Allow plugins to unregister commands (#522)

* Add unregister function

* Add unregister_command to plugin context

* Send command suggestions packet to all players

* cargo clippy

* cargo clippy again

pumpkin/src/command/dispatcher.rs

@@ -316,6 +316,25 @@ impl CommandDispatcher {
         self.commands
             .insert(primary_name.to_string(), Command::Tree(tree));
     }
+
+    /// Remove a command from the dispatcher by its primary name.
+    pub(crate) fn unregister(&mut self, name: &str) {
+        let mut to_remove = Vec::new();
+        for (key, value) in &self.commands {
+            if key == name {
+                to_remove.push(key.clone());
+            } else if let Command::Alias(target) = value {
+                if target == name {
+                    to_remove.push(key.clone());
+                }
+            }
+        }
+
+        for key in to_remove {
+            self.commands.remove(&key);
+            self.permissions.remove(&key);
+        }
+    }
 }
 
 #[cfg(test)]

pumpkin/src/plugin/api/context.rs

@@ -1,5 +1,6 @@
 use std::{fs, path::Path, sync::Arc};
 
+use crate::command::client_cmd_suggestions;
 use pumpkin_util::PermissionLvl;
 use tokio::sync::RwLock;
 
@@ -48,8 +49,37 @@ impl Context {
         tree: crate::command::tree::CommandTree,
         permission: PermissionLvl,
     ) {
-        let mut dispatcher_lock = self.server.command_dispatcher.write().await;
-        dispatcher_lock.register(tree, permission);
+        {
+            let mut dispatcher_lock = self.server.command_dispatcher.write().await;
+            dispatcher_lock.register(tree, permission);
+        };
+
+        for world in self.server.worlds.read().await.iter() {
+            for player in world.current_players.lock().await.values() {
+                client_cmd_suggestions::send_c_commands_packet(
+                    player,
+                    &self.server.command_dispatcher,
+                )
+                .await;
+            }
+        }
+    }
+
+    pub async fn unregister_command(&self, name: &str) {
+        {
+            let mut dispatcher_lock = self.server.command_dispatcher.write().await;
+            dispatcher_lock.unregister(name);
+        };
+
+        for world in self.server.worlds.read().await.iter() {
+            for player in world.current_players.lock().await.values() {
+                client_cmd_suggestions::send_c_commands_packet(
+                    player,
+                    &self.server.command_dispatcher,
+                )
+                .await;
+            }
+        }
     }
 
     pub async fn register_event<E: Event + 'static, H>(