BEGIN LICENSE BLOCK *****
Version: EPL 2.0/GPL 2.0/LGPL 2.1
The contents of this file are subject to the Eclipse Public
License Version 2.0 (the "License"); you may not use this file
except in compliance with the License. You may obtain a copy of
the License at http://www.eclipse.org/legal/epl-v20.html
Software distributed under the License is distributed on an "AS
IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
implied. See the License for the specific language governing
rights and limitations under the License.
Copyright (C) 2002-2004 Anders Bengtsson 
Copyright (C) 2002-2004 Jan Arne Petersen 
Copyright (C) 2004 Thomas E Enebo 
Copyright (C) 2004-2005 Charles O Nutter 
Copyright (C) 2004 Stefan Matthias Aust 
Alternatively, the contents of this file may be used under the terms of
either of the GNU General Public License Version 2 or later (the "GPL"),
or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
in which case the provisions of the GPL or the LGPL are applicable instead
of those above. If you wish to allow use of your version of this file only
under the terms of either the GPL or the LGPL, and not to allow others to
use your version of this file under the terms of the EPL, indicate your
decision by deleting the provisions above and replace them with the notice
and other provisions required by the GPL or the LGPL. If you do not delete
the provisions above, a recipient may use your version of this file under
the terms of any one of the EPL, the GPL or the LGPL.
END LICENSE BLOCK /***** BEGIN LICENSE BLOCK *****
 * Version: EPL 2.0/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Eclipse Public
 * License Version 2.0 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of
 * the License at http://www.eclipse.org/legal/epl-v20.html
 *
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * Copyright (C) 2002-2004 Anders Bengtsson <ndrsbngtssn@yahoo.se>
 * Copyright (C) 2002-2004 Jan Arne Petersen <jpetersen@uni-bonn.de>
 * Copyright (C) 2004 Thomas E Enebo <enebo@acm.org>
 * Copyright (C) 2004-2005 Charles O Nutter <headius@headius.com>
 * Copyright (C) 2004 Stefan Matthias Aust <sma@3plus4.de>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the EPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the EPL, the GPL or the LGPL.
 ***** END LICENSE BLOCK *****/

package org.jruby;

import java.io.Closeable;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.nio.file.FileSystems;
import java.nio.file.Path;
import java.nio.file.Watchable;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.regex.Pattern;

import jnr.posix.FileStat;
import jnr.posix.util.Platform;

import org.jcodings.Encoding;
import org.jruby.anno.JRubyMethod;
import org.jruby.anno.JRubyClass;
import org.jruby.exceptions.RaiseException;
import org.jruby.javasupport.JavaUtil;
import org.jruby.runtime.Block;
import org.jruby.runtime.ClassIndex;
import org.jruby.runtime.ObjectAllocator;
import org.jruby.runtime.ThreadContext;
import org.jruby.runtime.builtin.IRubyObject;
import org.jruby.util.*;
import org.jruby.ast.util.ArgsUtil;

import static org.jruby.RubyEnumerator.enumeratorize;
import static org.jruby.RubyString.UTF8;

The Ruby built-in class Dir.
Author:
 jvoegele/**
 * The Ruby built-in class Dir.
 *
 * @author  jvoegele
 */
@JRubyClass(name = "Dir", include = "Enumerable")
public class RubyDir extends RubyObject implements Closeable {
    private RubyString path;       // What we passed to the constructor for method 'path'
    protected FileResource dir;
    private long lastModified = Long.MIN_VALUE;
    private String[] snapshot;     // snapshot of contents of directory
    private int pos;               // current position in directory
    private boolean isOpen = true;
    private Encoding encoding;

    private static final Pattern PROTOCOL_PATTERN = Pattern.compile("^(uri|jar|file|classpath):([^:]*:)?//?.*");

    public RubyDir(Ruby runtime, RubyClass type) {
        super(runtime, type);
    }

    private static final ObjectAllocator DIR_ALLOCATOR = new ObjectAllocator() {
        @Override
        public IRubyObject allocate(Ruby runtime, RubyClass klass) {
            return new RubyDir(runtime, klass);
        }
    };

    public static RubyClass createDirClass(Ruby runtime) {
        RubyClass dirClass = runtime.defineClass("Dir", runtime.getObject(), DIR_ALLOCATOR);
        runtime.setDir(dirClass);

        dirClass.setClassIndex(ClassIndex.DIR);
        dirClass.setReifiedClass(RubyDir.class);

        dirClass.includeModule(runtime.getEnumerable());
        dirClass.defineAnnotatedMethods(RubyDir.class);

        return dirClass;
    }

    private final void checkDir() {
        checkDirIgnoreClosed();

        if (!isOpen) throw getRuntime().newIOError("closed directory");
    }

    private final void checkDirIgnoreClosed() {
        testFrozen("Dir");
        // update snapshot (if changed) :
        if (snapshot == null || dir.exists() && dir.lastModified() > lastModified) {
            lastModified = dir.lastModified();
            snapshot = list(dir);
        }
    }

    
Creates a new Dir.  This method takes a snapshot of the
contents of the directory at creation time, so changes to the contents
of the directory will not be reflected during the lifetime of the
Dir object returned, so a new Dir instance
must be created to reflect changes to the underlying file system.
Params:
context – current context
path – target path
Returns:
a new Dir object/**
     * Creates a new <code>Dir</code>.  This method takes a snapshot of the
     * contents of the directory at creation time, so changes to the contents
     * of the directory will not be reflected during the lifetime of the
     * <code>Dir</code> object returned, so a new <code>Dir</code> instance
     * must be created to reflect changes to the underlying file system.
     *
     * @param context current context
     * @param path target path
     * @return a new Dir object
     */
    @JRubyMethod(name = "initialize")
    public IRubyObject initialize(ThreadContext context, IRubyObject path) {
        Ruby runtime = context.runtime;

        return initializeCommon(context, path, runtime.getDefaultFilesystemEncoding(), runtime);
    }

    
Like initialize(ThreadContext, IRubyObject) but accepts an :encoding option. 
Params:
context – current context
path – target path
encOpts – encoding options
Returns:
a new Dir object/**
     * Like {@link #initialize(ThreadContext, IRubyObject)} but accepts an :encoding option.
     *
     * @param context current context
     * @param path target path
     * @param encOpts encoding options
     * @return a new Dir object
     */
    @JRubyMethod(name = "initialize")
    public IRubyObject initialize(ThreadContext context, IRubyObject path, IRubyObject encOpts) {
        Ruby runtime = context.runtime;

        Encoding encoding = null;

        if (!encOpts.isNil()) {
            RubyHash opts = encOpts.convertToHash();
            IRubyObject encodingArg = ArgsUtil.extractKeywordArg(context, opts, "encoding");
            if (encodingArg != null && !encodingArg.isNil()) {
                encoding = runtime.getEncodingService().getEncodingFromObject(encodingArg);
            }
        }

        if (encoding == null) encoding = runtime.getDefaultFilesystemEncoding();

        return initializeCommon(context, path, encoding, runtime);
    }

    private RubyDir initializeCommon(ThreadContext context, IRubyObject pathArg, Encoding encoding, Ruby runtime) {
        RubyString newPath = StringSupport.checkEmbeddedNulls(runtime, RubyFile.get_path(context, pathArg));
        this.path = newPath;
        this.pos = 0;

        this.encoding = encoding;

        String adjustedPath = RubyFile.adjustRootPathOnWindows(runtime, newPath.toString(), null);
        checkDirIsTwoSlashesOnWindows(getRuntime(), adjustedPath);

        this.dir = JRubyFile.createResource(context, adjustedPath);
        this.snapshot = getEntries(context, dir, adjustedPath);

        return this;
    }

    @Deprecated
    public IRubyObject initialize19(ThreadContext context, IRubyObject arg) {
        return initialize(context, arg);
    }

// ----- Ruby Class Methods ----------------------------------------------------

    private static ArrayList<ByteList> dirGlobs(ThreadContext context, String cwd, IRubyObject[] args, int flags) {
        ArrayList<ByteList> dirs = new ArrayList<>();

        for ( int i = 0; i < args.length; i++ ) {
            dirs.addAll(Dir.push_glob(context.runtime, cwd, globArgumentAsByteList(context, args[i]), flags));
        }

        return dirs;
    }

    private static RubyArray asRubyStringList(Ruby runtime, List<ByteList> dirs) {
        final int size = dirs.size();
        if ( size == 0 ) return RubyArray.newEmptyArray(runtime);

        IRubyObject[] dirStrings = new IRubyObject[ size ];
        for ( int i = 0; i < size; i++ ) {
            dirStrings[i] = RubyString.newStringNoCopy(runtime, dirs.get(i));
        }
        return RubyArray.newArrayMayCopy(runtime, dirStrings);
    }

    private static String getCWD(Ruby runtime) {
        final String cwd = runtime.getCurrentDirectory();
        // ^(uri|jar|file|classpath):([^:]*:)?//?.*
        if (cwd.startsWith("uri:") || cwd.startsWith("jar:") || cwd.startsWith("file:")) {
            // "classpath:" mapped into "uri:classloader:"
            return cwd;
        }
        try { // NOTE: likely not necessary as we already canonicalized while setting?
            return new JRubyFile(cwd).getCanonicalPath();
        }
        catch (IOException e) {
            return cwd;
        }
    }

    private static final String[] BASE = new String[] { "base" };
    private static final String[] BASE_FLAGS = new String[] { "base", "flags" };

    // returns null (no kwargs present), "" kwargs but no base key, "something" kwargs with base key (which might be "").
    private static String globOptions(ThreadContext context, IRubyObject[] args, int[] flags) {
        Ruby runtime = context.runtime;

        if (args.length > 1) {
            IRubyObject tmp = TypeConverter.checkHashType(runtime, args[args.length - 1]);
            if (tmp == context.nil) {
                if (flags != null) {
                    flags[0] = RubyNumeric.num2int(args[1]);
                }
            } else {
                String[] keys = flags != null ? BASE_FLAGS : BASE;
                IRubyObject[] rets = ArgsUtil.extractKeywordArgs(context, (RubyHash) tmp, keys);
                String base = rets[0] == null || rets[0] == context.nil ? "" : RubyFile.get_path(context, rets[0]).asJavaString();

                // Deep down in glob things are unhappy if base is not absolute.
                if (!base.isEmpty()) {
                    JRubyFile file = new JRubyFile(base);

                    // FIXME: This is a bit of a hot mess.  Deep down in the ancient caves of glob land we do not
                    // like see a base which is not an absolute path.  JRubyFile by itself uses what I am guessing
                    // is the JVM CWD and not the runtimes CWD so if path is not absolute I remake the thing again...
                    if (!file.isAbsolute()) {
                        base = new JRubyFile(runtime.getCurrentDirectory(), base).getAbsolutePath();
                    }
                }
                if (flags != null) flags[0] = rets[1] == null ? 0 : RubyNumeric.num2int(rets[1]);
                return base;
            }
        }

        return null;
    }

    @JRubyMethod(name = "[]", rest = true, meta = true)
    public static IRubyObject aref(ThreadContext context, IRubyObject recv, IRubyObject[] args) {
        Ruby runtime = context.runtime;
        String base = globOptions(context, args, null);
        List<ByteList> dirs;

        if (args.length == 1) {
            String dir = base == null || base.isEmpty() ? runtime.getCurrentDirectory() : base;
            dirs = Dir.push_glob(runtime, dir, globArgumentAsByteList(context, args[0]), 0);
        } else {
            IRubyObject[] arefArgs;
            if (base != null) { // kwargs are present
                arefArgs = ArraySupport.newCopy(args, args.length - 1);
            } else {
                arefArgs = args;
                base = "";
            }

            String dir = base.isEmpty() ? runtime.getCurrentDirectory() : base;
            dirs = dirGlobs(context, dir, arefArgs, 0);
        }

        return asRubyStringList(runtime, dirs);
    }

    private static ByteList globArgumentAsByteList(ThreadContext context, IRubyObject arg) {
        return RubyFile.get_path(context, arg).getByteList();
    }

    
Returns an array of filenames matching the specified wildcard pattern
pat. If a block is given, the array is iterated internally
with each filename is passed to the block in turn. In this case, Nil is
returned.
/**
     * Returns an array of filenames matching the specified wildcard pattern
     * <code>pat</code>. If a block is given, the array is iterated internally
     * with each filename is passed to the block in turn. In this case, Nil is
     * returned.
     */
    @JRubyMethod(required = 1, optional = 2, meta = true)
    public static IRubyObject glob(ThreadContext context, IRubyObject recv, IRubyObject[] args, Block block) {
        Ruby runtime = context.runtime;
        int[] flags = new int[] { 0 };
        String base = globOptions(context, args, flags);
        List<ByteList> dirs;

        if (!(base == null || base.isEmpty()) && !(new File(base).exists())){
            dirs = new ArrayList<ByteList>();
        } else {
            IRubyObject tmp = args[0].checkArrayType();
            String dir = base == null || base.isEmpty() ? runtime.getCurrentDirectory() : base;

            if (tmp.isNil()) {
                dirs = Dir.push_glob(runtime, dir, globArgumentAsByteList(context, args[0]), flags[0]);
            } else {
                dirs = dirGlobs(context, dir, ((RubyArray) tmp).toJavaArray(), flags[0]);
            }
        }

        if (block.isGiven()) {
            for (int i = 0; i < dirs.size(); i++) {
                block.yield(context, RubyString.newString(runtime, dirs.get(i)));
            }

            return runtime.getNil();
        }

        return asRubyStringList(runtime, dirs);
    }

    
Returns:
all entries for this Dir/**
     * @return all entries for this Dir
     */
    @JRubyMethod(name = "entries")
    public RubyArray entries() {
        JavaUtil.StringConverter converter = new JavaUtil.StringConverter(encoding);
        return RubyArray.newArrayMayCopy(getRuntime(), JavaUtil.convertStringArrayToRuby(getRuntime(), snapshot, converter));
    }

    @Deprecated
    public static RubyArray entries(IRubyObject recv, IRubyObject path) {
        return entries(recv.getRuntime().getCurrentContext(), recv, path);
    }

    @Deprecated
    public static RubyArray entries(IRubyObject recv, IRubyObject path, IRubyObject arg, IRubyObject opts) {
        return entries(recv.getRuntime().getCurrentContext(), recv, path, opts);
    }

    
Returns an array containing all of the filenames in the given directory.
/**
     * Returns an array containing all of the filenames in the given directory.
     */
    @JRubyMethod(name = "entries", meta = true)
    public static RubyArray entries(ThreadContext context, IRubyObject recv, IRubyObject arg) {
        Ruby runtime = context.runtime;

        RubyString path = StringSupport.checkEmbeddedNulls(runtime, RubyFile.get_path(context, arg));

        return entriesCommon(context, path.asJavaString(), runtime.getDefaultEncoding(), false);
    }

    @JRubyMethod(name = "entries", meta = true)
    public static RubyArray entries(ThreadContext context, IRubyObject recv, IRubyObject arg, IRubyObject opts) {
        Ruby runtime = context.runtime;
        Encoding encoding = null;

        RubyString path = StringSupport.checkEmbeddedNulls(runtime, RubyFile.get_path(context, arg));

        if (opts instanceof RubyHash) {
            IRubyObject encodingArg = ArgsUtil.extractKeywordArg(context, (RubyHash) opts, "encoding");
            if (encodingArg != null && !encodingArg.isNil()) {
                encoding = runtime.getEncodingService().getEncodingFromObject(encodingArg);
            }
        }
        if (encoding == null) encoding = runtime.getDefaultEncoding();

        return entriesCommon(context, path.asJavaString(), encoding, false);
    }

    private static RubyArray entriesCommon(ThreadContext context, String path, Encoding encoding, final boolean childrenOnly) {
        Ruby runtime = context.runtime;
        String adjustedPath = RubyFile.adjustRootPathOnWindows(runtime, path, null);
        checkDirIsTwoSlashesOnWindows(runtime, adjustedPath);

        FileResource directory = JRubyFile.createResource(context, path);
        String[] files = getEntries(context, directory, adjustedPath);

        RubyArray result = RubyArray.newArray(runtime, files.length);
        for (String file : files) {
            if (childrenOnly) { // removeIf(f -> f.equals(".") || f.equals(".."));
                final int len = file.length();
                if (len == 1 && file.charAt(0) == '.') continue;
                if (len == 2 && file.charAt(0) == '.' && file.charAt(1) == '.') continue;
            }

            result.append( RubyString.newString(runtime, file, encoding) );
        }
        return result;
    }

    private static final String[] NO_FILES = StringSupport.EMPTY_STRING_ARRAY;

    private static String[] getEntries(ThreadContext context, FileResource dir, String path) {
        if (!dir.isDirectory()) {
            if (dir.exists()) {
                throw context.runtime.newErrnoENOTDIRError(path);
            }
            throw context.runtime.newErrnoENOENTError(path);
        }
        if (!dir.canRead()) throw context.runtime.newErrnoEACCESError(path);

        String[] list = dir.list();

        return list == null ? NO_FILES : list;
    }

    // MRI behavior: just plain '//' or '\\\\' are considered illegal on Windows.
    private static void checkDirIsTwoSlashesOnWindows(Ruby runtime, String path) {
        if (Platform.IS_WINDOWS && ("//".equals(path) || "\\\\".equals(path))) {
            throw runtime.newErrnoEINVALError("Invalid argument - " + path);
        }
    }

    
Changes the current directory to path /** Changes the current directory to <code>path</code> */
    @JRubyMethod(optional = 1, meta = true)
    public static IRubyObject chdir(ThreadContext context, IRubyObject recv, IRubyObject[] args, Block block) {
        Ruby runtime = context.runtime;
        RubyString path = args.length == 1 ?
            StringSupport.checkEmbeddedNulls(runtime, RubyFile.get_path(context, args[0])) :
            getHomeDirectoryPath(context);

        String adjustedPath = RubyFile.adjustRootPathOnWindows(runtime, path.asJavaString(), null);
        checkDirIsTwoSlashesOnWindows(runtime, adjustedPath);

        adjustedPath = getExistingDir(runtime, adjustedPath).canonicalPath();

        IRubyObject result;
        if (block.isGiven()) {
            final String oldCwd = runtime.getCurrentDirectory();
            // FIXME: Don't allow multiple threads to do this at once
            runtime.setCurrentDirectory(adjustedPath);
            try {
                result = block.yield(context, path);
            } finally {
                getExistingDir(runtime, oldCwd); // needed in case the block deleted the oldCwd
                runtime.setCurrentDirectory(oldCwd);
            }
        } else {
            runtime.setCurrentDirectory(adjustedPath);
            result = runtime.newFixnum(0);
        }

        return result;
    }

    
Changes the root directory (only allowed by super user).  Not available on all platforms.
/**
     * Changes the root directory (only allowed by super user).  Not available on all platforms.
     */
    @JRubyMethod(name = "chroot", required = 1, meta = true)
    public static IRubyObject chroot(IRubyObject recv, IRubyObject path) {
        throw recv.getRuntime().newNotImplementedError("chroot not implemented: chroot is non-portable and is not supported.");
    }

    
Returns an array containing all of the filenames except for "." and ".." in the given directory.
/**
     * Returns an array containing all of the filenames except for "." and ".." in the given directory.
     */
    @JRubyMethod(name = "children", meta = true)
    public static RubyArray children(ThreadContext context, IRubyObject recv, IRubyObject arg) {
        return children(context, recv, arg, context.nil);
    }

    @JRubyMethod(name = "children", meta = true)
    public static RubyArray children(ThreadContext context, IRubyObject recv, IRubyObject arg, IRubyObject opts) {
        Encoding encoding = null;
        if (opts instanceof RubyHash) {
            IRubyObject encodingArg = ArgsUtil.extractKeywordArg(context, (RubyHash) opts, "encoding");
            if (encodingArg != null && !encodingArg.isNil()) {
                encoding = context.runtime.getEncodingService().getEncodingFromObject(encodingArg);
            }
        }
        if (encoding == null) encoding = context.runtime.getDefaultEncoding();

        return entriesCommon(context, RubyFile.get_path(context, arg).asJavaString(), encoding, true);
    }

    
Deletes the directory specified by path.  The directory must be empty.
/**
     * Deletes the directory specified by <code>path</code>.  The directory must be empty.
     */
    public static IRubyObject rmdir(IRubyObject recv, IRubyObject path) {
        return rmdir19(recv.getRuntime().getCurrentContext(), recv, path);
    }

    @JRubyMethod(name = {"rmdir", "unlink", "delete"}, required = 1, meta = true)
    public static IRubyObject rmdir19(ThreadContext context, IRubyObject recv, IRubyObject path) {
        Ruby runtime = context.runtime;
        RubyString cleanPath = StringSupport.checkEmbeddedNulls(runtime, RubyFile.get_path(context, path));
        return rmdirCommon(runtime, cleanPath.asJavaString());
    }

    private static RubyFixnum rmdirCommon(Ruby runtime, String path) {
        JRubyFile directory = getDirForRmdir(runtime, path);

        // at this point, only thing preventing delete should be non-emptiness
        if (runtime.getPosix().rmdir(directory.toString()) < 0) {
            throw runtime.newErrnoENOTEMPTYError(path);
        }

        return runtime.newFixnum(0);
    }

    
Executes the block once for each entry in the directory except
for "." and "..", passing the filename of each entry as parameter
to the block.
/**
     * Executes the block once for each entry in the directory except
     * for "." and "..", passing the filename of each entry as parameter
     * to the block.
     */
    @JRubyMethod(name = "each_child", meta = true)
    public static IRubyObject each_child(ThreadContext context, IRubyObject recv, IRubyObject arg, Block block) {
        return eachChildCommon(context, recv, RubyFile.get_path(context, arg), null, block);
    }

    
Executes the block once for each entry in the directory except
for "." and "..", passing the filename of each entry as parameter
to the block.
/**
     * Executes the block once for each entry in the directory except
     * for "." and "..", passing the filename of each entry as parameter
     * to the block.
     */
    @JRubyMethod(name = "each_child", meta = true)
    public static IRubyObject each_child(ThreadContext context, IRubyObject recv, IRubyObject arg, IRubyObject enc, Block block) {
        RubyEncoding encoding;

        if (enc instanceof RubyEncoding) {
            encoding = (RubyEncoding) enc;
        } else {
            throw context.runtime.newTypeError(enc, context.runtime.getEncoding());
        }

        return eachChildCommon(context, recv, RubyFile.get_path(context, arg), encoding, block);
    }

    
Executes the block once for each file in the directory specified by
path.
/**
     * Executes the block once for each file in the directory specified by
     * <code>path</code>.
     */
    @JRubyMethod(name = "foreach", meta = true)
    public static IRubyObject foreach(ThreadContext context, IRubyObject recv, IRubyObject path, Block block) {
        return foreachCommon(context, recv, RubyFile.get_path(context, path), null, block);
    }

    @JRubyMethod(name = "foreach", meta = true)
    public static IRubyObject foreach(ThreadContext context, IRubyObject recv, IRubyObject path, IRubyObject encOpts, Block block) {
        Encoding encoding = null;

        if(!encOpts.isNil()) {
        	IRubyObject opts = TypeConverter.checkHashType(context.runtime, encOpts);
	        IRubyObject encodingArg = ArgsUtil.extractKeywordArg(context, (RubyHash) opts, "encoding");
	        if (encodingArg != null && !encodingArg.isNil()) {
	        	encoding = context.runtime.getEncodingService().getEncodingFromObject(encodingArg);
	        }
        }

        if (encoding == null) encoding = context.runtime.getDefaultFilesystemEncoding();

        return foreachCommon(context, recv, RubyFile.get_path(context, path), encoding, block);
    }

    @Deprecated
    public static IRubyObject foreach19(ThreadContext context, IRubyObject recv, IRubyObject path, Block block) {
        return foreachCommon(context, recv, RubyFile.get_path(context, path), null, block);
    }

    @Deprecated
    public static IRubyObject foreach19(ThreadContext context, IRubyObject recv, IRubyObject path, IRubyObject enc, Block block) {
        return foreachCommon(context, recv, RubyFile.get_path(context, path), context.runtime.getEncodingService().getEncodingFromObject(enc), block);
    }

    private static IRubyObject eachChildCommon(ThreadContext context, IRubyObject recv, RubyString path, RubyEncoding encoding, Block block) {
        final Ruby runtime = context.runtime;
        if (block.isGiven()) {
            RubyDir dir = (RubyDir) runtime.getDir().newInstance(context, path, Block.NULL_BLOCK);

            dir.each_child(context, encoding == null ? runtime.getDefaultEncoding() : encoding.getEncoding(), block);
            return context.nil;
        }

        if (encoding == null) {
            return enumeratorize(runtime, recv, "each_child", path);
        }
        return enumeratorize(runtime, recv, "each_child", path, encoding);
    }

    private static IRubyObject foreachCommon(ThreadContext context, IRubyObject recv, RubyString path, Encoding encoding, Block block) {
        final Ruby runtime = context.runtime;
        if (block.isGiven()) {
            RubyDir dir = (RubyDir) runtime.getDir().newInstance(context, path, Block.NULL_BLOCK);

            dir.each(context, encoding == null ? runtime.getDefaultEncoding() : encoding, block);
            return context.nil;
        }

        if (encoding == null) {
            return enumeratorize(runtime, recv, "foreach", path);
        }
        
        IRubyObject rubyEncoding = runtime.getEncodingService().getEncoding(encoding); 
        return enumeratorize(runtime, recv, "foreach", path, rubyEncoding);
    }

    
Returns the current directory. /** Returns the current directory. */
    @JRubyMethod(name = {"getwd", "pwd"}, meta = true)
    public static RubyString getwd(IRubyObject recv) {
        Ruby runtime = recv.getRuntime();

        RubyString pwd = RubyString.newUnicodeString(runtime, getCWD(runtime));
        pwd.setTaint(true);
        return pwd;
    }

    
Returns the home directory of the current user or the named user if given.
/**
     * Returns the home directory of the current user or the named user if given.
     */
    @JRubyMethod(name = "home", optional = 1, meta = true)
    public static IRubyObject home(ThreadContext context, IRubyObject recv, IRubyObject[] args) {
        if (args.length > 0 && args[0] != context.nil) return getHomeDirectoryPath(context, args[0].toString());

        return getHomeDirectoryPath(context);
    }

    
Creates the directory specified by path.  Note that the
mode parameter is provided only to support existing Ruby
code, and is ignored.
/**
     * Creates the directory specified by <code>path</code>.  Note that the
     * <code>mode</code> parameter is provided only to support existing Ruby
     * code, and is ignored.
     */
    @JRubyMethod(name = "mkdir", required = 1, optional = 1, meta = true)
    public static IRubyObject mkdir(ThreadContext context, IRubyObject recv, IRubyObject... args) {
        Ruby runtime = context.runtime;
        RubyString path = StringSupport.checkEmbeddedNulls(runtime, RubyFile.get_path(context, args[0]));
        return mkdirCommon(runtime, path.asJavaString(), args);
    }

    @Deprecated
    public static IRubyObject mkdir(IRubyObject recv, IRubyObject[] args) {
        return mkdir(recv.getRuntime().getCurrentContext(), recv, args);
    }

    @Deprecated
    public static IRubyObject mkdir19(ThreadContext context, IRubyObject recv, IRubyObject[] args) {
        return mkdir(context, recv, args);
    }

    private static IRubyObject mkdirCommon(Ruby runtime, String path, IRubyObject[] args) {
        if (path.startsWith("uri:")) throw runtime.newErrnoEACCESError(path);

        path = dirFromPath(path, runtime);
        FileResource res = JRubyFile.createResource(runtime, path);
        if (res.isDirectory()) throw runtime.newErrnoEEXISTError(path);

        String name = path.replace('\\', '/');
        boolean startsWithDriveLetterOnWindows = RubyFile.startsWithDriveLetterOnWindows(name);

        // don't attempt to create a dir for drive letters
        if (startsWithDriveLetterOnWindows) {
            // path is just drive letter plus :
            if (path.length() == 2) return RubyFixnum.zero(runtime);
            // path is drive letter plus : plus leading or trailing /
            if (path.length() == 3 && (path.charAt(0) == '/' || path.charAt(2) == '/')) return RubyFixnum.zero(runtime);
            // path is drive letter plus : plus leading and trailing /
            if (path.length() == 4 && (path.charAt(0) == '/' && path.charAt(3) == '/')) return RubyFixnum.zero(runtime);
        }

        File newDir = res.unwrap(File.class);
        if (File.separatorChar == '\\') newDir = new File(newDir.getPath());

        int mode = args.length == 2 ? ((int) args[1].convertToInteger().getLongValue()) : 0777;

        if (runtime.getPosix().mkdir(newDir.getAbsolutePath(), mode) < 0) {
            // FIXME: This is a system error based on errno
            throw runtime.newSystemCallError("mkdir failed");
        }

        return RubyFixnum.zero(runtime);
    }

    
Returns a new directory object for path.  If a block is
provided, a new directory object is passed to the block, which closes the
directory object before terminating.
/**
     * Returns a new directory object for <code>path</code>.  If a block is
     * provided, a new directory object is passed to the block, which closes the
     * directory object before terminating.
     */
    @JRubyMethod(name = "open", meta = true)
    public static IRubyObject open(ThreadContext context, IRubyObject recv, IRubyObject path, Block block) {
        RubyDir directory = (RubyDir) context.runtime.getDir().newInstance(context, path, Block.NULL_BLOCK);

        if (!block.isGiven()) return directory;

        try {
            return block.yield(context, directory);
        } finally {
            directory.close();
        }
    }

    @JRubyMethod(name = "open", meta = true)
    public static IRubyObject open(ThreadContext context, IRubyObject recv, IRubyObject path, IRubyObject encOpts, Block block) {
        RubyDir directory = (RubyDir) context.runtime.getDir().newInstance(context, path, encOpts, Block.NULL_BLOCK);

        if (!block.isGiven()) return directory;

        try {
            return block.yield(context, directory);
        } finally {
            directory.close();
        }
    }

    @Deprecated
    public static IRubyObject open19(ThreadContext context, IRubyObject recv, IRubyObject path, Block block) {
        return open(context, recv, path, block);
    }

// ----- Ruby Instance Methods -------------------------------------------------

    
Closes the directory stream.
/**
     * Closes the directory stream.
     */
    @JRubyMethod(name = "close")
    public IRubyObject close(ThreadContext context) {
        close();
        return context.nil;
    }

    public final void close() {
        // Make sure any read()s after close fail.
        checkDirIgnoreClosed();
        isOpen = false;
    }

    
Executes the block once for each entry in the directory.
/**
     * Executes the block once for each entry in the directory.
     */
    public IRubyObject each(ThreadContext context, Encoding enc, Block block) {
        checkDir();

        String[] contents = snapshot;
        for (pos = 0; pos < contents.length; pos++) {
            block.yield(context, RubyString.newString(context.runtime, contents[pos], enc));
        }

        return this;
    }

    
Executes the block once for each entry in the directory.
/**
     * Executes the block once for each entry in the directory.
     */
    @JRubyMethod(name = "each")
    public IRubyObject each(ThreadContext context, Block block) {
        return block.isGiven() ? each(context, encoding, block) : enumeratorize(context.runtime, this, "each");
    }

    @JRubyMethod(name = "each")
    public IRubyObject each(ThreadContext context, IRubyObject encoding, Block block) {
        if (!(encoding instanceof RubyEncoding)) throw context.runtime.newTypeError(encoding, context.runtime.getEncoding());

        return block.isGiven() ? each(context, ((RubyEncoding) encoding).getEncoding(), block) : enumeratorize(context.runtime, this, "each", encoding);
    }

    @Deprecated
    public IRubyObject each19(ThreadContext context, Block block) {
        return each(context, block);
    }

    @Deprecated
    public IRubyObject each19(ThreadContext context, IRubyObject encoding, Block block) {
        return each(context, encoding, block);
    }

    
Executes the block once for each child in the directory
(i.e. all the directory entries except for "." and "..").
/**
     * Executes the block once for each child in the directory
     * (i.e. all the directory entries except for "." and "..").
     */
    public IRubyObject each_child(ThreadContext context, Encoding enc, Block block) {
        checkDir();

        String[] contents = snapshot;
        for (pos = 0; pos < contents.length; pos++) {
            if (StringSupport.contentEquals(contents[pos], '.')) continue; /* current dir */
            if (StringSupport.contentEquals(contents[pos], '.', '.')) continue; /* parent dir */
            block.yield(context, RubyString.newString(context.runtime, contents[pos], enc));
        }

        return this;
    }

    
Executes the block once for each child in the directory
(i.e. all the directory entries except for "." and "..").
/**
     * Executes the block once for each child in the directory
     * (i.e. all the directory entries except for "." and "..").
     */
    public IRubyObject each_child(ThreadContext context, Block block) {
        return each_child(context, encoding, block);
    }

    @Override
    @JRubyMethod
    public IRubyObject inspect() {
        Ruby runtime = getRuntime();
        StringBuilder part = new StringBuilder();
        String cname = getMetaClass().getRealClass().getName();
        part.append("#<").append(cname).append(':');
        if (path != null) { part.append(path.asJavaString()); }
        part.append('>');

        return runtime.newString(part.toString());
    }

    
Returns the current position in the directory.
/**
     * Returns the current position in the directory.
     */
    @JRubyMethod(name = {"tell", "pos"})
    public RubyInteger tell() {
        checkDir();
        return getRuntime().newFixnum(pos);
    }

    
Moves to a position d.  pos must be a value
returned by tell or 0.
/**
     * Moves to a position <code>d</code>.  <code>pos</code> must be a value
     * returned by <code>tell</code> or 0.
     */

    @JRubyMethod(name = "seek", required = 1)
    public IRubyObject seek(IRubyObject newPos) {
        checkDir();

        set_pos(newPos);
        return this;
    }

    @JRubyMethod(name = "pos=", required = 1)
    public IRubyObject set_pos(IRubyObject newPos) {
        int pos2 = RubyNumeric.fix2int(newPos);
        if (pos2 >= 0) this.pos = pos2;
        return newPos;
    }

    @JRubyMethod(name = {"path", "to_path"})
    public IRubyObject path(ThreadContext context) {
        return path == null ? context.nil : path.strDup(context.runtime);
    }

    @JRubyMethod
    public IRubyObject to_path(ThreadContext context) {
        return path(context);
    }

    public String getPath() {
        if (path == null) return null;
        return path.asJavaString();
    }

    
Returns the next entry from this directory. /** Returns the next entry from this directory. */
    @JRubyMethod(name = "read")
    public IRubyObject read() {
        checkDir();

        final String[] snapshot = this.snapshot;
        if (pos >= snapshot.length) return getRuntime().getNil();

        RubyString result = RubyString.newString(getRuntime(), snapshot[pos], encoding);
        pos++;
        return result;
    }

    
Moves position in this directory to the first entry. /** Moves position in this directory to the first entry. */
    @JRubyMethod(name = "rewind")
    public IRubyObject rewind() {
        checkDir();

        pos = 0;
        return this;
    }

    @JRubyMethod(name = "empty?", meta = true)
    public static IRubyObject empty_p(ThreadContext context, IRubyObject recv, IRubyObject arg) {
        Ruby runtime = context.runtime;
        RubyString path = StringSupport.checkEmbeddedNulls(runtime, RubyFile.get_path(context, arg));
        RubyFileStat fileStat = runtime.newFileStat(path.asJavaString(), false);
        boolean isDirectory = fileStat.directory_p().isTrue();
        return runtime.newBoolean(isDirectory && entries(context, recv, arg).getLength() <= 2);
    }

    @JRubyMethod(name = "exist?", meta = true)
    public static IRubyObject exist(ThreadContext context, IRubyObject recv, IRubyObject arg) {
        Ruby runtime = context.runtime;
        // Capture previous exception if any.
        IRubyObject exception = runtime.getGlobalVariables().get("$!");
        RubyString path = StringSupport.checkEmbeddedNulls(runtime, RubyFile.get_path(context, arg));

        try {
            return runtime.newFileStat(path.asJavaString(), false).directory_p();
        } catch (Exception e) {
            // Restore $!
            runtime.getGlobalVariables().set("$!", exception);
            return runtime.newBoolean(false);
        }
    }

    @JRubyMethod(name = "exists?", meta = true)
    public static IRubyObject exists_p(ThreadContext context, IRubyObject recv, IRubyObject arg) {
        if (context.runtime.warningsEnabled()) {
            context.runtime.getWarnings().warn("Dir.exists? is a deprecated name, use Dir.exist? instead");
        }

        return exist(context, recv, arg);
    }

    @JRubyMethod(name = "fileno", notImplemented = true)
    public IRubyObject fileno(ThreadContext context) {
        throw context.runtime.newNotImplementedError("Dir#fileno");
    }

// ----- Helper Methods --------------------------------------------------------
    
Returns a Java File object for the specified path.  If
path is not a directory, throws IOError.
Params:
path – path for which to return the File object.
mustExist – is true the directory must exist.  If false it must not./** Returns a Java <code>File</code> object for the specified path.  If
     * <code>path</code> is not a directory, throws <code>IOError</code>.
     *
     * @param   path path for which to return the <code>File</code> object.
     * @param   mustExist is true the directory must exist.  If false it must not.
     */ // split out - no longer used
    protected static FileResource getDir(final Ruby runtime, final String path, final boolean mustExist) {
        String dir = dirFromPath(path, runtime);

        FileResource result = JRubyFile.createResource(runtime, dir);

        if (mustExist && (result == null || !result.exists())) {
            throw runtime.newErrnoENOENTError(dir);
        }

        boolean isDirectory = result.isDirectory();

        if (mustExist && !isDirectory) {
            throw runtime.newErrnoENOTDIRError(path);
        }

        if (!mustExist && isDirectory) {
            throw runtime.newErrnoEEXISTError(dir);
        }

        return result;
    }

    private static FileResource getExistingDir(final Ruby runtime, final String path) {
        FileResource result = JRubyFile.createResource(runtime, path);
        if (result == null || !result.exists()) {
            throw runtime.newErrnoENOENTError(path);
        }
        if (!result.isDirectory()) {
            throw runtime.newErrnoENOTDIRError(path);
        }
        return result;
    }

    
Similar to getDir, but performs different checks to match rmdir behavior.
Params:
runtime – 
path – 
Returns:
/**
     * Similar to getDir, but performs different checks to match rmdir behavior.
     * @param runtime
     * @param path
     * @return
     */
    protected static JRubyFile getDirForRmdir(final Ruby runtime, final String path) {
        String dir = dirFromPath(path, runtime);

        JRubyFile directory = JRubyFile.create(runtime.getCurrentDirectory(), dir);

        // Order is important here...File.exists() will return false if the parent
        // dir can't be read, so we check permissions first

        // no permission
        File parentFile = directory.getParentFile();
        if (parentFile.exists() && ! parentFile.canWrite()) {
            throw runtime.newErrnoEACCESError(path);
        }

        // Since we transcode we depend on posix to lookup stat stuff since
        // java.io.File does not seem to cut it.  A failed stat will throw ENOENT.
        FileStat stat = runtime.getPosix().stat(directory.toString());

        // is not directory
        if (!stat.isDirectory()) throw runtime.newErrnoENOTDIRError(path);

        return directory;
    }

    private static String dirFromPath(final String path, final Ruby runtime) throws RaiseException {
        String dir = path;
        String[] pathParts = RubyFile.splitURI(path);
        if (pathParts != null) {
            if (pathParts[0].startsWith("file:") && pathParts[1].length() > 0 && pathParts[1].indexOf(".jar!/") == -1) {
                dir = pathParts[1];
            } else {
                throw runtime.newErrnoENOTDIRError(dir);
            }
        }
        return dir;
    }

    private static String[] list(FileResource directory) {
        final String[] contents = directory.list();
        // If an IO exception occurs (something odd, but possible)
        // A directory may return null.
        return contents == null ? NO_FILES : contents;
    }

    
Deprecated:
no longer used/**
     * @deprecated no longer used
     */
    protected static List<String> getContents(FileResource directory) {
        final String[] contents = directory.list();

        final List<String> result;
        // If an IO exception occurs (something odd, but possible)
        // A directory may return null.
        if (contents != null) {
            result = Arrays.asList(contents);
        }
        else {
             result = Collections.emptyList();
        }
        return result;
    }

    
Deprecated:
no longer used/**
     * @deprecated no longer used
     */
    protected static List<RubyString> getContents(FileResource directory, Ruby runtime) {
        final String[] contents = directory.list();

        final List<RubyString> result;
        if (contents != null) {
            result = new ArrayList<>(contents.length);
            for (int i = 0; i < contents.length; i++) {
                result.add( runtime.newString(contents[i]) );
            }
        }
        else {
            result = Collections.emptyList();
        }

        return result;
    }

    
Returns the home directory of the specified user on the
system. If the home directory of the specified user cannot be found,
an ArgumentError it thrown.
/**
     * Returns the home directory of the specified <code>user</code> on the
     * system. If the home directory of the specified user cannot be found,
     * an <code>ArgumentError it thrown</code>.
     */
    public static IRubyObject getHomeDirectoryPath(ThreadContext context, String user) {
        /*
         * TODO: This version is better than the hackish previous one. Windows
         *       behavior needs to be defined though. I suppose this version
         *       could be improved more too.
         * TODO: /etc/passwd is also inadequate for MacOSX since it does not
         *       use /etc/passwd for regular user accounts
         */
        Ruby runtime = context.runtime;

        try {
            // try to use POSIX for this first
            return runtime.newString(runtime.getPosix().getpwnam(user).getHome());
        } catch (Exception e) {
            // otherwise fall back on the old way
            String passwd;
            try {
                FileInputStream stream = new FileInputStream("/etc/passwd");
                int readBytes = stream.available();
                byte[] bytes = new byte[readBytes];
                readBytes = stream.read(bytes);
                stream.close();
                passwd = new String(bytes, 0, readBytes);
            } catch (IOException ioe) {
                return runtime.getNil();
            }

            List<String> rows = StringSupport.split(passwd, '\n');
            for (int i = 0; i < rows.size(); i++) {
                List<String> fields = StringSupport.split(rows.get(i), ':');
                if (fields.get(0).equals(user)) {
                    return runtime.newString(fields.get(5));
                }
            }
        }

        throw runtime.newArgumentError("user " + user + " doesn't exist");
    }

    static final ByteList HOME = new ByteList(new byte[] {'H','O','M','E'}, false);

    public static RubyString getHomeDirectoryPath(ThreadContext context) {
        final RubyString homeKey = RubyString.newStringShared(context.runtime, HOME);
        return getHomeDirectoryPath(context, context.runtime.getENV().op_aref(context, homeKey));
    }

    private static final ByteList user_home = new ByteList(new byte[] {'u','s','e','r','.','h','o','m','e'}, false);

    static RubyString getHomeDirectoryPath(ThreadContext context, IRubyObject home) {
        final Ruby runtime = context.runtime;

        if (home == null || home == context.nil) {
            IRubyObject ENV_JAVA = runtime.getObject().getConstant("ENV_JAVA");
            home = ENV_JAVA.callMethod(context, "[]", RubyString.newString(runtime, user_home, UTF8));
        }

        if (home == null || home == context.nil) {
            home = context.runtime.getENV().op_aref(context, runtime.newString("LOGDIR"));
        }

        if (home == null || home == context.nil) {
            throw runtime.newArgumentError("user.home/LOGDIR not set");
        }

        return (RubyString) home.dup();
    }

    @Override
    public <T> T toJava(Class<T> target) {
        if (target == File.class) {
            final String path = getPath();
            return path == null ? null : (T) new File(path);
        }
        if (target == Path.class || target == Watchable.class) {
            final String path = getPath();
            return path == null ? null : (T) FileSystems.getDefault().getPath(path);
        }
        return super.toJava(target);
    }

    @Deprecated
    public static RubyArray entries19(ThreadContext context, IRubyObject recv, IRubyObject arg) {
        return entries(context, recv, arg);
    }

    @Deprecated
    public static RubyArray entries19(ThreadContext context, IRubyObject recv, IRubyObject arg, IRubyObject opts) {
        return entries(context, recv, arg, opts);
    }

}