// Copyright (C) 2018 The Android Open Source Project
//
// 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.

package com.googlesource.gerrit.plugins.kafka;

import static com.google.common.truth.Truth.assertThat;

import com.google.common.base.Supplier;
import com.google.gerrit.acceptance.GerritConfig;
import com.google.gerrit.acceptance.LightweightPluginDaemonTest;
import com.google.gerrit.acceptance.NoHttpd;
import com.google.gerrit.acceptance.PushOneCommit;
import com.google.gerrit.acceptance.TestPlugin;
import com.google.gerrit.acceptance.UseLocalDisk;
import com.google.gerrit.extensions.api.changes.ReviewInput;
import com.google.gerrit.extensions.common.ChangeMessageInfo;
import com.google.gerrit.server.events.CommentAddedEvent;
import com.google.gerrit.server.events.Event;
import com.google.gerrit.server.events.EventDeserializer;
import com.google.gerrit.server.events.SupplierDeserializer;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.googlesource.gerrit.plugins.kafka.config.KafkaProperties;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import org.apache.kafka.clients.consumer.Consumer;
import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.apache.kafka.clients.consumer.ConsumerRecords;
import org.apache.kafka.clients.consumer.KafkaConsumer;
import org.junit.Test;

/*
 * This tests assumes that Kafka server is running on: localhost:9092.
 * Alternatively, testcontainers library can be used to set up dockerized
 * Kafka instance from withing JUnit test.
 */
@NoHttpd
@TestPlugin(name = "kafka-events", sysModule = "com.googlesource.gerrit.plugins.kafka.Module")
public class EventConsumerIT extends LightweightPluginDaemonTest {
  static final long KAFKA_POLL_TIMEOUT = 10000L;

  @Test
  @UseLocalDisk
  @GerritConfig(name = "plugin.kafka-events.bootstrapServers", value = "localhost:9092")
  @GerritConfig(name = "plugin.kafka-events.groupId", value = "test-consumer-group")
  @GerritConfig(
      name = "plugin.kafka-events.keyDeserializer",
      value = "org.apache.kafka.common.serialization.StringDeserializer")
  @GerritConfig(
      name = "plugin.kafka-events.valueDeserializer",
      value = "org.apache.kafka.common.serialization.StringDeserializer")
  public void consumeEvents() throws Exception {
    PushOneCommit.Result r = createChange();

    ReviewInput in = ReviewInput.recommend();
    in.message = "LGTM";
    gApi.changes().id(r.getChangeId()).revision("current").review(in);
    List<ChangeMessageInfo> messages =
        new ArrayList<>(gApi.changes().id(r.getChangeId()).get().messages);
    assertThat(messages).hasSize(2);
    String expectedMessage = "Patch Set 1: Code-Review+1\n\nLGTM";
    assertThat(messages.get(1).message).isEqualTo(expectedMessage);

    KafkaProperties kafkaProperties = kafkaProperties();
    List<String> events = new ArrayList<>();
    try (Consumer<String, String> consumer = new KafkaConsumer<>(kafkaProperties)) {
      consumer.subscribe(Collections.singleton(kafkaProperties.getTopic()));
      ConsumerRecords<String, String> records = consumer.poll(KAFKA_POLL_TIMEOUT);
      for (ConsumerRecord<String, String> record : records) {
        events.add(record.value());
      }
    }

    // The received 6 events in order:
    //
    // 1. refUpdate:        ref: refs/sequences/changes
    // 2. refUpdate:        ref: refs/changes/01/1/1
    // 3. refUpdate:        ref: refs/changes/01/1/meta
    // 4. patchset-created: ref: refs/changes/01/1/1
    // 5. refUpdate:        ref: refs/changes/01/1/meta"
    // 6. comment-added:    ref: refs/heads/master
    assertThat(events).hasSize(6);
    String commentAddedEventJson = events.get(5);

    Gson gson =
        new GsonBuilder()
            .registerTypeAdapter(Event.class, new EventDeserializer())
            .registerTypeAdapter(Supplier.class, new SupplierDeserializer())
            .create();
    Event event = gson.fromJson(commentAddedEventJson, Event.class);
    assertThat(event).isInstanceOf(CommentAddedEvent.class);

    CommentAddedEvent commentAddedEvent = (CommentAddedEvent) event;
    assertThat(commentAddedEvent.comment).isEqualTo(expectedMessage);
  }

  private KafkaProperties kafkaProperties() {
    return plugin.getSysInjector().getInstance(KafkaProperties.class);
  }
}