// Copyright 2021 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 <memory>
#include <string>
#include <utility>

#include "absl/status/status.h"
#include "absl/strings/string_view.h"

#include <grpc/grpc.h>
#include <grpc/grpc_security.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/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/security/authorization/authorization_policy_provider.h"
#include "src/core/lib/security/authorization/grpc_authorization_policy_provider.h"
#include "test/core/end2end/cq_verifier.h"
#include "test/core/end2end/end2end_tests.h"
#include "test/core/util/test_config.h"
#include "test/core/util/tls_utils.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, "%s", std::string(80, '*').c_str());
  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;
}

static void test_allow_authorized_request(CoreTestFixture* f) {
  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_status_code status;
  const char* error_string = nullptr;
  grpc_call_error error;
  grpc_slice details = grpc_empty_slice();
  int was_cancelled = 2;

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

  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("/foo"),
                               nullptr, deadline, nullptr);
  GPR_ASSERT(c);

  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),
                                grpc_core::CqVerifier::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(),
                                   grpc_core::CqVerifier::tag(101));
  GPR_ASSERT(GRPC_CALL_OK == error);
  cqv.Expect(grpc_core::CqVerifier::tag(101), true);
  cqv.Verify();

  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_OK;
  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),
                                grpc_core::CqVerifier::tag(102), nullptr);
  GPR_ASSERT(GRPC_CALL_OK == error);

  cqv.Expect(grpc_core::CqVerifier::tag(102), true);
  cqv.Expect(grpc_core::CqVerifier::tag(1), true);
  cqv.Verify();
  GPR_ASSERT(GRPC_STATUS_OK == status);
  GPR_ASSERT(0 == grpc_slice_str_cmp(details, "xyz"));

  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);
}

static void test_deny_unauthorized_request(CoreTestFixture* f) {
  grpc_call* c;
  grpc_op ops[6];
  grpc_op* op;
  grpc_metadata_array initial_metadata_recv;
  grpc_metadata_array trailing_metadata_recv;
  grpc_status_code status;
  const char* error_string = nullptr;
  grpc_call_error error;
  grpc_slice details = grpc_empty_slice();

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

  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("/foo"),
                               nullptr, deadline, nullptr);
  GPR_ASSERT(c);

  grpc_metadata_array_init(&initial_metadata_recv);
  grpc_metadata_array_init(&trailing_metadata_recv);

  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),
                                grpc_core::CqVerifier::tag(1), nullptr);
  GPR_ASSERT(GRPC_CALL_OK == error);
  cqv.Expect(grpc_core::CqVerifier::tag(1), true);
  cqv.Verify();

  GPR_ASSERT(GRPC_STATUS_PERMISSION_DENIED == status);
  GPR_ASSERT(0 ==
             grpc_slice_str_cmp(details, "Unauthorized RPC request rejected."));

  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_call_unref(c);
}

static void test_static_init_allow_authorized_request(
    const CoreTestConfiguration& config) {
  const char* authz_policy =
      "{"
      "  \"name\": \"authz\","
      "  \"allow_rules\": ["
      "    {"
      "      \"name\": \"allow_foo\","
      "      \"request\": {"
      "        \"paths\": ["
      "          \"*/foo\""
      "        ]"
      "      }"
      "    }"
      "  ]"
      "}";
  grpc_status_code code = GRPC_STATUS_OK;
  const char* error_details;
  grpc_authorization_policy_provider* provider =
      grpc_authorization_policy_provider_static_data_create(authz_policy, &code,
                                                            &error_details);
  GPR_ASSERT(GRPC_STATUS_OK == code);
  grpc_arg args[] = {
      grpc_channel_arg_pointer_create(
          const_cast<char*>(GRPC_ARG_AUTHORIZATION_POLICY_PROVIDER), provider,
          grpc_authorization_policy_provider_arg_vtable()),
  };
  grpc_channel_args server_args = {GPR_ARRAY_SIZE(args), args};

  auto f = begin_test(config, "test_static_init_allow_authorized_request",
                      nullptr, &server_args);
  grpc_authorization_policy_provider_release(provider);
  test_allow_authorized_request(f.get());
}

static void test_static_init_deny_unauthorized_request(
    const CoreTestConfiguration& config) {
  const char* authz_policy =
      "{"
      "  \"name\": \"authz\","
      "  \"allow_rules\": ["
      "    {"
      "      \"name\": \"allow_bar\","
      "      \"request\": {"
      "        \"paths\": ["
      "          \"*/bar\""
      "        ]"
      "      }"
      "    }"
      "  ],"
      "  \"deny_rules\": ["
      "    {"
      "      \"name\": \"deny_foo\","
      "      \"request\": {"
      "        \"paths\": ["
      "          \"*/foo\""
      "        ]"
      "      }"
      "    }"
      "  ]"
      "}";
  grpc_status_code code = GRPC_STATUS_OK;
  const char* error_details;
  grpc_authorization_policy_provider* provider =
      grpc_authorization_policy_provider_static_data_create(authz_policy, &code,
                                                            &error_details);
  GPR_ASSERT(GRPC_STATUS_OK == code);
  grpc_arg args[] = {
      grpc_channel_arg_pointer_create(
          const_cast<char*>(GRPC_ARG_AUTHORIZATION_POLICY_PROVIDER), provider,
          grpc_authorization_policy_provider_arg_vtable()),
  };
  grpc_channel_args server_args = {GPR_ARRAY_SIZE(args), args};

  auto f = begin_test(config, "test_static_init_deny_unauthorized_request",
                      nullptr, &server_args);
  grpc_authorization_policy_provider_release(provider);
  test_deny_unauthorized_request(f.get());
}

static void test_static_init_deny_request_no_match_in_policy(
    const CoreTestConfiguration& config) {
  const char* authz_policy =
      "{"
      "  \"name\": \"authz\","
      "  \"allow_rules\": ["
      "    {"
      "      \"name\": \"allow_bar\","
      "      \"request\": {"
      "        \"paths\": ["
      "          \"*/bar\""
      "        ]"
      "      }"
      "    }"
      "  ]"
      "}";
  grpc_status_code code = GRPC_STATUS_OK;
  const char* error_details;
  grpc_authorization_policy_provider* provider =
      grpc_authorization_policy_provider_static_data_create(authz_policy, &code,
                                                            &error_details);
  GPR_ASSERT(GRPC_STATUS_OK == code);
  grpc_arg args[] = {
      grpc_channel_arg_pointer_create(
          const_cast<char*>(GRPC_ARG_AUTHORIZATION_POLICY_PROVIDER), provider,
          grpc_authorization_policy_provider_arg_vtable()),
  };
  grpc_channel_args server_args = {GPR_ARRAY_SIZE(args), args};

  auto f =
      begin_test(config, "test_static_init_deny_request_no_match_in_policy",
                 nullptr, &server_args);
  grpc_authorization_policy_provider_release(provider);
  test_deny_unauthorized_request(f.get());
}

static void test_file_watcher_init_allow_authorized_request(
    const CoreTestConfiguration& config) {
  const char* authz_policy =
      "{"
      "  \"name\": \"authz\","
      "  \"allow_rules\": ["
      "    {"
      "      \"name\": \"allow_foo\","
      "      \"request\": {"
      "        \"paths\": ["
      "          \"*/foo\""
      "        ]"
      "      }"
      "    }"
      "  ]"
      "}";
  grpc_core::testing::TmpFile tmp_policy(authz_policy);
  grpc_status_code code = GRPC_STATUS_OK;
  const char* error_details;
  grpc_authorization_policy_provider* provider =
      grpc_authorization_policy_provider_file_watcher_create(
          tmp_policy.name().c_str(), /*refresh_interval_sec=*/1, &code,
          &error_details);
  GPR_ASSERT(GRPC_STATUS_OK == code);
  grpc_arg args[] = {
      grpc_channel_arg_pointer_create(
          const_cast<char*>(GRPC_ARG_AUTHORIZATION_POLICY_PROVIDER), provider,
          grpc_authorization_policy_provider_arg_vtable()),
  };
  grpc_channel_args server_args = {GPR_ARRAY_SIZE(args), args};

  auto f = begin_test(config, "test_file_watcher_init_allow_authorized_request",
                      nullptr, &server_args);
  grpc_authorization_policy_provider_release(provider);
  test_allow_authorized_request(f.get());
}

static void test_file_watcher_init_deny_unauthorized_request(
    const CoreTestConfiguration& config) {
  const char* authz_policy =
      "{"
      "  \"name\": \"authz\","
      "  \"allow_rules\": ["
      "    {"
      "      \"name\": \"allow_bar\","
      "      \"request\": {"
      "        \"paths\": ["
      "          \"*/bar\""
      "        ]"
      "      }"
      "    }"
      "  ],"
      "  \"deny_rules\": ["
      "    {"
      "      \"name\": \"deny_foo\","
      "      \"request\": {"
      "        \"paths\": ["
      "          \"*/foo\""
      "        ]"
      "      }"
      "    }"
      "  ]"
      "}";
  grpc_core::testing::TmpFile tmp_policy(authz_policy);
  grpc_status_code code = GRPC_STATUS_OK;
  const char* error_details;
  grpc_authorization_policy_provider* provider =
      grpc_authorization_policy_provider_file_watcher_create(
          tmp_policy.name().c_str(), /*refresh_interval_sec=*/1, &code,
          &error_details);
  GPR_ASSERT(GRPC_STATUS_OK == code);
  grpc_arg args[] = {
      grpc_channel_arg_pointer_create(
          const_cast<char*>(GRPC_ARG_AUTHORIZATION_POLICY_PROVIDER), provider,
          grpc_authorization_policy_provider_arg_vtable()),
  };
  grpc_channel_args server_args = {GPR_ARRAY_SIZE(args), args};

  auto f =
      begin_test(config, "test_file_watcher_init_deny_unauthorized_request",
                 nullptr, &server_args);
  grpc_authorization_policy_provider_release(provider);
  test_deny_unauthorized_request(f.get());
}

static void test_file_watcher_init_deny_request_no_match_in_policy(
    const CoreTestConfiguration& config) {
  const char* authz_policy =
      "{"
      "  \"name\": \"authz\","
      "  \"allow_rules\": ["
      "    {"
      "      \"name\": \"allow_bar\","
      "      \"request\": {"
      "        \"paths\": ["
      "          \"*/bar\""
      "        ]"
      "      }"
      "    }"
      "  ]"
      "}";
  grpc_core::testing::TmpFile tmp_policy(authz_policy);
  grpc_status_code code = GRPC_STATUS_OK;
  const char* error_details;
  grpc_authorization_policy_provider* provider =
      grpc_authorization_policy_provider_file_watcher_create(
          tmp_policy.name().c_str(), /*refresh_interval_sec=*/1, &code,
          &error_details);
  GPR_ASSERT(GRPC_STATUS_OK == code);
  grpc_arg args[] = {
      grpc_channel_arg_pointer_create(
          const_cast<char*>(GRPC_ARG_AUTHORIZATION_POLICY_PROVIDER), provider,
          grpc_authorization_policy_provider_arg_vtable()),
  };
  grpc_channel_args server_args = {GPR_ARRAY_SIZE(args), args};

  auto f = begin_test(config,
                      "test_file_watcher_init_deny_request_no_match_in_policy",
                      nullptr, &server_args);
  grpc_authorization_policy_provider_release(provider);
  test_deny_unauthorized_request(f.get());
}

static void test_file_watcher_valid_policy_reload(
    const CoreTestConfiguration& config) {
  const char* authz_policy =
      "{"
      "  \"name\": \"authz\","
      "  \"allow_rules\": ["
      "    {"
      "      \"name\": \"allow_foo\","
      "      \"request\": {"
      "        \"paths\": ["
      "          \"*/foo\""
      "        ]"
      "      }"
      "    }"
      "  ]"
      "}";
  grpc_core::testing::TmpFile tmp_policy(authz_policy);
  grpc_status_code code = GRPC_STATUS_OK;
  const char* error_details;
  grpc_authorization_policy_provider* provider =
      grpc_authorization_policy_provider_file_watcher_create(
          tmp_policy.name().c_str(), /*refresh_interval_sec=*/1, &code,
          &error_details);
  GPR_ASSERT(GRPC_STATUS_OK == code);
  grpc_arg args[] = {
      grpc_channel_arg_pointer_create(
          const_cast<char*>(GRPC_ARG_AUTHORIZATION_POLICY_PROVIDER), provider,
          grpc_authorization_policy_provider_arg_vtable()),
  };
  grpc_channel_args server_args = {GPR_ARRAY_SIZE(args), args};

  auto f = begin_test(config, "test_file_watcher_valid_policy_reload", nullptr,
                      &server_args);
  grpc_authorization_policy_provider_release(provider);
  test_allow_authorized_request(f.get());
  gpr_event on_reload_done;
  gpr_event_init(&on_reload_done);
  std::function<void(bool contents_changed, absl::Status status)> callback =
      [&on_reload_done](bool contents_changed, absl::Status status) {
        if (contents_changed) {
          GPR_ASSERT(status.ok());
          gpr_event_set(&on_reload_done, reinterpret_cast<void*>(1));
        }
      };
  dynamic_cast<grpc_core::FileWatcherAuthorizationPolicyProvider*>(provider)
      ->SetCallbackForTesting(std::move(callback));
  // Replace existing policy in file with a different authorization policy.
  authz_policy =
      "{"
      "  \"name\": \"authz\","
      "  \"allow_rules\": ["
      "    {"
      "      \"name\": \"allow_bar\","
      "      \"request\": {"
      "        \"paths\": ["
      "          \"*/bar\""
      "        ]"
      "      }"
      "    }"
      "  ],"
      "  \"deny_rules\": ["
      "    {"
      "      \"name\": \"deny_foo\","
      "      \"request\": {"
      "        \"paths\": ["
      "          \"*/foo\""
      "        ]"
      "      }"
      "    }"
      "  ]"
      "}";
  tmp_policy.RewriteFile(authz_policy);
  GPR_ASSERT(
      reinterpret_cast<void*>(1) ==
      gpr_event_wait(&on_reload_done, gpr_inf_future(GPR_CLOCK_MONOTONIC)));
  test_deny_unauthorized_request(f.get());
  dynamic_cast<grpc_core::FileWatcherAuthorizationPolicyProvider*>(provider)
      ->SetCallbackForTesting(nullptr);
}

static void test_file_watcher_invalid_policy_skip_reload(
    const CoreTestConfiguration& config) {
  const char* authz_policy =
      "{"
      "  \"name\": \"authz\","
      "  \"allow_rules\": ["
      "    {"
      "      \"name\": \"allow_foo\","
      "      \"request\": {"
      "        \"paths\": ["
      "          \"*/foo\""
      "        ]"
      "      }"
      "    }"
      "  ]"
      "}";
  grpc_core::testing::TmpFile tmp_policy(authz_policy);
  grpc_status_code code = GRPC_STATUS_OK;
  const char* error_details;
  grpc_authorization_policy_provider* provider =
      grpc_authorization_policy_provider_file_watcher_create(
          tmp_policy.name().c_str(), /*refresh_interval_sec=*/1, &code,
          &error_details);
  GPR_ASSERT(GRPC_STATUS_OK == code);
  grpc_arg args[] = {
      grpc_channel_arg_pointer_create(
          const_cast<char*>(GRPC_ARG_AUTHORIZATION_POLICY_PROVIDER), provider,
          grpc_authorization_policy_provider_arg_vtable()),
  };
  grpc_channel_args server_args = {GPR_ARRAY_SIZE(args), args};

  auto f = begin_test(config, "test_file_watcher_invalid_policy_skip_reload",
                      nullptr, &server_args);
  grpc_authorization_policy_provider_release(provider);
  test_allow_authorized_request(f.get());
  gpr_event on_reload_done;
  gpr_event_init(&on_reload_done);
  std::function<void(bool contents_changed, absl::Status status)> callback =
      [&on_reload_done](bool contents_changed, absl::Status status) {
        if (contents_changed) {
          GPR_ASSERT(absl::StatusCode::kInvalidArgument == status.code());
          GPR_ASSERT("\"name\" field is not present." == status.message());
          gpr_event_set(&on_reload_done, reinterpret_cast<void*>(1));
        }
      };
  dynamic_cast<grpc_core::FileWatcherAuthorizationPolicyProvider*>(provider)
      ->SetCallbackForTesting(std::move(callback));
  // Replace exisiting policy in file with an invalid policy.
  authz_policy = "{}";
  tmp_policy.RewriteFile(authz_policy);
  GPR_ASSERT(
      reinterpret_cast<void*>(1) ==
      gpr_event_wait(&on_reload_done, gpr_inf_future(GPR_CLOCK_MONOTONIC)));
  test_allow_authorized_request(f.get());
  dynamic_cast<grpc_core::FileWatcherAuthorizationPolicyProvider*>(provider)
      ->SetCallbackForTesting(nullptr);
}

static void test_file_watcher_recovers_from_failure(
    const CoreTestConfiguration& config) {
  const char* authz_policy =
      "{"
      "  \"name\": \"authz\","
      "  \"allow_rules\": ["
      "    {"
      "      \"name\": \"allow_foo\","
      "      \"request\": {"
      "        \"paths\": ["
      "          \"*/foo\""
      "        ]"
      "      }"
      "    }"
      "  ]"
      "}";
  grpc_core::testing::TmpFile tmp_policy(authz_policy);
  grpc_status_code code = GRPC_STATUS_OK;
  const char* error_details;
  grpc_authorization_policy_provider* provider =
      grpc_authorization_policy_provider_file_watcher_create(
          tmp_policy.name().c_str(), /*refresh_interval_sec=*/1, &code,
          &error_details);
  GPR_ASSERT(GRPC_STATUS_OK == code);
  grpc_arg args[] = {
      grpc_channel_arg_pointer_create(
          const_cast<char*>(GRPC_ARG_AUTHORIZATION_POLICY_PROVIDER), provider,
          grpc_authorization_policy_provider_arg_vtable()),
  };
  grpc_channel_args server_args = {GPR_ARRAY_SIZE(args), args};

  auto f = begin_test(config, "test_file_watcher_recovers_from_failure",
                      nullptr, &server_args);
  grpc_authorization_policy_provider_release(provider);
  test_allow_authorized_request(f.get());
  gpr_event on_first_reload_done;
  gpr_event_init(&on_first_reload_done);
  std::function<void(bool contents_changed, absl::Status status)> callback1 =
      [&on_first_reload_done](bool contents_changed, absl::Status status) {
        if (contents_changed) {
          GPR_ASSERT(absl::StatusCode::kInvalidArgument == status.code());
          GPR_ASSERT("\"name\" field is not present." == status.message());
          gpr_event_set(&on_first_reload_done, reinterpret_cast<void*>(1));
        }
      };
  dynamic_cast<grpc_core::FileWatcherAuthorizationPolicyProvider*>(provider)
      ->SetCallbackForTesting(std::move(callback1));
  // Replace exisiting policy in file with an invalid policy.
  authz_policy = "{}";
  tmp_policy.RewriteFile(authz_policy);
  GPR_ASSERT(reinterpret_cast<void*>(1) ==
             gpr_event_wait(&on_first_reload_done,
                            gpr_inf_future(GPR_CLOCK_MONOTONIC)));
  test_allow_authorized_request(f.get());
  gpr_event on_second_reload_done;
  gpr_event_init(&on_second_reload_done);
  std::function<void(bool contents_changed, absl::Status status)> callback2 =
      [&on_second_reload_done](bool contents_changed, absl::Status status) {
        if (contents_changed) {
          GPR_ASSERT(status.ok());
          gpr_event_set(&on_second_reload_done, reinterpret_cast<void*>(1));
        }
      };
  dynamic_cast<grpc_core::FileWatcherAuthorizationPolicyProvider*>(provider)
      ->SetCallbackForTesting(std::move(callback2));
  // Recover from reload errors, by replacing invalid policy in file with a
  // valid policy.
  authz_policy =
      "{"
      "  \"name\": \"authz\","
      "  \"allow_rules\": ["
      "    {"
      "      \"name\": \"allow_bar\","
      "      \"request\": {"
      "        \"paths\": ["
      "          \"*/bar\""
      "        ]"
      "      }"
      "    }"
      "  ],"
      "  \"deny_rules\": ["
      "    {"
      "      \"name\": \"deny_foo\","
      "      \"request\": {"
      "        \"paths\": ["
      "          \"*/foo\""
      "        ]"
      "      }"
      "    }"
      "  ]"
      "}";
  tmp_policy.RewriteFile(authz_policy);
  GPR_ASSERT(reinterpret_cast<void*>(1) ==
             gpr_event_wait(&on_second_reload_done,
                            gpr_inf_future(GPR_CLOCK_MONOTONIC)));
  test_deny_unauthorized_request(f.get());
  dynamic_cast<grpc_core::FileWatcherAuthorizationPolicyProvider*>(provider)
      ->SetCallbackForTesting(nullptr);
}

void grpc_authz(const CoreTestConfiguration& config) {
  test_static_init_allow_authorized_request(config);
  test_static_init_deny_unauthorized_request(config);
  test_static_init_deny_request_no_match_in_policy(config);
  test_file_watcher_init_allow_authorized_request(config);
  test_file_watcher_init_deny_unauthorized_request(config);
  test_file_watcher_init_deny_request_no_match_in_policy(config);
  test_file_watcher_valid_policy_reload(config);
  test_file_watcher_invalid_policy_skip_reload(config);
  test_file_watcher_recovers_from_failure(config);
}

void grpc_authz_pre_init(void) {}
