/*
    * 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.sharding.distsql.handler.update;
  
  import lombok.Setter;
  import org.apache.shardingsphere.distsql.handler.required.DistSQLExecutorCurrentRuleRequired;
  import org.apache.shardingsphere.distsql.handler.engine.update.rdl.rule.spi.database.DatabaseRuleAlterExecutor;
  import org.apache.shardingsphere.infra.metadata.database.ShardingSphereDatabase;
  import org.apache.shardingsphere.sharding.api.config.ShardingRuleConfiguration;
  import org.apache.shardingsphere.sharding.api.config.rule.ShardingAutoTableRuleConfiguration;
  import org.apache.shardingsphere.sharding.api.config.rule.ShardingTableRuleConfiguration;
  import org.apache.shardingsphere.sharding.distsql.handler.checker.ShardingTableRuleStatementChecker;
  import org.apache.shardingsphere.sharding.distsql.handler.converter.ShardingTableRuleStatementConverter;
  import org.apache.shardingsphere.sharding.distsql.statement.AlterShardingTableRuleStatement;
  import org.apache.shardingsphere.sharding.rule.ShardingRule;
  
  import java.util.Collection;
  import java.util.stream.Collectors;
  
  /**
   * Alter sharding table rule executor.
   */
  @DistSQLExecutorCurrentRuleRequired(ShardingRule.class)
  @Setter
  public final class AlterShardingTableRuleExecutor implements DatabaseRuleAlterExecutor<AlterShardingTableRuleStatement, ShardingRule, ShardingRuleConfiguration> {
      
      private ShardingSphereDatabase database;
      
      private ShardingRule rule;
      
      @Override
      public void checkBeforeUpdate(final AlterShardingTableRuleStatement sqlStatement) {
          ShardingTableRuleStatementChecker.checkAlteration(database, sqlStatement.getRules(), rule.getConfiguration());
      }
      
      @Override
      public ShardingRuleConfiguration buildToBeAlteredRuleConfiguration(final AlterShardingTableRuleStatement sqlStatement) {
          return ShardingTableRuleStatementConverter.convert(sqlStatement.getRules());
      }
      
      @Override
      public ShardingRuleConfiguration buildToBeDroppedRuleConfiguration(final ShardingRuleConfiguration toBeAlteredRuleConfig) {
          ShardingRuleConfiguration result = new ShardingRuleConfiguration();
          Collection<String> toBeAlteredShardingTableNames = toBeAlteredRuleConfig.getTables().stream().map(ShardingTableRuleConfiguration::getLogicTable).collect(Collectors.toSet());
          for (ShardingAutoTableRuleConfiguration each : rule.getConfiguration().getAutoTables()) {
              if (toBeAlteredShardingTableNames.contains(each.getLogicTable())) {
                  result.getAutoTables().add(each);
              }
          }
          Collection<String> toBeAlteredAutoTableNames = toBeAlteredRuleConfig.getAutoTables().stream().map(ShardingAutoTableRuleConfiguration::getLogicTable).collect(Collectors.toSet());
          for (ShardingTableRuleConfiguration each : rule.getConfiguration().getTables()) {
              if (toBeAlteredAutoTableNames.contains(each.getLogicTable())) {
                  result.getTables().add(each);
              }
          }
          UnusedAlgorithmFinder.findUnusedShardingAlgorithm(rule.getConfiguration()).forEach(each -> result.getShardingAlgorithms().put(each, rule.getConfiguration().getShardingAlgorithms().get(each)));
          UnusedAlgorithmFinder.findUnusedKeyGenerator(rule.getConfiguration()).forEach(each -> result.getKeyGenerators().put(each, rule.getConfiguration().getKeyGenerators().get(each)));
          UnusedAlgorithmFinder.findUnusedAuditor(rule.getConfiguration()).forEach(each -> result.getAuditors().put(each, rule.getConfiguration().getAuditors().get(each)));
          return result;
      }
      
      @Override
      public Class<ShardingRule> getRuleClass() {
          return ShardingRule.class;
      }
      
      @Override
      public Class<AlterShardingTableRuleStatement> getType() {
          return AlterShardingTableRuleStatement.class;
      }
  }