Add basic api with connect event

src/main/java/net/md_5/bungee/BungeeCord.java

@@ -18,6 +18,7 @@ import net.md_5.bungee.command.CommandList;
 import net.md_5.bungee.command.CommandSender;
 import net.md_5.bungee.command.CommandServer;
 import net.md_5.bungee.command.ConsoleCommandSender;
+import net.md_5.bungee.plugin.JavaPluginManager;
 
 public class BungeeCord {
 
@@ -56,7 +57,11 @@ public class BungeeCord {
     /**
      * Registered commands.
      */
-    private Map<String, Command> commandMap = new HashMap<>();
+    public Map<String, Command> commandMap = new HashMap<>();
+    /**
+     * Plugin manager.
+     */
+    public final JavaPluginManager pluginManager = new JavaPluginManager();
 
     {
         commandMap.put("end", new CommandEnd());
@@ -105,6 +110,8 @@ public class BungeeCord {
         config.load();
         isRunning = true;
 
+        pluginManager.loadPlugins();
+
         InetSocketAddress addr = Util.getAddr(config.bindHost);
         listener = new ListenThread(addr);
         listener.start();
@@ -115,6 +122,8 @@ public class BungeeCord {
 
     public void stop() {
         this.isRunning = false;
+        $().info("Disabling plugin");
+        pluginManager.onDisable();
 
         $().info("Closing listen thread");
         try {

src/main/java/net/md_5/bungee/InitialHandler.java

@@ -9,6 +9,7 @@ import net.md_5.bungee.packet.PacketFCEncryptionResponse;
 import net.md_5.bungee.packet.PacketFDEncryptionRequest;
 import net.md_5.bungee.packet.PacketFFKick;
 import net.md_5.bungee.packet.PacketInputStream;
+import net.md_5.bungee.plugin.ConnectEvent;
 import org.bouncycastle.crypto.io.CipherInputStream;
 import org.bouncycastle.crypto.io.CipherOutputStream;
 
@@ -32,6 +33,13 @@ public class InitialHandler implements Runnable {
             switch (id) {
                 case 0x02:
                     Packet2Handshake handshake = new Packet2Handshake(packet);
+                    // fire connect event
+                    ConnectEvent event = new ConnectEvent(handshake.username, socket.getInetAddress());
+                    BungeeCord.instance.pluginManager.onConnect(event);
+                    if (event.isCancelled()) {
+                        throw new KickException(event.getCancelReason());
+                    }
+
                     PacketFDEncryptionRequest request = EncryptionUtil.encryptRequest();
                     out.write(request.getPacket());
                     PacketFCEncryptionResponse response = new PacketFCEncryptionResponse(in.readPacket());

src/main/java/net/md_5/bungee/plugin/Cancellable.java

@@ -0,0 +1,8 @@
+package net.md_5.bungee.plugin;
+
+public interface Cancellable {
+
+    public void setCancelled(boolean cancelled);
+
+    public boolean isCancelled();
+}

src/main/java/net/md_5/bungee/plugin/ConnectEvent.java

@@ -0,0 +1,13 @@
+package net.md_5.bungee.plugin;
+
+import java.net.InetAddress;
+import lombok.Data;
+
+@Data
+public class ConnectEvent implements Cancellable {
+
+    private boolean cancelled;
+    private String cancelReason;
+    private final String username;
+    private final InetAddress address;
+}

src/main/java/net/md_5/bungee/plugin/InvalidPluginException.java

@@ -0,0 +1,14 @@
+package net.md_5.bungee.plugin;
+
+public class InvalidPluginException extends RuntimeException {
+
+    private static final long serialVersionUID = 1L;
+
+    public InvalidPluginException(String message, Throwable cause) {
+        super(message, cause);
+    }
+
+    public InvalidPluginException(String message) {
+        super(message);
+    }
+}

src/main/java/net/md_5/bungee/plugin/JavaPlugin.java

@@ -0,0 +1,38 @@
+package net.md_5.bungee.plugin;
+
+import net.md_5.bungee.BungeeCord;
+import net.md_5.bungee.command.Command;
+
+public abstract class JavaPlugin {
+
+    /**
+     * Description file.
+     */
+    PluginDescription description;
+
+    /**
+     * Called on enable.
+     */
+    public void onEnable() {
+    }
+
+    /**
+     * Called on disable.
+     */
+    public void onDisable() {
+    }
+
+    /**
+     * Called when a user connects with their name and address. To keep things
+     * simple this name has not been checked with minecraft.net.
+     */
+    public void onConnect(ConnectEvent event) {
+    }
+
+    /**
+     * Register a command.
+     */
+    protected void registerCommand(String label, Command command) {
+        BungeeCord.instance.commandMap.put(label, command);
+    }
+}

src/main/java/net/md_5/bungee/plugin/JavaPluginManager.java

@@ -0,0 +1,66 @@
+package net.md_5.bungee.plugin;
+
+import com.google.common.io.PatternFilenameFilter;
+import java.io.File;
+import java.io.InputStream;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.jar.JarFile;
+import java.util.zip.ZipEntry;
+import lombok.Getter;
+import static net.md_5.bungee.Logger.$;
+
+public class JavaPluginManager extends JavaPlugin {
+
+    @Getter
+    private final Set<JavaPlugin> plugins = new HashSet<>();
+
+    public void loadPlugins() {
+        File dir = new File("plugins");
+        dir.mkdir();
+
+        for (File file : dir.listFiles(new PatternFilenameFilter(".*\\.jar"))) {
+            try {
+                JarFile jar = new JarFile(file);
+                ZipEntry entry = jar.getEntry("plugin.yml");
+                if (entry == null) {
+                    throw new InvalidPluginException("Jar does not contain a plugin.yml");
+                }
+
+                PluginDescription description;
+                try (InputStream is = jar.getInputStream(entry)) {
+                    description = PluginDescription.load(is);
+                }
+                URLClassLoader classloader = new URLClassLoader(new URL[]{file.toURI().toURL()}, getClass().getClassLoader());
+                Class<?> clazz = Class.forName(description.getMain(), true, classloader);
+                Class<? extends JavaPlugin> subClazz = clazz.asSubclass(JavaPlugin.class);
+                JavaPlugin plugin = subClazz.getDeclaredConstructor().newInstance();
+
+                plugin.description = description;
+                plugin.onEnable();
+                plugins.add(plugin);
+
+                $().info("Loaded plugin: " + plugin.description.getName());
+            } catch (Exception ex) {
+                $().severe("Could not load plugin: " + file);
+                ex.printStackTrace();
+            }
+        }
+    }
+
+    @Override
+    public void onDisable() {
+        for (JavaPlugin p : plugins) {
+            p.onDisable();
+        }
+    }
+
+    @Override
+    public void onConnect(ConnectEvent event) {
+        for (JavaPlugin p : plugins) {
+            p.onConnect(event);
+        }
+    }
+}

src/main/java/net/md_5/bungee/plugin/PluginDescription.java

@@ -0,0 +1,36 @@
+package net.md_5.bungee.plugin;
+
+import java.io.InputStream;
+import java.lang.reflect.Field;
+import lombok.Data;
+import org.yaml.snakeyaml.Yaml;
+
+@Data
+public class PluginDescription {
+
+    private String name;
+    private String main;
+    private String version;
+    private String author;
+
+    private PluginDescription() {
+    }
+
+    public static PluginDescription load(InputStream is) {
+        PluginDescription ret = new Yaml().loadAs(is, PluginDescription.class);
+        if (ret == null) {
+            throw new InvalidPluginException("Could not load plugin description file.");
+        }
+
+        for (Field f : PluginDescription.class.getDeclaredFields()) {
+            try {
+                if (f.get(ret) == null) {
+                    throw new InvalidPluginException(f.getName() + " is not set properly in plugin description");
+                }
+            } catch (IllegalArgumentException | IllegalAccessException ex) {
+            }
+        }
+
+        return ret;
+    }
+}