/*******************************************************************************
 * Copyright (c) 2009, 2011 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.wst.xml.ui.internal.text;

import org.eclipse.jface.preference.IPreferenceStore;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.source.ISourceViewer;
import org.eclipse.jface.util.IPropertyChangeListener;
import org.eclipse.jface.util.PropertyChangeEvent;
import org.eclipse.swt.graphics.Point;
import org.eclipse.wst.sse.core.internal.provisional.text.IStructuredDocument;
import org.eclipse.wst.sse.core.internal.provisional.text.IStructuredDocumentRegion;
import org.eclipse.wst.sse.core.internal.provisional.text.ITextRegion;
import org.eclipse.wst.sse.ui.typing.AbstractCharacterPairInserter;
import org.eclipse.wst.xml.core.internal.regions.DOMRegionContext;
import org.eclipse.wst.xml.ui.internal.XMLUIPlugin;
import org.eclipse.wst.xml.ui.internal.preferences.XMLUIPreferenceNames;

public class CharacterPairInserter extends AbstractCharacterPairInserter implements IPropertyChangeListener {

	// preferences
	private boolean fCloseStrings = true;
	private boolean fCloseBrackets = true;

	protected boolean shouldPair(ISourceViewer viewer, char c) {
		switch (c) {
			case '\'':
			case '"':
				return fCloseStrings ? checkRegion(viewer, c) : false;
			default:
				return fCloseBrackets;
		}
	}

	/**
	 * Checks if the region should support paired quotes
	 * @param viewer the viewer
	 * @return true if the region is not in an XML attribute value
	 */
	private boolean checkRegion(ISourceViewer viewer, char c) {
		IDocument doc = viewer.getDocument();
		final Point selection= viewer.getSelectedRange();
		final int offset= selection.x;

		if (doc instanceof IStructuredDocument) {
			IStructuredDocumentRegion[] regions = ((IStructuredDocument) doc).getStructuredDocumentRegions(offset, 0);
			if (regions != null && regions.length > 0) {
				ITextRegion region = regions[0].getRegionAtCharacterOffset(offset);
				if (region != null) {
					final String type = region.getType();
					if (DOMRegionContext.XML_TAG_ATTRIBUTE_EQUALS.equals(type))
						return true;
					else if (DOMRegionContext.XML_TAG_CLOSE.equals(type) || DOMRegionContext.XML_EMPTY_TAG_CLOSE.equals(type)) {
						if (regions[0].containsOffset(offset - 1)) {
							region = regions[0].getRegionAtCharacterOffset(offset - 1);
							if (region != null && DOMRegionContext.XML_TAG_ATTRIBUTE_EQUALS.equals(region.getType()))
								return true;
						}
					}
					return c != '\'' && DOMRegionContext.XML_CONTENT.equals(type); 
				}
			}
		}
		return true;
	}

	public boolean hasPair(char c) {
		switch (c) {
			case '"':
			case '\'':
			case '[':
			case '(':
				return true;
			default:
				return false;
		}
	}

	protected char getPair(char c) {
		switch (c) {
			case '\'':
			case '"':
				return c;
			case '(':
				return ')';
			case '[':
				return ']';
			default:
				throw new IllegalArgumentException();
		}
	}

	public void initialize() {
		IPreferenceStore store = XMLUIPlugin.getInstance().getPreferenceStore();
		fCloseStrings = store.getBoolean(XMLUIPreferenceNames.TYPING_CLOSE_STRINGS);
		fCloseBrackets = store.getBoolean(XMLUIPreferenceNames.TYPING_CLOSE_BRACKETS);
		store.addPropertyChangeListener(this);
	}

	public void dispose() {
		XMLUIPlugin.getInstance().getPreferenceStore().removePropertyChangeListener(this);
	}

	public void propertyChange(PropertyChangeEvent event) {
		if (XMLUIPreferenceNames.TYPING_CLOSE_BRACKETS.equals(event.getProperty()))
			fCloseBrackets = ((Boolean) event.getNewValue()).booleanValue();
		else if (XMLUIPreferenceNames.TYPING_CLOSE_STRINGS.equals(event.getProperty()))
			fCloseStrings = ((Boolean) event.getNewValue()).booleanValue();
	}
}