/*
 * Copyright Red Hat, Inc. and/or its affiliates
 * and other contributors as indicated by the @author tags and
 * the COPYRIGHT.txt file distributed with this work.
 *
 * 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.
 */

package org.teiid.query.sql;

import java.lang.reflect.Field;
import java.util.HashSet;
import java.util.Set;

import org.teiid.language.SQLConstants;

/**
 * Special variable names in stored procedure language.
 */
public class ProcedureReservedWords {

    public static final String ROWCOUNT = "ROWCOUNT"; //$NON-NLS-1$

    public static final String CHANGING = "CHANGING"; //$NON-NLS-1$

    public static final String VARIABLES = "VARIABLES"; //$NON-NLS-1$

    public static final String DVARS = "DVARS"; //$NON-NLS-1$

    /**
      * Set of CAPITALIZED reserved words for checking whether a string is a reserved word.
      */
    private static final Set<String> RESERVED_WORDS = new HashSet<String>();

    // Initialize RESERVED_WORDS set - This is a poor man's enum.  To much legacy code expects the constants to be Strings.
     static {
         Field[] fields = SQLConstants.class.getDeclaredFields();
         for (Field field : fields) {
             if (field.getType() == String.class) {
                 try {
                    RESERVED_WORDS.add((String)field.get(null));
                } catch (Exception e) {
                }
             }
         }
     }

    /** Can't construct */
    private ProcedureReservedWords() {}

    /**
     * Check whether a string is a procedure reserved word.
     * @param str String to check
     * @return True if procedure reserved word, false if not or null
     */
    public static final boolean isProcedureReservedWord(String str) {
        if (str == null) {
            return false;
        }
        return RESERVED_WORDS.contains(str.toUpperCase());
    }
}
