Implement alias command

src/main/java/wtf/beatrice/hidekobot/commands/message/AliasCommand.java

@@ -1,2 +1,73 @@
-package wtf.beatrice.hidekobot.commands.message;public class AliasCommand {
+package wtf.beatrice.hidekobot.commands.message;
+
+import net.dv8tion.jda.api.Permission;
+import net.dv8tion.jda.api.events.message.MessageReceivedEvent;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+import wtf.beatrice.hidekobot.Cache;
+import wtf.beatrice.hidekobot.objects.commands.CommandCategory;
+import wtf.beatrice.hidekobot.objects.commands.MessageCommand;
+
+import java.util.Arrays;
+import java.util.LinkedList;
+import java.util.List;
+
+public class AliasCommand implements MessageCommand
+{
+
+    @Override
+    public LinkedList<String> getCommandLabels() {
+        return new LinkedList<>(Arrays.asList("alias", "aliases"));
+    }
+
+    @Nullable
+    @Override
+    public List<Permission> getPermissions() {
+        return null; // anyone can use it
+    }
+
+    @Override
+    public boolean passRawArgs() {
+        return false;
+    }
+
+    @NotNull
+    @Override
+    public CommandCategory getCategory() {
+        return CommandCategory.TOOLS;
+    }
+
+    @Override
+    public void runCommand(MessageReceivedEvent event, String label, String[] args)
+    {
+        if(args.length == 0)
+        {
+            event.getMessage().reply("\uD83D\uDE20 Hey, you have to specify a command!").queue();
+            return;
+        }
+
+        String commandLabel = args[0].toLowerCase();
+        MessageCommand command = Cache.getMessageCommandListener().getRegisteredCommand(commandLabel);
+        if(command == null)
+        {
+            event.getMessage().reply("Unrecognized command: `" + commandLabel + "`!").queue(); // todo prettier
+            return;
+        }
+
+        LinkedList<String> aliases = command.getCommandLabels();
+        StringBuilder aliasesStringBuilder = new StringBuilder();
+        aliasesStringBuilder.append("Aliases for **").append(aliases.get(0)).append("**: ");
+        for(int i = 0; i < aliases.size(); i++)
+        {
+            aliasesStringBuilder.append("`").append(aliases.get(i)).append("`");
+
+            if(i + 1 != aliases.size())
+                aliasesStringBuilder.append(", "); // separate with comma except on last iteration
+        }
+
+        event.getMessage()
+                .reply(aliasesStringBuilder.toString())
+                .queue();
+
+    }
 }