--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/org/tmatesoft/hg/core/HgLogCommand.java	Wed Feb 16 20:47:56 2011 +0100
@@ -0,0 +1,298 @@
+/*
+ * Copyright (c) 2011 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 static org.tmatesoft.hg.repo.HgRepository.TIP;
+
+import java.util.Calendar;
+import java.util.Collections;
+import java.util.ConcurrentModificationException;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Set;
+import java.util.TreeSet;
+
+import org.tmatesoft.hg.repo.HgChangelog.Changeset;
+import org.tmatesoft.hg.repo.HgChangelog;
+import org.tmatesoft.hg.repo.HgDataFile;
+import org.tmatesoft.hg.repo.HgRepository;
+import org.tmatesoft.hg.repo.HgStatusCollector;
+import org.tmatesoft.hg.util.PathPool;
+
+
+/**
+ * Access to changelog, 'hg log' command counterpart.
+ * 
+ * <pre>
+ * Usage:
+ *   new LogCommand().limit(20).branch("maintenance-2.1").user("me").execute(new MyHandler());
+ * </pre>
+ * Not thread-safe (each thread has to use own {@link HgLogCommand} instance).
+ * 
+ * @author Artem Tikhomirov
+ * @author TMate Software Ltd.
+ */
+public class HgLogCommand implements HgChangelog.Inspector {
+
+	private final HgRepository repo;
+	private Set<String> users;
+	private Set<String> branches;
+	private int limit = 0, count = 0;
+	private int startRev = 0, endRev = TIP;
+	private Handler delegate;
+	private Calendar date;
+	private Path file;
+	private boolean followHistory; // makes sense only when file != null
+	private HgChangeset changeset;
+	
+	public HgLogCommand(HgRepository hgRepo) {
+		repo = hgRepo;
+	}
+
+	/**
+	 * Limit search to specified user. Multiple user names may be specified.
+	 * @param user - full or partial name of the user, case-insensitive, non-null.
+	 * @return <code>this</code> instance for convenience
+	 */
+	public HgLogCommand user(String user) {
+		if (user == null) {
+			throw new IllegalArgumentException();
+		}
+		if (users == null) {
+			users = new TreeSet<String>();
+		}
+		users.add(user.toLowerCase());
+		return this;
+	}
+
+	/**
+	 * Limit search to specified branch. Multiple branch specification possible (changeset from any of these 
+	 * would be included in result). If unspecified, all branches are considered.
+	 * @param branch - branch name, case-sensitive, non-null.
+	 * @return <code>this</code> instance for convenience
+	 */
+	public HgLogCommand branch(String branch) {
+		if (branch == null) {
+			throw new IllegalArgumentException();
+		}
+		if (branches == null) {
+			branches = new TreeSet<String>();
+		}
+		branches.add(branch);
+		return this;
+	}
+	
+	// limit search to specific date
+	// multiple?
+	public HgLogCommand date(Calendar date) {
+		this.date = date;
+		// FIXME implement
+		// isSet(field) - false => don't use in detection of 'same date'
+		throw HgRepository.notImplemented();
+	}
+	
+	/**
+	 * 
+	 * @param num - number of changeset to produce. Pass 0 to clear the limit. 
+	 * @return <code>this</code> instance for convenience
+	 */
+	public HgLogCommand limit(int num) {
+		limit = num;
+		return this;
+	}
+
+	/**
+	 * Limit to specified subset of Changelog, [min(rev1,rev2), max(rev1,rev2)], inclusive.
+	 * Revision may be specified with {@link HgRepository#TIP}  
+	 * @param rev1
+	 * @param rev2
+	 * @return <code>this</code> instance for convenience
+	 */
+	public HgLogCommand range(int rev1, int rev2) {
+		if (rev1 != TIP && rev2 != TIP) {
+			startRev = rev2 < rev1 ? rev2 : rev1;
+			endRev = startRev == rev2 ? rev1 : rev2;
+		} else if (rev1 == TIP && rev2 != TIP) {
+			startRev = rev2;
+			endRev = rev1;
+		} else {
+			startRev = rev1;
+			endRev = rev2;
+		}
+		return this;
+	}
+	
+	/**
+	 * Visit history of a given file only.
+	 * @param file path relative to repository root. Pass <code>null</code> to reset.
+	 * @param followCopyRename true to report changesets of the original file(-s), if copy/rename ever occured to the file. 
+	 */
+	public HgLogCommand file(Path file, boolean followCopyRename) {
+		// multiple? Bad idea, would need to include extra method into Handler to tell start of next file
+		this.file = file;
+		followHistory = followCopyRename;
+		return this;
+	}
+
+	/**
+	 * Similar to {@link #execute(org.tmatesoft.hg.repo.Changeset.Inspector)}, collects and return result as a list.
+	 */
+	public List<HgChangeset> execute() {
+		CollectHandler collector = new CollectHandler();
+		execute(collector);
+		return collector.getChanges();
+	}
+
+	/**
+	 * 
+	 * @param inspector
+	 * @throws IllegalArgumentException when inspector argument is null
+	 * @throws ConcurrentModificationException if this log command instance is already running
+	 */
+	public void execute(Handler handler) {
+		if (handler == null) {
+			throw new IllegalArgumentException();
+		}
+		if (delegate != null) {
+			throw new ConcurrentModificationException();
+		}
+		try {
+			delegate = handler;
+			count = 0;
+			changeset = new HgChangeset(new HgStatusCollector(repo), new PathPool(repo.getPathHelper()));
+			if (file == null) {
+				repo.getChangelog().range(startRev, endRev, this);
+			} else {
+				HgDataFile fileNode = repo.getFileNode(file);
+				fileNode.history(startRev, endRev, this);
+				if (fileNode.isCopy()) {
+					// even if we do not follow history, report file rename
+					do {
+						if (handler instanceof FileHistoryHandler) {
+							FileRevision src = new FileRevision(repo, fileNode.getCopySourceRevision(), fileNode.getCopySourceName());
+							FileRevision dst = new FileRevision(repo, fileNode.getRevision(0), fileNode.getPath());
+							((FileHistoryHandler) handler).copy(src, dst);
+						}
+						if (limit > 0 && count >= limit) {
+							// if limit reach, follow is useless.
+							break;
+						}
+						if (followHistory) {
+							fileNode = repo.getFileNode(fileNode.getCopySourceName());
+							fileNode.history(this);
+						}
+					} while (followHistory && fileNode.isCopy());
+				}
+			}
+		} finally {
+			delegate = null;
+			changeset = null;
+		}
+	}
+
+	//
+	
+	public void next(int revisionNumber, Nodeid nodeid, Changeset cset) {
+		if (limit > 0 && count >= limit) {
+			return;
+		}
+		if (branches != null && !branches.contains(cset.branch())) {
+			return;
+		}
+		if (users != null) {
+			String csetUser = cset.user().toLowerCase();
+			boolean found = false;
+			for (String u : users) {
+				if (csetUser.indexOf(u) != -1) {
+					found = true;
+					break;
+				}
+			}
+			if (!found) {
+				return;
+			}
+		}
+		if (date != null) {
+			// FIXME
+		}
+		count++;
+		changeset.init(revisionNumber, nodeid, cset);
+		delegate.next(changeset);
+	}
+
+	public interface Handler {
+		/**
+		 * @param changeset not necessarily a distinct instance each time, {@link HgChangeset#clone() clone()} if need a copy.
+		 */
+		void next(HgChangeset changeset);
+	}
+	
+	/**
+	 * When {@link HgLogCommand} is executed against file, handler passed to {@link HgLogCommand#execute(Handler)} may optionally
+	 * implement this interface to get information about file renames. Method {@link #copy(FileRevision, FileRevision)} would
+	 * get invoked prior any changeset of the original file (if file history being followed) is reported via {@link #next(HgChangeset)}.
+	 * 
+	 * For {@link HgLogCommand#file(Path, boolean)} with renamed file path and follow argument set to false, 
+	 * {@link #copy(FileRevision, FileRevision)} would be invoked for the first copy/rename in the history of the file, but not 
+	 * followed by any changesets. 
+	 *
+	 * @author Artem Tikhomirov
+	 * @author TMate Software Ltd.
+	 */
+	public interface FileHistoryHandler extends Handler {
+		// XXX perhaps, should distinguish copy from rename? And what about merged revisions and following them?
+		void copy(FileRevision from, FileRevision to);
+	}
+	
+	public static class CollectHandler implements Handler {
+		private final List<HgChangeset> result = new LinkedList<HgChangeset>();
+
+		public List<HgChangeset> getChanges() {
+			return Collections.unmodifiableList(result);
+		}
+
+		public void next(HgChangeset changeset) {
+			result.add(changeset.clone());
+		}
+	}
+
+	public static final class FileRevision {
+		private final HgRepository repo;
+		private final Nodeid revision;
+		private final Path path;
+		
+		/*package-local*/FileRevision(HgRepository hgRepo, Nodeid rev, Path p) {
+			if (hgRepo == null || rev == null || p == null) {
+				throw new IllegalArgumentException();
+			}
+			repo = hgRepo;
+			revision = rev;
+			path = p;
+		}
+		
+		public Path getPath() {
+			return path;
+		}
+		public Nodeid getRevision() {
+			return revision;
+		}
+		public byte[] getContent() {
+			// XXX Content wrapper, to allow formats other than byte[], e.g. Stream, DataAccess, etc?
+			return repo.getFileNode(path).content(revision);
+		}
+	}
+}