/*
    * 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.binder.context.statement.ddl;
  
  import lombok.Getter;
  import org.apache.shardingsphere.infra.binder.context.segment.table.TablesContext;
  import org.apache.shardingsphere.infra.binder.context.statement.CommonSQLStatementContext;
  import org.apache.shardingsphere.infra.binder.context.type.IndexAvailable;
  import org.apache.shardingsphere.infra.binder.context.type.TableAvailable;
  import org.apache.shardingsphere.infra.metadata.database.schema.util.IndexMetaDataUtils;
  import org.apache.shardingsphere.sql.parser.sql.common.segment.ddl.index.IndexNameSegment;
  import org.apache.shardingsphere.sql.parser.sql.common.segment.ddl.index.IndexSegment;
  import org.apache.shardingsphere.sql.parser.sql.common.segment.dml.column.ColumnSegment;
  import org.apache.shardingsphere.sql.parser.sql.common.segment.generic.table.SimpleTableSegment;
  import org.apache.shardingsphere.sql.parser.sql.common.statement.ddl.CreateIndexStatement;
  import org.apache.shardingsphere.sql.parser.sql.common.value.identifier.IdentifierValue;
  import org.apache.shardingsphere.sql.parser.sql.dialect.handler.ddl.CreateIndexStatementHandler;
  
  import java.util.Collection;
  import java.util.Collections;
  
  /**
   * Create index statement context.
   */
  @Getter
  public final class CreateIndexStatementContext extends CommonSQLStatementContext implements TableAvailable, IndexAvailable {
      
      private final TablesContext tablesContext;
      
      private final boolean generatedIndex;
      
      public CreateIndexStatementContext(final CreateIndexStatement sqlStatement) {
          super(sqlStatement);
          tablesContext = new TablesContext(sqlStatement.getTable(), getDatabaseType());
          generatedIndex = null == sqlStatement.getIndex();
      }
      
      @Override
      public CreateIndexStatement getSqlStatement() {
          return (CreateIndexStatement) super.getSqlStatement();
      }
      
      @Override
      public Collection<SimpleTableSegment> getAllTables() {
          return null == getSqlStatement().getTable() ? Collections.emptyList() : Collections.singletonList(getSqlStatement().getTable());
      }
      
      @Override
      public Collection<IndexSegment> getIndexes() {
          if (null == getSqlStatement().getIndex()) {
              return CreateIndexStatementHandler.getGeneratedIndexStartIndex(getSqlStatement()).map(each -> Collections.singletonList(new IndexSegment(each, each,
                      new IndexNameSegment(each, each, new IdentifierValue(IndexMetaDataUtils.getGeneratedLogicIndexName(getSqlStatement().getColumns())))))).orElseGet(Collections::emptyList);
          }
          return Collections.singletonList(getSqlStatement().getIndex());
      }
      
      @Override
      public Collection<ColumnSegment> getIndexColumns() {
          return getSqlStatement().getColumns();
      }
  }