Refactor Nomination Pool to support multiple staking strategies

Cargo.toml

@@ -372,7 +372,8 @@ members = [
 	"substrate/frame/nomination-pools/benchmarking",
 	"substrate/frame/nomination-pools/fuzzer",
 	"substrate/frame/nomination-pools/runtime-api",
-	"substrate/frame/nomination-pools/test-staking",
+	"substrate/frame/nomination-pools/test-delegate-stake",
+	"substrate/frame/nomination-pools/test-transfer-stake",
 	"substrate/frame/offences",
 	"substrate/frame/offences/benchmarking",
 	"substrate/frame/paged-list",

polkadot/runtime/westend/Cargo.toml

@@ -82,6 +82,7 @@ pallet-society = { path = "../../../substrate/frame/society", default-features =
 pallet-staking = { path = "../../../substrate/frame/staking", default-features = false }
 pallet-staking-reward-curve = { package = "pallet-staking-reward-curve", path = "../../../substrate/frame/staking/reward-curve" }
 pallet-staking-runtime-api = { path = "../../../substrate/frame/staking/runtime-api", default-features = false }
+pallet-delegated-staking = { path = "../../../substrate/frame/delegated-staking", default-features = false }
 pallet-state-trie-migration = { path = "../../../substrate/frame/state-trie-migration", default-features = false }
 pallet-sudo = { path = "../../../substrate/frame/sudo", default-features = false }
 pallet-timestamp = { path = "../../../substrate/frame/timestamp", default-features = false }
@@ -159,6 +160,7 @@ std = [
 	"pallet-beefy/std",
 	"pallet-collective/std",
 	"pallet-conviction-voting/std",
+	"pallet-delegated-staking/std",
 	"pallet-democracy/std",
 	"pallet-election-provider-multi-phase/std",
 	"pallet-election-provider-support-benchmarking?/std",
@@ -242,6 +244,7 @@ runtime-benchmarks = [
 	"pallet-balances/runtime-benchmarks",
 	"pallet-collective/runtime-benchmarks",
 	"pallet-conviction-voting/runtime-benchmarks",
+	"pallet-delegated-staking/runtime-benchmarks",
 	"pallet-democracy/runtime-benchmarks",
 	"pallet-election-provider-multi-phase/runtime-benchmarks",
 	"pallet-election-provider-support-benchmarking/runtime-benchmarks",
@@ -302,6 +305,7 @@ try-runtime = [
 	"pallet-beefy/try-runtime",
 	"pallet-collective/try-runtime",
 	"pallet-conviction-voting/try-runtime",
+	"pallet-delegated-staking/try-runtime",
 	"pallet-democracy/try-runtime",
 	"pallet-election-provider-multi-phase/try-runtime",
 	"pallet-elections-phragmen/try-runtime",

polkadot/runtime/westend/src/lib.rs

@@ -647,7 +647,7 @@ impl pallet_staking::Config for Runtime {
 	type HistoryDepth = frame_support::traits::ConstU32<84>;
 	type MaxControllersInDeprecationBatch = MaxControllersInDeprecationBatch;
 	type BenchmarkingConfig = runtime_common::StakingBenchmarkingConfig;
-	type EventListeners = NominationPools;
+	type EventListeners = (NominationPools, DelegatedStaking);
 	type WeightInfo = weights::pallet_staking::WeightInfo<Runtime>;
 	type DisablingStrategy = pallet_staking::UpToLimitDisablingStrategy;
 }
@@ -1359,7 +1359,8 @@ impl pallet_nomination_pools::Config for Runtime {
 	type RewardCounter = FixedU128;
 	type BalanceToU256 = BalanceToU256;
 	type U256ToBalance = U256ToBalance;
-	type Staking = Staking;
+	type StakeAdapter =
+		pallet_nomination_pools::adapter::DelegateStake<Self, Staking, DelegatedStaking>;
 	type PostUnbondingPoolsWindow = ConstU32<4>;
 	type MaxMetadataLen = ConstU32<256>;
 	// we use the same number of allowed unlocking chunks as with staking.
@@ -1369,6 +1370,21 @@ impl pallet_nomination_pools::Config for Runtime {
 	type AdminOrigin = EitherOf<EnsureRoot<AccountId>, StakingAdmin>;
 }
 
+parameter_types! {
+	pub const DelegatedStakingPalletId: PalletId = PalletId(*b"py/dlstk");
+	pub const SlashRewardFraction: Perbill = Perbill::from_percent(1);
+}
+
+impl pallet_delegated_staking::Config for Runtime {
+	type RuntimeEvent = RuntimeEvent;
+	type PalletId = DelegatedStakingPalletId;
+	type Currency = Balances;
+	type OnSlash = ();
+	type SlashRewardFraction = SlashRewardFraction;
+	type RuntimeHoldReason = RuntimeHoldReason;
+	type CoreStaking = Staking;
+}
+
 impl pallet_root_testing::Config for Runtime {
 	type RuntimeEvent = RuntimeEvent;
 }
@@ -1517,6 +1533,10 @@ mod runtime {
 	#[runtime::pallet_index(37)]
 	pub type Treasury = pallet_treasury;
 
+	// Staking extension for delegation
+	#[runtime::pallet_index(38)]
+	pub type DelegatedStaking = pallet_delegated_staking;
+
 	// Parachains pallets. Start indices at 40 to leave room.
 	#[runtime::pallet_index(41)]
 	pub type ParachainsOrigin = parachains_origin;
@@ -1656,7 +1676,12 @@ pub mod migrations {
 	}
 
 	/// Unreleased migrations. Add new ones here:
-	pub type Unreleased = (pallet_staking::migrations::v15::MigrateV14ToV15<Runtime>,);
+	pub type Unreleased = (
+		// Migrate NominationPools to `DelegateStake` adapter. This is unversioned upgrade and
+		// should not be applied yet in Kusama/Polkadot.
+		pallet_nomination_pools::migration::unversioned::DelegationStakeMigration<Runtime>,
+		pallet_staking::migrations::v15::MigrateV14ToV15<Runtime>,
+	);
 }
 
 /// Unchecked extrinsic type as expected by this runtime.