1 files changed, 193 insertions, 100 deletions

diff --git a/ecs/src/system/stateful.rs b/ecs/src/system/stateful.rs
index 80ac346..e74ef31 100644
--- a/ecs/src/system/stateful.rs
+++ b/ecs/src/system/stateful.rs
@@ -1,150 +1,243 @@
-use std::any::{Any, TypeId};
+use std::mem::transmute;
 use std::panic::{RefUnwindSafe, UnwindSafe};
 
-use hashbrown::HashMap;
 use seq_macro::seq;
 
-use crate::component::Component;
-use crate::lock::Lock;
-use crate::system::{
-    ComponentRefMut,
-    Into as IntoSystem,
-    Param,
-    ParamWithInputFilter,
-    System,
-    TypeErased,
+use crate::component::local::SystemWithLocalComponents;
+use crate::component::Parts as ComponentParts;
+use crate::event::Emitted as EmittedEvent;
+use crate::system::initializable::{Initializable, MaybeInitializableParamTuple};
+use crate::system::observer::{
+    Observe,
+    Observed,
+    Observer,
+    WrapperComponent as ObserverWrapperComponent,
 };
-use crate::tuple::{
-    Reduce as TupleReduce,
-    Tuple,
-    WithAllElemLtStatic as TupleWithAllElemLtStatic,
-};
-use crate::uid::Uid;
+use crate::system::{Into as IntoSystem, Metadata, Param, System, TypeErased};
 use crate::World;
 
 /// A stateful system.
 pub struct Stateful<Func>
 {
     func: Func,
-    local_components: HashMap<Uid, Lock<Box<dyn Component>>>,
+    local_components: Vec<ComponentParts>,
 }
 
 macro_rules! impl_system {
     ($c: tt) => {
         seq!(I in 0..$c {
-            impl<'world, Func, #(TParam~I,)*> System<'world, fn(&'world (), #(TParam~I,)*)>
-                for Stateful<Func>
+            impl<'world, Func, #(TParam~I,)*>
+                System<'world, fn(&'world (), #(TParam~I,)*)> for Stateful<Func>
             where
                 Func: Fn(#(TParam~I,)*) + Copy + RefUnwindSafe + UnwindSafe + 'static,
-                #(TParam~I: Param<'world>,)*
-                #(TParam~I::Input: 'static,)*
-                (#(TParam~I::Input,)*): TupleReduce<
-                    ParamWithInputFilter,
-                    Out: Tuple<InOptions: TupleWithAllElemLtStatic>
-                >,
+                #(TParam~I: Param<'world, Input: 'static>,)*
             {
-                type Input =
-                    <(#(TParam~I::Input,)*) as TupleReduce<ParamWithInputFilter>>::Out;
+                type Callbacks = Callbacks;
 
-                fn initialize(mut self, input: Self::Input) -> Self
+                fn finish(self) -> (TypeErased, Self::Callbacks)
                 {
-                    let mut option_input = input.into_in_options();
-
-                    let mut index = 0;
-
-                    #(
-                        if TypeId::of::<TParam~I::Input>() !=
-                            TypeId::of::<()>()
-                        {
-                            let input = option_input
-                                .get_mut::<Option<TParam~I::Input>>(index)
-                                .expect("Input element index out of range")
-                                .take()
-                                .expect("Input element is already taken");
-
-                            TParam~I::initialize(
-                                &mut self,
-                                input
-                            );
-
-                            #[allow(unused_assignments)]
-                            {
-                                index += 1;
-                            }
-                        }
-                    )*
+                    let Self { func, local_components } = self;
 
-                    self
+                    let callbacks = Callbacks { local_components };
+
+                    let type_erased = TypeErased {
+                        run: Box::new(move |world, metadata| {
+                            // SAFETY: The caller of TypeErased::run ensures the lifetime
+                            // is correct
+                            let world = unsafe { &*std::ptr::from_ref(world) };
+
+                            func(#({
+                                TParam~I::new(&world, &metadata)
+                            },)*);
+                        }),
+                    };
+
+
+                    (type_erased, callbacks)
                 }
+            }
 
-                fn run<'this>(&'this self, world: &'world World)
-                where
-                    'this: 'world
+            impl<'world, Func, #(TParam~I,)*>
+                Initializable<'world, fn(&'world (), #(TParam~I,)*)> for Stateful<Func>
+            where
+                Func: Fn(#(TParam~I,)*) + Copy + RefUnwindSafe + UnwindSafe + 'static,
+                #(TParam~I: Param<'world, Input: 'static>,)*
+                (#(TParam~I,)*): MaybeInitializableParamTuple<'world, Self>
+            {
+                type Inputs = <
+                    (#(TParam~I,)*) as MaybeInitializableParamTuple<'world, Self>
+                >::Inputs;
+
+                fn initialize(mut self, inputs: Self::Inputs) -> Self
                 {
-                    let func = self.func;
+                    init_initializable_params::<_, (#(TParam~I,)*)>(&mut self, inputs);
 
-                    func(#({
-                        TParam~I::new(self, &world)
-                    },)*);
+                    self
                 }
+            }
 
-                fn into_type_erased(self) -> TypeErased
+            impl<'world, Func, #(TParam~I,)*> IntoSystem<'world, fn(#(TParam~I,)*)>
+                for Func
+            where
+                #(TParam~I: Param<'world>,)*
+                Func: Fn(#(TParam~I,)*) + Copy + 'static,
+            {
+                type System = Stateful<Func>;
+
+                fn into_system(self) -> Self::System
                 {
-                    TypeErased {
-                        data: Box::new(self),
-                        run: Box::new(|data, world| {
-                            // SAFETY: The caller of TypeErased::run ensures the lifetime
-                            // is correct
-                            let data = unsafe { &*std::ptr::from_ref::<dyn Any>(data) };
+                    Self::System {
+                        func: self,
+                        local_components: Vec::new(), // TODO: Use Vec::with_capacity
+                    }
+                }
+            }
+        });
+    };
+}
 
-                            let me = data.downcast_ref::<Self>().unwrap();
+seq!(C in 1..16 {
+    impl_system!(C);
+});
 
-                            // SAFETY: The caller of TypeErased::run ensures the lifetime
-                            // is correct
-                            let world = unsafe { &*std::ptr::from_ref(world) };
+impl<Func> SystemWithLocalComponents for Stateful<Func>
+{
+    fn add_local_component(&mut self, component_parts: ComponentParts)
+    {
+        self.local_components.push(component_parts);
+    }
+}
 
-                            me.run(world);
-                        }),
-                    }
+#[derive(Debug)]
+pub struct Callbacks
+{
+    local_components: Vec<ComponentParts>,
+}
+
+impl crate::system::Callbacks for Callbacks
+{
+    fn on_created(&mut self, world: &mut World, metadata: Metadata)
+    {
+        for local_comp_parts in self.local_components.drain(..) {
+            world.add_component(metadata.ent_id, local_comp_parts);
+        }
+    }
+}
+
+fn init_initializable_params<'world, SystemT, Params>(
+    system: &mut SystemT,
+    inputs: Params::Inputs,
+) where
+    Params: MaybeInitializableParamTuple<'world, SystemT>,
+{
+    Params::init_initializable(system, inputs);
+}
+
+macro_rules! impl_observer {
+    ($c: tt) => {
+        seq!(I in 0..$c {
+            impl<'world, ObservedT, Func, #(TParam~I,)*> System<
+                'world,
+                fn(Observe<'world, ObservedT>, #(TParam~I,)*)
+            > for Stateful<Func>
+            where
+                ObservedT: Observed,
+                Func: Fn(Observe<'world, ObservedT>, #(TParam~I,)*) + Copy + 'static,
+                #(TParam~I: Param<'world>,)*
+            {
+                type Callbacks = Callbacks;
+
+                fn finish(self) -> (TypeErased, Callbacks)
+                {
+                    unimplemented!();
                 }
+            }
 
-                fn get_local_component_mut<LocalComponent: Component>(
-                    &self,
-                ) -> Option<ComponentRefMut<LocalComponent>>
+            impl<'world, ObservedT, Func, #(TParam~I,)*> Initializable<
+                'world,
+                fn(Observe<'world, ObservedT>, #(TParam~I,)*)
+            > for Stateful<Func>
+            where
+                ObservedT: Observed,
+                Func: Fn(Observe<'world, ObservedT>, #(TParam~I,)*) + Copy + 'static,
+                #(TParam~I: Param<'world>,)*
+                (#(TParam~I,)*): MaybeInitializableParamTuple<'world, Self>
+            {
+                type Inputs = <
+                    (#(TParam~I,)*) as MaybeInitializableParamTuple<'world, Self>
+                >::Inputs;
+
+                fn initialize(mut self, inputs: Self::Inputs) -> Self
                 {
-                    let local_component = self.local_components
-                        .get(&LocalComponent::id())?
-                        .write_nonblock()
-                        .expect("Failed to aquire read-write local component lock");
+                    init_initializable_params::<_, (#(TParam~I,)*)>(&mut self, inputs);
 
-                    Some(ComponentRefMut::new(local_component))
+                    self
                 }
+            }
+
+            impl<'world, ObservedT, Func, #(TParam~I,)*> Observer<
+                'world,
+                fn(Observe<'world, ObservedT>, #(TParam~I,)*)
+            > for Stateful<Func>
+            where
+                ObservedT: Observed,
+                Func: Fn(Observe<'world, ObservedT>, #(TParam~I,)*) + Copy + 'static,
+                #(TParam~I: Param<'world>,)*
+            {
+                type ObservedEvents = ObservedT::Events;
 
-                fn set_local_component<LocalComponent: Component>(
-                    &mut self,
-                    local_component: LocalComponent,
-                )
+                fn observed_events() -> Self::ObservedEvents
                 {
-                    self.local_components
-                        .insert(
-                            LocalComponent::id(),
-                            Lock::new(Box::new(local_component))
-                        );
+                    ObservedT::events()
+                }
+
+                fn finish_observer(self) -> (ObserverWrapperComponent, Callbacks)
+                {
+                    let Self { func, local_components } = self;
+
+                    let callbacks = Callbacks { local_components };
+
+                    let wrapper_comp = ObserverWrapperComponent::new(
+                        move |world, metadata, emitted_event| {
+                            // SAFETY: The caller of TypeErased::run ensures the lifetime
+                            // is correct
+                            let world = unsafe { &*std::ptr::from_ref(world) };
+
+                            // SAFETY: The caller of TypeErased::run ensures the lifetime
+                            // is correct
+                            let emitted_event = unsafe {
+                                transmute::<EmittedEvent<'_>, EmittedEvent<'_>>(
+                                    emitted_event
+                                )
+                            };
+
+                            func(Observe::new(world, emitted_event), #({
+                                TParam~I::new(world, &metadata)
+                            },)*);
+                        },
+                    );
+
+                    (wrapper_comp, callbacks)
                 }
             }
 
-            impl<Func, #(TParam~I,)*> IntoSystem<fn(#(TParam~I,)*)>
-                for Func
+            impl<'world, Func, ObservedT, #(TParam~I,)*> IntoSystem<
+                'world,
+                fn(Observe<'world, ObservedT>,
+                #(TParam~I,)*)
+            > for Func
             where
-                Func: Fn(#(TParam~I,)*) + Copy + 'static,
+                ObservedT: Observed,
+                #(TParam~I: Param<'world>,)*
+                Func: Fn(Observe<'world, ObservedT>, #(TParam~I,)*) + Copy + 'static,
             {
                 type System = Stateful<Func>;
 
-                fn into_system(self) -> Self::System
+                fn into_system(self) -> Stateful<Func>
                 {
-                    Self::System {
+                    Stateful {
                         func: self,
-                        local_components: HashMap::new(),
+                        local_components: Vec::new(), // TODO: Use Vec::with_capacity
                     }
                 }
             }
@@ -153,5 +246,5 @@ macro_rules! impl_system {
 }
 
 seq!(C in 1..16 {
-    impl_system!(C);
+    impl_observer!(C);
 });