From 4a7cdfab80d9df76a995853e40a30f994010b64b Mon Sep 17 00:00:00 2001
From: SeanOMik <seanomik@gmail.com>
Date: Sat, 24 Feb 2024 14:30:09 -0500
Subject: [PATCH] ecs: fix executing deferred fn system arguments

---
 lyra-ecs/src/system/fn_sys.rs |  3 ++-
 lyra-ecs/src/system/graph.rs  | 23 +++++++++++++++++++++--
 2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/lyra-ecs/src/system/fn_sys.rs b/lyra-ecs/src/system/fn_sys.rs
index 856ce16..fd7ac5c 100644
--- a/lyra-ecs/src/system/fn_sys.rs
+++ b/lyra-ecs/src/system/fn_sys.rs
@@ -80,12 +80,13 @@ macro_rules! impl_fn_system_tuple {
 
             fn execute_deferred(&mut self, world: NonNull<World>) -> anyhow::Result<()> {
                 let state = self.arg_state.as_mut().expect("Somehow there was no state");
+                state.reverse();
 
                 $(
                     let arg_state_box = state.pop()
                         .expect("Missing expected arg state");
                     let arg_state = *arg_state_box.downcast::<$name::State>()
-                        .unwrap();
+                        .expect("Somehow the state cannot be downcasted from boxed Any");
                     $name::apply_deferred(arg_state, world);
                 )+
 
diff --git a/lyra-ecs/src/system/graph.rs b/lyra-ecs/src/system/graph.rs
index 18ef23a..40ac0cc 100644
--- a/lyra-ecs/src/system/graph.rs
+++ b/lyra-ecs/src/system/graph.rs
@@ -2,7 +2,7 @@ use std::{collections::{HashMap, VecDeque, HashSet}, ptr::NonNull};
 
 use super::System;
 
-use crate::world::World;
+use crate::{world::World, CommandQueue, Commands};
 
 #[derive(thiserror::Error, Debug)]
 pub enum GraphExecutorError {
@@ -58,7 +58,7 @@ impl GraphExecutor {
     }
 
     /// Executes the systems in the graph
-    pub fn execute(&mut self, world_ptr: NonNull<World>, stop_on_error: bool) -> Result<Vec<GraphExecutorError>, GraphExecutorError> {
+    pub fn execute(&mut self, mut world_ptr: NonNull<World>, stop_on_error: bool) -> Result<Vec<GraphExecutorError>, GraphExecutorError> {
         let mut stack = VecDeque::new();
         let mut visited = HashSet::new();
 
@@ -91,6 +91,25 @@ impl GraphExecutor {
                 possible_errors.push(e);
                 unimplemented!("Cannot resume topological execution from error"); // TODO: resume topological execution from error
             }
+
+            let world = unsafe { world_ptr.as_mut() };
+            if let Some(mut queue) = world.try_get_resource_mut::<CommandQueue>() {
+                // Safety: Commands only borrows world.entities when adding commands
+                let world = unsafe { world_ptr.as_mut() };
+                let mut commands = Commands::new(&mut queue, world);
+
+                let world = unsafe { world_ptr.as_mut() };
+                if let Err(e) = commands.execute(world)
+                        .map_err(|e| GraphExecutorError::Command(e)) {
+
+                    if stop_on_error {
+                        return Err(e);
+                    }
+    
+                    possible_errors.push(e);
+                    unimplemented!("Cannot resume topological execution from error"); // TODO: resume topological execution from error
+                }
+            }
         }
 
         Ok(possible_errors)