/*
    * Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org> and others
    *
    * This program and the accompanying materials are made available under the
    * terms of the Eclipse Distribution License v. 1.0 which is available at
    * https://www.eclipse.org/org/documents/edl-v10.php.
    *
    * SPDX-License-Identifier: BSD-3-Clause
    */
  
  package org.eclipse.jgit.util;
  
  import static java.nio.charset.StandardCharsets.UTF_8;
  
  import java.io.File;
  import java.io.OutputStream;
  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.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 static final 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;
 	}
 
 	@Override
 	String shellQuote(String cmd) {
 		return QuotedString.BOURNE.quote(cmd.replace(File.separatorChar, '/'));
 	}
 
 	/** {@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, OutputStream outRedirect, OutputStream errRedirect,
 			String stdinArgs) throws JGitInternalException {
 		return internalRunHookIfPresent(repository, hookName, args, outRedirect,
 				errRedirect, stdinArgs);
 	}
 }