/*
 *  eXist Open Source Native XML Database
 *  Copyright (C) 2001 Wolfgang M. Meier
 *  wolfgang@exist-db.org
 *  http://exist-db.org
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public License
 *  as published by the Free Software Foundation; either version 2
 *  of the License, or (at your option) any later version.
 *
 *  This program 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 Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 * 
 *  $Id$
 */
package org.exist.xquery;

import org.exist.memtree.MemTreeBuilder;
import org.exist.memtree.NodeImpl;
import org.exist.xquery.util.ExpressionDumper;
import org.exist.xquery.value.Item;
import org.exist.xquery.value.Sequence;
import org.exist.xquery.value.StringValue;

/**
 * Direct constructor for text nodes.
 * 
 * @author wolf
 */
public class TextConstructor extends NodeConstructor {

	private final String text;
	private boolean isWhitespaceOnly = true;

    public TextConstructor(XQueryContext context, String text) throws XPathException {
		super(context);
		this.text = StringValue.expand(text);
		for(int i = 0; i < text.length(); i++)
			if(!isWhiteSpace(text.charAt(i))) {
				isWhitespaceOnly = false;
				break;
			}
	}
    
	/* (non-Javadoc)
	 * @see org.exist.xquery.Expression#eval(org.exist.xquery.StaticContext, org.exist.dom.DocumentSet, org.exist.xquery.value.Sequence, org.exist.xquery.value.Item)
	 */
	public Sequence eval(
		Sequence contextSequence,
		Item contextItem)
		throws XPathException {
		if(isWhitespaceOnly && context.stripWhitespace())
			return Sequence.EMPTY_SEQUENCE;
        if (newDocumentContext)
            context.pushDocumentContext();
        try {
            MemTreeBuilder builder = context.getDocumentBuilder();
            context.proceed(this, builder);
            int nodeNr = builder.characters(text);
            NodeImpl node = builder.getDocument().getNode(nodeNr);
            return node;
        } finally {
            if (newDocumentContext)
                context.popDocumentContext();
        }
    }

	/* (non-Javadoc)
     * @see org.exist.xquery.Expression#dump(org.exist.xquery.util.ExpressionDumper)
     */
    public void dump(ExpressionDumper dumper) {
        dumper.display("text {");
        dumper.startIndent();
        dumper.display(text);
        dumper.endIndent();
        dumper.nl().display("}");
    }
    
    public String toString() {
    	StringBuilder result = new StringBuilder();
    	result.append("text {");
    	result.append(text.toString());
        result.append("}");
        return result.toString();
    }    
    
	protected final static boolean isWhiteSpace(char ch) {
		return (ch == 0x20) || (ch == 0x09) || (ch == 0xD) || (ch == 0xA);
	}
}