Basic Command API

You can annotate commands with @command. Registering is done through
the Server's CommandManager. Commands are fired through Reflection.

Signed-off-by: Jadon Fowler <jadonflower@gmail.com>

src/main/java/org/fountainmc/api/Server.java

@@ -3,13 +3,16 @@
 import javax.annotation.Nonnull;
 
 import org.fountainmc.api.plugin.PluginManager;
+import org.fountainmc.api.command.CommandManager;;
 
 import static com.google.common.base.Preconditions.*;
 
 @Nonnull
 public interface Server extends ServerInfo {
 
     public PluginManager getPluginManager();
+
+    public CommandManager getCommandManager();
 
     public String[] getLaunchArguments();
 

src/main/java/org/fountainmc/api/command/Command.java

@@ -0,0 +1,25 @@
+package org.fountainmc.api.command;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.METHOD)
+public @interface Command {
+
+    public String name();
+
+    public String permission() default "";
+
+    public String noPermissionMessage() default "You do not have permission to run this command";
+
+    public String[] aliases() default {};
+
+    public String description() default "";
+
+    public String usage() default "";
+
+    public Class<? extends CommandSender> allow() default CommandSender.class;
+}

src/main/java/org/fountainmc/api/command/CommandManager.java

@@ -0,0 +1,57 @@
+package org.fountainmc.api.command;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
+import java.util.ArrayList;
+import java.util.List;
+
+public class CommandManager {
+
+    private final List<CommandHandler> commands;
+
+    public CommandManager() {
+        this.commands = new ArrayList<CommandHandler>();
+    }
+
+    public void registerCommands(Object source) {
+        for (Method method : source.getClass().getDeclaredMethods()) {
+            if (Modifier.isPublic(method.getModifiers())) {
+                if (method.isAnnotationPresent(Command.class)) {
+                    Command command = method.getAnnotation(Command.class);
+                    commands.add(new CommandHandler(command, method, source));
+                }
+            }
+        }
+    }
+
+    public void fireCommand(String command, String[] arguments, CommandSender sender) {
+        for (CommandHandler handler : commands) {
+            if (handler.command.name().equalsIgnoreCase(command)) {
+                Class<? extends CommandSender> senderClass = handler.command.allow();
+                if (sender.getClass().isInstance(senderClass)) {
+                    try {
+                        handler.method.invoke(handler.source, arguments, senderClass.cast(sender));
+                    }
+                    catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
+                        e.printStackTrace();
+                    }
+                }
+            }
+        }
+    }
+
+    private class CommandHandler {
+
+        private final Command command;
+        private final Method method;
+        private final Object source;
+
+        public CommandHandler(Command command, Method method, Object source) {
+            this.command = command;
+            this.method = method;
+            this.source = source;
+        }
+    }
+
+}

src/main/java/org/fountainmc/api/command/CommandSender.java

@@ -0,0 +1,6 @@
+package org.fountainmc.api.command;
+
+
+public interface CommandSender {
+
+}

src/main/java/org/fountainmc/api/entity/Player.java

@@ -1,8 +1,9 @@
 package org.fountainmc.api.entity;
 
 import java.util.UUID;
+import org.fountainmc.api.command.CommandSender;
 
-public interface Player extends EntityLiving {
+public interface Player extends EntityLiving, CommandSender {
 
     String getName();