/*
    * 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.shardingsphere.globalclock.rule;
  
  import lombok.Getter;
  import org.apache.shardingsphere.globalclock.api.config.GlobalClockRuleConfiguration;
  import org.apache.shardingsphere.globalclock.provider.GlobalClockProvider;
  import org.apache.shardingsphere.infra.database.DatabaseTypeEngine;
  import org.apache.shardingsphere.infra.database.core.type.DatabaseType;
  import org.apache.shardingsphere.infra.metadata.database.ShardingSphereDatabase;
  import org.apache.shardingsphere.infra.metadata.database.resource.unit.StorageUnit;
  import org.apache.shardingsphere.infra.rule.scope.GlobalRule;
  import org.apache.shardingsphere.infra.rule.attribute.RuleAttributes;
  import org.apache.shardingsphere.infra.spi.type.typed.TypedSPILoader;
  import org.apache.shardingsphere.transaction.spi.TransactionHook;
  
  import java.util.Collection;
  import java.util.Map;
  import java.util.Optional;
  import java.util.Properties;
  
  /**
   * Global clock rule.
   */
  public final class GlobalClockRule implements GlobalRule {
      
      @Getter
      private final GlobalClockRuleConfiguration configuration;
      
      public GlobalClockRule(final GlobalClockRuleConfiguration ruleConfig, final Map<String, ShardingSphereDatabase> databases) {
          configuration = ruleConfig;
          if (ruleConfig.isEnabled()) {
              TypedSPILoader.getService(GlobalClockProvider.class, getGlobalClockProviderType(), configuration.getProps());
              TypedSPILoader.getService(TransactionHook.class, "GLOBAL_CLOCK", createProperties(databases));
          }
      }
      
      private Properties createProperties(final Map<String, ShardingSphereDatabase> databases) {
          Properties result = new Properties();
          DatabaseType storageType = findStorageType(databases.values()).orElseGet(DatabaseTypeEngine::getDefaultStorageType);
          result.setProperty("trunkType", storageType.getTrunkDatabaseType().orElse(storageType).getType());
          result.setProperty("enabled", String.valueOf(configuration.isEnabled()));
          result.setProperty("type", configuration.getType());
          result.setProperty("provider", configuration.getProvider());
          return result;
      }
      
      private Optional<DatabaseType> findStorageType(final Collection<ShardingSphereDatabase> databases) {
          return databases.stream()
                  .flatMap(each -> each.getResourceMetaData().getStorageUnits().values().stream()).findFirst().map(StorageUnit::getStorageType);
      }
      
      /**
       * Get global clock provider type.
       * 
       * @return global clock provider type
       */
      public String getGlobalClockProviderType() {
          return String.join(".", configuration.getType(), configuration.getProvider());
      }
      
      @Override
      public RuleAttributes getAttributes() {
          return new RuleAttributes();
      }
  }