Revamp nomination pool reward scheme (#11669)

* make pool roles optional

* undo lock file changes?

* add migration

* add the ability for pools to chill themselves

* boilerplate of tests

* somewhat stable, but I think I found another bug as well

* Fix it all

* Add more more sophisticated test + capture one more bug.

* Update frame/staking/src/lib.rs

* reduce the diff a little bit

* add some test for the slashing bug

* cleanup

* fix lock file?

* Fix

* fmt

* Update frame/nomination-pools/src/lib.rs

Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Update frame/nomination-pools/src/lib.rs

Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Update frame/nomination-pools/src/lib.rs

Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Update frame/nomination-pools/src/mock.rs

Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Fix build

* fix some fishy tests..

* add one last integrity check for MinCreateBond

* remove bad assertion -- needs to be dealt with later

* nits

* fix tests and add benchmarks for chill

* remove stuff

* fix benchmarks

* cargo run --quiet --profile=production  --features=runtime-benchmarks --manifest-path=bin/node/cli/Cargo.toml -- benchmark pallet --chain=dev --steps=50 --repeat=20 --pallet=pallet_nomination_pools --extrinsic=* --execution=wasm --wasm-execution=compiled --heap-pages=4096 --output=./frame/nomination-pools/src/weights.rs --template=./.maintain/frame-weight-template.hbs

* remove defensive

* first working version

* bring back all tests

* ALL new tests work now

* cleanup

* make sure benchmarks and all work

* cargo run --quiet --profile=production  --features=runtime-benchmarks --manifest-path=bin/node/cli/Cargo.toml -- benchmark pallet --chain=dev --steps=50 --repeat=20 --pallet=pallet_nomination_pools --extrinsic=* --execution=wasm --wasm-execution=compiled --heap-pages=4096 --output=./frame/nomination-pools/src/weights.rs --template=./.maintain/frame-weight-template.hbs

* round of self-review, make arithmetic safe

* fix warn

* add migration code

* Fix doc

* add precision notes

* make arithmetic fallible

* fix node runtime

* a lot of precision tests and notes and stuff

* document MaxPOintsToBalance better

* :round of self-review

* fmt

* fix some comments

* Fix proportional slashing logic

* Update frame/nomination-pools/src/tests.rs

Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Update frame/nomination-pools/src/tests.rs

Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Update frame/nomination-pools/src/lib.rs

Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* track poinst in migration

* fix

* fmt

* fix migration

* remove event read

* Apply suggestions from code review

* Update frame/staking/src/lib.rs

Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com>

* Update frame/nomination-pools/src/lib.rs

Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com>

* Update frame/nomination-pools/src/lib.rs

Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com>

* update

* fmt

* fmt

* add one last test

* fmt

Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>
Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com>
Co-authored-by: Parity Bot <admin@parity.io>

substrate/bin/node/runtime/src/lib.rs

@@ -68,7 +68,7 @@ use sp_runtime::{
 		SaturatedConversion, StaticLookup,
 	},
 	transaction_validity::{TransactionPriority, TransactionSource, TransactionValidity},
-	ApplyExtrinsicResult, FixedPointNumber, Perbill, Percent, Permill, Perquintill,
+	ApplyExtrinsicResult, FixedPointNumber, FixedU128, Perbill, Percent, Permill, Perquintill,
 };
 use sp_std::prelude::*;
 #[cfg(any(feature = "std", test))]
@@ -730,7 +730,7 @@ impl pallet_bags_list::Config for Runtime {
 parameter_types! {
 	pub const PostUnbondPoolsWindow: u32 = 4;
 	pub const NominationPoolsPalletId: PalletId = PalletId(*b"py/nopls");
-	pub const MinPointsToBalance: u32 = 10;
+	pub const MaxPointsToBalance: u8 = 10;
 }
 
 use sp_runtime::traits::Convert;
@@ -751,6 +751,8 @@ impl pallet_nomination_pools::Config for Runtime {
 	type WeightInfo = ();
 	type Event = Event;
 	type Currency = Balances;
+	type CurrencyBalance = Balance;
+	type RewardCounter = FixedU128;
 	type BalanceToU256 = BalanceToU256;
 	type U256ToBalance = U256ToBalance;
 	type StakingInterface = pallet_staking::Pallet<Self>;
@@ -758,7 +760,7 @@ impl pallet_nomination_pools::Config for Runtime {
 	type MaxMetadataLen = ConstU32<256>;
 	type MaxUnbonding = ConstU32<8>;
 	type PalletId = NominationPoolsPalletId;
-	type MinPointsToBalance = MinPointsToBalance;
+	type MaxPointsToBalance = MaxPointsToBalance;
 }
 
 parameter_types! {
@@ -1675,6 +1677,7 @@ pub type Executive = frame_executive::Executive<
 	frame_system::ChainContext<Runtime>,
 	Runtime,
 	AllPalletsWithSystem,
+	pallet_nomination_pools::migration::v2::MigrateToV2<Runtime>,
 >;
 
 /// MMR helper types.