Copyright (c) 2000, 2016 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
/*******************************************************************************
 * Copyright (c) 2000, 2016 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jdt.core.refactoring;

import org.eclipse.osgi.util.TextProcessor;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.core.runtime.SubMonitor;

import org.eclipse.core.resources.IFile;

import org.eclipse.text.edits.UndoEdit;

import org.eclipse.ltk.core.refactoring.Change;
import org.eclipse.ltk.core.refactoring.ContentStamp;
import org.eclipse.ltk.core.refactoring.UndoTextFileChange;

import org.eclipse.jdt.core.ICompilationUnit;

import org.eclipse.jdt.internal.core.manipulation.JavaManipulationMessages;
import org.eclipse.jdt.internal.core.manipulation.JavaManipulationPlugin;
import org.eclipse.jdt.internal.core.manipulation.Messages;

/* package */ class UndoCompilationUnitChange extends UndoTextFileChange {

	private ICompilationUnit fCUnit;

	public UndoCompilationUnitChange(String name, ICompilationUnit unit, UndoEdit undo, ContentStamp stampToRestore, int saveMode) throws CoreException {
		super(name, getFile(unit), undo, stampToRestore, saveMode);
		fCUnit= unit;
	}

	private static IFile getFile(ICompilationUnit cunit) throws CoreException {
		IFile file= (IFile)cunit.getResource();
		if (file == null) {
			String message= Messages.format(JavaManipulationMessages.UndoCompilationUnitChange_no_file, TextProcessor.process(cunit.getElementName()));
			throw new CoreException(new Status(IStatus.ERROR, JavaManipulationPlugin.getPluginId(), message));
		}
		return file;
	}

	@Override
	public Object getModifiedElement() {
		return fCUnit;
	}

	@Override
	protected Change createUndoChange(UndoEdit edit, ContentStamp stampToRestore) throws CoreException {
		return new UndoCompilationUnitChange(getName(), fCUnit, edit, stampToRestore, getSaveMode());
	}

	@Override
	public Change perform(IProgressMonitor pm) throws CoreException {
		SubMonitor subMonitor= SubMonitor.convert(pm, 2);
		fCUnit.becomeWorkingCopy(subMonitor.split(1));
		try {
			return super.perform(subMonitor.split(1));
		} finally {
			fCUnit.discardWorkingCopy();
		}
	}
}