--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/org/tmatesoft/hg/core/HgRevertCommand.java	Tue Jan 15 17:07:19 2013 +0100
@@ -0,0 +1,160 @@
+/*
+ * Copyright (c) 2013 TMate Software Ltd
+ *  
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * For information on how to redistribute this software under
+ * the terms of a license other than GNU General Public License
+ * contact TMate Software at support@hg4j.com
+ */
+package org.tmatesoft.hg.core;
+
+import java.io.File;
+import java.util.Arrays;
+import java.util.LinkedHashSet;
+import java.util.Set;
+
+import org.tmatesoft.hg.internal.DirstateBuilder;
+import org.tmatesoft.hg.internal.DirstateReader;
+import org.tmatesoft.hg.internal.Experimental;
+import org.tmatesoft.hg.internal.Internals;
+import org.tmatesoft.hg.repo.HgInvalidRevisionException;
+import org.tmatesoft.hg.repo.HgManifest;
+import org.tmatesoft.hg.repo.HgRepository;
+import org.tmatesoft.hg.repo.HgRuntimeException;
+import org.tmatesoft.hg.repo.HgManifest.Flags;
+import org.tmatesoft.hg.util.CancelledException;
+import org.tmatesoft.hg.util.Path;
+
+/**
+ * WORK IN PROGRESS.
+ * 
+ * Restore files to their checkout state, 'hg revert' counterpart.
+ * 
+ * @author Artem Tikhomirov
+ * @author TMate Software Ltd.
+ */
+@Experimental(reason="Work in progress")
+public class HgRevertCommand extends HgAbstractCommand<HgRevertCommand> {
+
+	private final HgRepository repo;
+	private final Set<Path> files = new LinkedHashSet<Path>();
+	private int changesetToCheckout = HgRepository.WORKING_COPY; // XXX WORKING_COPY_PARENT, in fact
+	private boolean keepOriginal = true;
+
+	public HgRevertCommand(HgRepository hgRepo) {
+		repo = hgRepo;
+	}
+
+	/**
+	 * Additive
+	 * 
+	 * @param paths files to revert
+	 * @return <code>this</code> for convenience
+	 */
+	public HgRevertCommand file(Path... paths) {
+		files.addAll(Arrays.asList(paths));
+		return this;
+	}
+
+	/**
+	 * Revert the given files to their states as of a specific revision
+	 * 
+	 * @param changesetRevIndex
+	 * @return <code>this</code> for convenience
+	 * @throws HgBadArgumentException
+	 */
+	public HgRevertCommand changeset(int changesetRevIndex) throws HgBadArgumentException {
+		int lastCsetIndex = repo.getChangelog().getLastRevision();
+		if (changesetRevIndex < 0 || changesetRevIndex > lastCsetIndex) {
+			throw new HgBadArgumentException(String.format("Bad revision index %d, value from [0..%d] expected", changesetRevIndex, lastCsetIndex), null).setRevisionIndex(changesetRevIndex);
+		}
+		changesetToCheckout = changesetRevIndex;
+		return this;
+	}
+	
+	/**
+	 * Handy supplement to {@link #changeset(int)}
+	 * 
+	 * @param revision
+	 * @return <code>this</code> for convenience
+	 * @throws HgBadArgumentException
+	 */
+	public HgRevertCommand changeset(Nodeid revision) throws HgBadArgumentException {
+		try {
+			return changeset(repo.getChangelog().getRevisionIndex(revision));
+		} catch (HgInvalidRevisionException ex) {
+			throw new HgBadArgumentException("Can't find revision", ex).setRevision(revision);
+		}
+	}
+	
+	// TODO keepOriginal() to save .orig
+
+	/**
+	 * Perform the back out for the given files
+	 * 
+	 * @throws HgIOException 
+	 * @throws HgException
+	 * @throws CancelledException
+	 */
+	public void execute() throws HgException, CancelledException {
+		try {
+			final int csetRevision;
+			if (changesetToCheckout == HgRepository.WORKING_COPY) {
+				csetRevision = repo.getChangelog().getRevisionIndex(repo.getWorkingCopyParents().first());
+			} else {
+				csetRevision = changesetToCheckout;
+			}
+			Internals implRepo = Internals.getInstance(repo);
+			final DirstateBuilder dirstateBuilder = new DirstateBuilder(implRepo);
+			dirstateBuilder.fillFrom(new DirstateReader(implRepo, new Path.SimpleSource()));
+			final HgCheckoutCommand.CheckoutWorker worker = new HgCheckoutCommand.CheckoutWorker(implRepo);
+			
+			HgManifest.Inspector insp = new HgManifest.Inspector() {
+				
+				public boolean next(Nodeid nid, Path fname, Flags flags) {
+					if (worker.next(nid, fname, flags)) {
+						dirstateBuilder.recordUncertain(fname);
+						return true;
+					}
+					return false;
+				}
+				
+				public boolean end(int manifestRevision) {
+					return false;
+				}
+				
+				public boolean begin(int mainfestRevision, Nodeid nid, int changelogRevision) {
+					return true;
+				}
+			};
+
+			for (Path file : files) {
+				File f = new File(repo.getWorkingDir(), file.toString());
+				if (f.isFile()) {
+					if (keepOriginal) {
+						File copy = new File(f.getParentFile(), f.getName() + ".orig");
+						if (copy.exists()) {
+							copy.delete();
+						}
+						f.renameTo(copy);
+					} else {
+						f.delete();
+					}
+				}
+				repo.getManifest().walkFileRevisions(file, insp, csetRevision);
+				worker.checkFailed();
+			}
+			dirstateBuilder.serialize();
+		} catch (HgRuntimeException ex) {
+			throw new HgLibraryFailureException(ex);
+		}
+	}
+}