Made better cmd error msgs.

ArAbstractSelect will euggest a matching option if,
an invalid arg was passed & a matching one exists at.
If an invalid subcommand aliases were passed,
a matching subcommand will be suggested.
After feedback from MonMarty a few misc messages was changed.

src/com/massivecraft/massivecore/Lang.java

@@ -7,7 +7,10 @@ public class Lang
 	
 	public static final String COMMAND_SENDER_MUST_BE_PLAYER = "<b>This command can only be used by ingame players.";
 	public static final String COMMAND_SENDER_MUSNT_BE_PLAYER = "<b>This command can not be used by ingame players.";
-	public static final String COMMAND_TO_FEW_ARGS = "<b>Too few arguments. <i>Use like this:";
+	public static final String COMMAND_TOO_FEW_ARGS = "<b>Not enough command input. <i>You should use it like this:";
-	public static final String COMMAND_TO_MANY_ARGS = "<b>Strange arguments %s<b>.";
+	public static final String COMMAND_TOO_MANY_ARGS = "<b>Too much command input %s<b>.";
-	public static final String COMMAND_TO_MANY_ARGS2 = "<i>Use the command like this:";
+	public static final String COMMAND_TOO_MANY_ARGS2 = "<i>You should use the command like this:";
+	public static final String COMMAND_NO_SUCH_SUB = "<b>The server couldn't find the command \"<c>%s<b>\".";
+	public static final String COMMAND_SUGGEST_SUB = "<i>Maybe you could try %s";
+	public static final String COMMAND_GET_HELP = "<i>Use %s <i>to see commands.";
 }

src/com/massivecraft/massivecore/cmd/MassiveCommand.java

@@ -10,6 +10,7 @@ import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Set;
 
+import org.apache.commons.lang.StringUtils;
 import org.bukkit.command.CommandSender;
 import org.bukkit.entity.Player;
 import org.bukkit.plugin.Plugin;
@@ -102,6 +103,7 @@ public class MassiveCommand
 	protected List<MassiveCommand> subCommands;
 	public List<MassiveCommand> getSubCommands() { return this.subCommands; }
 	public void setSubCommands(List<MassiveCommand> subCommands) { this.subCommands = subCommands; }
+	public boolean isParentCommand() { return this.getSubCommands().size() > 0; }
 	
 	public MassiveCommand getSubCommand(String alias)
 	{
@@ -437,8 +439,8 @@ public class MassiveCommand
 		{
 			if (sender != null)
 			{
-				msg(Lang.COMMAND_TO_FEW_ARGS);
+				msg(Lang.COMMAND_TOO_FEW_ARGS);
-				sender.sendMessage(this.getUseageTemplate());
+				sendMessage(this.getUseageTemplate());
 			}
 			return false;
 		}
@@ -447,11 +449,33 @@ public class MassiveCommand
 		{
 			if (sender != null)
 			{
-				// Get the to many string slice
+				if (this.isParentCommand())
-				List<String> theToMany = args.subList(this.getRequiredArgs().size() + this.optionalArgs.size(), args.size());
+				{
-				msg(Lang.COMMAND_TO_MANY_ARGS, Txt.implodeCommaAndDot(theToMany, Txt.parse("<aqua>%s"), Txt.parse("<b>, "), Txt.parse("<b> and "), ""));
+					String arg = this.arg(0);
-				msg(Lang.COMMAND_TO_MANY_ARGS2);
+					
-				sender.sendMessage(this.getUseageTemplate());
+					// Try Levenshtein
+					List<String> matches = this.getSimilarSubcommandAliases(arg, this.getMaxLevenshteinDistanceForArg(arg));
+					
+					msg(Lang.COMMAND_NO_SUCH_SUB, this.getUseageTemplate() + " " + arg);
+					if ( ! matches.isEmpty())
+					{
+						String suggest = Txt.parse(Txt.implodeCommaAnd(matches, "<i>, <c>", " <i>or <c>"));
+						msg(Lang.COMMAND_SUGGEST_SUB, this.getUseageTemplate() + " " + suggest);
+					}
+					else
+					{
+						msg(Lang.COMMAND_GET_HELP, this.getUseageTemplate());
+					}
+					
+				}
+				else
+				{
+					// Get the too many string slice
+					List<String> theTooMany = args.subList(this.getRequiredArgs().size() + this.optionalArgs.size(), args.size());
+					msg(Lang.COMMAND_TOO_MANY_ARGS, Txt.implodeCommaAndDot(theTooMany, Txt.parse("<aqua>%s"), Txt.parse("<b>, "), Txt.parse("<b> and "), ""));
+					msg(Lang.COMMAND_TOO_MANY_ARGS2);
+					sendMessage(this.getUseageTemplate());
+				}
 			}
 			return false;
 		}
@@ -462,6 +486,47 @@ public class MassiveCommand
 		return this.isArgsValid(args, null);
 	}
 	
+	// -------------------------------------------- //
+	// MATCHING SUGGESTIONS
+	// -------------------------------------------- //
+	
+	public List<String> getSimilarAliases(String arg, int maxLevenshteinDistance)
+	{
+		arg = arg.toLowerCase();
+		
+		List<String> matches = new ArrayList<String>();
+		
+		for (String alias : this.getAliases())
+		{
+			String aliaslc = alias.toLowerCase();
+			int distance = StringUtils.getLevenshteinDistance(arg, aliaslc);
+			if (distance > maxLevenshteinDistance) continue;
+			matches.add(alias);
+		}
+		return matches;
+	}
+	
+	public List<String> getSimilarSubcommandAliases(String arg, int maxLevenshteinDistance)
+	{
+		// Try Levenshtein
+		List<String> matches = new ArrayList<String>();
+		
+		for (MassiveCommand sub : this.getSubCommands())
+		{
+			matches.addAll(sub.getSimilarAliases(arg, maxLevenshteinDistance));
+		}
+		return matches;
+	}
+	
+	public int getMaxLevenshteinDistanceForArg(String arg)
+	{
+		if (arg.length() <= 1) return 0; // When dealing with 1 character aliases, there is way too many options. So we don't suggest.
+		if (arg.length() <= 3) return 1; // When dealing with low length aliases, there too many options. So we won't suggest much
+		if (arg.length() < 8) return 2; // 2 is default.
+		
+		return 3; // If it were 8 characters or more, we end up here. Because many characters allow for more typos.
+	}
+	
 	// -------------------------------------------- //
 	// HELP AND USAGE INFORMATION
 	// -------------------------------------------- //

src/com/massivecraft/massivecore/cmd/arg/ARAbstractSelect.java

@@ -1,7 +1,10 @@
 package com.massivecraft.massivecore.cmd.arg;
 
+import java.util.ArrayList;
 import java.util.Collection;
+import java.util.List;
 
+import org.apache.commons.lang.StringUtils;
 import org.bukkit.command.CommandSender;
 
 import com.massivecraft.massivecore.MassiveException;
@@ -33,36 +36,68 @@ public abstract class ARAbstractSelect<T> extends ArgReaderAbstract<T>
 	{
 		T result = this.select(arg, sender);
 		
-		if (result == null)
+		if (result != null) return result;
-		{
-			MassiveException exception = new MassiveException();
-			exception.addMsg("<b>No %s matches \"<h>%s<b>\".", this.typename(), arg);
-			
-			if (this.canList(sender))
-			{
-				Collection<String> names = this.altNames(sender);
-				if (names.size() == 0)
-				{
-					exception.addMsg("<i>Note: There is no %s available.", this.typename());
-				}
-				else if (names.size() > LIST_COUNT_MAX)
-				{
-					exception.addMsg("<i>More than %d alternatives available.", LIST_COUNT_MAX);
-				}
-				else
-				{
-					String format = Txt.parse("<h>%s");
-					String comma = Txt.parse("<i>, ");
-					String and = Txt.parse(" <i>or ");
-					String dot = Txt.parse("<i>.");
-					exception.addMsg("<i>Use %s", Txt.implodeCommaAndDot(names, format, comma, and, dot));
-				}
-			}
-			
-			throw exception;
-		}
 		
-		return result;
+		MassiveException exception = new MassiveException();
+		exception.addMsg("<b>No %s matches \"<h>%s<b>\".", this.typename(), arg);
+		
+		if (this.canList(sender))
+		{			
+			Collection<String> names = this.altNames(sender);
+			
+			// Try Levenshtein
+			List<String> matches = this.getMatchingAltNames(arg, sender, this.getMaxLevenshteinDistanceForArg(arg));
+			
+			if (names.isEmpty())
+			{
+				exception.addMsg("<i>Note: There is no %s available.", this.typename());
+			}
+			else if ( ! matches.isEmpty() && matches.size() < LIST_COUNT_MAX)
+			{
+				// For some reason the arguments doesn't get parsed.
+				String suggest = Txt.parse(Txt.implodeCommaAnd(matches, "<i>, <h>", " <i>or <h>"));
+				exception.addMsg("<i>Did you mean <h>%s<i>?", suggest);
+			}
+			else if (names.size() > LIST_COUNT_MAX)
+			{
+				exception.addMsg("<i>More than %d alternatives available.", LIST_COUNT_MAX);
+			}
+			else
+			{
+				String format = Txt.parse("<h>%s");
+				String comma = Txt.parse("<i>, ");
+				String and = Txt.parse(" <i>or ");
+				String dot = Txt.parse("<i>.");
+				exception.addMsg("<i>Use %s", Txt.implodeCommaAndDot(names, format, comma, and, dot));
+			}
+		}
+			
+		throw exception;
+	}
+	
+	public List<String> getMatchingAltNames(String arg, CommandSender sender, int maxLevenshteinDistance)
+	{
+		arg = arg.toLowerCase();
+		
+		// Try Levenshtein
+		List<String> matches = new ArrayList<String>();
+		
+		for (String alias : this.altNames(sender))
+		{
+			String aliaslc = alias.toLowerCase();
+			int distance = StringUtils.getLevenshteinDistance(arg, aliaslc);
+			if (distance > maxLevenshteinDistance) continue;
+			matches.add(alias);
+		}
+		return matches;
+	}
+	
+	public int getMaxLevenshteinDistanceForArg(String arg)
+	{
+		if (arg.length() <= 1) return 0; // When dealing with 1 character aliases, there is way too many options.
+		if (arg.length() < 8) return 1; // 1 is default.
+		
+		return 2;  // If it were 8 characters or more, we end up here. Because many characters allow for more typos.
 	}
 	
 }