Merge pull request 'Add Message Dispatcher' (#12) from TheRedApricot/Gen_Hack-and-Slash-Roguelite:main into main

Server/src/network_service.rs

@@ -1,3 +1,4 @@
+mod message_dispatcher;
 mod tcp_server;
 
 use tcp_server::TcpServer;

Server/src/network_service/message_dispatcher.rs

@@ -0,0 +1,68 @@
+use std::collections::HashMap;
+use std::sync::LazyLock;
+
+use tokio::sync::RwLock;
+
+pub(crate) struct MessageDispatcher<H>
+where
+    H: Fn(String) + Send + Sync,
+{
+    handlers: RwLock<HashMap<String, H>>,
+}
+
+pub(crate) static DISPATCHER: LazyLock<MessageDispatcher<Box<dyn Fn(String) + Send + Sync>>> =
+    LazyLock::new(MessageDispatcher::new);
+
+impl<H> MessageDispatcher<H>
+where
+    H: Fn(String) + Send + Sync,
+{
+    fn new() -> Self {
+        Self {
+            handlers: RwLock::new(HashMap::new()),
+        }
+    }
+
+    pub(crate) async fn register_handler(&self, handler_name: String, handler: H) {
+        let mut handlers = self.handlers.write().await;
+        handlers.insert(handler_name, handler);
+    }
+
+    pub(crate) async fn dispatch(&self, handler_name: String, message: String) {
+        let handlers = self.handlers.read().await;
+
+        match handlers.get(&handler_name) {
+            Some(handler) => handler(message),
+            None => log::error!(
+                "The handler corresponds to this kind of message hasn't been registered!"
+            ),
+        }
+    }
+}
+
+mod test {
+    #[tokio::test]
+    async fn test_dispatch() {
+        use super::DISPATCHER;
+
+        DISPATCHER
+            .register_handler(
+                "UserLogin".into(),
+                Box::new(|message| println!("Received message: {message}")),
+            )
+            .await;
+        DISPATCHER
+            .register_handler(
+                "UserSignUp".into(),
+                Box::new(|message| println!("Received message: {message}")),
+            )
+            .await;
+
+        DISPATCHER
+            .dispatch("UserLogin".into(), "I want to login".into())
+            .await;
+        DISPATCHER
+            .dispatch("UserSignUp".into(), "I want to signup".into())
+            .await;
+    }
+}