/*

* Copyright (c) 2006 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of the License "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description: 

*

*/

package com.nokia.sdt.sourcegen.patcher;

import com.nokia.sdt.sourcegen.ISourceGenPatch;

import com.nokia.cpp.internal.api.utils.core.Check;

import com.nokia.cpp.internal.api.utils.core.Pair;

import java.util.List;

/**

 * 

 *

 */

public class DeleteLinesPatchInstruction extends MatchLinesPatchInstruction {

	/**

	 */

	public DeleteLinesPatchInstruction(List<String> removedLines) {

		super(removedLines);

	}

	/* (non-Javadoc)

	 * @see src.IPatchInstruction#apply(int, java.util.List)

	 */

	public int apply(ISourceGenPatch patch, int index, IPatchHandler handler) {

		Pair<Integer, Integer> info = getAppliedLineRange(contextLines, index, handler);

		return handler.replaceLines(patch, info.first, info.second, null);

	}

	static Pair<Integer, Integer> getAppliedLineRange(List<String> contextLines, int index, IPatchHandler handler) {

		// remove the lines at this index

		int i = 0;

		int lastIndex = index;

		while (i < contextLines.size()) {

			Check.checkState(handler.hasLine(index));

			String line = handler.getLine(index);

			Check.checkState(line != null);

			String ctxLine = contextLines.get(i);

			if (handler.matchLines(line, ctxLine)) {

				index++;

				i++;

			} else if (handler.isLineEmpty(line) && !handler.isLineEmpty(ctxLine)) {

				// skip blank lines in the source between context lines,

				// but not blank lines before the context lines

				if (lastIndex == index)

					lastIndex++;

				index++;

				continue;

			} else {

				Check.checkState(false);

			}

		}

		return new Pair(lastIndex, index);

	}

}