/*******************************************************************************
 * Copyright (c) 2009 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
 *     Zend Technologies
 *******************************************************************************/
package org.eclipse.php.internal.core.format;

import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.IRegion;
import org.eclipse.php.internal.core.documentModel.parser.PHPRegionContext;
import org.eclipse.php.internal.core.documentModel.parser.regions.IPHPScriptRegion;
import org.eclipse.php.internal.core.documentModel.parser.regions.PHPRegionTypes;
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.core.internal.provisional.text.ITextRegionContainer;

public class CurlyCloseIndentationStrategy implements IIndentationStrategy {

	public void placeMatchingBlanks(IStructuredDocument document, StringBuilder result, int lineNumber, int forOffset)
			throws BadLocationException {
		final IRegion curlyOpenLine = getCurlyOpenLineInformation(document, forOffset);
		if (curlyOpenLine == null) {
			return;
		}
		IndentationBaseDetector indentationDetector = new IndentationBaseDetector(document,
				document.getLineOfOffset(curlyOpenLine.getOffset()), forOffset);
		int indentationBaseLineIndex = indentationDetector.getIndentationBaseLine(true);
		final IRegion indentationBaseLine = document.getLineInformation(indentationBaseLineIndex);
		String blanks = ""; //$NON-NLS-1$
		if (indentationBaseLine != null) {
			blanks = FormatterUtils.getLineBlanks(document, indentationBaseLine);
		} else { // if no matching bracket was found leaving the bracket as is.
			blanks = FormatterUtils.getLineBlanks(document, document.getLineInformationOfOffset(forOffset));
		}
		result.append(blanks);
	}

	/**
	 * This function returns the line in which the corresponding '{' of the '}'
	 * found
	 * 
	 * TODO this function has a bug in it: if there is a '{' inside inner state
	 * then it will not ignore it as it should.
	 */
	protected IRegion getCurlyOpenLineInformation(IStructuredDocument document, int forOffset)
			throws BadLocationException {
		int offset = forOffset;
		int curlyCount = 0;

		IStructuredDocumentRegion sdRegion = document.getRegionAtCharacterOffset(offset);
		if (sdRegion == null) {
			return null;
		}
		ITextRegion tRegion = sdRegion.getRegionAtCharacterOffset(offset);
		if (tRegion == null && offset == document.getLength()) {
			tRegion = sdRegion.getRegionAtCharacterOffset(offset - 1);
		}
		int regionStart = sdRegion.getStartOffset(tRegion);

		// in case of container we have to extract the PhpScriptRegion
		if (tRegion instanceof ITextRegionContainer) {
			ITextRegionContainer container = (ITextRegionContainer) tRegion;
			tRegion = container.getRegionAtCharacterOffset(offset);
			regionStart += tRegion.getStart();
		}
		do {
			if (tRegion instanceof IPHPScriptRegion) {
				IPHPScriptRegion scriptRegion = (IPHPScriptRegion) tRegion;
				tRegion = scriptRegion.getPHPToken(offset - regionStart - 1);

				// go backward over the region to find a 'case' or 'default'
				// region
				// in this case is the same indentation
				// other case if look for the '{' of the 'switch' region
				while (true) {
					String token = tRegion.getType();
					if (token == PHPRegionTypes.PHP_CURLY_OPEN) {
						curlyCount--;
						if (curlyCount < 0) {
							return document.getLineInformationOfOffset(tRegion.getStart() + regionStart);
						}
					} else if (token == PHPRegionTypes.PHP_CURLY_CLOSE) {
						curlyCount++;
					}
					if (tRegion.getStart() > 0) {
						tRegion = scriptRegion.getPHPToken(tRegion.getStart() - 1);
					} else {
						break;
					}
				}
			}

			tRegion = null;

			if (sdRegion == null) {
				return null;
			}

			// looking for the previous php block, maybe the '{' is in it
			// (https://bugs.eclipse.org/bugs/show_bug.cgi?id=201648)
			while ((sdRegion = sdRegion.getPrevious()) != null) {
				if (sdRegion.getFirstRegion().getType().equals(PHPRegionContext.PHP_OPEN)) {
					tRegion = sdRegion.getRegions().get(1);
					regionStart = sdRegion.getStartOffset(tRegion);
					offset = sdRegion.getEndOffset(tRegion);
					break;
				}
			}
		} while (tRegion != null);
		return null;

	}

}