--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hg4j/src/main/java/org/tmatesoft/hg/repo/HgLookup.java	Tue May 10 10:52:53 2011 +0200
@@ -0,0 +1,128 @@
+/*
+ * Copyright (c) 2010-2011 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.repo;
+
+import java.io.File;
+import java.io.IOException;
+import java.net.MalformedURLException;
+import java.net.URL;
+
+import org.tmatesoft.hg.core.HgBadArgumentException;
+import org.tmatesoft.hg.core.HgException;
+import org.tmatesoft.hg.internal.ConfigFile;
+import org.tmatesoft.hg.internal.DataAccessProvider;
+import org.tmatesoft.hg.internal.Internals;
+
+/**
+ * Utility methods to find Mercurial repository at a given location
+ * 
+ * @author Artem Tikhomirov
+ * @author TMate Software Ltd.
+ */
+public class HgLookup {
+
+	private ConfigFile globalCfg;
+
+	public HgRepository detectFromWorkingDir() throws HgException {
+		return detect(System.getProperty("user.dir"));
+	}
+
+	public HgRepository detect(String location) throws HgException {
+		return detect(new File(location));
+	}
+
+	// look up in specified location and above
+	public HgRepository detect(File location) throws HgException {
+		File dir = location.getAbsoluteFile();
+		File repository;
+		do {
+			repository = new File(dir, ".hg");
+			if (repository.exists() && repository.isDirectory()) {
+				break;
+			}
+			repository = null;
+			dir = dir.getParentFile();
+			
+		} while(dir != null);
+		if (repository == null) {
+			// return invalid repository
+			return new HgRepository(location.getPath());
+		}
+		try {
+			String repoPath = repository.getParentFile().getCanonicalPath();
+			return new HgRepository(repoPath, repository);
+		} catch (IOException ex) {
+			throw new HgException(location.toString(), ex);
+		}
+	}
+	
+	public HgBundle loadBundle(File location) throws HgException {
+		if (location == null || !location.canRead()) {
+			throw new IllegalArgumentException();
+		}
+		return new HgBundle(new DataAccessProvider(), location).link();
+	}
+	
+	/**
+	 * Try to instantiate remote server.
+	 * @param key either URL or a key from configuration file that points to remote server  
+	 * @param hgRepo <em>NOT USED YET<em> local repository that may have extra config, or default remote location
+	 * @return an instance featuring access to remote repository, check {@link HgRemoteRepository#isInvalid()} before actually using it
+	 * @throws HgBadArgumentException if anything is wrong with the remote server's URL
+	 */
+	public HgRemoteRepository detectRemote(String key, HgRepository hgRepo) throws HgBadArgumentException {
+		URL url;
+		Exception toReport;
+		try {
+			url = new URL(key);
+			toReport = null;
+		} catch (MalformedURLException ex) {
+			url = null;
+			toReport = ex;
+		}
+		if (url == null) {
+			String server = getGlobalConfig().getSection("paths").get(key);
+			if (server == null) {
+				throw new HgBadArgumentException(String.format("Can't find server %s specification in the config", key), toReport);
+			}
+			try {
+				url = new URL(server);
+			} catch (MalformedURLException ex) {
+				throw new HgBadArgumentException(String.format("Found %s server spec in the config, but failed to initialize with it", key), ex);
+			}
+		}
+		return new HgRemoteRepository(url);
+	}
+	
+	public HgRemoteRepository detect(URL url) throws HgException {
+		if (url == null) {
+			throw new IllegalArgumentException();
+		}
+		if (Boolean.FALSE.booleanValue()) {
+			throw HgRepository.notImplemented();
+		}
+		return new HgRemoteRepository(url);
+	}
+
+	private ConfigFile getGlobalConfig() {
+		if (globalCfg == null) {
+			globalCfg = new Internals().newConfigFile();
+			globalCfg.addLocation(new File(System.getProperty("user.home"), ".hgrc"));
+		}
+		return globalCfg;
+	}
+}