Initial Commit

src/main/java/emu/nebula/command/CommandManager.java

@@ -0,0 +1,168 @@
+package emu.nebula.command;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import org.reflections.Reflections;
+
+import emu.nebula.Nebula;
+import emu.nebula.game.player.Player;
+import it.unimi.dsi.fastutil.objects.Object2ObjectMap;
+import it.unimi.dsi.fastutil.objects.Object2ObjectOpenHashMap;
+import lombok.Getter;
+
+@Getter
+public class CommandManager {
+    private Object2ObjectMap<String, CommandHandler> labels;
+    private Object2ObjectMap<String, CommandHandler> commands;
+    
+    public CommandManager() {
+        this.labels = new Object2ObjectOpenHashMap<>();
+        this.commands = new Object2ObjectOpenHashMap<>();
+        
+        // Scan for commands
+        var commandClasses = new Reflections(CommandManager.class.getPackageName()).getTypesAnnotatedWith(Command.class);
+        
+        for (var cls : commandClasses) {
+            if (!CommandHandler.class.isAssignableFrom(cls)) {
+                continue;
+            }
+            
+            try {
+                CommandHandler handler = (CommandHandler) cls.getDeclaredConstructor().newInstance();
+                this.registerCommand(handler);
+            } catch (Exception e) {
+                e.printStackTrace();
+            }
+        }
+    }
+    
+    /**
+     * Adds a command that players and server console users can use. Command handlers must have the proper command annotation attached to them.
+     */
+    public CommandManager registerCommand(CommandHandler handler) {
+        Command command = handler.getClass().getAnnotation(Command.class);
+        if (command == null) return this;
+        
+        this.getLabels().put(command.label(), handler);
+        this.getCommands().put(command.label(), handler);
+        
+        for (String alias : command.aliases()) {
+            this.getCommands().put(alias, handler);
+        }
+        
+        return this;
+    }
+    
+    /**
+     * Removes a command from use.
+     * @param label The command name
+     * @return
+     */
+    public CommandManager unregisterCommand(String label) {
+        CommandHandler handler = this.getLabels().get(label);
+        if (handler == null) return this;
+        
+        Command command = handler.getClass().getAnnotation(Command.class);
+        if (command == null) {
+            return this;
+        }
+        
+        this.getLabels().remove(command.label());
+        this.getCommands().remove(command.label());
+        
+        for (String alias : command.aliases()) {
+            this.getCommands().remove(alias);
+        }
+        
+        return this;
+    }
+    
+    /**
+     * Checks if the sender has permission to use this command. Will always return true if the sender is the server console.
+     * @param sender The sender of the command.
+     * @param command
+     * @return true if the sender has permission to use this command
+     */
+    public boolean checkPermission(Player sender, Command command) {
+        if (sender == null || command.permission().isEmpty()) {
+            return true;
+        }
+        
+        return sender.getAccount().hasPermission(command.permission());
+    }
+    
+    /**
+     * Checks if the sender has permission to use this command on other players. Will always return true if the sender is the server console.
+     * @param sender The sender of the command.
+     * @param command
+     * @return true if the sender has permission to use this command
+     */
+    private boolean checkTargetPermission(Player sender, Command command) {
+        if (sender == null || command.permission().isEmpty()) {
+            return true;
+        }
+        
+        return sender.getAccount().hasPermission("target." + command.permission());
+    }
+    
+    public void invoke(Player sender, String message) {
+        // Parse message into arguments
+        List<String> args = Arrays.stream(message.split(" ")).collect(Collectors.toCollection(ArrayList::new));
+        
+        // Get command label
+        String label = args.remove(0).toLowerCase();
+        
+        // Filter out command prefixes
+        if (label.startsWith("/") || label.startsWith("!")) {
+            label = label.substring(1);
+        }
+        
+        // Get command handler
+        CommandHandler handler = this.commands.get(label);
+
+        // Execute command
+        if (handler != null) {
+            // Get command annotation data
+            Command command = handler.getData();
+            
+            // Check if sender has permission to run the command.
+            if (sender != null && !this.checkPermission(sender, command)) {
+                // We have a double null check here just in case
+                sender.sendMessage("You do not have permission to use this command.");
+                return;
+            }
+            
+            // Build command arguments
+            CommandArgs cmdArgs = new CommandArgs(sender, args);
+            
+            // Check targeted permission
+            if (sender != cmdArgs.getTarget() && !this.checkTargetPermission(sender, command)) {
+                cmdArgs.sendMessage("You do not have permission to use this command on another player.");
+                return;
+            }
+            
+            // Make sure our command has a target
+            if (command.requireTarget() && cmdArgs.getTarget() == null) {
+                cmdArgs.sendMessage("Error: Targeted player not found or offline");
+                return;
+            }
+            
+            // Log
+            if (sender != null && Nebula.getConfig().getLogOptions().commands) {
+                Nebula.getLogger().info("[UID: " + sender.getUid() + "] " + sender.getName() + " used command: " + message);
+            }
+            
+            // Run command
+            handler.execute(cmdArgs);
+        } else {
+            if (sender != null) {
+                sender.sendMessage("Invalid Command!");
+            } else {
+                Nebula.getLogger().info("Invalid Command!");
+            }
+        }
+    }
+}