plugins/org.eclipse.app4mc.amalthea.model.editor.extended/src/org/eclipse/app4mc/amalthea/model/editor/handler/CompressHandler.java

/**
 ********************************************************************************
 * Copyright (c) 2021-2022 Robert Bosch GmbH and others.
 *
 * This program and the accompanying materials are made
 * available under the terms of the Eclipse Public License 2.0
 * which is available at https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     Robert Bosch GmbH - initial API and implementation
 ********************************************************************************
 */

package org.eclipse.app4mc.amalthea.model.editor.handler;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.file.Files;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

import javax.inject.Named;

import org.eclipse.app4mc.amalthea.model.editor.container.AmaltheaModelContainer;
import org.eclipse.app4mc.amalthea.model.editor.util.AmaltheaEditorUtil;
import org.eclipse.app4mc.amalthea.model.emf.AmaltheaResource;
import org.eclipse.app4mc.amalthea.model.io.AmaltheaFileHelper;
import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.Platform;
import org.eclipse.e4.core.di.annotations.Execute;
import org.eclipse.e4.ui.services.IServiceConstants;
import org.eclipse.emf.ecore.resource.Resource;
import org.eclipse.emf.ecore.resource.ResourceSet;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.ui.IDecoratorManager;

public class CompressHandler {

	private static final int BUFFER_SIZE = 2048;
	private static final String COMPRESS_ERROR = "Compress error";

	@Execute
	public void execute(@Named(IServiceConstants.ACTIVE_SELECTION) IStructuredSelection selection, Shell shell, IDecoratorManager decoratorManager) {
		Object firstElement = selection.getFirstElement();
		if (firstElement instanceof IFile
				&& AmaltheaFileHelper.isModelFileExtension(((IFile) firstElement).getFileExtension())) {

			IFile iFile = (IFile) firstElement;
			AmaltheaModelContainer modelContainer = AmaltheaEditorUtil.getModelContainer(iFile);

			if (modelContainer != null && modelContainer.getInitialModelFiles().contains(iFile)) {
				// Resource is available (model is in memory)
				markResourceZipped(iFile, modelContainer);
			} else {
				// Zip model file
				zipModelFile(iFile, shell, decoratorManager);
			}

		}
	}

	private void markResourceZipped(IFile iFile, AmaltheaModelContainer modelContainer) {
		ResourceSet resourceSet = modelContainer.getResourceSet();
		if (resourceSet != null) {
			for (Resource resource : resourceSet.getResources()) {
				if (resource instanceof AmaltheaResource && resource.getURI().lastSegment().equals(iFile.getName())) {
					// Modify zip flag of loaded resource
					((AmaltheaResource) resource).setUseZip(true);
					// Mark resource as modified
					resource.setModified(true);
					// Mark editors dirty
					modelContainer.updateDirtyStateOfEditors();
					break;
				}
			}
		}
	}

	/**
	 * Creates a Zip file (generic implementation based on java.util.zip package)
	 *
	 * @param iFile
	 * @param shell
	 * @param decoratorManager
	 */
	private void zipModelFile(IFile iFile, Shell shell, IDecoratorManager decoratorManager) {
		File modelFile = new File(iFile.getLocationURI());
		File modelFileTmp = new File(modelFile.getParentFile(), modelFile.getName() + ".tmp");

		// Zip model file (write to temporary file)
		try (	FileInputStream inputStream = new FileInputStream(modelFile);
				ZipOutputStream outputStream = new ZipOutputStream(new FileOutputStream(modelFileTmp));)
		{
			ZipEntry zipEntry = new ZipEntry("ResourceContents");
			outputStream.putNextEntry(zipEntry);
	        byte[] bytes = new byte[BUFFER_SIZE];
	        int length;
	        while((length = inputStream.read(bytes)) >= 0) {
	        	outputStream.write(bytes, 0, length);
	        }
		} catch (IOException e) {
			MessageDialog.openError(shell, COMPRESS_ERROR, "Failed to compress model file! " + e.getMessage());
			return; // stop further actions
		}

		// Delete old model file and rename temporary file
		try {
			Files.delete(modelFile.toPath());
			Files.move(modelFileTmp.toPath(), modelFile.toPath());
		} catch (IOException e) {
			MessageDialog.openError(shell, COMPRESS_ERROR, "Failed to replace model file! " + e.getMessage());
		}

		// Refresh file and decorators
		try {
			iFile.refreshLocal(IResource.DEPTH_INFINITE, null);
			decoratorManager.update("org.eclipse.app4mc.amalthea.file.compressed.decorator");
		} catch (CoreException e) {
			Platform.getLog(getClass()).error(e.getLocalizedMessage(), e);
		}
	}

}