/*
    * 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.infra.connection.refresher.type.table;
  
  import org.apache.shardingsphere.infra.config.props.ConfigurationProperties;
  import org.apache.shardingsphere.infra.connection.refresher.MetaDataRefresher;
  import org.apache.shardingsphere.infra.connection.refresher.util.TableRefreshUtils;
  import org.apache.shardingsphere.infra.database.core.type.DatabaseType;
  import org.apache.shardingsphere.infra.instance.mode.ModeContextManager;
  import org.apache.shardingsphere.infra.metadata.database.ShardingSphereDatabase;
  import org.apache.shardingsphere.infra.metadata.database.rule.RuleMetaData;
  import org.apache.shardingsphere.infra.metadata.database.schema.builder.GenericSchemaBuilder;
  import org.apache.shardingsphere.infra.metadata.database.schema.builder.GenericSchemaBuilderMaterial;
  import org.apache.shardingsphere.infra.metadata.database.schema.model.ShardingSphereSchema;
  import org.apache.shardingsphere.infra.metadata.database.schema.model.ShardingSphereTable;
  import org.apache.shardingsphere.infra.metadata.database.schema.pojo.AlterSchemaMetaDataPOJO;
  import org.apache.shardingsphere.infra.rule.attribute.datanode.MutableDataNodeRuleAttribute;
  import org.apache.shardingsphere.sql.parser.sql.common.statement.ddl.AlterTableStatement;
  
  import java.sql.SQLException;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.LinkedList;
  import java.util.Map;
  import java.util.Optional;
  
  /**
   * Schema refresher for alter table statement.
   */
  public final class AlterTableStatementSchemaRefresher implements MetaDataRefresher<AlterTableStatement> {
      
      @Override
      public void refresh(final ModeContextManager modeContextManager, final ShardingSphereDatabase database, final Collection<String> logicDataSourceNames,
                          final String schemaName, final DatabaseType databaseType, final AlterTableStatement sqlStatement, final ConfigurationProperties props) throws SQLException {
          String tableName = TableRefreshUtils.getTableName(databaseType, sqlStatement.getTable().getTableName().getIdentifier());
          AlterSchemaMetaDataPOJO alterSchemaMetaDataPOJO = new AlterSchemaMetaDataPOJO(database.getName(), schemaName, logicDataSourceNames);
          if (sqlStatement.getRenameTable().isPresent()) {
              String renameTable = sqlStatement.getRenameTable().get().getTableName().getIdentifier().getValue();
              alterSchemaMetaDataPOJO.getAlteredTables().add(getTable(database, logicDataSourceNames, schemaName, renameTable, props));
              alterSchemaMetaDataPOJO.getDroppedTables().add(tableName);
          } else {
              alterSchemaMetaDataPOJO.getAlteredTables().add(getTable(database, logicDataSourceNames, schemaName, tableName, props));
          }
          modeContextManager.alterSchemaMetaData(alterSchemaMetaDataPOJO);
      }
      
      private ShardingSphereTable getTable(final ShardingSphereDatabase database, final Collection<String> logicDataSourceNames, final String schemaName,
                                           final String tableName, final ConfigurationProperties props) throws SQLException {
          RuleMetaData ruleMetaData = new RuleMetaData(new LinkedList<>(database.getRuleMetaData().getRules()));
          if (TableRefreshUtils.isSingleTable(tableName, database)) {
              ruleMetaData.getAttributes(MutableDataNodeRuleAttribute.class).forEach(each -> each.put(logicDataSourceNames.iterator().next(), schemaName, tableName));
          }
          GenericSchemaBuilderMaterial material = new GenericSchemaBuilderMaterial(
                  database.getProtocolType(), database.getResourceMetaData().getStorageUnits(), ruleMetaData.getRules(), props, schemaName);
          Map<String, ShardingSphereSchema> schemaMap = GenericSchemaBuilder.build(Collections.singletonList(tableName), material);
          return Optional.ofNullable(schemaMap.get(schemaName)).map(optional -> optional.getTable(tableName))
                  .orElseGet(() -> new ShardingSphereTable(tableName, Collections.emptyList(), Collections.emptyList(), Collections.emptyList()));
      }
      
      @Override
      public Class<AlterTableStatement> getType() {
          return AlterTableStatement.class;
      }
  }