/*
 * Copyright 2016-2018 shardingsphere.io.
 * <p>
 * Licensed 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.
 * </p>
 */

package io.shardingsphere.core.parsing.antlr.extractor.statement.handler;

import org.antlr.v4.runtime.ParserRuleContext;

import com.google.common.base.Optional;

import io.shardingsphere.core.parsing.antlr.extractor.statement.handler.result.ExtractResult;
import io.shardingsphere.core.parsing.antlr.extractor.statement.handler.result.RenameTableExtractResult;
import io.shardingsphere.core.parsing.antlr.extractor.statement.util.ASTUtils;
import io.shardingsphere.core.parsing.antlr.sql.ddl.AlterTableStatement;
import io.shardingsphere.core.parsing.parser.sql.SQLStatement;

/**
 * Rename table extract handler.
 * 
 * @author duhongjun
 */
public final class RenameTableExtractHandler implements ASTExtractHandler,ASTExtractHandler1 {
    
    @Override
    public void extract(final ParserRuleContext ancestorNode, final SQLStatement statement) {
        AlterTableStatement alterStatement = (AlterTableStatement) statement;
        Optional<ParserRuleContext> renameTableNode = ASTUtils.findFirstChildNode(ancestorNode, RuleName.RENAME_TABLE);
        if (renameTableNode.isPresent() && 0 < renameTableNode.get().getChildCount()) {
            alterStatement.setNewTableName(renameTableNode.get().getChild(renameTableNode.get().getChildCount() - 1).getText());
        }
    }

    @Override
    public ExtractResult extract(ParserRuleContext ancestorNode) {
        RenameTableExtractResult extractResult = new RenameTableExtractResult();
        Optional<ParserRuleContext> renameTableNode = ASTUtils.findFirstChildNode(ancestorNode, RuleName.RENAME_TABLE);
        if (renameTableNode.isPresent() && 0 < renameTableNode.get().getChildCount()) {
            extractResult.setNewTableName(renameTableNode.get().getChild(renameTableNode.get().getChildCount() - 1).getText());
        }
        return null;
    }
}

/*
 * Copyright 2016-2018 shardingsphere.io.
 * <p>
 * Licensed 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.
 * </p>
 */

package io.shardingsphere.core.parsing.antlr.extractor.statement.handler;

import org.antlr.v4.runtime.ParserRuleContext;

import com.google.common.base.Optional;

import io.shardingsphere.core.parsing.antlr.extractor.statement.handler.result.ExtractResult;
import io.shardingsphere.core.parsing.antlr.extractor.statement.handler.result.RenameTableExtractResult;
import io.shardingsphere.core.parsing.antlr.extractor.statement.util.ASTUtils;
import io.shardingsphere.core.parsing.antlr.sql.ddl.AlterTableStatement;
import io.shardingsphere.core.parsing.parser.sql.SQLStatement;

/**
 * Rename table extract handler.
 * 
 * @author duhongjun
 */
public final class RenameTableExtractHandler implements ASTExtractHandler,ASTExtractHandler1 {
    
    @Override
    public void extract(final ParserRuleContext ancestorNode, final SQLStatement statement) {
        AlterTableStatement alterStatement = (AlterTableStatement) statement;
        Optional<ParserRuleContext> renameTableNode = ASTUtils.findFirstChildNode(ancestorNode, RuleName.RENAME_TABLE);
        if (renameTableNode.isPresent() && 0 < renameTableNode.get().getChildCount()) {
            alterStatement.setNewTableName(renameTableNode.get().getChild(renameTableNode.get().getChildCount() - 1).getText());
        }
    }

    @Override
    public ExtractResult extract(ParserRuleContext ancestorNode) {
        RenameTableExtractResult extractResult = new RenameTableExtractResult();
        Optional<ParserRuleContext> renameTableNode = ASTUtils.findFirstChildNode(ancestorNode, RuleName.RENAME_TABLE);
        if (renameTableNode.isPresent() && 0 < renameTableNode.get().getChildCount()) {
            extractResult.setNewTableName(renameTableNode.get().getChild(renameTableNode.get().getChildCount() - 1).getText());
        }
        return extractResult;
    }
}

fix NPE