[Bleeding] Implemented command aliases in help. Addresses BUKKIT-1028

src/main/java/org/bukkit/craftbukkit/help/CommandAliasHelpTopic.java

@@ -0,0 +1,43 @@
+package org.bukkit.craftbukkit.help;
+
+import org.bukkit.ChatColor;
+import org.bukkit.command.Command;
+import org.bukkit.command.CommandSender;
+import org.bukkit.help.HelpMap;
+import org.bukkit.help.HelpTopic;
+
+public class CommandAliasHelpTopic extends HelpTopic {
+
+    private String aliasFor;
+    private Command command;
+    private HelpMap helpMap;
+    
+    public CommandAliasHelpTopic(String alias, String aliasFor, Command command, HelpMap helpMap) {
+        this.aliasFor = aliasFor.startsWith("/") ? aliasFor : "/" + aliasFor;
+        this.helpMap = helpMap;
+        this.command = command;
+        this.name = alias.startsWith("/") ? alias : "/" + alias;
+        this.shortText = ChatColor.YELLOW + "Alias for " + ChatColor.WHITE + this.aliasFor;
+    }
+
+    @Override
+    public String getFullText(CommandSender forWho) {
+        StringBuilder sb = new StringBuilder(shortText);
+        HelpTopic aliasForTopic = helpMap.getHelpTopic(aliasFor);
+        if (aliasForTopic != null) {
+            sb.append("\n");
+            sb.append(aliasForTopic.getFullText(forWho));
+        }
+        return sb.toString();
+    }
+
+    @Override
+    public boolean canSee(CommandSender commandSender) {
+        HelpTopic aliasForTopic = helpMap.getHelpTopic(aliasFor);
+        if (aliasForTopic != null) {
+            return aliasForTopic.canSee(commandSender);
+        } else {
+            return false;
+        }
+    }
+}

src/main/java/org/bukkit/craftbukkit/help/SimpleHelpMap.java

@@ -1,5 +1,7 @@
 package org.bukkit.craftbukkit.help;
 
+import com.google.common.base.Predicates;
+import com.google.common.collect.Collections2;
 import org.bukkit.command.Command;
 import org.bukkit.command.CommandExecutor;
 import org.bukkit.command.MultipleCommandAlias;
@@ -21,7 +23,7 @@ public class SimpleHelpMap implements HelpMap {
 
     public SimpleHelpMap() {
         helpTopics = new TreeMap<String, HelpTopic>(new HelpTopicComparator()); // Using a TreeMap for its explicit sorting on key
-        defaultTopic = new IndexHelpTopic(helpTopics.values());
+        defaultTopic = new IndexHelpTopic(null, null, null, Collections2.filter(helpTopics.values(), Predicates.not(Predicates.instanceOf(CommandAliasHelpTopic.class))));
         topicFactoryMap = new HashMap<Class, HelpTopicFactory>();
 
         registerHelpTopicFactory(MultipleCommandAlias.class, new MultipleCommandAliasHelpTopicFactory());
@@ -85,6 +87,13 @@ public class SimpleHelpMap implements HelpMap {
             addTopic(new GenericCommandHelpTopic(command));
         }
         
+        // Initialize command alias help topics
+        for (Command command : server.getCommandMap().getCommands()) {
+            for (String alias : command.getAliases()) {
+                addTopic(new CommandAliasHelpTopic(alias, command.getLabel(), command, this));
+            }
+        }
+
         // Initialize help topics from the server's fallback commands
         for (VanillaCommand command : server.getCommandMap().getFallbackCommands()) {
             addTopic(new GenericCommandHelpTopic(command));
@@ -97,6 +106,9 @@ public class SimpleHelpMap implements HelpMap {
                 helpTopics.get(amendment.getTopicName()).amendTopic(amendment.getShortText(), amendment.getFullText());
             }
         }
+
+        // Add alias sub-index
+        addTopic(new IndexHelpTopic("Aliases", "Lists command aliases", null, Collections2.filter(helpTopics.values(), Predicates.instanceOf(CommandAliasHelpTopic.class))));
     }
 
     public void registerHelpTopicFactory(Class commandClass, HelpTopicFactory factory) {