From 0795a07a2c83fadc5c8206f7cd078c910ad0e8a9 Mon Sep 17 00:00:00 2001
From: Natsu Kagami <nki@nkagami.me>
Date: Sun, 25 Feb 2024 20:03:05 +0100
Subject: [PATCH] Introduce composed_framework to compose multiple frameworks

---
 youmubot/src/compose_framework.rs | 48 +++++++++++++++++++++++++++++++
 youmubot/src/main.rs              |  7 ++++-
 2 files changed, 54 insertions(+), 1 deletion(-)
 create mode 100644 youmubot/src/compose_framework.rs

diff --git a/youmubot/src/compose_framework.rs b/youmubot/src/compose_framework.rs
new file mode 100644
index 0000000..ec338d4
--- /dev/null
+++ b/youmubot/src/compose_framework.rs
@@ -0,0 +1,48 @@
+use std::{future::Future, pin::Pin};
+
+use serenity::{client::FullEvent, framework::Framework, model::channel::Message};
+use youmubot_prelude::*;
+
+/// A Framework to compose other frameworks.
+pub(crate) struct ComposedFramework {
+    frameworks: Box<[Box<dyn Framework>]>,
+}
+
+impl ComposedFramework {
+    /// Create a new composed framework.
+    pub fn new(frameworks: Vec<Box<dyn Framework>>) -> Self {
+        Self {
+            frameworks: frameworks.into_boxed_slice(),
+        }
+    }
+}
+
+#[async_trait]
+impl Framework for ComposedFramework {
+    async fn dispatch(&self, ctx: Context, msg: FullEvent) -> () {
+        if !self.frameworks.is_empty() {
+            self.dispatch_loop(self.frameworks.len() - 1, ctx, msg)
+                .await
+        }
+    }
+}
+impl ComposedFramework {
+    /// Dispatch to all inner frameworks in a loop. Returns a `Pin<Box<Future>>` because rust.
+    fn dispatch_loop<'a>(
+        &'a self,
+        index: usize,
+        ctx: Context,
+        msg: FullEvent,
+    ) -> Pin<Box<dyn Future<Output = ()> + Send + 'a>> {
+        Box::pin(async move {
+            if index == 0 {
+                self.frameworks[index].dispatch(ctx, msg).await
+            } else {
+                self.frameworks[index]
+                    .dispatch(ctx.clone(), msg.clone())
+                    .await;
+                self.dispatch_loop(index - 1, ctx, msg).await
+            }
+        })
+    }
+}
diff --git a/youmubot/src/main.rs b/youmubot/src/main.rs
index 1a18019..5e28d41 100644
--- a/youmubot/src/main.rs
+++ b/youmubot/src/main.rs
@@ -1,3 +1,4 @@
+use compose_framework::ComposedFramework;
 use dotenv::var;
 use serenity::{
     framework::standard::{
@@ -11,6 +12,8 @@ use serenity::{
 };
 use youmubot_prelude::*;
 
+mod compose_framework;
+
 struct Handler {
     hooks: Vec<RwLock<Box<dyn Hook>>>,
 }
@@ -92,6 +95,8 @@ async fn main() {
     // Set up base framework
     let fw = setup_framework(&token[..]).await;
 
+    let composed = ComposedFramework::new(vec![Box::new(fw)]);
+
     // Sets up a client
     let mut client = {
         // Attempt to connect and set up a framework
@@ -105,7 +110,7 @@ async fn main() {
             | GatewayIntents::DIRECT_MESSAGES
             | GatewayIntents::DIRECT_MESSAGE_REACTIONS;
         Client::builder(token, intents)
-            .framework(fw)
+            .framework(composed)
             .event_handler(handler)
             .await
             .unwrap()