debug/stats.h"
#include "src/core/lib/debug/stats_data.h"
#include "test/core/end2end/cq_verifier.h"
#include "test/core/end2end/end2end_tests.h"
#include "test/core/util/test_config.h"

static void* tag(intptr_t t) { return reinterpret_cast<void*>(t); }

static grpc_end2end_test_fixture begin_test(grpc_end2end_test_config config,
                                            const char* test_name,
                                            grpc_channel_args* client_args,
                                            grpc_channel_args* server_args) {
  grpc_end2end_test_fixture f;
  gpr_log(GPR_INFO, "%s", std::string(100, '*').c_str());
  gpr_log(GPR_INFO, "Running test: %s/%s", test_name, config.name);
  f = config.create_fixture(client_args, server_args);
  config.init_server(&f, server_args);
  config.init_client(&f, client_args);
  return f;
}

static gpr_timespec n_seconds_from_now(int n) {
  return grpc_timeout_seconds_to_deadline(n);
}

static gpr_timespec five_seconds_from_now(void) {
  return n_seconds_from_now(5);
}

static void drain_cq(grpc_completion_queue* cq) {
  grpc_event ev;
  do {
    ev = grpc_completion_queue_next(cq, five_seconds_from_now(), nullptr);
  } while (ev.type != GRPC_QUEUE_SHUTDOWN);
}

static void shutdown_server(grpc_end2end_test_fixture* f) {
  if (!f->server) return;
  grpc_server_shutdown_and_notify(f->server, f->cq, tag(1000));
  grpc_event ev;
  do {
    ev = grpc_completion_queue_next(f->cq, grpc_timeout_seconds_to_deadline(5),
                                    nullptr);
  } while (ev.type != GRPC_OP_COMPLETE || ev.tag != tag(1000));
  grpc_server_destroy(f->server);
  f->server = nullptr;
}

static void shutdown_client(grpc_end2end_test_fixture* f) {
  if (!f->client) return;
  grpc_channel_destroy(f->client);
  f->client = nullptr;
}

static void end_test(grpc_end2end_test_fixture* f) {
  shutdown_server(f);
  shutdown_client(f);

  grpc_completion_queue_shutdown(f->cq);
  drain_cq(f->cq);
  grpc_completion_queue_destroy(f->cq);
}

static void check_peer(char* peer_name) {
  // If the peer name is a uds path, then check if it is filled
  if (strncmp(peer_name, "unix:/", strlen("unix:/")) == 0) {
    GPR_ASSERT(strncmp(peer_name, "unix:/tmp/grpc_fullstack_test.",
                       strlen("unix:/tmp/grpc_fullstack_test.")) == 0);
  }
}

static void simple_request_body(grpc_end2end_test_config config,
                                grpc_end2end_test_fixture f) {
  grpc_call* c;
  grpc_call* s;
  grpc_core::CqVerifier cqv(f.cq);
  grpc_op ops[6];
  grpc_op* op;
  grpc_metadata_array initial_metadata_recv;
  grpc_metadata_array trailing_metadata_recv;
  grpc_metadata_array request_metadata_recv;
  grpc_call_details call_details;
  grpc_status_code status;
  const char* error_string;
  grpc_call_error error;
  grpc_slice details;
  int was_cancelled = 2;
  char* peer;

  auto before = grpc_core::global_stats().Collect();

  gpr_timespec deadline = five_seconds_from_now();
  c = grpc_channel_create_call(f.client, nullptr, GRPC_PROPAGATE_DEFAULTS, f.cq,
                               grpc_slice_from_static_string("/foo"), nullptr,
                               deadline, nullptr);
  GPR_ASSERT(c);

  peer = grpc_call_get_peer(c);
  GPR_ASSERT(peer != nullptr);
  gpr_log(GPR_DEBUG, "client_peer_before_call=%s", peer);
  gpr_free(peer);

  grpc_metadata_array_init(&initial_metadata_recv);
  grpc_metadata_array_init(&trailing_metadata_recv);
  grpc_metadata_array_init(&request_metadata_recv);
  grpc_call_details_init(&call_details);

  memset(ops, 0, sizeof(ops));
  op = ops;
  op->op = GRPC_OP_SEND_INITIAL_METADATA;
  op->data.send_initial_metadata.count = 0;
  op->flags = 0;
  op->reserved = nullptr;
  op++;
  op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
  op->flags = 0;
  op->reserved = nullptr;
  op++;
  op->op = GRPC_OP_RECV_INITIAL_METADATA;
  op->data.recv_initial_metadata.recv_initial_metadata = &initial_metadata_recv;
  op->flags = 0;
  op->reserved = nullptr;
  op++;
  op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
  op->data.recv_status_on_client.trailing_metadata = &trailing_metadata_recv;
  op->data.recv_status_on_client.status = &status;
  op->data.recv_status_on_client.status_details = &details;
  op->data.recv_status_on_client.error_string = &error_string;
  op->flags = 0;
  op->reserved = nullptr;
  op++;
  error = grpc_call_start_batch(c, ops, static_cast<size_t>(op - ops), tag(1),
                                nullptr);
  GPR_ASSERT(GRPC_CALL_OK == error);

  error =
      grpc_server_request_call(f.server, &s, &call_details,
                               &request_metadata_recv, f.cq, f.cq, tag(101));
  GPR_ASSERT(GRPC_CALL_OK == error);
  cqv.Expect(tag(101), true);
  cqv.Verify();

  peer = grpc_call_get_peer(s);
  GPR_ASSERT(peer != nullptr);
  gpr_log(GPR_DEBUG, "server_peer=%s", peer);
  check_peer(peer);
  gpr_free(peer);
  peer = grpc_call_get_peer(c);
  GPR_ASSERT(peer != nullptr);
  gpr_log(GPR_DEBUG, "client_peer=%s", peer);
  check_peer(peer);
  gpr_free(peer);

  memset(ops, 0, sizeof(ops));
  op = ops;
  op->op = GRPC_OP_SEND_INITIAL_METADATA;
  op->data.send_initial_metadata.count = 0;
  op->flags = 0;
  op->reserved = nullptr;
  op++;
  op->op = GRPC_OP_SEND_STATUS_FROM_SERVER;
  op->data.send_status_from_server.trailing_metadata_count = 0;
  op->data.send_status_from_server.status = GRPC_STATUS_UNIMPLEMENTED;
  grpc_slice status_details = grpc_slice_from_static_string("xyz");
  op->data.send_status_from_server.status_details = &status_details;
  op->flags = 0;
  op->reserved = nullptr;
  op++;
  op->op = GRPC_OP_RECV_CLOSE_ON_SERVER;
  op->data.recv_close_on_server.cancelled = &was_cancelled;
  op->flags = 0;
  op->reserved = nullptr;
  op++;
  error = grpc_call_start_batch(s, ops, static_cast<size_t>(op - ops), tag(102),
                                nullptr);
  GPR_ASSERT(GRPC_CALL_OK == error);

  cqv.Expect(tag(102), true);
  cqv.Expect(tag(1), true);
  cqv.Verify();

  GPR_ASSERT(status == GRPC_STATUS_UNIMPLEMENTED);
  GPR_ASSERT(0 == grpc_slice_str_cmp(details, "xyz"));
  // the following sanity check makes sure that the requested error string is
  // correctly populated by the core. It looks for certain substrings that are
  // not likely to change much. Some parts of the error, like time created,
  // obviously are not checked.
  GPR_ASSERT(nullptr != strstr(error_string, "xyz"));
  GPR_ASSERT(nullptr != strstr(error_string, "Error received from peer"));
  GPR_ASSERT(nullptr != strstr(error_string, "grpc_message"));
  GPR_ASSERT(nullptr != strstr(error_string, "grpc_status"));
  GPR_ASSERT(0 == grpc_slice_str_cmp(call_details.method, "/foo"));
  GPR_ASSERT(was_cancelled == 0);

  grpc_slice_unref(details);
  gpr_free(const_cast<char*>(error_string));
  grpc_metadata_array_destroy(&initial_metadata_recv);
  grpc_metadata_array_destroy(&trailing_metadata_recv);
  grpc_metadata_array_destroy(&request_metadata_recv);
  grpc_call_details_destroy(&call_details);

  grpc_call_unref(c);
  grpc_call_unref(s);

  uint64_t expected_calls = 1;
  if (config.feature_mask & FEATURE_MASK_SUPPORTS_REQUEST_PROXYING) {
    expected_calls *= 2;
  }

  auto after = grpc_core::global_stats().Collect();

  gpr_log(GPR_DEBUG, "%s", grpc_core::StatsAsJson(after.get()).c_str());

  GPR_ASSERT(after->client_calls_created - before->client_calls_created ==
             expected_calls);
  GPR_ASSERT(after->server_calls_created - before->server_calls_created ==
             expected_calls);
}

static void test_invoke_simple_request(grpc_end2end_test_config config) {
  grpc_end2end_test_fixture f;

  f = begin_test(config, "test_invoke_simple_request", nullptr, nullptr);
  simple_request_body(config, f);
  end_test(&f);
  config.tear_down_data(&f);
}

static void test_invoke_10_simple_requests(grpc_end2end_test_config config) {
  int i;
  grpc_end2end_test_fixture f =
      begin_test(config, "test_invoke_10_simple_requests", nullptr, nullptr);
  for (i = 0; i < 10; i++) {
    simple_request_body(config, f);
    gpr_log(GPR_INFO, "Running test: Passed simple request %d", i);
  }
  end_test(&f);
  config.tear_down_data(&f);
}

void simple_request(grpc_end2end_test_config config) {
  int i;
  for (i = 0; i < 10; i++) {
    test_invoke_simple_request(config);
  }
  test_invoke_10_simple_requests(config);
}

void simple_request_pre_init(void) {}