org.eclipse.mdm.nucleus/org.eclipse.mdm.api.atfxadapter/src/main/java/org/eclipse/mdm/api/atfxadapter/filetransfer/ATFXFileService.java

/*******************************************************************************
 * Copyright (c) 2020 Contributors to the Eclipse Foundation
 *
 * See the NOTICE file(s) distributed with this work for additional
 * information regarding copyright ownership.
 *
 * 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.mdm.api.atfxadapter.filetransfer;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.time.Duration;
import java.time.LocalTime;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.UUID;
import java.util.concurrent.atomic.AtomicLong;
import java.util.stream.Collectors;

import org.eclipse.mdm.api.base.file.FileService;
import org.eclipse.mdm.api.base.model.Entity;
import org.eclipse.mdm.api.base.model.FileLink;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * @author akn
 *
 */
public class ATFXFileService implements FileService {

	private static final Logger LOGGER = LoggerFactory.getLogger(ATFXFileService.class);

	private final Path parentDirectory;

	public ATFXFileService(File parentDirectory) {
		this.parentDirectory = parentDirectory.toPath();
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * org.eclipse.mdm.api.base.file.FileService#downloadSequential(org.eclipse.mdm.
	 * api.base.model.Entity, java.nio.file.Path, java.util.Collection,
	 * org.eclipse.mdm.api.base.file.FileService.ProgressListener)
	 */
	@Override
	public void downloadSequential(Entity entity, Path target, Collection<FileLink> fileLinks,
			ProgressListener progressListener) throws IOException {
		Map<String, List<FileLink>> groups = fileLinks.stream().filter(FileLink::isRemote)
				.collect(Collectors.groupingBy(FileLink::getRemotePath));

		long totalSize = calculateDownloadSize(groups);
		final AtomicLong transferred = new AtomicLong();
		LocalTime start = LocalTime.now();
		UUID id = UUID.randomUUID();
		LOGGER.debug("Sequential download of {} file(s) with id '{}' started.", groups.size(), id);
		for (List<FileLink> group : groups.values()) {
			FileLink fileLink = group.get(0);

			download(entity, target, fileLink, (b, p) -> {
				double tranferredBytes = transferred.addAndGet(b);
				if (progressListener != null) {
					progressListener.progress(b, (float) (tranferredBytes / totalSize));
				}
			});

			for (FileLink other : group.subList(1, group.size())) {
				other.setLocalStream(fileLink.getLocalStream());
			}
		}
		LOGGER.debug("Sequential download with id '{}' finished in {}.", id, Duration.between(start, LocalTime.now()));

	}

	private long calculateDownloadSize(Map<String, List<FileLink>> groups) {
		List<FileLink> links = groups.values().stream().map(l -> l.get(0)).collect(Collectors.toList());
		long totalSize = 0;
		for (FileLink fileLink : links) {
			File f = new File(fileLink.getRemotePath());
			// overflow may occur in case of total size exceeds 9223 PB!
			totalSize = Math.addExact(totalSize, f.length());
		}

		return totalSize;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * org.eclipse.mdm.api.base.file.FileService#downloadParallel(org.eclipse.mdm.
	 * api.base.model.Entity, java.nio.file.Path, java.util.Collection,
	 * org.eclipse.mdm.api.base.file.FileService.ProgressListener)
	 */
	@Override
	public void downloadParallel(Entity entity, Path target, Collection<FileLink> fileLinks,
			ProgressListener progressListener) throws IOException {
		// TODO Auto-generated method stub

	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * org.eclipse.mdm.api.base.file.FileService#download(org.eclipse.mdm.api.base.
	 * model.Entity, java.nio.file.Path, org.eclipse.mdm.api.base.model.FileLink,
	 * org.eclipse.mdm.api.base.file.FileService.ProgressListener)
	 */
	@Override
	public void download(Entity entity, Path target, FileLink fileLink, ProgressListener progressListener)
			throws IOException {
		if (Files.exists(target)) {
			if (!Files.isDirectory(target)) {
				throw new IllegalArgumentException("Target path is not a directory.");
			}
		} else {
			Files.createDirectory(target);
		}

		try (InputStream inputStream = openStream(entity, fileLink)) {
			Path absolutePath = target.resolve(fileLink.getFileName()).toAbsolutePath();
			String remotePath = fileLink.getRemotePath();
			LOGGER.debug("Starting download of file '{}' to '{}'.", remotePath, absolutePath);
			LocalTime start = LocalTime.now();
			Files.copy(inputStream, absolutePath);
			LOGGER.debug("File '{}' successfully downloaded in {} to '{}'.", remotePath,
					Duration.between(start, LocalTime.now()), absolutePath);
		}
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * org.eclipse.mdm.api.base.file.FileService#openStream(org.eclipse.mdm.api.base
	 * .model.Entity, org.eclipse.mdm.api.base.model.FileLink,
	 * org.eclipse.mdm.api.base.file.FileService.ProgressListener)
	 */
	@Override
	public InputStream openStream(Entity entity, FileLink fileLink, ProgressListener progressListener)
			throws IOException {

		return new FileInputStream(parentDirectory.resolve(fileLink.getRemotePath()).toFile());
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * org.eclipse.mdm.api.base.file.FileService#loadSize(org.eclipse.mdm.api.base.
	 * model.Entity, org.eclipse.mdm.api.base.model.FileLink)
	 */
	@Override
	public void loadSize(Entity entity, FileLink fileLink) throws IOException {
		// TODO Auto-generated method stub

	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * org.eclipse.mdm.api.base.file.FileService#uploadSequential(org.eclipse.mdm.
	 * api.base.model.Entity, java.util.Collection,
	 * org.eclipse.mdm.api.base.file.FileService.ProgressListener)
	 */
	@Override
	public void uploadSequential(Entity entity, Collection<FileLink> fileLinks, ProgressListener progressListener)
			throws IOException {
		// TODO Auto-generated method stub

	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * org.eclipse.mdm.api.base.file.FileService#uploadParallel(org.eclipse.mdm.api.
	 * base.model.Entity, java.util.Collection,
	 * org.eclipse.mdm.api.base.file.FileService.ProgressListener)
	 */
	@Override
	public void uploadParallel(Entity entity, Collection<FileLink> fileLinks, ProgressListener progressListener)
			throws IOException {
		// TODO Auto-generated method stub

	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * org.eclipse.mdm.api.base.file.FileService#delete(org.eclipse.mdm.api.base.
	 * model.Entity, java.util.Collection)
	 */
	@Override
	public void delete(Entity entity, Collection<FileLink> fileLinks) {
		// TODO Auto-generated method stub

	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * org.eclipse.mdm.api.base.file.FileService#delete(org.eclipse.mdm.api.base.
	 * model.Entity, org.eclipse.mdm.api.base.model.FileLink)
	 */
	@Override
	public void delete(Entity entity, FileLink fileLink) {
		// TODO Auto-generated method stub

	}

}