/*
 * Copyright (c) 2003-2004 Christopher Lenz 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:
 *     Christopher Lenz - initial API and implementation
 * 
 * $Id: StyleSheet.java,v 1.1 2004-09-02 18:07:12 jsurfer Exp $
 */

package net.sourceforge.phpeclipse.css.core.internal.model;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import net.sourceforge.phpeclipse.core.model.SourceReference;
import net.sourceforge.phpeclipse.css.core.internal.parser.DefaultCssParser;
import net.sourceforge.phpeclipse.css.core.model.IRule;
import net.sourceforge.phpeclipse.css.core.model.IStyleSheet;
import net.sourceforge.phpeclipse.css.core.parser.ICssParser;
import net.sourceforge.phpeclipse.css.core.parser.IProblemCollector;
import net.sourceforge.phpeclipse.css.core.parser.LexicalErrorException;
import net.sourceforge.phpeclipse.css.core.parser.SyntaxErrorException;

import org.eclipse.core.runtime.Platform;
import org.eclipse.jface.text.DocumentEvent;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.IDocumentListener;
import org.eclipse.jface.text.IRegion;

/**
 * 
 */
public class StyleSheet extends SourceReference
	implements IStyleSheet, IDocumentListener {

	// Instance Variables ------------------------------------------------------

	/**
	 * The list of top-level CSS rules defined in the style sheet.
	 */
	private List rules = new ArrayList();

	private Object dirtyLock = new Object();
	private boolean dirty = true;

	// Constructors ------------------------------------------------------------

	/**
	 * Constructor.
	 * 
	 * @param document The document that contains the style sheet
	 */
	public StyleSheet(IDocument document) {
		super(document);
	}

	// IAdaptable Implementation -----------------------------------------------

	/*
	 * @see IAdaptable#getAdapter(Class)
	 */
	public Object getAdapter(Class adapter) {
		return Platform.getAdapterManager().getAdapter(this, adapter);
	}

	// IStyleSheet Implementation ----------------------------------------------

	/*
	 * @see IStyleSheet#getRuleAt(int)
	 */
	public IRule getRuleAt(int offset) {
		return getRuleAtInternal(getRules(), offset);
	}

	/*
	 * @see IStyleSheet#getRules()
	 */
	public IRule[] getRules() {
		return (IRule[]) rules.toArray(new IRule[rules.size()]);
	}

	/*
	 * @see IStyleSheet#reconcile(IProblemCollector)
	 */
	public void reconcile(IProblemCollector problemCollector)
		throws LexicalErrorException, SyntaxErrorException {
		
		synchronized (dirtyLock) {
			if (!dirty) {
				return;
			}
			dirty = false;
		}

		synchronized (this) {
			rules.clear();
			ICssParser parser = new DefaultCssParser();
			parser.setProblemCollector(problemCollector);
			parser.setSource(getDocument());
			rules.addAll(Arrays.asList(parser.parseRules(this)));
		}
	}

	// IDocumentListener Implementation ----------------------------------------

	/*
	 * @see IDocumentListener#documentAboutToBeChanged(DocumentEvent)
	 */
	public void documentAboutToBeChanged(DocumentEvent event) {
		// do nothing yet
	}

	/*
	 * @see IDocumentListener#documentChanged(DocumentEvent)
	 */
	public void documentChanged(DocumentEvent event) {
		synchronized (dirtyLock) {
			dirty = true;
		}
	}

	// Public Methods ----------------------------------------------------------

	/**
	 * Adds a rule to the style sheet.
	 * 
	 * @param rule The rule to add
	 */
	public void addRule(IRule rule) {
		rules.add(rule);
	}

	// Private Methods ---------------------------------------------------------

	private static IRule getRuleAtInternal(IRule rules[], int offset) {
		IRule retVal = null;
		for (int i = 0; i < rules.length; i++) {
			IRule rule = rules[i];
			IRegion region = rule.getSourceRegion();
			if ((offset > region.getOffset())
			 && (offset < (region.getOffset() + region.getLength()))) {
				if (rule.getChildren().length > 0) {
					retVal = getRuleAtInternal(rule.getChildren(), offset);
					if (retVal != null) {
						break;
					}
				}
				if (retVal == null) {
					retVal = rule;
				}
			}
		}
		return retVal;
	}

}