/*******************************************************************************
 * Copyright (c) 2009, 2010 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.css.ui.internal.text;

import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.link.ILinkedModeListener;
import org.eclipse.jface.text.link.LinkedModeModel;
import org.eclipse.jface.text.link.LinkedModeUI.ExitFlags;
import org.eclipse.jface.text.link.LinkedModeUI.IExitPolicy;
import org.eclipse.swt.events.VerifyEvent;
import org.eclipse.wst.sse.ui.typing.AbstractCharacterPairInserter;

public class CSSCharacterPairInserter extends AbstractCharacterPairInserter {

	public boolean hasPair(char c) {
		switch (c) {
			case '"':
			case '\'':
			case '[':
			case '(':
			case '{':
				return true;
			default:
				return false;
		}
	}

	protected char getPair(char c) {
		switch (c) {
			case '\'':
			case '"':
				return c;
			case '(':
				return ')';
			case '[':
				return ']';
			case '{':
				return '}';
			default:
				throw new IllegalArgumentException();
		}
	}

	class ExitPolicy implements IExitPolicy {

		private char fExit;
		private char fEscape;
		private IDocument fDocument;

		public ExitPolicy(char exit, char escape, IDocument document) {
			fExit = exit;
			fEscape = escape;
			fDocument = document;
		}

		public ExitFlags doExit(LinkedModeModel model, VerifyEvent event, int offset, int length) {
			if(!isMasked(offset)) {
				if (event.character == fExit)
					return new ExitFlags(ILinkedModeListener.UPDATE_CARET, false);
				if (event.character == '\r' || event.character == '\n' && offset > 0) {
					try {
						if (fDocument.getChar(offset - 1) == '{') {
							return new ExitFlags(ILinkedModeListener.EXIT_ALL, true);
						}
					} catch (BadLocationException e) {
					}
				}
			}
			return null;
		}

		private boolean isMasked(int offset) {
			try {
				return fEscape == fDocument.getChar(offset - 1);
			} catch (BadLocationException e) {
			}
			return false;
		}
	}

	protected IExitPolicy getExitPolicy(char exit, char escape, IDocument document) {
		return new ExitPolicy(exit, escape, document);
	}
}