/*
 * 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.SQLTokenExtractResult;
import io.shardingsphere.core.parsing.antlr.extractor.statement.util.ASTUtils;
import io.shardingsphere.core.parsing.lexer.token.Symbol;
import io.shardingsphere.core.parsing.parser.token.TableToken;

/**
 * Single table name extract handler.
 *
 * @author duhongjun
 */
public class TableNameExtractHandler implements ASTExtractHandler {

    /**
     * Extract AST.
     *
     * @param ancestorNode ancestor node of ast
     * @return Extract Result
     */
    @Override
    public ExtractResult extract(final ParserRuleContext ancestorNode) {
        Optional<ParserRuleContext> tableNameNode = ASTUtils.findFirstChildNode(ancestorNode, RuleName.TABLE_NAME);
        if (!tableNameNode.isPresent()) {
            return null;
        }
        SQLTokenExtractResult extractResult = new SQLTokenExtractResult();
        String tableText = tableNameNode.get().getText();
        int dotPosition = tableText.contains(Symbol.DOT.getLiterals()) ? tableText.lastIndexOf(Symbol.DOT.getLiterals()) : 0;
        extractResult.getSqlTokens().add(new TableToken(tableNameNode.get().getStart().getStartIndex(), dotPosition, tableText));
        return extractResult;
    }
}

@@ -1312,16 +1312,20 @@
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@@ -1396,19 +1396,19 @@
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@@ -1463,16 +1463,25 @@
  public 
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 ExtractR
@@ -1477,32 +1477,33 @@
 al%3CExtractResult
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@@ -1716,12 +1716,25 @@
 urn 
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+Optional.absent()
 ;%0A  
@@ -1771,24 +1771,17 @@
 tResult 
-extractR
+r
 esult = 
@@ -2001,24 +2001,17 @@
         
-extractR
+r
 esult.ge
@@ -2131,17 +2131,27 @@
  return 
-e
+Optional.%3CE
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@@ -2154,16 +2154,27 @@
 ctResult
+%3Eof(result)
 ;%0A    %7D%0A

use optional for checkstyle