/*
 * Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
 * and other copyright owners as documented in the project's IP log.
 *
 * This program and the accompanying materials are made available
 * under the terms of the Eclipse Distribution License v1.0 which
 * accompanies this distribution, is reproduced below, and is
 * available at http://www.eclipse.org/org/documents/edl-v10.php
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or
 * without modification, are permitted provided that the following
 * conditions are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following
 *   disclaimer in the documentation and/or other materials provided
 *   with the distribution.
 *
 * - Neither the name of the Eclipse Foundation, Inc. nor the
 *   names of its contributors may be used to endorse or promote
 *   products derived from this software without specific prior
 *   written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.eclipse.jgit.util;

import static java.nio.charset.StandardCharsets.UTF_8;

import java.io.File;
import java.io.PrintStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import org.eclipse.jgit.api.errors.JGitInternalException;
import org.eclipse.jgit.errors.CommandFailedException;
import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.Repository;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * FS implementation for Cygwin on Windows
 *
 * @since 3.0
 */
public class FS_Win32_Cygwin extends FS_Win32 {
	private final static Logger LOG = LoggerFactory
			.getLogger(FS_Win32_Cygwin.class);

	private static String cygpath;

	/**
	 * Whether cygwin is found
	 *
	 * @return true if cygwin is found
	 */
	public static boolean isCygwin() {
		final String path = AccessController
				.doPrivileged((PrivilegedAction<String>) () -> System
						.getProperty("java.library.path") //$NON-NLS-1$
				);
		if (path == null)
			return false;
		File found = FS.searchPath(path, "cygpath.exe"); //$NON-NLS-1$
		if (found != null)
			cygpath = found.getPath();
		return cygpath != null;
	}

	/**
	 * Constructor
	 */
	public FS_Win32_Cygwin() {
		super();
	}

	/**
	 * Constructor
	 *
	 * @param src
	 *            instance whose attributes to copy
	 */
	protected FS_Win32_Cygwin(FS src) {
		super(src);
	}

	/** {@inheritDoc} */
	@Override
	public FS newInstance() {
		return new FS_Win32_Cygwin(this);
	}

	/** {@inheritDoc} */
	@Override
	public File resolve(File dir, String pn) {
		String useCygPath = System.getProperty("jgit.usecygpath"); //$NON-NLS-1$
		if (useCygPath != null && useCygPath.equals("true")) { //$NON-NLS-1$
			String w;
			try {
				w = readPipe(dir, //
					new String[] { cygpath, "--windows", "--absolute", pn }, // //$NON-NLS-1$ //$NON-NLS-2$
					UTF_8.name());
			} catch (CommandFailedException e) {
				LOG.warn(e.getMessage());
				return null;
			}
			if (!StringUtils.isEmptyOrNull(w)) {
				return new File(w);
			}
		}
		return super.resolve(dir, pn);
	}

	/** {@inheritDoc} */
	@Override
	protected File userHomeImpl() {
		final String home = AccessController.doPrivileged(
				(PrivilegedAction<String>) () -> System.getenv("HOME") //$NON-NLS-1$
		);
		if (home == null || home.length() == 0)
			return super.userHomeImpl();
		return resolve(new File("."), home); //$NON-NLS-1$
	}

	/** {@inheritDoc} */
	@Override
	public ProcessBuilder runInShell(String cmd, String[] args) {
		List<String> argv = new ArrayList<>(4 + args.length);
		argv.add("sh.exe"); //$NON-NLS-1$
		argv.add("-c"); //$NON-NLS-1$
		argv.add(cmd + " \"$@\""); //$NON-NLS-1$
		argv.add(cmd);
		argv.addAll(Arrays.asList(args));
		ProcessBuilder proc = new ProcessBuilder();
		proc.command(argv);
		return proc;
	}

	/** {@inheritDoc} */
	@Override
	public String relativize(String base, String other) {
		final String relativized = super.relativize(base, other);
		return relativized.replace(File.separatorChar, '/');
	}

	/** {@inheritDoc} */
	@Override
	public ProcessResult runHookIfPresent(Repository repository, String hookName,
			String[] args, PrintStream outRedirect, PrintStream errRedirect,
			String stdinArgs) throws JGitInternalException {
		return internalRunHookIfPresent(repository, hookName, args, outRedirect,
				errRedirect, stdinArgs);
	}

	/** {@inheritDoc} */
	@Override
	public File findHook(Repository repository, String hookName) {
		final File gitdir = repository.getDirectory();
		if (gitdir == null) {
			return null;
		}
		final Path hookPath = gitdir.toPath().resolve(Constants.HOOKS)
				.resolve(hookName);
		if (Files.isExecutable(hookPath))
			return hookPath.toFile();
		return null;
	}
}