/**
 * Copyright 2008-2009 DRIVER PROJECT (ICM UW)
 * Original author: Marek Horst
 *
 * 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.
 */
// $Id: CQLBooleanNode.java 5239 2008-03-17 09:00:00Z icmdriver $

package org.z3950.zing.cql;
import java.util.Properties;
import java.util.Vector;

/**
 * Represents a boolean node in a CQL parse-tree.
 *
 * @version	$Id: CQLBooleanNode.java 5239 2008-03-17 09:00:00Z icmdriver $
 */
public abstract class CQLBooleanNode extends CQLNode {
    /**
     * The root of a parse-tree representing the left-hand side.
     */ 
    public CQLNode left;

    /**
     * The root of a parse-tree representing the right-hand side.
     */ 
    public CQLNode right;

    /**
     * The set of modifiers that are applied to this boolean.
     */
    public ModifierSet ms;

    protected CQLBooleanNode(CQLNode left, CQLNode right, ModifierSet ms) {
	this.left = left;
	this.right = right;
	this.ms = ms;
    }

    public String toXCQL(int level, Vector<CQLPrefix> prefixes,
			 Vector<ModifierSet> sortkeys) {
	return (indent(level) + "<triple>\n" +
		renderPrefixes(level+1, prefixes) +
		ms.toXCQL(level+1, "boolean") +
		indent(level+1) + "<leftOperand>\n" +
		left.toXCQL(level+2) +
		indent(level+1) + "</leftOperand>\n" +
		indent(level+1) + "<rightOperand>\n" +
		right.toXCQL(level+2) +
		indent(level+1) + "</rightOperand>\n" +
		renderSortKeys(level+1, sortkeys) +
		indent(level) + "</triple>\n");
    }

    public String toCQL() {
	// ### We don't always need parens around the operands
	return ("(" + left.toCQL() + ")" +
		" " + ms.toCQL() + " " +
		"(" + right.toCQL() + ")");
    }

    public String toPQF(Properties config) throws PQFTranslationException {
	return ("@" + opPQF() +
		" " + left.toPQF(config) +
		" " + right.toPQF(config));
    }

    // represents the operation for PQF: overridden for CQLProxNode
    String opPQF() { return ms.getBase(); }

    public byte[] toType1BER(Properties config) throws PQFTranslationException {
        System.out.println("in CQLBooleanNode.toType1BER(): PQF=" +
			   toPQF(config));
        byte[] rpn1 = left.toType1BER(config);
        byte[] rpn2 = right.toType1BER(config);
        byte[] op = opType1();
        byte[] rpnStructure = new byte[rpn1.length+rpn2.length+op.length+4];
        
	// rpnRpnOp
        int offset = putTag(CONTEXT, 1, CONSTRUCTED, rpnStructure, 0);

        rpnStructure[offset++] = (byte)(0x80&0xff); // indefinite length
        System.arraycopy(rpn1, 0, rpnStructure, offset, rpn1.length);
        offset += rpn1.length;
        System.arraycopy(rpn2, 0, rpnStructure, offset, rpn2.length);
        offset += rpn2.length;
        System.arraycopy(op, 0, rpnStructure, offset, op.length);
        offset += op.length;
        rpnStructure[offset++] = 0x00; // end rpnRpnOp
        rpnStructure[offset++] = 0x00;
        return rpnStructure;
    }

    abstract byte[] opType1();
}