--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/org/tmatesoft/hg/core/HgUpdateConfigCommand.java	Thu Feb 09 04:15:17 2012 +0100
@@ -0,0 +1,146 @@
+/*
+ * Copyright (c) 2012 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.io.IOException;
+import java.util.ArrayList;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.tmatesoft.hg.internal.ConfigFile;
+import org.tmatesoft.hg.internal.Experimental;
+import org.tmatesoft.hg.internal.Internals;
+import org.tmatesoft.hg.repo.HgRepository;
+
+/**
+ * WORK IN PROGRESS, DO NOT USE
+ *
+ * @author Artem Tikhomirov
+ * @author TMate Software Ltd.
+ */
+@Experimental(reason="Investigating approaches to alter Hg configuration files")
+public final class HgUpdateConfigCommand extends HgAbstractCommand<HgUpdateConfigCommand> {
+	
+	private final HgRepository repo;
+	private final File configFile;
+	
+	private Map<String,List<String>> toRemove;
+	private Map<String,Map<String,String>> toSet;
+
+	private HgUpdateConfigCommand(HgRepository hgRepo, File configurationFile) {
+		repo = hgRepo;
+		configFile = configurationFile;
+	}
+	
+	public static HgUpdateConfigCommand forRepository(HgRepository hgRepo) {
+		return new HgUpdateConfigCommand(hgRepo, new File(".hg/hgrc"));
+	}
+	
+	public static HgUpdateConfigCommand forUser(HgRepository hgRepo) {
+		return new HgUpdateConfigCommand(null, Internals.getUserConfigurationFileToWrite());
+	}
+	
+	public static HgUpdateConfigCommand forInstallation() {
+		return new HgUpdateConfigCommand(null, Internals.getInstallationConfigurationFileToWrite());
+	}
+	
+	/**
+	 * Remove a property altogether
+	 * @return <code>this</code> for convenience
+	 */
+	public HgUpdateConfigCommand remove(String section, String key) {
+		if (toRemove == null) {
+			toRemove = new LinkedHashMap<String, List<String>>();
+		}
+		List<String> s = toRemove.get(section);
+		if (s == null) {
+			toRemove.put(section, s = new ArrayList<String>(5));
+		}
+		s.add(key);
+		if (toSet != null && toSet.containsKey(section)) {
+			toSet.get(section).remove(key);
+		}
+		return this;
+	}
+
+	/**
+	 * Delete single attribute in a multi-valued property
+	 * @return <code>this</code> for convenience
+	 */
+	public HgUpdateConfigCommand remove(String section, String key, String value) {
+		throw new UnsupportedOperationException();
+	}
+	
+	/**
+	 * Set single-valued properties or update multi-valued with a single value
+	 * @return <code>this</code> for convenience
+	 */
+	public HgUpdateConfigCommand put(String section, String key, String value) {
+		if (toSet == null) {
+			toSet =  new LinkedHashMap<String, Map<String,String>>();
+		}
+		Map<String,String> s = toSet.get(section);
+		if (s == null) {
+			toSet.put(section, s = new LinkedHashMap<String, String>());
+		}
+		s.put(key, value);
+		return this;
+	}
+	
+	/**
+	 * Multi-valued properties
+	 * @return <code>this</code> for convenience
+	 */
+	public HgUpdateConfigCommand add(String section, String key, String value) {
+		throw new UnsupportedOperationException();
+	}
+	
+	public void execute() throws HgException {
+		try {
+			ConfigFile cfg = new ConfigFile();
+			cfg.addLocation(configFile);
+			if (toRemove != null) {
+				for (Map.Entry<String,List<String>> s : toRemove.entrySet()) {
+					for (String e : s.getValue()) {
+						cfg.putString(s.getKey(), e, null);
+					}
+				}
+			}
+			if (toSet != null) {
+				for (Map.Entry<String,Map<String,String>> s : toSet.entrySet()) {
+					for (Map.Entry<String, String> e : s.getValue().entrySet()) {
+						cfg.putString(s.getKey(), e.getKey(), e.getValue());
+					}
+				}
+			}
+			cfg.writeTo(configFile);
+		} catch (IOException ex) {
+			throw new HgInvalidFileException("Failed to update configuration file", ex, configFile);
+		}
+	}
+
+
+	public static void main(String[] args) throws Exception {
+		HgUpdateConfigCommand cmd = HgUpdateConfigCommand.forUser(null);
+		cmd.remove("test1", "sample1");
+		cmd.put("test2", "sample2", "value2");
+		cmd.put("ui", "user-name", "Another User <email@domain.com>");
+		cmd.execute();
+	}
+}