//
//
// Copyright 2023 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/cpp/ext/otel/otel_plugin.h"

#include "absl/functional/any_invocable.h"
#include "api/include/opentelemetry/metrics/provider.h"
#include "gmock/gmock.h"
#include "gtest/gtest.h"
#include "opentelemetry/sdk/metrics/meter_provider.h"
#include "opentelemetry/sdk/metrics/metric_reader.h"

#include <grpcpp/grpcpp.h>

#include "src/core/lib/channel/call_tracer.h"
#include "src/core/lib/config/core_configuration.h"
#include "test/core/util/test_config.h"
#include "test/cpp/end2end/test_service_impl.h"
#include "test/cpp/ext/otel/otel_test_library.h"

namespace grpc {
namespace testing {
namespace {

TEST(OTelPluginBuildTest, ApiDependency) {
  opentelemetry::metrics::Provider::GetMeterProvider();
}

TEST(OTelPluginBuildTest, SdkDependency) {
  opentelemetry::sdk::metrics::MeterProvider();
}

TEST_F(OTelPluginEnd2EndTest, ClientAttemptStarted) {
  Init({grpc::internal::OTelClientAttemptStartedInstrumentName()});
  SendRPC();
  const char* kMetricName = "grpc.client.attempt.started";
  auto data = ReadCurrentMetricsData(
      [&](const absl::flat_hash_map<
          std::string,
          std::vector<opentelemetry::sdk::metrics::PointDataAttributes>>&
              data) { return !data.contains(kMetricName); });
  ASSERT_EQ(data[kMetricName].size(), 1);
  auto point_data = absl::get_if<opentelemetry::sdk::metrics::SumPointData>(
      &data[kMetricName][0].point_data);
  ASSERT_NE(point_data, nullptr);
  auto client_started_value = absl::get_if<int64_t>(&point_data->value_);
  ASSERT_NE(client_started_value, nullptr);
  EXPECT_EQ(*client_started_value, 1);
  const auto& attributes = data[kMetricName][0].attributes.GetAttributes();
  EXPECT_EQ(attributes.size(), 2);
  const auto* method_value =
      absl::get_if<std::string>(&attributes.at("grpc.method"));
  ASSERT_NE(method_value, nullptr);
  EXPECT_EQ(*method_value, kMethodName);
  const auto* target_value =
      absl::get_if<std::string>(&attributes.at("grpc.target"));
  ASSERT_NE(target_value, nullptr);
  EXPECT_EQ(*target_value, canonical_server_address_);
}

TEST_F(OTelPluginEnd2EndTest, ClientAttemptDuration) {
  Init({grpc::internal::OTelClientAttemptDurationInstrumentName()});
  SendRPC();
  const char* kMetricName = "grpc.client.attempt.duration";
  auto data = ReadCurrentMetricsData(
      [&](const absl::flat_hash_map<
          std::string,
          std::vector<opentelemetry::sdk::metrics::PointDataAttributes>>&
              data) { return !data.contains(kMetricName); });
  ASSERT_EQ(data[kMetricName].size(), 1);
  auto point_data =
      absl::get_if<opentelemetry::sdk::metrics::HistogramPointData>(
          &data[kMetricName][0].point_data);
  ASSERT_NE(point_data, nullptr);
  ASSERT_EQ(point_data->count_, 1);
  const auto& attributes = data[kMetricName][0].attributes.GetAttributes();
  EXPECT_EQ(attributes.size(), 3);
  const auto* method_value =
      absl::get_if<std::string>(&attributes.at("grpc.method"));
  ASSERT_NE(method_value, nullptr);
  EXPECT_EQ(*method_value, kMethodName);
  const auto* target_value =
      absl::get_if<std::string>(&attributes.at("grpc.target"));
  ASSERT_NE(target_value, nullptr);
  EXPECT_EQ(*target_value, canonical_server_address_);
  const auto* status_value =
      absl::get_if<std::string>(&attributes.at("grpc.status"));
  ASSERT_NE(status_value, nullptr);
  EXPECT_EQ(*status_value, "OK");
}

TEST_F(OTelPluginEnd2EndTest, ClientAttemptSentTotalCompressedMessageSize) {
  Init({grpc::internal::
            OTelClientAttemptSentTotalCompressedMessageSizeInstrumentName()});
  SendRPC();
  const char* kMetricName =
      "grpc.client.attempt.sent_total_compressed_message_size";
  auto data = ReadCurrentMetricsData(
      [&](const absl::flat_hash_map<
          std::string,
          std::vector<opentelemetry::sdk::metrics::PointDataAttributes>>&
              data) { return !data.contains(kMetricName); });
  ASSERT_EQ(data[kMetricName].size(), 1);
  auto point_data =
      absl::get_if<opentelemetry::sdk::metrics::HistogramPointData>(
          &data[kMetricName][0].point_data);
  ASSERT_NE(point_data, nullptr);
  ASSERT_EQ(point_data->count_, 1);
  const auto& attributes = data[kMetricName][0].attributes.GetAttributes();
  EXPECT_EQ(attributes.size(), 3);
  const auto* method_value =
      absl::get_if<std::string>(&attributes.at("grpc.method"));
  ASSERT_NE(method_value, nullptr);
  EXPECT_EQ(*method_value, kMethodName);
  const auto* target_value =
      absl::get_if<std::string>(&attributes.at("grpc.target"));
  ASSERT_NE(target_value, nullptr);
  EXPECT_EQ(*target_value, canonical_server_address_);
  const auto* status_value =
      absl::get_if<std::string>(&attributes.at("grpc.status"));
  ASSERT_NE(status_value, nullptr);
  EXPECT_EQ(*status_value, "OK");
}

TEST_F(OTelPluginEnd2EndTest, ClientAttemptRcvdTotalCompressedMessageSize) {
  Init({grpc::internal::
            OTelClientAttemptRcvdTotalCompressedMessageSizeInstrumentName()});
  SendRPC();
  const char* kMetricName =
      "grpc.client.attempt.rcvd_total_compressed_message_size";
  auto data = ReadCurrentMetricsData(
      [&](const absl::flat_hash_map<
          std::string,
          std::vector<opentelemetry::sdk::metrics::PointDataAttributes>>&
              data) { return !data.contains(kMetricName); });
  ASSERT_EQ(data[kMetricName].size(), 1);
  auto point_data =
      absl::get_if<opentelemetry::sdk::metrics::HistogramPointData>(
          &data[kMetricName][0].point_data);
  ASSERT_NE(point_data, nullptr);
  ASSERT_EQ(point_data->count_, 1);
  const auto& attributes = data[kMetricName][0].attributes.GetAttributes();
  EXPECT_EQ(attributes.size(), 3);
  const auto* method_value =
      absl::get_if<std::string>(&attributes.at("grpc.method"));
  ASSERT_NE(method_value, nullptr);
  EXPECT_EQ(*method_value, kMethodName);
  const auto* target_value =
      absl::get_if<std::string>(&attributes.at("grpc.target"));
  ASSERT_NE(target_value, nullptr);
  EXPECT_EQ(*target_value, canonical_server_address_);
  const auto* status_value =
      absl::get_if<std::string>(&attributes.at("grpc.status"));
  ASSERT_NE(status_value, nullptr);
  EXPECT_EQ(*status_value, "OK");
}

TEST_F(OTelPluginEnd2EndTest, ServerCallStarted) {
  Init({grpc::internal::OTelServerCallStartedInstrumentName()});
  SendRPC();
  const char* kMetricName = "grpc.server.call.started";
  auto data = ReadCurrentMetricsData(
      [&](const absl::flat_hash_map<
          std::string,
          std::vector<opentelemetry::sdk::metrics::PointDataAttributes>>&
              data) { return !data.contains(kMetricName); });
  ASSERT_EQ(data[kMetricName].size(), 1);
  auto point_data = absl::get_if<opentelemetry::sdk::metrics::SumPointData>(
      &data[kMetricName][0].point_data);
  ASSERT_NE(point_data, nullptr);
  auto server_started_value = absl::get_if<int64_t>(&point_data->value_);
  ASSERT_NE(server_started_value, nullptr);
  ASSERT_EQ(*server_started_value, 1);
  const auto& attributes = data[kMetricName][0].attributes.GetAttributes();
  EXPECT_EQ(attributes.size(), 1);
  const auto* method_value =
      absl::get_if<std::string>(&attributes.at("grpc.method"));
  ASSERT_NE(method_value, nullptr);
  EXPECT_EQ(*method_value, kMethodName);
}

TEST_F(OTelPluginEnd2EndTest, ServerCallDuration) {
  Init({grpc::internal::OTelServerCallDurationInstrumentName()});
  SendRPC();
  const char* kMetricName = "grpc.server.call.duration";
  auto data = ReadCurrentMetricsData(
      [&](const absl::flat_hash_map<
          std::string,
          std::vector<opentelemetry::sdk::metrics::PointDataAttributes>>&
              data) { return !data.contains(kMetricName); });
  ASSERT_EQ(data[kMetricName].size(), 1);
  auto point_data =
      absl::get_if<opentelemetry::sdk::metrics::HistogramPointData>(
          &data[kMetricName][0].point_data);
  ASSERT_NE(point_data, nullptr);
  ASSERT_EQ(point_data->count_, 1);
  const auto& attributes = data[kMetricName][0].attributes.GetAttributes();
  EXPECT_EQ(attributes.size(), 2);
  const auto* method_value =
      absl::get_if<std::string>(&attributes.at("grpc.method"));
  ASSERT_NE(method_value, nullptr);
  EXPECT_EQ(*method_value, kMethodName);
  const auto* status_value =
      absl::get_if<std::string>(&attributes.at("grpc.status"));
  ASSERT_NE(status_value, nullptr);
  EXPECT_EQ(*status_value, "OK");
}

TEST_F(OTelPluginEnd2EndTest, ServerCallSentTotalCompressedMessageSize) {
  Init({grpc::internal::
            OTelServerCallSentTotalCompressedMessageSizeInstrumentName()});
  SendRPC();
  const char* kMetricName =
      "grpc.server.call.sent_total_compressed_message_size";
  auto data = ReadCurrentMetricsData(
      [&](const absl::flat_hash_map<
          std::string,
          std::vector<opentelemetry::sdk::metrics::PointDataAttributes>>&
              data) { return !data.contains(kMetricName); });
  ASSERT_EQ(data[kMetricName].size(), 1);
  auto point_data =
      absl::get_if<opentelemetry::sdk::metrics::HistogramPointData>(
          &data[kMetricName][0].point_data);
  ASSERT_NE(point_data, nullptr);
  EXPECT_EQ(point_data->count_, 1);
  const auto& attributes = data[kMetricName][0].attributes.GetAttributes();
  EXPECT_EQ(attributes.size(), 2);
  const auto* method_value =
      absl::get_if<std::string>(&attributes.at("grpc.method"));
  ASSERT_NE(method_value, nullptr);
  EXPECT_EQ(*method_value, kMethodName);
  const auto* status_value =
      absl::get_if<std::string>(&attributes.at("grpc.status"));
  ASSERT_NE(status_value, nullptr);
  EXPECT_EQ(*status_value, "OK");
}

TEST_F(OTelPluginEnd2EndTest, ServerCallRcvdTotalCompressedMessageSize) {
  Init({grpc::internal::
            OTelServerCallRcvdTotalCompressedMessageSizeInstrumentName()});
  SendRPC();
  const char* kMetricName =
      "grpc.server.call.rcvd_total_compressed_message_size";
  auto data = ReadCurrentMetricsData(
      [&](const absl::flat_hash_map<
          std::string,
          std::vector<opentelemetry::sdk::metrics::PointDataAttributes>>&
              data) { return !data.contains(kMetricName); });
  ASSERT_EQ(data[kMetricName].size(), 1);
  auto point_data =
      absl::get_if<opentelemetry::sdk::metrics::HistogramPointData>(
          &data[kMetricName][0].point_data);
  ASSERT_NE(point_data, nullptr);
  ASSERT_EQ(point_data->count_, 1);
  const auto& attributes = data[kMetricName][0].attributes.GetAttributes();
  EXPECT_EQ(attributes.size(), 2);
  const auto* method_value =
      absl::get_if<std::string>(&attributes.at("grpc.method"));
  ASSERT_NE(method_value, nullptr);
  EXPECT_EQ(*method_value, kMethodName);
  const auto* status_value =
      absl::get_if<std::string>(&attributes.at("grpc.status"));
  ASSERT_NE(status_value, nullptr);
  EXPECT_EQ(*status_value, "OK");
}

// Make sure that no meter provider results in normal operations.
TEST_F(OTelPluginEnd2EndTest, NoMeterProviderRegistered) {
  Init({grpc::internal::OTelClientAttemptStartedInstrumentName()},
       /*resource=*/opentelemetry::sdk::resource::Resource::Create({}),
       /*labels_injector=*/nullptr,
       /*test_no_meter_provider=*/true);
  SendRPC();
}

// Test that a channel selector returning true records metrics on the channel.
TEST_F(OTelPluginEnd2EndTest, TargetSelectorReturnsTrue) {
  Init({grpc::internal::OTelClientAttemptStartedInstrumentName()}, /*resource=*/
       opentelemetry::sdk::resource::Resource::Create({}),
       /*labels_injector=*/nullptr,
       /*test_no_meter_provider=*/false,
       /*target_selector=*/
       [](absl::string_view /*target*/) { return true; });
  SendRPC();
  const char* kMetricName = "grpc.client.attempt.started";
  auto data = ReadCurrentMetricsData(
      [&](const absl::flat_hash_map<
          std::string,
          std::vector<opentelemetry::sdk::metrics::PointDataAttributes>>&
              data) { return !data.contains(kMetricName); });
  ASSERT_EQ(data[kMetricName].size(), 1);
  auto point_data = absl::get_if<opentelemetry::sdk::metrics::SumPointData>(
      &data[kMetricName][0].point_data);
  ASSERT_NE(point_data, nullptr);
  auto client_started_value = absl::get_if<int64_t>(&point_data->value_);
  ASSERT_NE(client_started_value, nullptr);
  EXPECT_EQ(*client_started_value, 1);
  const auto& attributes = data[kMetricName][0].attributes.GetAttributes();
  EXPECT_EQ(attributes.size(), 2);
  const auto* method_value =
      absl::get_if<std::string>(&attributes.at("grpc.method"));
  ASSERT_NE(method_value, nullptr);
  EXPECT_EQ(*method_value, kMethodName);
  const auto* target_value =
      absl::get_if<std::string>(&attributes.at("grpc.target"));
  ASSERT_NE(target_value, nullptr);
  EXPECT_EQ(*target_value, canonical_server_address_);
}

// Test that a target selector returning false does not record metrics on the
// channel.
TEST_F(OTelPluginEnd2EndTest, TargetSelectorReturnsFalse) {
  Init({grpc::internal::OTelClientAttemptStartedInstrumentName()}, /*resource=*/
       opentelemetry::sdk::resource::Resource::Create({}),
       /*labels_injector=*/nullptr,
       /*test_no_meter_provider=*/false,
       /*target_selector=*/
       [](absl::string_view /*target*/) { return false; });
  SendRPC();
  auto data = ReadCurrentMetricsData(
      [&](const absl::flat_hash_map<
          std::string,
          std::vector<opentelemetry::sdk::metrics::PointDataAttributes>>&
          /*data*/) { return false; });
  ASSERT_TRUE(data.empty());
}

// Test that a target attribute filter returning true records metrics with the
// target as is on the channel.
TEST_F(OTelPluginEnd2EndTest, TargetAttributeFilterReturnsTrue) {
  Init({grpc::internal::OTelClientAttemptStartedInstrumentName()}, /*resource=*/
       opentelemetry::sdk::resource::Resource::Create({}),
       /*labels_injector=*/nullptr,
       /*test_no_meter_provider=*/false,
       /*target_selector=*/absl::AnyInvocable<bool(absl::string_view) const>(),
       /*target_attribute_filter=*/[](absl::string_view /*target*/) {
         return true;
       });
  SendRPC();
  const char* kMetricName = "grpc.client.attempt.started";
  auto data = ReadCurrentMetricsData(
      [&](const absl::flat_hash_map<
          std::string,
          std::vector<opentelemetry::sdk::metrics::PointDataAttributes>>&
              data) { return !data.contains(kMetricName); });
  ASSERT_EQ(data[kMetricName].size(), 1);
  auto point_data = absl::get_if<opentelemetry::sdk::metrics::SumPointData>(
      &data[kMetricName][0].point_data);
  ASSERT_NE(point_data, nullptr);
  auto client_started_value = absl::get_if<int64_t>(&point_data->value_);
  ASSERT_NE(client_started_value, nullptr);
  EXPECT_EQ(*client_started_value, 1);
  const auto& attributes = data[kMetricName][0].attributes.GetAttributes();
  EXPECT_EQ(attributes.size(), 2);
  const auto* method_value =
      absl::get_if<std::string>(&attributes.at("grpc.method"));
  ASSERT_NE(method_value, nullptr);
  EXPECT_EQ(*method_value, kMethodName);
  const auto* target_value =
      absl::get_if<std::string>(&attributes.at("grpc.target"));
  ASSERT_NE(target_value, nullptr);
  EXPECT_EQ(*target_value, canonical_server_address_);
}

// Test that a target attribute filter returning false records metrics with the
// target as "other".
TEST_F(OTelPluginEnd2EndTest, TargetAttributeFilterReturnsFalse) {
  Init({grpc::internal::OTelClientAttemptStartedInstrumentName()}, /*resource=*/
       opentelemetry::sdk::resource::Resource::Create({}),
       /*labels_injector=*/nullptr,
       /*test_no_meter_provider=*/false,
       /*target_selector=*/absl::AnyInvocable<bool(absl::string_view) const>(),
       /*target_attribute_filter=*/
       [server_address = canonical_server_address_](
           absl::string_view /*target*/) { return false; });
  SendRPC();
  const char* kMetricName = "grpc.client.attempt.started";
  auto data = ReadCurrentMetricsData(
      [&](const absl::flat_hash_map<
          std::string,
          std::vector<opentelemetry::sdk::metrics::PointDataAttributes>>&
          /*data*/) { return false; });
  ASSERT_EQ(data[kMetricName].size(), 1);
  auto point_data = absl::get_if<opentelemetry::sdk::metrics::SumPointData>(
      &data[kMetricName][0].point_data);
  ASSERT_NE(point_data, nullptr);
  auto client_started_value = absl::get_if<int64_t>(&point_data->value_);
  ASSERT_NE(client_started_value, nullptr);
  EXPECT_EQ(*client_started_value, 1);
  const auto& attributes = data[kMetricName][0].attributes.GetAttributes();
  EXPECT_EQ(attributes.size(), 2);
  const auto* method_value =
      absl::get_if<std::string>(&attributes.at("grpc.method"));
  ASSERT_NE(method_value, nullptr);
  EXPECT_EQ(*method_value, kMethodName);
  const auto* target_value =
      absl::get_if<std::string>(&attributes.at("grpc.target"));
  ASSERT_NE(target_value, nullptr);
  EXPECT_EQ(*target_value, "other");
}

}  // namespace
}  // namespace testing
}  // namespace grpc

int main(int argc, char** argv) {
  grpc::testing::TestEnvironment env(&argc, argv);
  ::testing::InitGoogleTest(&argc, argv);
  return RUN_ALL_TESTS();
}