/*
 * Copyright (c) 2013, OpenCloudDB/MyCAT and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software;Designed and Developed mainly by many Chinese 
 * opensource volunteers. you can redistribute it and/or modify it under the 
 * terms of the GNU General Public License version 2 only, as published by the
 * Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 * 
 * Any questions about this component can be directed to it's project Web address 
 * https://code.google.com/p/opencloudb/.
 *
 */
package com.akiban.sql.parser;

import com.akiban.sql.StandardException;
import com.akiban.sql.types.TypeId;

import java.sql.Types;

public class BitConstantNode extends ConstantNode
{
    private int bitLength;

    /**
     * Initializer for a BitConstantNode.
     *
     * @param arg1 A Bit containing the value of the constant OR The TypeId for the type of the node
     *
     * @exception StandardException
     */

    public void init(Object arg1) throws StandardException {
        super.init(arg1,
                   Boolean.TRUE,
                   0);
    }

    public void init(Object arg1, Object arg2) throws StandardException {
        String a1 = (String)arg1;

        byte[] nv = fromHexString(a1, 0, a1.length()); 

        Integer bitLengthO = (Integer)arg2;
        bitLength = bitLengthO.intValue();

        init(TypeId.getBuiltInTypeId(Types.BINARY),
             Boolean.FALSE,
             bitLengthO);

        setValue(nv);
    }

    /**
     * Fill this node with a deep copy of the given node.
     */
    public void copyFrom(QueryTreeNode node) throws StandardException {
        super.copyFrom(node);

        BitConstantNode other = (BitConstantNode)node;
        this.bitLength = other.bitLength;
    }

    /**
       Convert a hexidecimal string generated by toHexString() back
       into a byte array.

       @param s String to convert
       @param offset starting character (zero based) to convert.
       @param length number of characters to convert.

       @return the converted byte array. Returns null if the length is
       not a multiple of 2.
    */
    public static byte[] fromHexString(String s, int offset, int length) {
        if ((length%2) != 0)
            return null;

        byte[] byteArray = new byte[length/2];

        int j = 0;
        int end = offset+length;
        for (int i = offset; i < end; i += 2) {
            int high_nibble = Character.digit(s.charAt(i), 16);
            int low_nibble = Character.digit(s.charAt(i+1), 16);

            if (high_nibble == -1 || low_nibble == -1) {
                // illegal format
                return null;
            }

            byteArray[j++] = (byte)(((high_nibble << 4) & 0xf0) | (low_nibble & 0x0f));
        }
        return byteArray;
    }

}