/*
 * 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.skywalking.oap.server.configuration.apollo;

import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import lombok.extern.slf4j.Slf4j;
import org.apache.skywalking.oap.server.configuration.api.ConfigChangeWatcher;
import org.apache.skywalking.oap.server.configuration.api.ConfigurationModule;
import org.apache.skywalking.oap.server.configuration.api.DynamicConfigurationService;
import org.apache.skywalking.oap.server.configuration.api.GroupConfigChangeWatcher;
import org.apache.skywalking.oap.server.library.module.ModuleDefine;
import org.apache.skywalking.oap.server.library.module.ModuleProvider;
import org.apache.skywalking.oap.server.library.module.ModuleStartException;
import org.apache.skywalking.oap.server.library.module.ServiceNotProvidedException;

@Slf4j
public class ApolloConfigurationTestProvider extends ModuleProvider {
    ConfigChangeWatcher watcher;
    GroupConfigChangeWatcher groupWatcher;

    @Override
    public String name() {
        return "default";
    }

    @Override
    public Class<? extends ModuleDefine> module() {
        return ApolloConfigurationTestModule.class;
    }

    @Override
    public ConfigCreator newConfigCreator() {
        return null;
    }

    @Override
    public void prepare() throws ServiceNotProvidedException, ModuleStartException {
        watcher = new ConfigChangeWatcher(ApolloConfigurationTestModule.NAME, this, "testKey") {
            private volatile String testValue;

            @Override
            public void notify(ConfigChangeWatcher.ConfigChangeEvent value) {
                log.info("ConfigChangeWatcher.ConfigChangeEvent: {}", value);
                if (EventType.DELETE.equals(value.getEventType())) {
                    testValue = null;
                } else {
                    testValue = value.getNewValue();
                }
            }

            @Override
            public String value() {
                return testValue;
            }
        };

        groupWatcher = new GroupConfigChangeWatcher(ApolloConfigurationTestModule.NAME, this, "testKeyGroup") {
            private Map<String, String> config = new ConcurrentHashMap<>();

            @Override
            public void notifyGroup(Map<String, ConfigChangeEvent> groupItems) {
                log.info("GroupConfigChangeWatcher.ConfigChangeEvents: {}", groupItems);
                groupItems.forEach((groupItemName, event) -> {
                    if (EventType.DELETE.equals(event.getEventType())) {
                        config.remove(groupItemName);
                    } else {
                        config.put(groupItemName, event.getNewValue());
                    }
                });
            }

            @Override
            public Map<String, String> groupItems() {
                return config;
            }
        };
    }

    @Override
    public void start() throws ServiceNotProvidedException {
        getManager().find(ConfigurationModule.NAME)
                    .provider()
                    .getService(DynamicConfigurationService.class)
                    .registerConfigChangeWatcher(watcher);

        getManager().find(ConfigurationModule.NAME)
                    .provider()
                    .getService(DynamicConfigurationService.class)
                    .registerConfigChangeWatcher(groupWatcher);
    }

    @Override
    public void notifyAfterCompleted() throws ServiceNotProvidedException {

    }

    @Override
    public String[] requiredModules() {
        return new String[] {
            ConfigurationModule.NAME
        };
    }
}
