/*******************************************************************************
 * Copyright (c) 2007, 2017 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Red Hat Inc. - Bug 460967
 *******************************************************************************/
package org.eclipse.equinox.internal.p2.touchpoint.natives;

import java.io.*;
import java.net.URI;
import java.util.*;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;
import org.eclipse.core.runtime.*;
import org.eclipse.equinox.internal.p2.core.helpers.LogHelper;
import org.eclipse.equinox.p2.core.*;
import org.eclipse.equinox.p2.engine.IProfile;
import org.eclipse.equinox.p2.repository.IRepository;
import org.eclipse.equinox.p2.repository.artifact.*;
import org.eclipse.osgi.util.NLS;

public class Util {

	public static void log(String message) {
		LogHelper.log(createError(message));
	}

	public static IStatus createError(String message) {
		return new Status(IStatus.ERROR, Activator.ID, message);
	}

	public static String getInstallFolder(IProfile profile) {
		return profile.getProperty(IProfile.PROP_INSTALL_FOLDER);
	}

	private static IAgentLocation getAgentLocation(IProvisioningAgent agent) {
		return (IAgentLocation) agent.getService(IAgentLocation.SERVICE_NAME);
	}

	public static IArtifactRepositoryManager getArtifactRepositoryManager(IProvisioningAgent agent) {
		return (IArtifactRepositoryManager) agent.getService(IArtifactRepositoryManager.SERVICE_NAME);
	}

	public static IFileArtifactRepository getDownloadCacheRepo(IProvisioningAgent agent) throws ProvisionException {
		URI location = getDownloadCacheLocation(agent);
		if (location == null)
			throw new IllegalStateException(Messages.could_not_obtain_download_cache);
		IArtifactRepositoryManager manager = getArtifactRepositoryManager(agent);
		if (manager == null)
			throw new IllegalStateException(Messages.artifact_repo_not_found);
		IArtifactRepository repository;
		try {
			repository = manager.loadRepository(location, null);
		} catch (ProvisionException e) {
			// the download cache doesn't exist or couldn't be read. Create new cache.
			String repositoryName = location + " - Agent download cache"; //$NON-NLS-1$
			Map<String, String> properties = new HashMap<>(1);
			properties.put(IRepository.PROP_SYSTEM, Boolean.TRUE.toString());
			repository = manager.createRepository(location, repositoryName, IArtifactRepositoryManager.TYPE_SIMPLE_REPOSITORY, properties);
		}

		IFileArtifactRepository downloadCache = repository.getAdapter(IFileArtifactRepository.class);
		if (downloadCache == null)
			throw new ProvisionException(NLS.bind(Messages.download_cache_not_writeable, location));
		return downloadCache;
	}

	static private URI getDownloadCacheLocation(IProvisioningAgent agent) {
		IAgentLocation location = getAgentLocation(agent);
		if (location == null)
			return null;
		return URIUtil.append(location.getDataArea("org.eclipse.equinox.p2.core"), "cache/"); //$NON-NLS-1$ //$NON-NLS-2$
	}

	/**
	 * Unzip from a File to an output directory, with progress indication and backup.
	 * monitor and backup store may be null.
	 */
	public static File[] unzipFile(File zipFile, File outputDir, IBackupStore store, String taskName, IProgressMonitor monitor) throws IOException {
		return unzipFile(zipFile, outputDir, null /*path*/, null /*includes*/, null /*excludes*/, store, taskName, monitor);
	}

	/**
	 * Unzip from a File to an output directory, with progress indication and backup.
	 * monitor and backup store may be null.
	 * It takes in count exclude/exclude pattern (that can be null, case when everything is unzipped).
	 * If a path is specified, the path is consider as entry point in zip, as when the to directory in zip would have been the specified path.
	 */
	public static File[] unzipFile(File zipFile, File outputDir, String path, String[] includePatterns, String[] excludePatterns, IBackupStore store, String taskName, IProgressMonitor monitor) throws IOException {
		try (InputStream in = new FileInputStream(zipFile)) {
			return unzipStream(in, zipFile.length(), outputDir, path, includePatterns, excludePatterns, store, taskName, monitor);
		} catch (IOException e) {
			// add the file name to the message
			IOException ioException = new IOException(NLS.bind(Messages.Util_Error_Unzipping, zipFile, e.getMessage()));
			ioException.initCause(e);
			throw ioException;
		}
	}

	/**
	 * Unzip from an InputStream to an output directory using backup of overwritten files
	 * if backup store is not null.
	 */
	public static File[] unzipStream(InputStream stream, long size, File outputDir, IBackupStore store, String taskName, IProgressMonitor monitor) throws IOException {
		return unzipStream(stream, size, outputDir, null /*path*/, null /*includes*/, null /*excludes*/, store, taskName, monitor);
	}

	/**
	 * Unzip from an InputStream to an output directory using backup of overwritten files
	 * if backup store is not null.
	 * It takes in count exclude/exclude pattern (that can be null, case when everything is unzipped).
	 * If a path is specified, the path is consider as entry point in zip, as when the to directory in zip would have been the specified path.
	 */
	public static File[] unzipStream(InputStream stream, long size, File outputDir, String path, String[] includePatterns, String[] excludePatterns, IBackupStore store, String taskName, IProgressMonitor monitor) throws IOException {
		InputStream is = monitor == null ? stream : stream; // new ProgressMonitorInputStream(stream, size, size, taskName, monitor); TODO Commented code
		try (ZipInputStream in = new ZipInputStream(new BufferedInputStream(is))) {
			ZipEntry ze = in.getNextEntry();
			if (ze == null) {
				// There must be at least one entry in a zip file.
				// When there isn't getNextEntry returns null.
				in.close();
				throw new IOException(Messages.Util_Invalid_Zip_File_Format);
			}

			if (path != null && path.trim().length() == 0)
				path = null;
			Pattern pathRegex = path == null ? null : createAntStylePattern("(" + path + ")(*)"); //$NON-NLS-1$ //$NON-NLS-2$

			Collection<Pattern> includeRegexp = new ArrayList<>();
			Collection<Pattern> excludeRegexp = new ArrayList<>();
			if (includePatterns != null) {
				for (String pattern : includePatterns) {
					if (pattern != null) {
						includeRegexp.add(createAntStylePattern(pattern));
					}
				}
			}
			if (excludePatterns != null) {
				for (String pattern : excludePatterns) {
					if (pattern != null) {
						excludeRegexp.add(createAntStylePattern(pattern));
					}
				}
			}
			ArrayList<File> unzippedFiles = new ArrayList<>();
			do {
				String name = ze.getName();
				if (pathRegex == null || pathRegex.matcher(name).matches()) {
					boolean unzip = includeRegexp.isEmpty();
					for (Pattern pattern : includeRegexp) {
						unzip = pattern.matcher(name).matches();
						if (unzip)
							break;
					}
					if (unzip && !excludeRegexp.isEmpty()) {
						for (Pattern pattern : excludeRegexp) {
							if (pattern.matcher(name).matches()) {
								unzip = false;
								break;
							}
						}
					}
					if (unzip) {
						if (pathRegex != null) {
							Matcher matcher = pathRegex.matcher(name);
							if (matcher.matches()) {
								name = matcher.group(2);
								if (name.startsWith("/")) //$NON-NLS-1$
									name = name.substring(1);
							}
						}
						File outFile = new File(outputDir, name);
						unzippedFiles.add(outFile);
						if (ze.isDirectory()) {
							outFile.mkdirs();
						} else {
							if (outFile.exists()) {
								if (store != null)
									store.backup(outFile);
								else
									outFile.delete();
							} else {
								outFile.getParentFile().mkdirs();
							}
							try {
								copyStream(in, false, new FileOutputStream(outFile), true);
							} catch (FileNotFoundException e) {
								// TEMP: ignore this for now in case we're trying to replace
								// a running eclipse.exe
							}
							outFile.setLastModified(ze.getTime());
						}
					}
				}
				in.closeEntry();
			} while ((ze = in.getNextEntry()) != null);
			return unzippedFiles.toArray(new File[unzippedFiles.size()]);
		}

	}

	/**
	 * Copy an input stream to an output stream.
	 * Optionally close the streams when done.
	 * Return the number of bytes written.
	 */
	public static int copyStream(InputStream in, boolean closeIn, OutputStream out, boolean closeOut) throws IOException {
		try {
			int written = 0;
			byte[] buffer = new byte[16 * 1024];
			int len;
			while ((len = in.read(buffer)) != -1) {
				out.write(buffer, 0, len);
				written += len;
			}
			return written;
		} finally {
			try {
				if (closeIn) {
					in.close();
				}
			} finally {
				if (closeOut) {
					out.close();
				}
			}
		}
	}

	private static Pattern createAntStylePattern(String pattern) {
		StringBuffer sb = new StringBuffer();
		for (int c = 0; c < pattern.length(); c++) {
			switch (pattern.charAt(c)) {
				case '.' :
					sb.append("\\."); //$NON-NLS-1$
					break;
				case '*' :
					sb.append(".*"); //$NON-NLS-1$
					break;
				case '?' :
					sb.append(".?"); //$NON-NLS-1$
					break;
				default :
					sb.append(pattern.charAt(c));
					break;
			}
		}
		String string = sb.toString();
		if (string.endsWith("\\..*")) { //$NON-NLS-1$
			sb.append("|"); //$NON-NLS-1$
			sb.append(string.substring(0, string.length() - 4));
		}
		return Pattern.compile(sb.toString());
	}

}