core/plugins/org.eclipse.dltk.ui/core refactoring/org/eclipse/dltk/internal/corext/refactoring/changes/DeleteProjectFragmentChange.java

/*******************************************************************************
 * Copyright (c) 2000, 2018 IBM Corporation and others.
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 * 
 * SPDX-License-Identifier: EPL-2.0
 *
 *******************************************************************************/
package org.eclipse.dltk.internal.corext.refactoring.changes;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map.Entry;

import org.eclipse.core.filebuffers.FileBuffers;
import org.eclipse.core.filebuffers.ITextFileBufferManager;
import org.eclipse.core.filebuffers.LocationKind;
import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.runtime.Assert;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.NullProgressMonitor;
import org.eclipse.core.runtime.Status;
import org.eclipse.core.runtime.SubProgressMonitor;
import org.eclipse.dltk.core.DLTKCore;
import org.eclipse.dltk.core.IProjectFragment;
import org.eclipse.dltk.core.IScriptProject;
import org.eclipse.dltk.core.ModelException;
import org.eclipse.dltk.internal.core.ScriptProject;
import org.eclipse.dltk.internal.corext.refactoring.RefactoringCoreMessages;
import org.eclipse.dltk.internal.corext.refactoring.reorg.IProjectFragmentManipulationQuery;
import org.eclipse.dltk.internal.corext.refactoring.util.ModelElementUtil;
import org.eclipse.dltk.internal.corext.util.Messages;
import org.eclipse.dltk.ui.DLTKUIPlugin;
import org.eclipse.ltk.core.refactoring.Change;
import org.eclipse.ltk.core.refactoring.CompositeChange;
import org.eclipse.ltk.core.refactoring.NullChange;
import org.eclipse.ltk.core.refactoring.RefactoringStatus;
import org.eclipse.ltk.core.refactoring.TextFileChange;
import org.eclipse.text.edits.ReplaceEdit;
import org.eclipse.ui.ide.undo.ResourceDescription;

public class DeleteProjectFragmentChange extends AbstractDeleteChange {

	private final String fHandle;
	private final boolean fIsExecuteChange;
	private final IProjectFragmentManipulationQuery fUpdateClasspathQuery;

	public DeleteProjectFragmentChange(IProjectFragment root,
			boolean isExecuteChange,
			IProjectFragmentManipulationQuery updateClasspathQuery) {
		Assert.isNotNull(root);
		Assert.isTrue(!root.isExternal());
		fHandle = root.getHandleIdentifier();
		fIsExecuteChange = isExecuteChange;
		fUpdateClasspathQuery = updateClasspathQuery;
	}

	@Override
	public String getName() {
		return Messages.format(
				RefactoringCoreMessages.DeleteProjectFragmentChange_delete,
				getRoot().getElementName());
	}

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

	private IProjectFragment getRoot() {
		return (IProjectFragment) DLTKCore.create(fHandle);
	}

	@Override
	public RefactoringStatus isValid(IProgressMonitor pm) throws CoreException {
		if (fIsExecuteChange) {
			// don't check for read-only resources since we already
			// prompt the user via a dialog to confirm deletion of
			// read only resource. The change is currently not used
			// as
			return super.isValid(pm, DIRTY);
		}
		return super.isValid(pm, READ_ONLY | DIRTY);
	}

	@Override
	protected Change doDelete(IProgressMonitor pm) throws CoreException {
		if (!confirmDeleteIfReferenced())
			return new NullChange();
		int resourceUpdateFlags = IResource.KEEP_HISTORY;
		int jCoreUpdateFlags = IProjectFragment.ORIGINATING_PROJECT_BUILDPATH
				| IProjectFragment.OTHER_REFERRING_PROJECTS_BUILDPATH;

		pm.beginTask("", 2); //$NON-NLS-1$
		IProjectFragment root = getRoot();
		IResource rootResource = root.getResource();
		CompositeChange result = new CompositeChange(getName());

		ResourceDescription rootDescription = ResourceDescription
				.fromResource(rootResource);
		IScriptProject[] referencingProjects = ModelElementUtil
				.getReferencingProjects(root);
		HashMap<IFile, String> classpathFilesContents = new HashMap<>();
		for (int i = 0; i < referencingProjects.length; i++) {
			IScriptProject javaProject = referencingProjects[i];
			IFile classpathFile = javaProject.getProject()
					.getFile(ScriptProject.BUILDPATH_FILENAME);
			if (classpathFile.exists()) {
				classpathFilesContents.put(classpathFile,
						getFileContents(classpathFile));
			}
		}

		root.delete(resourceUpdateFlags, jCoreUpdateFlags,
				new SubProgressMonitor(pm, 1));

		rootDescription.recordStateFromHistory(rootResource,
				new SubProgressMonitor(pm, 1));
		for (Iterator<Entry<IFile, String>> iterator = classpathFilesContents
				.entrySet().iterator(); iterator.hasNext();) {
			Entry<IFile, String> entry = iterator.next();
			IFile file = entry.getKey();
			String contents = entry.getValue();
			// Restore time stamps? This should probably be some sort of
			// UndoTextFileChange.
			TextFileChange classpathUndo = new TextFileChange(Messages.format(
					RefactoringCoreMessages.DeleteProjectFragmentChange_restore_file,
					file.getFullPath().toOSString()), file);
			classpathUndo
					.setEdit(new ReplaceEdit(0, getFileLength(file), contents));
			result.add(classpathUndo);
		}
		result.add(new UndoDeleteResourceChange(rootDescription));

		pm.done();
		return result;
	}

	private boolean confirmDeleteIfReferenced() throws ModelException {
		if (!getRoot().isArchive()) // for source folders, you don't ask, just
									// do it
			return true;
		if (fUpdateClasspathQuery == null)
			return true;
		IScriptProject[] referencingProjects = ModelElementUtil
				.getReferencingProjects(getRoot());
		if (referencingProjects.length == 0)
			return true;
		return fUpdateClasspathQuery.confirmManipulation(getRoot(),
				referencingProjects);
	}

	private static int getFileLength(IFile file) throws CoreException {
		// Cannot use file buffers here, since they are not yet in sync at this
		// point.
		InputStream contents = file.getContents();
		InputStreamReader reader;
		try {
			reader = new InputStreamReader(contents, file.getCharset());
		} catch (UnsupportedEncodingException e) {
			DLTKUIPlugin.log(e);
			reader = new InputStreamReader(contents);
		}
		try {
			return (int) reader.skip(Integer.MAX_VALUE);
		} catch (IOException e) {
			throw new CoreException(new Status(IStatus.ERROR,
					DLTKUIPlugin.getPluginId(), e.getMessage(), e));
		}
	}

	private static String getFileContents(IFile file) throws CoreException {
		ITextFileBufferManager manager = FileBuffers.getTextFileBufferManager();
		IPath path = file.getFullPath();
		manager.connect(path, LocationKind.IFILE, new NullProgressMonitor());
		try {
			return manager.getTextFileBuffer(path, LocationKind.IFILE)
					.getDocument().get();
		} finally {
			manager.disconnect(path, LocationKind.IFILE,
					new NullProgressMonitor());
		}
	}
}