/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.kafka.clients.admin;

import org.apache.kafka.clients.MockClient;
import org.apache.kafka.clients.admin.internals.AdminMetadataManager;
import org.apache.kafka.common.Cluster;
import org.apache.kafka.common.Node;
import org.apache.kafka.common.utils.LogContext;
import org.apache.kafka.common.utils.Time;

import java.time.Duration;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * Simple utility for setting up a mock {@link KafkaAdminClient} that uses a {@link MockClient} for a supplied
 * {@link Cluster}. Create a {@link Cluster} manually or use {@link org.apache.kafka.test.TestUtils} methods to
 * easily create a simple cluster.
 * <p>
 * To use in a test, create an instance and prepare its {@link #kafkaClient() MockClient} with the expected responses
 * for the {@link Admin}. Then, use the {@link #adminClient() AdminClient} in the test, which will then use the MockClient
 * and receive the responses you provided.
 *
 * Since {@link #kafkaClient() MockClient} is not thread-safe,
 * users should be wary of calling its methods after the {@link #adminClient() AdminClient} is instantiated.
 *
 * <p>
 * When finished, be sure to {@link #close() close} the environment object.
 */
public class AdminClientUnitTestEnv implements AutoCloseable {
    private final Time time;
    private final Cluster cluster;
    private final MockClient mockClient;
    private final KafkaAdminClient adminClient;

    public AdminClientUnitTestEnv(Cluster cluster, String... vals) {
        this(Time.SYSTEM, cluster, vals);
    }

    public AdminClientUnitTestEnv(Time time, Cluster cluster, String... vals) {
        this(time, cluster, clientConfigs(vals));
    }

    public AdminClientUnitTestEnv(Time time, Cluster cluster) {
        this(time, cluster, clientConfigs());
    }

    public AdminClientUnitTestEnv(Time time, Cluster cluster, Map<String, Object> config) {
        this(time, cluster, config, Collections.emptyMap());
    }

    public AdminClientUnitTestEnv(Time time, Cluster cluster, Map<String, Object> config, Map<Node, Long> unreachableNodes) {
        this.time = time;
        this.cluster = cluster;
        AdminClientConfig adminClientConfig = new AdminClientConfig(config);

        AdminMetadataManager metadataManager = new AdminMetadataManager(new LogContext(),
                adminClientConfig.getLong(AdminClientConfig.RETRY_BACKOFF_MS_CONFIG),
                adminClientConfig.getLong(AdminClientConfig.METADATA_MAX_AGE_CONFIG));
        this.mockClient = new MockClient(time, new MockClient.MockMetadataUpdater() {
            @Override
            public List<Node> fetchNodes() {
                return cluster.nodes();
            }

            @Override
            public boolean isUpdateNeeded() {
                return false;
            }

            @Override
            public void update(Time time, MockClient.MetadataUpdate update) {
                throw new UnsupportedOperationException();
            }
        });

        metadataManager.update(cluster, time.milliseconds());
        unreachableNodes.forEach(mockClient::setUnreachable);
        this.adminClient = KafkaAdminClient.createInternal(adminClientConfig, metadataManager, mockClient, time);
    }

    public Time time() {
        return time;
    }

    public Cluster cluster() {
        return cluster;
    }

    public Admin adminClient() {
        return adminClient;
    }

    public MockClient kafkaClient() {
        return mockClient;
    }

    @Override
    public void close() {
        // tell the admin client to close now
        this.adminClient.close(Duration.ZERO);
        // block for up to a minute until the internal threads shut down.
        this.adminClient.close(Duration.ofMinutes(1));
    }

    static Map<String, Object> clientConfigs(String... overrides) {
        Map<String, Object> map = new HashMap<>();
        map.put(AdminClientConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:8121");
        map.put(AdminClientConfig.REQUEST_TIMEOUT_MS_CONFIG, "1000");
        if (overrides.length % 2 != 0) {
            throw new IllegalStateException();
        }
        for (int i = 0; i < overrides.length; i += 2) {
            map.put(overrides[i], overrides[i + 1]);
        }
        return map;
    }

    public static String kafkaAdminClientNetworkThreadPrefix() {
        return KafkaAdminClient.NETWORK_THREAD_PREFIX;
    }
}
