/*
 * 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.
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package org.apache.pulsar.broker.loadbalance.extensions;

import static org.mockito.Mockito.reset;
import static org.mockito.Mockito.spy;
import com.google.common.collect.Sets;
import java.util.concurrent.CompletableFuture;
import org.apache.commons.lang3.reflect.FieldUtils;
import org.apache.commons.lang3.tuple.Pair;
import org.apache.pulsar.broker.PulsarService;
import org.apache.pulsar.broker.ServiceConfiguration;
import org.apache.pulsar.broker.auth.MockedPulsarServiceBaseTest;
import org.apache.pulsar.broker.loadbalance.extensions.channel.ServiceUnitStateChannelImpl;
import org.apache.pulsar.broker.loadbalance.extensions.scheduler.TransferShedder;
import org.apache.pulsar.broker.testcontext.PulsarTestContext;
import org.apache.pulsar.client.admin.PulsarAdminException;
import org.apache.pulsar.client.impl.LookupService;
import org.apache.pulsar.common.naming.NamespaceBundle;
import org.apache.pulsar.common.naming.SystemTopicNames;
import org.apache.pulsar.common.naming.TopicName;
import org.apache.pulsar.common.policies.data.ClusterData;
import org.apache.pulsar.common.policies.data.TenantInfoImpl;
import org.apache.pulsar.common.policies.data.TopicType;
import org.testng.annotations.AfterClass;
import org.testng.annotations.BeforeClass;
import org.testng.annotations.BeforeMethod;

public abstract class ExtensibleLoadManagerImplBaseTest extends MockedPulsarServiceBaseTest {

    protected PulsarService pulsar1;
    protected PulsarService pulsar2;

    protected PulsarTestContext additionalPulsarTestContext;

    protected ExtensibleLoadManagerImpl primaryLoadManager;

    protected ExtensibleLoadManagerImpl secondaryLoadManager;

    protected ServiceUnitStateChannelImpl channel1;
    protected ServiceUnitStateChannelImpl channel2;

    protected final String defaultTestNamespace;

    protected LookupService lookupService;

    protected ExtensibleLoadManagerImplBaseTest(String defaultTestNamespace) {
        this.defaultTestNamespace = defaultTestNamespace;
    }

    protected ServiceConfiguration initConfig(ServiceConfiguration conf) {
        conf.setForceDeleteNamespaceAllowed(true);
        conf.setAllowAutoTopicCreationType(TopicType.NON_PARTITIONED);
        conf.setAllowAutoTopicCreation(true);
        conf.setLoadManagerClassName(ExtensibleLoadManagerImpl.class.getName());
        conf.setLoadBalancerLoadSheddingStrategy(TransferShedder.class.getName());
        conf.setLoadBalancerSheddingEnabled(false);
        conf.setLoadBalancerDebugModeEnabled(true);
        conf.setTopicLevelPoliciesEnabled(true);
        return conf;
    }

    @Override
    @BeforeClass(alwaysRun = true)
    protected void setup() throws Exception {
        initConfig(conf);
        super.internalSetup(conf);
        pulsar1 = pulsar;
        var conf2 = initConfig(getDefaultConf());
        additionalPulsarTestContext = createAdditionalPulsarTestContext(conf2);
        pulsar2 = additionalPulsarTestContext.getPulsarService();

        setPrimaryLoadManager();
        setSecondaryLoadManager();

        admin.clusters().createCluster(this.conf.getClusterName(),
                ClusterData.builder().serviceUrl(pulsar.getWebServiceAddress()).build());
        admin.tenants().createTenant("public",
                new TenantInfoImpl(Sets.newHashSet("appid1", "appid2"),
                        Sets.newHashSet(this.conf.getClusterName())));
        admin.namespaces().createNamespace("public/default");
        admin.namespaces().setNamespaceReplicationClusters("public/default",
                Sets.newHashSet(this.conf.getClusterName()));

        admin.namespaces().createNamespace(defaultTestNamespace, 128);
        admin.namespaces().setNamespaceReplicationClusters(defaultTestNamespace,
                Sets.newHashSet(this.conf.getClusterName()));
        lookupService = (LookupService) FieldUtils.readDeclaredField(pulsarClient, "lookup", true);
    }

    @Override
    @AfterClass(alwaysRun = true)
    protected void cleanup() throws Exception {
        this.additionalPulsarTestContext.close();
        super.internalCleanup();
    }

    @BeforeMethod(alwaysRun = true)
    protected void initializeState() throws PulsarAdminException, IllegalAccessException {
        admin.namespaces().unload(defaultTestNamespace);
        reset(primaryLoadManager, secondaryLoadManager);
        FieldUtils.writeDeclaredField(pulsarClient, "lookup", lookupService, true);
    }

    protected void setPrimaryLoadManager() throws IllegalAccessException {
        ExtensibleLoadManagerWrapper wrapper =
                (ExtensibleLoadManagerWrapper) pulsar1.getLoadManager().get();
        primaryLoadManager = spy((ExtensibleLoadManagerImpl)
                FieldUtils.readField(wrapper, "loadManager", true));
        FieldUtils.writeField(wrapper, "loadManager", primaryLoadManager, true);
        channel1 = (ServiceUnitStateChannelImpl)
                FieldUtils.readField(primaryLoadManager, "serviceUnitStateChannel", true);
    }

    private void setSecondaryLoadManager() throws IllegalAccessException {
        ExtensibleLoadManagerWrapper wrapper =
                (ExtensibleLoadManagerWrapper) pulsar2.getLoadManager().get();
        secondaryLoadManager = spy((ExtensibleLoadManagerImpl)
                FieldUtils.readField(wrapper, "loadManager", true));
        FieldUtils.writeField(wrapper, "loadManager", secondaryLoadManager, true);
        channel2 = (ServiceUnitStateChannelImpl)
                FieldUtils.readField(secondaryLoadManager, "serviceUnitStateChannel", true);
    }

    protected CompletableFuture<NamespaceBundle> getBundleAsync(PulsarService pulsar, TopicName topic) {
        return pulsar.getNamespaceService().getBundleAsync(topic);
    }

    protected Pair<TopicName, NamespaceBundle> getBundleIsNotOwnByChangeEventTopic(String topicNamePrefix)
            throws Exception {
        TopicName changeEventsTopicName =
                TopicName.get(defaultTestNamespace + "/" + SystemTopicNames.NAMESPACE_EVENTS_LOCAL_NAME);
        NamespaceBundle changeEventsBundle = getBundleAsync(pulsar1, changeEventsTopicName).get();
        int i = 0;
        while(true) {
            TopicName topicName = TopicName.get(defaultTestNamespace + "/" + topicNamePrefix + "-" + i);
            NamespaceBundle bundle = getBundleAsync(pulsar1, topicName).get();
            if (!bundle.equals(changeEventsBundle)) {
                return Pair.of(topicName, bundle);
            }
            i++;
        }
    }
}