/*
 * Copyright (c) 2002-2004 Widespace, OU and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 *
 * Contributors:
 *     Igor Malinin - initial contribution
 *
 * $Id: XMLCDATAScanner.java,v 1.2 2005-05-06 00:55:41 stefanbjarni Exp $
 */

package net.sourceforge.phpeclipse.xml.ui.internal.text;

import java.util.Map;

import net.sourceforge.phpeclipse.xml.ui.text.IXMLSyntaxConstants;

import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.rules.IToken;
import org.eclipse.jface.text.rules.ITokenScanner;
import org.eclipse.jface.text.rules.Token;

/**
 * @author Igor Malinin
 */
public class XMLCDATAScanner implements ITokenScanner {

	private Map tokens;

	private IDocument document;

	private int begin;

	private int end;

	private int offset;

	private int length;

	private int position;

	public XMLCDATAScanner(Map tokens) {
		this.tokens = tokens;
	}

	/*
	 * @see ITokenScanner#setRange(IDocument, int, int)
	 */
	public void setRange(IDocument document, int offset, int length) {
		this.document = document;

		this.begin = offset;
		this.end = offset + length;

		this.offset = offset;
		this.position = offset;
		this.length = 0;
	}

	/*
	 * @see ITokenScanner#nextToken()
	 */
	public IToken nextToken() {
		offset += length;

		if (position == begin) {
			position += 3; // <![

			try {
				if (document.get(position, 6).equals("CDATA[")) {
					position += 6;
				}
			} catch (BadLocationException e) {
			}

			return getToken(IXMLSyntaxConstants.XML_CDATA);
		}

		if (position == end) {
			return getToken(null);
		}

		try {
			int p = end - 3;
			if (document.get(p, 3).equals("]]>")) {
				if (position == p) {
					position = end;
					return getToken(IXMLSyntaxConstants.XML_CDATA);
				}

				position = p;
			} else {
				position = end;
			}
		} catch (BadLocationException e) {
		}

		return getToken(IXMLSyntaxConstants.XML_DEFAULT);
	}

	private IToken getToken(String type) {
		length = position - offset;

		if (length == 0) {
			return Token.EOF;
		}

		if (type == null) {
			return Token.UNDEFINED;
		}

		IToken token = (IToken) tokens.get(type);
		if (token == null) {
			return Token.UNDEFINED;
		}

		return token;
	}

	/*
	 * @see ITokenScanner#getTokenOffset()
	 */
	public int getTokenOffset() {
		return offset;
	}

	/*
	 * @see ITokenScanner#getTokenLength()
	 */
	public int getTokenLength() {
		return length;
	}
}