1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
// This file is part of Substrate.

// Copyright (C) Parity Technologies (UK) Ltd.
// SPDX-License-Identifier: Apache-2.0

// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// 	http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use super::*;
use crate::log;
use alloc::{collections::btree_map::BTreeMap, vec::Vec};
use frame_support::traits::{OnRuntimeUpgrade, UncheckedOnRuntimeUpgrade};

#[cfg(feature = "try-runtime")]
use sp_runtime::TryRuntimeError;

/// Exports for versioned migration `type`s for this pallet.
pub mod versioned {
	use super::*;

	/// v8: Adds commission claim permissions to `BondedPools`.
	pub type V7ToV8<T> = frame_support::migrations::VersionedMigration<
		7,
		8,
		v8::VersionUncheckedMigrateV7ToV8<T>,
		crate::pallet::Pallet<T>,
		<T as frame_system::Config>::DbWeight,
	>;

	/// Migration V6 to V7 wrapped in a [`frame_support::migrations::VersionedMigration`], ensuring
	/// the migration is only performed when on-chain version is 6.
	pub type V6ToV7<T> = frame_support::migrations::VersionedMigration<
		6,
		7,
		v7::VersionUncheckedMigrateV6ToV7<T>,
		crate::pallet::Pallet<T>,
		<T as frame_system::Config>::DbWeight,
	>;

	/// Wrapper over `MigrateToV6` with convenience version checks.
	pub type V5toV6<T> = frame_support::migrations::VersionedMigration<
		5,
		6,
		v6::MigrateToV6<T>,
		crate::pallet::Pallet<T>,
		<T as frame_system::Config>::DbWeight,
	>;
}

pub mod unversioned {
	use super::*;

	/// Checks and updates `TotalValueLocked` if out of sync.
	pub struct TotalValueLockedSync<T>(core::marker::PhantomData<T>);
	impl<T: Config> OnRuntimeUpgrade for TotalValueLockedSync<T> {
		#[cfg(feature = "try-runtime")]
		fn pre_upgrade() -> Result<Vec<u8>, TryRuntimeError> {
			Ok(Vec::new())
		}

		fn on_runtime_upgrade() -> Weight {
			let migrated = BondedPools::<T>::count();

			// recalculate the `TotalValueLocked` to compare with the current on-chain TVL which may
			// be out of sync.
			let tvl: BalanceOf<T> = helpers::calculate_tvl_by_total_stake::<T>();
			let onchain_tvl = TotalValueLocked::<T>::get();

			let writes = if tvl != onchain_tvl {
				TotalValueLocked::<T>::set(tvl);

				log!(
					info,
					"on-chain TVL was out of sync, update. Old: {:?}, new: {:?}",
					onchain_tvl,
					tvl
				);

				// writes: onchain version + set total value locked.
				2
			} else {
				log!(info, "on-chain TVL was OK: {:?}", tvl);

				// writes: onchain version write.
				1
			};

			// reads: migrated * (BondedPools +  Staking::total_stake) + count + onchain
			// version
			//
			// writes: current version + (maybe) TVL
			T::DbWeight::get()
				.reads_writes(migrated.saturating_mul(2).saturating_add(2).into(), writes)
		}

		#[cfg(feature = "try-runtime")]
		fn post_upgrade(_: Vec<u8>) -> Result<(), TryRuntimeError> {
			Ok(())
		}
	}

	/// Migrate existing pools from [`adapter::StakeStrategyType::Transfer`] to
	/// [`adapter::StakeStrategyType::Delegate`].
	///
	/// Note: This only migrates the pools, the members are not migrated. They can use the
	/// permission-less [`Pallet::migrate_delegation()`] to migrate their funds.
	///
	/// This migration does not break any existing pool storage item, does not need to happen in any
	/// sequence and hence can be applied unversioned on a production runtime.
	///
	/// Takes `MaxPools` as type parameter to limit the number of pools that should be migrated in a
	/// single block. It should be set such that migration weight does not exceed the block weight
	/// limit. If all pools can be safely migrated, it is good to keep this number a little higher
	/// than the actual number of pools to handle any extra pools created while the migration is
	/// proposed, and before it is executed.
	///
	/// If there are pools that fail to migrate or did not fit in the bounds, the remaining pools
	/// can be migrated via the permission-less extrinsic [`Call::migrate_pool_to_delegate_stake`].
	pub struct DelegationStakeMigration<T, MaxPools>(core::marker::PhantomData<(T, MaxPools)>);

	impl<T: Config, MaxPools: Get<u32>> OnRuntimeUpgrade for DelegationStakeMigration<T, MaxPools> {
		fn on_runtime_upgrade() -> Weight {
			let mut count: u32 = 0;

			BondedPools::<T>::iter_keys().take(MaxPools::get() as usize).for_each(|id| {
				let pool_acc = Pallet::<T>::generate_bonded_account(id);

				// only migrate if the pool is in Transfer Strategy.
				if T::StakeAdapter::pool_strategy(Pool::from(pool_acc)) ==
					adapter::StakeStrategyType::Transfer
				{
					let _ = Pallet::<T>::migrate_to_delegate_stake(id).map_err(|err| {
						log!(
							warn,
							"failed to migrate pool {:?} to delegate stake strategy with err: {:?}",
							id,
							err
						)
					});
					count.saturating_inc();
				}
			});

			log!(info, "migrated {:?} pools to delegate stake strategy", count);

			// reads: (bonded pool key + current pool strategy) * MaxPools (worst case)
			T::DbWeight::get()
				.reads_writes(2, 0)
				.saturating_mul(MaxPools::get() as u64)
				// migration weight: `pool_migrate` weight * count
				.saturating_add(T::WeightInfo::pool_migrate().saturating_mul(count.into()))
		}

		#[cfg(feature = "try-runtime")]
		fn pre_upgrade() -> Result<Vec<u8>, TryRuntimeError> {
			// ensure stake adapter is correct.
			ensure!(
				T::StakeAdapter::strategy_type() == adapter::StakeStrategyType::Delegate,
				"Current strategy is not `Delegate"
			);

			if BondedPools::<T>::count() > MaxPools::get() {
				// we log a warning if the number of pools exceeds the bound.
				log!(
					warn,
					"Number of pools {} exceeds the maximum bound {}. This would leave some pools unmigrated.", BondedPools::<T>::count(), MaxPools::get()
				);
			}

			let mut pool_balances: Vec<BalanceOf<T>> = Vec::new();
			BondedPools::<T>::iter_keys().take(MaxPools::get() as usize).for_each(|id| {
				let pool_account = Pallet::<T>::generate_bonded_account(id);

				// we ensure migration is idempotent.
				let pool_balance = T::StakeAdapter::total_balance(Pool::from(pool_account.clone()))
					// we check actual account balance if pool has not migrated yet.
					.unwrap_or(T::Currency::total_balance(&pool_account));

				pool_balances.push(pool_balance);
			});

			Ok(pool_balances.encode())
		}

		#[cfg(feature = "try-runtime")]
		fn post_upgrade(data: Vec<u8>) -> Result<(), TryRuntimeError> {
			let expected_pool_balances: Vec<BalanceOf<T>> = Decode::decode(&mut &data[..]).unwrap();

			for (index, id) in
				BondedPools::<T>::iter_keys().take(MaxPools::get() as usize).enumerate()
			{
				let pool_account = Pallet::<T>::generate_bonded_account(id);
				if T::StakeAdapter::pool_strategy(Pool::from(pool_account.clone())) ==
					adapter::StakeStrategyType::Transfer
				{
					log!(error, "Pool {} failed to migrate", id,);
					return Err(TryRuntimeError::Other("Pool failed to migrate"));
				}

				let actual_balance =
					T::StakeAdapter::total_balance(Pool::from(pool_account.clone()))
						.expect("after migration, this should return a value");
				let expected_balance = expected_pool_balances.get(index).unwrap();

				if actual_balance != *expected_balance {
					log!(
						error,
						"Pool {} balance mismatch. Expected: {:?}, Actual: {:?}",
						id,
						expected_balance,
						actual_balance
					);
					return Err(TryRuntimeError::Other("Pool balance mismatch"));
				}

				// account balance should be zero.
				let pool_account_balance = T::Currency::total_balance(&pool_account);
				if pool_account_balance != Zero::zero() {
					log!(
						error,
						"Pool account balance was expected to be zero. Pool: {}, Balance: {:?}",
						id,
						pool_account_balance
					);
					return Err(TryRuntimeError::Other("Pool account balance not migrated"));
				}
			}

			Ok(())
		}
	}
}

pub mod v8 {
	use super::{v7::V7BondedPoolInner, *};

	impl<T: Config> V7BondedPoolInner<T> {
		fn migrate_to_v8(self) -> BondedPoolInner<T> {
			BondedPoolInner {
				commission: Commission {
					current: self.commission.current,
					max: self.commission.max,
					change_rate: self.commission.change_rate,
					throttle_from: self.commission.throttle_from,
					// `claim_permission` is a new field.
					claim_permission: None,
				},
				member_counter: self.member_counter,
				points: self.points,
				roles: self.roles,
				state: self.state,
			}
		}
	}

	pub struct VersionUncheckedMigrateV7ToV8<T>(core::marker::PhantomData<T>);
	impl<T: Config> UncheckedOnRuntimeUpgrade for VersionUncheckedMigrateV7ToV8<T> {
		#[cfg(feature = "try-runtime")]
		fn pre_upgrade() -> Result<Vec<u8>, TryRuntimeError> {
			Ok(Vec::new())
		}

		fn on_runtime_upgrade() -> Weight {
			let mut translated = 0u64;
			BondedPools::<T>::translate::<V7BondedPoolInner<T>, _>(|_key, old_value| {
				translated.saturating_inc();
				Some(old_value.migrate_to_v8())
			});
			T::DbWeight::get().reads_writes(translated, translated + 1)
		}

		#[cfg(feature = "try-runtime")]
		fn post_upgrade(_: Vec<u8>) -> Result<(), TryRuntimeError> {
			// Check new `claim_permission` field is present.
			ensure!(
				BondedPools::<T>::iter()
					.all(|(_, inner)| inner.commission.claim_permission.is_none()),
				"`claim_permission` value has not been set correctly."
			);
			Ok(())
		}
	}
}

/// This migration accumulates and initializes the [`TotalValueLocked`] for all pools.
///
/// WARNING: This migration works under the assumption that the [`BondedPools`] cannot be inflated
/// arbitrarily. Otherwise this migration could fail due to too high weight.
pub(crate) mod v7 {
	use super::*;

	#[derive(Encode, Decode, MaxEncodedLen, TypeInfo, DebugNoBound, PartialEq, Clone)]
	#[codec(mel_bound(T: Config))]
	#[scale_info(skip_type_params(T))]
	pub struct V7Commission<T: Config> {
		pub current: Option<(Perbill, T::AccountId)>,
		pub max: Option<Perbill>,
		pub change_rate: Option<CommissionChangeRate<BlockNumberFor<T>>>,
		pub throttle_from: Option<BlockNumberFor<T>>,
	}

	#[derive(Encode, Decode, MaxEncodedLen, TypeInfo, DebugNoBound, PartialEq, Clone)]
	#[codec(mel_bound(T: Config))]
	#[scale_info(skip_type_params(T))]
	pub struct V7BondedPoolInner<T: Config> {
		pub commission: V7Commission<T>,
		pub member_counter: u32,
		pub points: BalanceOf<T>,
		pub roles: PoolRoles<T::AccountId>,
		pub state: PoolState,
	}

	#[allow(dead_code)]
	#[derive(RuntimeDebugNoBound)]
	#[cfg_attr(feature = "std", derive(Clone, PartialEq))]
	pub struct V7BondedPool<T: Config> {
		/// The identifier of the pool.
		id: PoolId,
		/// The inner fields.
		inner: V7BondedPoolInner<T>,
	}

	impl<T: Config> V7BondedPool<T> {
		#[allow(dead_code)]
		fn bonded_account(&self) -> T::AccountId {
			Pallet::<T>::generate_bonded_account(self.id)
		}
	}

	// NOTE: We cannot put a V7 prefix here since that would change the storage key.
	#[frame_support::storage_alias]
	pub type BondedPools<T: Config> =
		CountedStorageMap<Pallet<T>, Twox64Concat, PoolId, V7BondedPoolInner<T>>;

	pub struct VersionUncheckedMigrateV6ToV7<T>(core::marker::PhantomData<T>);
	impl<T: Config> UncheckedOnRuntimeUpgrade for VersionUncheckedMigrateV6ToV7<T> {
		fn on_runtime_upgrade() -> Weight {
			let migrated = BondedPools::<T>::count();
			// The TVL should be the sum of all the funds that are actively staked and in the
			// unbonding process of the account of each pool.
			let tvl: BalanceOf<T> = helpers::calculate_tvl_by_total_stake::<T>();

			TotalValueLocked::<T>::set(tvl);

			log!(info, "Upgraded {} pools with a TVL of {:?}", migrated, tvl);

			// reads: migrated * (BondedPools +  Staking::total_stake) + count + onchain
			// version
			//
			// writes: current version + TVL
			T::DbWeight::get().reads_writes(migrated.saturating_mul(2).saturating_add(2).into(), 2)
		}

		#[cfg(feature = "try-runtime")]
		fn pre_upgrade() -> Result<Vec<u8>, TryRuntimeError> {
			Ok(Vec::new())
		}

		#[cfg(feature = "try-runtime")]
		fn post_upgrade(_data: Vec<u8>) -> Result<(), TryRuntimeError> {
			// check that the `TotalValueLocked` written is actually the sum of `total_stake` of the
			// `BondedPools``
			let tvl: BalanceOf<T> = helpers::calculate_tvl_by_total_stake::<T>();
			ensure!(
				TotalValueLocked::<T>::get() == tvl,
				"TVL written is not equal to `Staking::total_stake` of all `BondedPools`."
			);

			// calculate the sum of `total_balance` of all `PoolMember` as the upper bound for the
			// `TotalValueLocked`.
			let total_balance_members: BalanceOf<T> = PoolMembers::<T>::iter()
				.map(|(_, member)| member.total_balance())
				.reduce(|acc, total_balance| acc + total_balance)
				.unwrap_or_default();

			ensure!(
				TotalValueLocked::<T>::get() <= total_balance_members,
				"TVL is greater than the balance of all PoolMembers."
			);

			ensure!(
				Pallet::<T>::on_chain_storage_version() >= 7,
				"nomination-pools::migration::v7: wrong storage version"
			);

			Ok(())
		}
	}
}

mod v6 {
	use super::*;

	/// This migration would restrict reward account of pools to go below ED by doing a named
	/// freeze on all the existing pools.
	pub struct MigrateToV6<T>(core::marker::PhantomData<T>);

	impl<T: Config> MigrateToV6<T> {
		fn freeze_ed(pool_id: PoolId) -> Result<(), ()> {
			let reward_acc = Pallet::<T>::generate_reward_account(pool_id);
			Pallet::<T>::freeze_pool_deposit(&reward_acc).map_err(|e| {
				log!(error, "Failed to freeze ED for pool {} with error: {:?}", pool_id, e);
				()
			})
		}
	}
	impl<T: Config> UncheckedOnRuntimeUpgrade for MigrateToV6<T> {
		fn on_runtime_upgrade() -> Weight {
			let mut success = 0u64;
			let mut fail = 0u64;

			BondedPools::<T>::iter_keys().for_each(|p| {
				if Self::freeze_ed(p).is_ok() {
					success.saturating_inc();
				} else {
					fail.saturating_inc();
				}
			});

			if fail > 0 {
				log!(error, "Failed to freeze ED for {} pools", fail);
			} else {
				log!(info, "Freezing ED succeeded for {} pools", success);
			}

			let total = success.saturating_add(fail);
			// freeze_ed = r:2 w:2
			// reads: (freeze_ed + bonded pool key) * total
			// writes: freeze_ed * total
			T::DbWeight::get().reads_writes(3u64.saturating_mul(total), 2u64.saturating_mul(total))
		}

		#[cfg(feature = "try-runtime")]
		fn post_upgrade(_data: Vec<u8>) -> Result<(), TryRuntimeError> {
			// there should be no ED imbalances anymore..
			Pallet::<T>::check_ed_imbalance()
		}
	}
}
pub mod v5 {
	use super::*;

	#[derive(Decode)]
	pub struct OldRewardPool<T: Config> {
		last_recorded_reward_counter: T::RewardCounter,
		last_recorded_total_payouts: BalanceOf<T>,
		total_rewards_claimed: BalanceOf<T>,
	}

	impl<T: Config> OldRewardPool<T> {
		fn migrate_to_v5(self) -> RewardPool<T> {
			RewardPool {
				last_recorded_reward_counter: self.last_recorded_reward_counter,
				last_recorded_total_payouts: self.last_recorded_total_payouts,
				total_rewards_claimed: self.total_rewards_claimed,
				total_commission_pending: Zero::zero(),
				total_commission_claimed: Zero::zero(),
			}
		}
	}

	/// This migration adds `total_commission_pending` and `total_commission_claimed` field to every
	/// `RewardPool`, if any.
	pub struct MigrateToV5<T>(core::marker::PhantomData<T>);
	impl<T: Config> OnRuntimeUpgrade for MigrateToV5<T> {
		fn on_runtime_upgrade() -> Weight {
			let in_code = Pallet::<T>::in_code_storage_version();
			let onchain = Pallet::<T>::on_chain_storage_version();

			log!(
				info,
				"Running migration with in-code storage version {:?} / onchain {:?}",
				in_code,
				onchain
			);

			if in_code == 5 && onchain == 4 {
				let mut translated = 0u64;
				RewardPools::<T>::translate::<OldRewardPool<T>, _>(|_id, old_value| {
					translated.saturating_inc();
					Some(old_value.migrate_to_v5())
				});

				in_code.put::<Pallet<T>>();
				log!(info, "Upgraded {} pools, storage to version {:?}", translated, in_code);

				// reads: translated + onchain version.
				// writes: translated + current.put.
				T::DbWeight::get().reads_writes(translated + 1, translated + 1)
			} else {
				log!(info, "Migration did not execute. This probably should be removed");
				T::DbWeight::get().reads(1)
			}
		}

		#[cfg(feature = "try-runtime")]
		fn pre_upgrade() -> Result<Vec<u8>, TryRuntimeError> {
			let rpool_keys = RewardPools::<T>::iter_keys().count();
			let rpool_values = RewardPools::<T>::iter_values().count();
			if rpool_keys != rpool_values {
				log!(info, "๐Ÿ”ฅ There are {} undecodable RewardPools in storage. This migration will try to correct them. keys: {}, values: {}", rpool_keys.saturating_sub(rpool_values), rpool_keys, rpool_values);
			}

			ensure!(
				PoolMembers::<T>::iter_keys().count() == PoolMembers::<T>::iter_values().count(),
				"There are undecodable PoolMembers in storage. This migration will not fix that."
			);
			ensure!(
				BondedPools::<T>::iter_keys().count() == BondedPools::<T>::iter_values().count(),
				"There are undecodable BondedPools in storage. This migration will not fix that."
			);
			ensure!(
				SubPoolsStorage::<T>::iter_keys().count() ==
					SubPoolsStorage::<T>::iter_values().count(),
				"There are undecodable SubPools in storage. This migration will not fix that."
			);
			ensure!(
				Metadata::<T>::iter_keys().count() == Metadata::<T>::iter_values().count(),
				"There are undecodable Metadata in storage. This migration will not fix that."
			);

			Ok((rpool_values as u64).encode())
		}

		#[cfg(feature = "try-runtime")]
		fn post_upgrade(data: Vec<u8>) -> Result<(), TryRuntimeError> {
			let old_rpool_values: u64 = Decode::decode(&mut &data[..]).unwrap();
			let rpool_keys = RewardPools::<T>::iter_keys().count() as u64;
			let rpool_values = RewardPools::<T>::iter_values().count() as u64;
			ensure!(
				rpool_keys == rpool_values,
				"There are STILL undecodable RewardPools - migration failed"
			);

			if old_rpool_values != rpool_values {
				log!(
					info,
					"๐ŸŽ‰ Fixed {} undecodable RewardPools.",
					rpool_values.saturating_sub(old_rpool_values)
				);
			}

			// ensure all RewardPools items now contain `total_commission_pending` and
			// `total_commission_claimed` field.
			ensure!(
				RewardPools::<T>::iter().all(|(_, reward_pool)| reward_pool
					.total_commission_pending >=
					Zero::zero() && reward_pool
					.total_commission_claimed >=
					Zero::zero()),
				"a commission value has been incorrectly set"
			);
			ensure!(
				Pallet::<T>::on_chain_storage_version() >= 5,
				"nomination-pools::migration::v5: wrong storage version"
			);

			// These should not have been touched - just in case.
			ensure!(
				PoolMembers::<T>::iter_keys().count() == PoolMembers::<T>::iter_values().count(),
				"There are undecodable PoolMembers in storage."
			);
			ensure!(
				BondedPools::<T>::iter_keys().count() == BondedPools::<T>::iter_values().count(),
				"There are undecodable BondedPools in storage."
			);
			ensure!(
				SubPoolsStorage::<T>::iter_keys().count() ==
					SubPoolsStorage::<T>::iter_values().count(),
				"There are undecodable SubPools in storage."
			);
			ensure!(
				Metadata::<T>::iter_keys().count() == Metadata::<T>::iter_values().count(),
				"There are undecodable Metadata in storage."
			);

			Ok(())
		}
	}
}

pub mod v4 {
	use super::*;

	#[derive(Decode)]
	pub struct OldBondedPoolInner<T: Config> {
		pub points: BalanceOf<T>,
		pub state: PoolState,
		pub member_counter: u32,
		pub roles: PoolRoles<T::AccountId>,
	}

	impl<T: Config> OldBondedPoolInner<T> {
		fn migrate_to_v4(self) -> BondedPoolInner<T> {
			BondedPoolInner {
				commission: Commission::default(),
				member_counter: self.member_counter,
				points: self.points,
				state: self.state,
				roles: self.roles,
			}
		}
	}

	/// Migrates from `v3` directly to `v5` to avoid the broken `v4` migration.
	#[allow(deprecated)]
	pub type MigrateV3ToV5<T, U> = (v4::MigrateToV4<T, U>, v5::MigrateToV5<T>);

	/// # Warning
	///
	/// To avoid mangled storage please use `MigrateV3ToV5` instead.
	/// See: github.com/paritytech/substrate/pull/13715
	///
	/// This migration adds a `commission` field to every `BondedPoolInner`, if
	/// any.
	#[deprecated(
		note = "To avoid mangled storage please use `MigrateV3ToV5` instead. See: github.com/paritytech/substrate/pull/13715"
	)]
	pub struct MigrateToV4<T, U>(core::marker::PhantomData<(T, U)>);
	#[allow(deprecated)]
	impl<T: Config, U: Get<Perbill>> OnRuntimeUpgrade for MigrateToV4<T, U> {
		fn on_runtime_upgrade() -> Weight {
			let current = Pallet::<T>::in_code_storage_version();
			let onchain = Pallet::<T>::on_chain_storage_version();

			log!(
				info,
				"Running migration with in-code storage version {:?} / onchain {:?}",
				current,
				onchain
			);

			if onchain == 3 {
				log!(warn, "Please run MigrateToV5 immediately after this migration. See github.com/paritytech/substrate/pull/13715");
				let initial_global_max_commission = U::get();
				GlobalMaxCommission::<T>::set(Some(initial_global_max_commission));
				log!(
					info,
					"Set initial global max commission to {:?}.",
					initial_global_max_commission
				);

				let mut translated = 0u64;
				BondedPools::<T>::translate::<OldBondedPoolInner<T>, _>(|_key, old_value| {
					translated.saturating_inc();
					Some(old_value.migrate_to_v4())
				});

				StorageVersion::new(4).put::<Pallet<T>>();
				log!(info, "Upgraded {} pools, storage to version {:?}", translated, current);

				// reads: translated + onchain version.
				// writes: translated + current.put + initial global commission.
				T::DbWeight::get().reads_writes(translated + 1, translated + 2)
			} else {
				log!(info, "Migration did not execute. This probably should be removed");
				T::DbWeight::get().reads(1)
			}
		}

		#[cfg(feature = "try-runtime")]
		fn pre_upgrade() -> Result<Vec<u8>, TryRuntimeError> {
			Ok(Vec::new())
		}

		#[cfg(feature = "try-runtime")]
		fn post_upgrade(_: Vec<u8>) -> Result<(), TryRuntimeError> {
			// ensure all BondedPools items now contain an `inner.commission: Commission` field.
			ensure!(
				BondedPools::<T>::iter().all(|(_, inner)|
					// Check current
					(inner.commission.current.is_none() ||
					inner.commission.current.is_some()) &&
					// Check max
					(inner.commission.max.is_none() || inner.commission.max.is_some()) &&
					// Check change_rate
					(inner.commission.change_rate.is_none() ||
					inner.commission.change_rate.is_some()) &&
					// Check throttle_from
					(inner.commission.throttle_from.is_none() ||
					inner.commission.throttle_from.is_some())),
				"a commission value has not been set correctly"
			);
			ensure!(
				GlobalMaxCommission::<T>::get() == Some(U::get()),
				"global maximum commission error"
			);
			ensure!(
				Pallet::<T>::on_chain_storage_version() >= 4,
				"nomination-pools::migration::v4: wrong storage version"
			);
			Ok(())
		}
	}
}

pub mod v3 {
	use super::*;

	/// This migration removes stale bonded-pool metadata, if any.
	pub struct MigrateToV3<T>(core::marker::PhantomData<T>);
	impl<T: Config> OnRuntimeUpgrade for MigrateToV3<T> {
		fn on_runtime_upgrade() -> Weight {
			let current = Pallet::<T>::in_code_storage_version();
			let onchain = Pallet::<T>::on_chain_storage_version();

			if onchain == 2 {
				log!(
					info,
					"Running migration with in-code storage version {:?} / onchain {:?}",
					current,
					onchain
				);

				let mut metadata_iterated = 0u64;
				let mut metadata_removed = 0u64;
				Metadata::<T>::iter_keys()
					.filter(|id| {
						metadata_iterated += 1;
						!BondedPools::<T>::contains_key(&id)
					})
					.collect::<Vec<_>>()
					.into_iter()
					.for_each(|id| {
						metadata_removed += 1;
						Metadata::<T>::remove(&id);
					});
				StorageVersion::new(3).put::<Pallet<T>>();
				// metadata iterated + bonded pools read + a storage version read
				let total_reads = metadata_iterated * 2 + 1;
				// metadata removed + a storage version write
				let total_writes = metadata_removed + 1;
				T::DbWeight::get().reads_writes(total_reads, total_writes)
			} else {
				log!(info, "MigrateToV3 should be removed");
				T::DbWeight::get().reads(1)
			}
		}

		#[cfg(feature = "try-runtime")]
		fn pre_upgrade() -> Result<Vec<u8>, TryRuntimeError> {
			Ok(Vec::new())
		}

		#[cfg(feature = "try-runtime")]
		fn post_upgrade(_: Vec<u8>) -> Result<(), TryRuntimeError> {
			ensure!(
				Metadata::<T>::iter_keys().all(|id| BondedPools::<T>::contains_key(&id)),
				"not all of the stale metadata has been removed"
			);
			ensure!(
				Pallet::<T>::on_chain_storage_version() >= 3,
				"nomination-pools::migration::v3: wrong storage version"
			);
			Ok(())
		}
	}
}

pub mod v2 {
	use super::*;
	use sp_runtime::Perbill;

	#[test]
	fn migration_assumption_is_correct() {
		// this migrations cleans all the reward accounts to contain exactly ed, and all members
		// having no claimable rewards. In this state, all fields of the `RewardPool` and
		// `member.last_recorded_reward_counter` are all zero.
		use crate::mock::*;
		ExtBuilder::default().build_and_execute(|| {
			let join = |x| {
				Currency::set_balance(&x, Balances::minimum_balance() + 10);
				frame_support::assert_ok!(Pools::join(RuntimeOrigin::signed(x), 10, 1));
			};

			assert_eq!(BondedPool::<Runtime>::get(1).unwrap().points, 10);
			assert_eq!(
				RewardPools::<Runtime>::get(1).unwrap(),
				RewardPool { ..Default::default() }
			);
			assert_eq!(
				PoolMembers::<Runtime>::get(10).unwrap().last_recorded_reward_counter,
				Zero::zero()
			);

			join(20);
			assert_eq!(BondedPool::<Runtime>::get(1).unwrap().points, 20);
			assert_eq!(
				RewardPools::<Runtime>::get(1).unwrap(),
				RewardPool { ..Default::default() }
			);
			assert_eq!(
				PoolMembers::<Runtime>::get(10).unwrap().last_recorded_reward_counter,
				Zero::zero()
			);
			assert_eq!(
				PoolMembers::<Runtime>::get(20).unwrap().last_recorded_reward_counter,
				Zero::zero()
			);

			join(30);
			assert_eq!(BondedPool::<Runtime>::get(1).unwrap().points, 30);
			assert_eq!(
				RewardPools::<Runtime>::get(1).unwrap(),
				RewardPool { ..Default::default() }
			);
			assert_eq!(
				PoolMembers::<Runtime>::get(10).unwrap().last_recorded_reward_counter,
				Zero::zero()
			);
			assert_eq!(
				PoolMembers::<Runtime>::get(20).unwrap().last_recorded_reward_counter,
				Zero::zero()
			);
			assert_eq!(
				PoolMembers::<Runtime>::get(30).unwrap().last_recorded_reward_counter,
				Zero::zero()
			);
		});
	}

	#[derive(Decode)]
	pub struct OldRewardPool<B> {
		pub balance: B,
		pub total_earnings: B,
		pub points: U256,
	}

	#[derive(Decode)]
	pub struct OldPoolMember<T: Config> {
		pub pool_id: PoolId,
		pub points: BalanceOf<T>,
		pub reward_pool_total_earnings: BalanceOf<T>,
		pub unbonding_eras: BoundedBTreeMap<EraIndex, BalanceOf<T>, T::MaxUnbonding>,
	}

	/// Migrate the pool reward scheme to the new version, as per
	/// <https://github.com/paritytech/substrate/pull/11669.>.
	pub struct MigrateToV2<T>(core::marker::PhantomData<T>);
	impl<T: Config> MigrateToV2<T> {
		fn run(current: StorageVersion) -> Weight {
			let mut reward_pools_translated = 0u64;
			let mut members_translated = 0u64;
			// just for logging.
			let mut total_value_locked = BalanceOf::<T>::zero();
			let mut total_points_locked = BalanceOf::<T>::zero();

			// store each member of the pool, with their active points. In the process, migrate
			// their data as well.
			let mut temp_members = BTreeMap::<PoolId, Vec<(T::AccountId, BalanceOf<T>)>>::new();
			PoolMembers::<T>::translate::<OldPoolMember<T>, _>(|key, old_member| {
				let id = old_member.pool_id;
				temp_members.entry(id).or_default().push((key, old_member.points));

				total_points_locked += old_member.points;
				members_translated += 1;
				Some(PoolMember::<T> {
					last_recorded_reward_counter: Zero::zero(),
					pool_id: old_member.pool_id,
					points: old_member.points,
					unbonding_eras: old_member.unbonding_eras,
				})
			});

			// translate all reward pools. In the process, do the last payout as well.
			RewardPools::<T>::translate::<OldRewardPool<BalanceOf<T>>, _>(
				|id, _old_reward_pool| {
					// each pool should have at least one member.
					let members = match temp_members.get(&id) {
						Some(x) => x,
						None => {
							log!(error, "pool {} has no member! deleting it..", id);
							return None
						},
					};
					let bonded_pool = match BondedPools::<T>::get(id) {
						Some(x) => x,
						None => {
							log!(error, "pool {} has no bonded pool! deleting it..", id);
							return None
						},
					};

					let accumulated_reward = RewardPool::<T>::current_balance(id);
					let reward_account = Pallet::<T>::generate_reward_account(id);
					let mut sum_paid_out = BalanceOf::<T>::zero();

					members
						.into_iter()
						.filter_map(|(who, points)| {
							let bonded_pool = match BondedPool::<T>::get(id) {
								Some(x) => x,
								None => {
									log!(error, "pool {} for member {:?} does not exist!", id, who);
									return None
								},
							};

							total_value_locked += bonded_pool.points_to_balance(*points);
							let portion = Perbill::from_rational(*points, bonded_pool.points);
							let last_claim = portion * accumulated_reward;

							log!(
								debug,
								"{:?} has {:?} ({:?}) of pool {} with total reward of {:?}",
								who,
								portion,
								last_claim,
								id,
								accumulated_reward
							);

							if last_claim.is_zero() {
								None
							} else {
								Some((who, last_claim))
							}
						})
						.for_each(|(who, last_claim)| {
							let outcome = T::Currency::transfer(
								&reward_account,
								&who,
								last_claim,
								Preservation::Preserve,
							);

							if let Err(reason) = outcome {
								log!(warn, "last reward claim failed due to {:?}", reason,);
							} else {
								sum_paid_out = sum_paid_out.saturating_add(last_claim);
							}

							Pallet::<T>::deposit_event(Event::<T>::PaidOut {
								member: who.clone(),
								pool_id: id,
								payout: last_claim,
							});
						});

					// this can only be because of rounding down, or because the person we
					// wanted to pay their reward to could not accept it (dust).
					let leftover = accumulated_reward.saturating_sub(sum_paid_out);
					if !leftover.is_zero() {
						// pay it all to depositor.
						let o = T::Currency::transfer(
							&reward_account,
							&bonded_pool.roles.depositor,
							leftover,
							Preservation::Preserve,
						);
						log!(warn, "paying {:?} leftover to the depositor: {:?}", leftover, o);
					}

					// finally, migrate the reward pool.
					reward_pools_translated += 1;

					Some(RewardPool {
						last_recorded_reward_counter: Zero::zero(),
						last_recorded_total_payouts: Zero::zero(),
						total_rewards_claimed: Zero::zero(),
						total_commission_claimed: Zero::zero(),
						total_commission_pending: Zero::zero(),
					})
				},
			);

			log!(
				info,
				"Upgraded {} members, {} reward pools, TVL {:?} TPL {:?}, storage to version {:?}",
				members_translated,
				reward_pools_translated,
				total_value_locked,
				total_points_locked,
				current
			);
			current.put::<Pallet<T>>();

			T::DbWeight::get().reads_writes(members_translated + 1, reward_pools_translated + 1)
		}
	}

	impl<T: Config> OnRuntimeUpgrade for MigrateToV2<T> {
		fn on_runtime_upgrade() -> Weight {
			let current = Pallet::<T>::in_code_storage_version();
			let onchain = Pallet::<T>::on_chain_storage_version();

			log!(
				info,
				"Running migration with in-code storage version {:?} / onchain {:?}",
				current,
				onchain
			);

			if current == 2 && onchain == 1 {
				Self::run(current)
			} else {
				log!(info, "MigrateToV2 did not executed. This probably should be removed");
				T::DbWeight::get().reads(1)
			}
		}

		#[cfg(feature = "try-runtime")]
		fn pre_upgrade() -> Result<Vec<u8>, TryRuntimeError> {
			// all reward accounts must have more than ED.
			RewardPools::<T>::iter().try_for_each(|(id, _)| -> Result<(), TryRuntimeError> {
				ensure!(
					<T::Currency as frame_support::traits::fungible::Inspect<T::AccountId>>::balance(&Pallet::<T>::generate_reward_account(id)) >=
						T::Currency::minimum_balance(),
					"Reward accounts must have greater balance than ED."
				);
				Ok(())
			})?;

			Ok(Vec::new())
		}

		#[cfg(feature = "try-runtime")]
		fn post_upgrade(_: Vec<u8>) -> Result<(), TryRuntimeError> {
			// new version must be set.
			ensure!(
				Pallet::<T>::on_chain_storage_version() == 2,
				"The onchain version must be updated after the migration."
			);

			// no reward or bonded pool has been skipped.
			ensure!(
				RewardPools::<T>::iter().count() as u32 == RewardPools::<T>::count(),
				"The count of reward pools must remain the same after the migration."
			);
			ensure!(
				BondedPools::<T>::iter().count() as u32 == BondedPools::<T>::count(),
				"The count of reward pools must remain the same after the migration."
			);

			// all reward pools must have exactly ED in them. This means no reward can be claimed,
			// and that setting reward counters all over the board to zero will work henceforth.
			RewardPools::<T>::iter().try_for_each(|(id, _)| -> Result<(), TryRuntimeError> {
				ensure!(
					RewardPool::<T>::current_balance(id) == Zero::zero(),
					"Reward pool balance must be zero.",
				);
				Ok(())
			})?;

			log!(info, "post upgrade hook for MigrateToV2 executed.");
			Ok(())
		}
	}
}

pub mod v1 {
	use super::*;

	#[derive(Decode)]
	pub struct OldPoolRoles<AccountId> {
		pub depositor: AccountId,
		pub root: AccountId,
		pub nominator: AccountId,
		pub bouncer: AccountId,
	}

	impl<AccountId> OldPoolRoles<AccountId> {
		fn migrate_to_v1(self) -> PoolRoles<AccountId> {
			PoolRoles {
				depositor: self.depositor,
				root: Some(self.root),
				nominator: Some(self.nominator),
				bouncer: Some(self.bouncer),
			}
		}
	}

	#[derive(Decode)]
	pub struct OldBondedPoolInner<T: Config> {
		pub points: BalanceOf<T>,
		pub state: PoolState,
		pub member_counter: u32,
		pub roles: OldPoolRoles<T::AccountId>,
	}

	impl<T: Config> OldBondedPoolInner<T> {
		fn migrate_to_v1(self) -> BondedPoolInner<T> {
			// Note: `commission` field not introduced to `BondedPoolInner` until
			// migration 4.
			BondedPoolInner {
				points: self.points,
				commission: Commission::default(),
				member_counter: self.member_counter,
				state: self.state,
				roles: self.roles.migrate_to_v1(),
			}
		}
	}

	/// Trivial migration which makes the roles of each pool optional.
	///
	/// Note: The depositor is not optional since they can never change.
	pub struct MigrateToV1<T>(core::marker::PhantomData<T>);
	impl<T: Config> OnRuntimeUpgrade for MigrateToV1<T> {
		fn on_runtime_upgrade() -> Weight {
			let current = Pallet::<T>::in_code_storage_version();
			let onchain = Pallet::<T>::on_chain_storage_version();

			log!(
				info,
				"Running migration with in-code storage version {:?} / onchain {:?}",
				current,
				onchain
			);

			if current == 1 && onchain == 0 {
				// this is safe to execute on any runtime that has a bounded number of pools.
				let mut translated = 0u64;
				BondedPools::<T>::translate::<OldBondedPoolInner<T>, _>(|_key, old_value| {
					translated.saturating_inc();
					Some(old_value.migrate_to_v1())
				});

				current.put::<Pallet<T>>();

				log!(info, "Upgraded {} pools, storage to version {:?}", translated, current);

				T::DbWeight::get().reads_writes(translated + 1, translated + 1)
			} else {
				log!(info, "Migration did not executed. This probably should be removed");
				T::DbWeight::get().reads(1)
			}
		}

		#[cfg(feature = "try-runtime")]
		fn post_upgrade(_: Vec<u8>) -> Result<(), TryRuntimeError> {
			// new version must be set.
			ensure!(
				Pallet::<T>::on_chain_storage_version() == 1,
				"The onchain version must be updated after the migration."
			);
			Pallet::<T>::try_state(frame_system::Pallet::<T>::block_number())?;
			Ok(())
		}
	}
}

mod helpers {
	use super::*;

	pub(crate) fn calculate_tvl_by_total_stake<T: Config>() -> BalanceOf<T> {
		BondedPools::<T>::iter_keys()
			.map(|id| {
				T::StakeAdapter::total_stake(Pool::from(Pallet::<T>::generate_bonded_account(id)))
			})
			.reduce(|acc, total_balance| acc + total_balance)
			.unwrap_or_default()
	}
}