auto nullification during finalization and appropriate tests

Signed-off-by: Uncle Stretch <uncle.stretch@ghostchain.io>

pallets/networks/src/lib.rs

@@ -8,13 +8,13 @@ use frame_support::{
 };
 use frame_system::pallet_prelude::*;
 use scale_info::TypeInfo;
+
 use sp_runtime::{
     traits::{CheckedSub, CheckedAdd, AtLeast32BitUnsigned, Member},
     curve::PiecewiseLinear,
     DispatchResult,
 };
-use sp_std::prelude::*;
-use sp_std::convert::TryInto;
+use sp_std::{prelude::*, convert::TryInto};
 
 pub use ghost_traits::networks::{
     NetworkDataBasicHandler, NetworkDataInspectHandler, 
@@ -93,6 +93,8 @@ where
             false => total_issuance.saturating_sub(Balance::from(bridged_in - bridged_out)),
         };
 
+        NullifyNeeded::<T>::set(true);
+
         match piecewise_linear
             .calculate_for_fraction_times_denominator(total_staked, adjusted_issuance)
             .checked_mul(&accumulated_balance)
@@ -165,6 +167,10 @@ pub mod module {
         NetworkRemoved { chain_id: T::NetworkId },
     }
 
+    #[pallet::storage]
+    #[pallet::getter(fn nullify_needed)]
+    pub type NullifyNeeded<T: Config> = StorageValue<_, bool, ValueQuery>;
+
     #[pallet::storage]
     #[pallet::getter(fn bridged_imbalance)]
     pub type BridgedImbalance<T: Config> =
@@ -221,7 +227,18 @@ pub mod module {
     pub struct Pallet<T>(PhantomData<T>);
 
     #[pallet::hooks]
-    impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {}
+    impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {
+        fn on_initialize(_: BlockNumberFor<T>) -> Weight {
+            T::DbWeight::get().reads_writes(1, 1)
+        }
+
+        fn on_finalize(_: BlockNumberFor<T>) {
+            if Self::nullify_needed() {
+                Self::nullify_commission();
+                NullifyNeeded::<T>::put(false);
+            }
+        }
+    }
 
     #[pallet::call]
     impl<T: Config> Pallet<T> {
@@ -596,6 +613,10 @@ impl<T: Config> NetworkDataInspectHandler<NetworkData> for Pallet<T> {
     fn iter() -> PrefixIterator<(Self::NetworkId, NetworkData)> {
         Networks::<T>::iter()
     }
+
+    fn is_nullification_period() -> bool {
+        NullifyNeeded::<T>::get()
+    }
 }
 
 impl<T: Config> NetworkDataMutateHandler<NetworkData, BalanceOf<T>> for Pallet<T> {