//
// Copyright 2017 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 <string.h>

#include <functional>
#include <initializer_list>
#include <memory>
#include <string>

#include "absl/strings/str_cat.h"
#include "absl/strings/str_format.h"
#include "absl/strings/string_view.h"
#include "absl/time/time.h"

#include <grpc/byte_buffer.h>
#include <grpc/grpc.h>
#include <grpc/impl/propagation_bits.h>
#include <grpc/slice.h>
#include <grpc/status.h>
#include <grpc/support/alloc.h>
#include <grpc/support/log.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/time_util.h"
#include "src/core/lib/slice/slice_internal.h"
#include "test/core/end2end/cq_verifier.h"
#include "test/core/end2end/end2end_tests.h"
#include "test/core/end2end/tests/cancel_test_helpers.h"
#include "test/core/util/test_config.h"

static std::unique_ptr<CoreTestFixture> begin_test(
    const CoreTestConfiguration& config, const char* test_name,
    grpc_channel_args* client_args, grpc_channel_args* server_args) {
  gpr_log(GPR_INFO, "Running test: %s/%s", test_name, config.name);
  auto f = config.create_fixture(grpc_core::ChannelArgs::FromC(client_args),
                                 grpc_core::ChannelArgs::FromC(server_args));
  f->InitServer(grpc_core::ChannelArgs::FromC(server_args));
  f->InitClient(grpc_core::ChannelArgs::FromC(client_args));
  return f;
}

// Tests retry cancellation during backoff.
static void test_retry_cancel_during_delay(const CoreTestConfiguration& config,
                                           cancellation_mode mode) {
  grpc_call* c;
  grpc_call* s;
  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_slice request_payload_slice = grpc_slice_from_static_string("foo");
  grpc_slice response_payload_slice = grpc_slice_from_static_string("bar");
  grpc_byte_buffer* request_payload =
      grpc_raw_byte_buffer_create(&request_payload_slice, 1);
  grpc_byte_buffer* response_payload =
      grpc_raw_byte_buffer_create(&response_payload_slice, 1);
  grpc_byte_buffer* request_payload_recv = nullptr;
  grpc_byte_buffer* response_payload_recv = nullptr;
  grpc_status_code status;
  grpc_call_error error;
  grpc_slice details;
  int was_cancelled = 2;
  char* peer;

  std::string service_config = absl::StrFormat(
      "{\n"
      "  \"methodConfig\": [ {\n"
      "    \"name\": [\n"
      "      { \"service\": \"service\", \"method\": \"method\" }\n"
      "    ],\n"
      "    \"retryPolicy\": {\n"
      "      \"maxAttempts\": 3,\n"
      "      \"initialBackoff\": \"%ds\",\n"
      "      \"maxBackoff\": \"120s\",\n"
      "      \"backoffMultiplier\": 1.6,\n"
      "      \"retryableStatusCodes\": [ \"ABORTED\" ]\n"
      "    }\n"
      "  } ]\n"
      "}",
      10 * grpc_test_slowdown_factor());

  grpc_arg args[] = {
      grpc_channel_arg_string_create(const_cast<char*>(GRPC_ARG_SERVICE_CONFIG),
                                     const_cast<char*>(service_config.c_str())),
  };
  grpc_channel_args client_args = {GPR_ARRAY_SIZE(args), args};
  std::string name = absl::StrCat("retry_cancel_during_delay/", mode.name);
  auto f = begin_test(config, name.c_str(), &client_args, nullptr);

  grpc_core::CqVerifier cqv(f->cq());

  gpr_timespec expect_finish_before = grpc_timeout_seconds_to_deadline(10);
  gpr_timespec deadline = grpc_timeout_seconds_to_deadline(5);
  c = grpc_channel_create_call(f->client(), nullptr, GRPC_PROPAGATE_DEFAULTS,
                               f->cq(),
                               grpc_slice_from_static_string("/service/method"),
                               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);
  grpc_slice status_details = grpc_slice_from_static_string("xyz");

  // Client starts a batch with all 6 ops.
  memset(ops, 0, sizeof(ops));
  op = ops;
  op->op = GRPC_OP_SEND_INITIAL_METADATA;
  op->data.send_initial_metadata.count = 0;
  op++;
  op->op = GRPC_OP_SEND_MESSAGE;
  op->data.send_message.send_message = request_payload;
  op++;
  op->op = GRPC_OP_RECV_MESSAGE;
  op->data.recv_message.recv_message = &response_payload_recv;
  op++;
  op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
  op++;
  op->op = GRPC_OP_RECV_INITIAL_METADATA;
  op->data.recv_initial_metadata.recv_initial_metadata = &initial_metadata_recv;
  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++;
  error = grpc_call_start_batch(c, ops, static_cast<size_t>(op - ops),
                                grpc_core::CqVerifier::tag(1), nullptr);
  GPR_ASSERT(GRPC_CALL_OK == error);

  // Server gets a call and fails with retryable status.
  error = grpc_server_request_call(f->server(), &s, &call_details,
                                   &request_metadata_recv, f->cq(), f->cq(),
                                   grpc_core::CqVerifier::tag(101));
  GPR_ASSERT(GRPC_CALL_OK == error);
  cqv.Expect(grpc_core::CqVerifier::tag(101), true);
  cqv.Verify();

  peer = grpc_call_get_peer(s);
  GPR_ASSERT(peer != nullptr);
  gpr_log(GPR_DEBUG, "server_peer=%s", peer);
  gpr_free(peer);
  peer = grpc_call_get_peer(c);
  GPR_ASSERT(peer != nullptr);
  gpr_log(GPR_DEBUG, "client_peer=%s", 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++;
  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_ABORTED;
  op->data.send_status_from_server.status_details = &status_details;
  op++;
  op->op = GRPC_OP_RECV_CLOSE_ON_SERVER;
  op->data.recv_close_on_server.cancelled = &was_cancelled;
  op++;
  error = grpc_call_start_batch(s, ops, static_cast<size_t>(op - ops),
                                grpc_core::CqVerifier::tag(102), nullptr);
  GPR_ASSERT(GRPC_CALL_OK == error);

  cqv.Expect(grpc_core::CqVerifier::tag(102), true);
  cqv.Verify();

  grpc_call_unref(s);
  grpc_metadata_array_destroy(&request_metadata_recv);
  grpc_metadata_array_init(&request_metadata_recv);
  grpc_call_details_destroy(&call_details);
  grpc_call_details_init(&call_details);

  // Server should never get a second call, because the initial retry
  // delay is longer than the call's deadline.
  error = grpc_server_request_call(f->server(), &s, &call_details,
                                   &request_metadata_recv, f->cq(), f->cq(),
                                   grpc_core::CqVerifier::tag(201));
  GPR_ASSERT(GRPC_CALL_OK == error);

  // Initiate cancellation.
  GPR_ASSERT(GRPC_CALL_OK == mode.initiate_cancel(c, nullptr));

  cqv.Expect(grpc_core::CqVerifier::tag(1), true);
  cqv.Verify();

  gpr_timespec finish_time = gpr_now(GPR_CLOCK_MONOTONIC);

  gpr_log(GPR_INFO, "status=%d expected=%d", status, mode.expect_status);
  gpr_log(GPR_INFO, "message=\"%s\"",
          std::string(grpc_core::StringViewFromSlice(details)).c_str());
  GPR_ASSERT(status == mode.expect_status);
  GPR_ASSERT(was_cancelled == 0);

  // Make sure we didn't wait the full deadline before failing.
  gpr_log(
      GPR_INFO, "Expect completion before: %s",
      absl::FormatTime(grpc_core::ToAbslTime(expect_finish_before)).c_str());
  GPR_ASSERT(gpr_time_cmp(finish_time, expect_finish_before) < 0);

  grpc_slice_unref(details);
  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_byte_buffer_destroy(request_payload);
  grpc_byte_buffer_destroy(response_payload);
  grpc_byte_buffer_destroy(request_payload_recv);
  grpc_byte_buffer_destroy(response_payload_recv);

  grpc_call_unref(c);
}

void retry_cancel_during_delay(const CoreTestConfiguration& config) {
  GPR_ASSERT(config.feature_mask & FEATURE_MASK_SUPPORTS_CLIENT_CHANNEL);
  for (size_t i = 0; i < GPR_ARRAY_SIZE(cancellation_modes); ++i) {
    test_retry_cancel_during_delay(config, cancellation_modes[i]);
  }
}

void retry_cancel_during_delay_pre_init(void) {}
