/*
    * 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.route.engine.validator.ddl;
  
  import org.apache.shardingsphere.infra.exception.dialect.exception.syntax.table.NoSuchTableException;
  import org.apache.shardingsphere.infra.exception.dialect.exception.syntax.table.TableExistsException;
  import org.apache.shardingsphere.infra.metadata.database.schema.model.ShardingSphereSchema;
  import org.apache.shardingsphere.infra.route.context.RouteContext;
  import org.apache.shardingsphere.sharding.exception.syntax.UnsupportedShardingOperationException;
  import org.apache.shardingsphere.sharding.route.engine.validator.ShardingStatementValidator;
  import org.apache.shardingsphere.sharding.rule.ShardingRule;
  import org.apache.shardingsphere.sql.parser.sql.common.segment.ddl.index.IndexSegment;
  import org.apache.shardingsphere.sql.parser.sql.common.segment.generic.table.SimpleTableSegment;
  
  import java.util.Collection;
  
  /**
   * Sharding DDL statement validator.
   */
  public abstract class ShardingDDLStatementValidator implements ShardingStatementValidator {
      
      /**
       * Validate sharding table.
       *
       * @param shardingRule sharding rule
       * @param operation operation
       * @param tables tables
       * @throws UnsupportedShardingOperationException unsupported sharding operation exception
       */
      protected void validateShardingTable(final ShardingRule shardingRule, final String operation, final Collection<SimpleTableSegment> tables) {
          for (SimpleTableSegment each : tables) {
              String tableName = each.getTableName().getIdentifier().getValue();
              if (shardingRule.isShardingTable(tableName)) {
                  throw new UnsupportedShardingOperationException(operation, tableName);
              }
          }
      }
      
      /**
       * Validate table exist.
       *
       * @param schema ShardingSphere schema
       * @param tables tables
       * @throws NoSuchTableException no such table exception
       */
      protected void validateTableExist(final ShardingSphereSchema schema, final Collection<SimpleTableSegment> tables) {
          for (SimpleTableSegment each : tables) {
              String tableName = each.getTableName().getIdentifier().getValue();
              if (!schema.containsTable(tableName)) {
                  throw new NoSuchTableException(tableName);
              }
          }
      }
      
      /**
       * Validate table not exist.
       *
       * @param schema ShardingSphere schema
       * @param tables tables
       * @throws TableExistsException table exists exception
       */
      protected void validateTableNotExist(final ShardingSphereSchema schema, final Collection<SimpleTableSegment> tables) {
          for (SimpleTableSegment each : tables) {
              String tableName = each.getTableName().getIdentifier().getValue();
              if (schema.containsTable(tableName)) {
                  throw new TableExistsException(tableName);
              }
          }
      }
      
      /**
       * Judge whether route unit and data node are different size.
       * 
       * @param shardingRule sharding rule
       * @param routeContext route context
       * @param tableName table name
       * @return route unit and data node are different size or not
       */
      protected boolean isRouteUnitDataNodeDifferentSize(final ShardingRule shardingRule, final RouteContext routeContext, final String tableName) {
          return shardingRule.isShardingTable(tableName) && shardingRule.getShardingTable(tableName).getActualDataNodes().size() != routeContext.getRouteUnits().size();
      }
      
      /**
       * Judge whether schema contains index or not.
      *
      * @param schema ShardingSphere schema
      * @param index index
      * @return whether schema contains index or not
      */
     protected boolean isSchemaContainsIndex(final ShardingSphereSchema schema, final IndexSegment index) {
         return schema.getAllTableNames().stream().anyMatch(each -> schema.getTable(each).containsIndex(index.getIndexName().getIdentifier().getValue()));
     }
 }