Allocate Hard supply/borrow rewards to legacy suppliers/borrowers (#833)

* initialize hard supply reward for empty rewards

* add god committee to integration test

* organize claim types, add helper methods

* reorder integration test's god committee

* legacy suppliers earn rewards + tests

* update InitializeHardBorrowReward + test

* remove formatting comments from tests

* allocate rewards to legacy borrowers + test

* apply change to update index denom methods

* Update querier to show synced rewards for legacy deposits/borrows (#834)

* update simulated sync method to show rewards for legacy deposits/borrows

* more explicity debuging logs

* revisions

Co-authored-by: Kevin Davis <karzak@users.noreply.github.com>

x/incentive/keeper/integration_test.go

@@ -4,9 +4,14 @@ import (
 	"time"
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/cosmos/cosmos-sdk/x/staking"
+
+	abci "github.com/tendermint/tendermint/abci/types"
+	tmtime "github.com/tendermint/tendermint/types/time"
 
 	"github.com/kava-labs/kava/app"
 	"github.com/kava-labs/kava/x/cdp"
+	committeetypes "github.com/kava-labs/kava/x/committee/types"
 	"github.com/kava-labs/kava/x/hard"
 	"github.com/kava-labs/kava/x/pricefeed"
 )
@@ -109,6 +114,7 @@ func NewPricefeedGenStateMulti() app.GenesisState {
 				{MarketID: "xrp:usd", BaseAsset: "xrp", QuoteAsset: "usd", Oracles: []sdk.AccAddress{}, Active: true},
 				{MarketID: "bnb:usd", BaseAsset: "bnb", QuoteAsset: "usd", Oracles: []sdk.AccAddress{}, Active: true},
 				{MarketID: "busd:usd", BaseAsset: "busd", QuoteAsset: "usd", Oracles: []sdk.AccAddress{}, Active: true},
+				{MarketID: "zzz:usd", BaseAsset: "zzz", QuoteAsset: "usd", Oracles: []sdk.AccAddress{}, Active: true},
 			},
 		},
 		PostedPrices: []pricefeed.PostedPrice{
@@ -142,6 +148,12 @@ func NewPricefeedGenStateMulti() app.GenesisState {
 				Price:         sdk.OneDec(),
 				Expiry:        time.Now().Add(1 * time.Hour),
 			},
+			{
+				MarketID:      "zzz:usd",
+				OracleAddress: sdk.AccAddress{},
+				Price:         sdk.MustNewDecFromStr("2.00"),
+				Expiry:        time.Now().Add(1 * time.Hour),
+			},
 		},
 	}
 	return app.GenesisState{pricefeed.ModuleName: pricefeed.ModuleCdc.MustMarshalJSON(pfGenesis)}
@@ -158,6 +170,7 @@ func NewHardGenStateMulti() app.GenesisState {
 			hard.NewMoneyMarket("bnb", hard.NewBorrowLimit(false, borrowLimit, loanToValue), "bnb:usd", sdk.NewInt(1000000), hard.NewInterestRateModel(sdk.MustNewDecFromStr("0.05"), sdk.MustNewDecFromStr("2"), sdk.MustNewDecFromStr("0.8"), sdk.MustNewDecFromStr("10")), sdk.MustNewDecFromStr("0.05"), sdk.ZeroDec()),
 			hard.NewMoneyMarket("btcb", hard.NewBorrowLimit(false, borrowLimit, loanToValue), "btc:usd", sdk.NewInt(1000000), hard.NewInterestRateModel(sdk.MustNewDecFromStr("0.05"), sdk.MustNewDecFromStr("2"), sdk.MustNewDecFromStr("0.8"), sdk.MustNewDecFromStr("10")), sdk.MustNewDecFromStr("0.05"), sdk.ZeroDec()),
 			hard.NewMoneyMarket("xrp", hard.NewBorrowLimit(false, borrowLimit, loanToValue), "xrp:usd", sdk.NewInt(1000000), hard.NewInterestRateModel(sdk.MustNewDecFromStr("0.05"), sdk.MustNewDecFromStr("2"), sdk.MustNewDecFromStr("0.8"), sdk.MustNewDecFromStr("10")), sdk.MustNewDecFromStr("0.05"), sdk.ZeroDec()),
+			hard.NewMoneyMarket("zzz", hard.NewBorrowLimit(false, borrowLimit, loanToValue), "zzz:usd", sdk.NewInt(1000000), hard.NewInterestRateModel(sdk.MustNewDecFromStr("0.05"), sdk.MustNewDecFromStr("2"), sdk.MustNewDecFromStr("0.8"), sdk.MustNewDecFromStr("10")), sdk.MustNewDecFromStr("0.05"), sdk.ZeroDec()),
 		},
 		sdk.NewDec(10),
 	), hard.DefaultAccumulationTimes, hard.DefaultDeposits, hard.DefaultBorrows,
@@ -166,3 +179,72 @@ func NewHardGenStateMulti() app.GenesisState {
 
 	return app.GenesisState{hard.ModuleName: hard.ModuleCdc.MustMarshalJSON(hardGS)}
 }
+
+func NewAuthGenState(addresses []sdk.AccAddress, coins sdk.Coins) app.GenesisState {
+	coinsList := []sdk.Coins{}
+	for range addresses {
+		coinsList = append(coinsList, coins)
+	}
+
+	// Load up our primary user address
+	if len(addresses) >= 4 {
+		coinsList[3] = sdk.NewCoins(
+			sdk.NewCoin("bnb", sdk.NewInt(1000000000000000)),
+			sdk.NewCoin("ukava", sdk.NewInt(1000000000000000)),
+			sdk.NewCoin("btcb", sdk.NewInt(1000000000000000)),
+			sdk.NewCoin("xrp", sdk.NewInt(1000000000000000)),
+			sdk.NewCoin("zzz", sdk.NewInt(1000000000000000)),
+		)
+	}
+
+	return app.NewAuthGenState(addresses, coinsList)
+}
+
+func NewStakingGenesisState() app.GenesisState {
+	genState := staking.DefaultGenesisState()
+	genState.Params.BondDenom = "ukava"
+	return app.GenesisState{
+		staking.ModuleName: staking.ModuleCdc.MustMarshalJSON(genState),
+	}
+}
+
+func (suite *KeeperTestSuite) SetupWithGenState() {
+	config := sdk.GetConfig()
+	app.SetBech32AddressPrefixes(config)
+
+	_, allAddrs := app.GeneratePrivKeyAddressPairs(10)
+	suite.addrs = allAddrs[:5]
+	for _, a := range allAddrs[5:] {
+		suite.validatorAddrs = append(suite.validatorAddrs, sdk.ValAddress(a))
+	}
+
+	tApp := app.NewTestApp()
+	ctx := tApp.NewContext(true, abci.Header{Height: 1, Time: tmtime.Now()})
+
+	tApp.InitializeFromGenesisStates(
+		NewAuthGenState(allAddrs, cs(c("ukava", 5_000_000))),
+		NewStakingGenesisState(),
+		NewPricefeedGenStateMulti(),
+		NewCDPGenStateMulti(),
+		NewHardGenStateMulti(),
+	)
+
+	// Set up a god committee
+	committeeModKeeper := tApp.GetCommitteeKeeper()
+	godCommittee := committeetypes.Committee{
+		ID:               1,
+		Description:      "This committee is for testing.",
+		Members:          suite.addrs[:2],
+		Permissions:      []committeetypes.Permission{committeetypes.GodPermission{}},
+		VoteThreshold:    d("0.667"),
+		ProposalDuration: time.Hour * 24 * 7,
+	}
+	committeeModKeeper.SetCommittee(ctx, godCommittee)
+
+	suite.app = tApp
+	suite.ctx = ctx
+	suite.keeper = tApp.GetIncentiveKeeper()
+	suite.hardKeeper = tApp.GetHardKeeper()
+	suite.stakingKeeper = tApp.GetStakingKeeper()
+	suite.committeeKeeper = committeeModKeeper
+}

x/incentive/keeper/keeper_test.go

@@ -16,6 +16,7 @@ import (
 	tmtime "github.com/tendermint/tendermint/types/time"
 
 	"github.com/kava-labs/kava/app"
+	committeekeeper "github.com/kava-labs/kava/x/committee/keeper"
 	hardkeeper "github.com/kava-labs/kava/x/hard/keeper"
 	"github.com/kava-labs/kava/x/incentive/keeper"
 	"github.com/kava-labs/kava/x/incentive/types"
@@ -25,13 +26,14 @@ import (
 type KeeperTestSuite struct {
 	suite.Suite
 
-	keeper         keeper.Keeper
+	keeper          keeper.Keeper
-	hardKeeper     hardkeeper.Keeper
+	hardKeeper      hardkeeper.Keeper
-	stakingKeeper  stakingkeeper.Keeper
+	stakingKeeper   stakingkeeper.Keeper
-	app            app.TestApp
+	committeeKeeper committeekeeper.Keeper
-	ctx            sdk.Context
+	app             app.TestApp
-	addrs          []sdk.AccAddress
+	ctx             sdk.Context
-	validatorAddrs []sdk.ValAddress
+	addrs           []sdk.AccAddress
+	validatorAddrs  []sdk.ValAddress
 }
 
 // The default state used by each test

x/incentive/keeper/rewards.go

@@ -262,10 +262,12 @@ func (k Keeper) InitializeHardSupplyReward(ctx sdk.Context, deposit hardtypes.De
 	var supplyRewardIndexes types.MultiRewardIndexes
 	for _, coin := range deposit.Amount {
 		globalRewardIndexes, foundGlobalRewardIndexes := k.GetHardSupplyRewardIndexes(ctx, coin.Denom)
-		if !foundGlobalRewardIndexes {
+		var multiRewardIndex types.MultiRewardIndex
-			continue
+		if foundGlobalRewardIndexes {
+			multiRewardIndex = types.NewMultiRewardIndex(coin.Denom, globalRewardIndexes)
+		} else {
+			multiRewardIndex = types.NewMultiRewardIndex(coin.Denom, types.RewardIndexes{})
 		}
-		multiRewardIndex := types.NewMultiRewardIndex(coin.Denom, globalRewardIndexes)
 		supplyRewardIndexes = append(supplyRewardIndexes, multiRewardIndex)
 	}
 
@@ -296,8 +298,8 @@ func (k Keeper) SynchronizeHardSupplyReward(ctx sdk.Context, deposit hardtypes.D
 			continue
 		}
 
-		userRewardIndexes, foundUserRewardIndexes := claim.SupplyRewardIndexes.GetRewardIndex(coin.Denom)
+		userMultiRewardIndex, foundUserMultiRewardIndex := claim.SupplyRewardIndexes.GetRewardIndex(coin.Denom)
-		if !foundUserRewardIndexes {
+		if !foundUserMultiRewardIndex {
 			continue
 		}
 
@@ -308,9 +310,14 @@ func (k Keeper) SynchronizeHardSupplyReward(ctx sdk.Context, deposit hardtypes.D
 		}
 
 		for _, globalRewardIndex := range globalRewardIndexes {
-			userRewardIndex, foundUserRewardIndex := userRewardIndexes.RewardIndexes.GetRewardIndex(globalRewardIndex.CollateralType)
+			userRewardIndex, foundUserRewardIndex := userMultiRewardIndex.RewardIndexes.GetRewardIndex(globalRewardIndex.CollateralType)
 			if !foundUserRewardIndex {
-				continue
+				// User deposited this coin type before it had rewards. When new rewards are added, legacy depositors
+				// should immediately begin earning rewards. Enable users to do so by updating their claim with the global
+				// reward index denom and start their reward factor at 0.0
+				userRewardIndex = types.NewRewardIndex(globalRewardIndex.CollateralType, sdk.ZeroDec())
+				userMultiRewardIndex.RewardIndexes = append(userMultiRewardIndex.RewardIndexes, userRewardIndex)
+				claim.SupplyRewardIndexes[userRewardIndexIndex] = userMultiRewardIndex
 			}
 
 			globalRewardFactor := globalRewardIndex.RewardFactor
@@ -324,7 +331,7 @@ func (k Keeper) SynchronizeHardSupplyReward(ctx sdk.Context, deposit hardtypes.D
 				continue
 			}
 
-			factorIndex, foundFactorIndex := userRewardIndexes.RewardIndexes.GetFactorIndex(globalRewardIndex.CollateralType)
+			factorIndex, foundFactorIndex := userMultiRewardIndex.RewardIndexes.GetFactorIndex(globalRewardIndex.CollateralType)
 			if !foundFactorIndex {
 				fmt.Printf("[LOG]: factor index for %s should always be found", coin.Denom) // TODO: remove before production
 				continue
@@ -348,10 +355,12 @@ func (k Keeper) InitializeHardBorrowReward(ctx sdk.Context, borrow hardtypes.Bor
 	var borrowRewardIndexes types.MultiRewardIndexes
 	for _, coin := range borrow.Amount {
 		globalRewardIndexes, foundGlobalRewardIndexes := k.GetHardBorrowRewardIndexes(ctx, coin.Denom)
-		if !foundGlobalRewardIndexes {
+		var multiRewardIndex types.MultiRewardIndex
-			continue
+		if foundGlobalRewardIndexes {
+			multiRewardIndex = types.NewMultiRewardIndex(coin.Denom, globalRewardIndexes)
+		} else {
+			multiRewardIndex = types.NewMultiRewardIndex(coin.Denom, types.RewardIndexes{})
 		}
-		multiRewardIndex := types.NewMultiRewardIndex(coin.Denom, globalRewardIndexes)
 		borrowRewardIndexes = append(borrowRewardIndexes, multiRewardIndex)
 	}
 
@@ -373,8 +382,8 @@ func (k Keeper) SynchronizeHardBorrowReward(ctx sdk.Context, borrow hardtypes.Bo
 			continue
 		}
 
-		userRewardIndexes, foundUserRewardIndexes := claim.BorrowRewardIndexes.GetRewardIndex(coin.Denom)
+		userMultiRewardIndex, foundUserMultiRewardIndex := claim.BorrowRewardIndexes.GetRewardIndex(coin.Denom)
-		if !foundUserRewardIndexes {
+		if !foundUserMultiRewardIndex {
 			continue
 		}
 
@@ -385,9 +394,14 @@ func (k Keeper) SynchronizeHardBorrowReward(ctx sdk.Context, borrow hardtypes.Bo
 		}
 
 		for _, globalRewardIndex := range globalRewardIndexes {
-			userRewardIndex, foundUserRewardIndex := userRewardIndexes.RewardIndexes.GetRewardIndex(globalRewardIndex.CollateralType)
+			userRewardIndex, foundUserRewardIndex := userMultiRewardIndex.RewardIndexes.GetRewardIndex(globalRewardIndex.CollateralType)
 			if !foundUserRewardIndex {
-				continue
+				// User borrowed this coin type before it had rewards. When new rewards are added, legacy borrowers
+				// should immediately begin earning rewards. Enable users to do so by updating their claim with the global
+				// reward index denom and start their reward factor at 0.0
+				userRewardIndex = types.NewRewardIndex(globalRewardIndex.CollateralType, sdk.ZeroDec())
+				userMultiRewardIndex.RewardIndexes = append(userMultiRewardIndex.RewardIndexes, userRewardIndex)
+				claim.BorrowRewardIndexes[userRewardIndexIndex] = userMultiRewardIndex
 			}
 
 			globalRewardFactor := globalRewardIndex.RewardFactor
@@ -401,7 +415,7 @@ func (k Keeper) SynchronizeHardBorrowReward(ctx sdk.Context, borrow hardtypes.Bo
 				continue
 			}
 
-			factorIndex, foundFactorIndex := userRewardIndexes.RewardIndexes.GetFactorIndex(globalRewardIndex.CollateralType)
+			factorIndex, foundFactorIndex := userMultiRewardIndex.RewardIndexes.GetFactorIndex(globalRewardIndex.CollateralType)
 			if !foundFactorIndex {
 				fmt.Printf("\n[LOG]: factor index for %s should always be found", coin.Denom) // TODO: remove before production
 				continue
@@ -425,11 +439,13 @@ func (k Keeper) UpdateHardSupplyIndexDenoms(ctx sdk.Context, deposit hardtypes.D
 	for _, coin := range deposit.Amount {
 		_, foundUserRewardIndexes := claim.SupplyRewardIndexes.GetRewardIndex(coin.Denom)
 		if !foundUserRewardIndexes {
-			globalRewardIndexes, foundGlobalRewardIndexes := k.GetHardSupplyRewardIndexes(ctx, coin.Denom)
+			globalSupplyRewardIndexes, foundGlobalSupplyRewardIndexes := k.GetHardSupplyRewardIndexes(ctx, coin.Denom)
-			if !foundGlobalRewardIndexes {
+			var multiRewardIndex types.MultiRewardIndex
-				continue // No rewards for this coin type
+			if foundGlobalSupplyRewardIndexes {
+				multiRewardIndex = types.NewMultiRewardIndex(coin.Denom, globalSupplyRewardIndexes)
+			} else {
+				multiRewardIndex = types.NewMultiRewardIndex(coin.Denom, types.RewardIndexes{})
 			}
-			multiRewardIndex := types.NewMultiRewardIndex(coin.Denom, globalRewardIndexes)
 			supplyRewardIndexes = append(supplyRewardIndexes, multiRewardIndex)
 		}
 	}
@@ -451,11 +467,13 @@ func (k Keeper) UpdateHardBorrowIndexDenoms(ctx sdk.Context, borrow hardtypes.Bo
 	for _, coin := range borrow.Amount {
 		_, foundUserRewardIndexes := claim.BorrowRewardIndexes.GetRewardIndex(coin.Denom)
 		if !foundUserRewardIndexes {
-			globalRewardIndexes, foundGlobalRewardIndexes := k.GetHardBorrowRewardIndexes(ctx, coin.Denom)
+			globalBorrowRewardIndexes, foundGlobalBorrowRewardIndexes := k.GetHardBorrowRewardIndexes(ctx, coin.Denom)
-			if !foundGlobalRewardIndexes {
+			var multiRewardIndex types.MultiRewardIndex
-				continue // No rewards for this coin type
+			if foundGlobalBorrowRewardIndexes {
+				multiRewardIndex = types.NewMultiRewardIndex(coin.Denom, globalBorrowRewardIndexes)
+			} else {
+				multiRewardIndex = types.NewMultiRewardIndex(coin.Denom, types.RewardIndexes{})
 			}
-			multiRewardIndex := types.NewMultiRewardIndex(coin.Denom, globalRewardIndexes)
 			borrowRewardIndexes = append(borrowRewardIndexes, multiRewardIndex)
 		}
 	}
@@ -678,14 +696,16 @@ func (k Keeper) SimulateHardSynchronization(ctx sdk.Context, claim types.HardLiq
 
 		userRewardIndexIndex, foundUserRewardIndexIndex := claim.SupplyRewardIndexes.GetRewardIndexIndex(ri.CollateralType)
 		if !foundUserRewardIndexIndex {
-			fmt.Printf("\n[LOG]: factor index for %s should always be found", ri.CollateralType) // TODO: remove before production
+			fmt.Printf("\n[LOG]: claim.SupplyRewardIndexes.GetRewardIndexIndex for %s should always be found", ri.CollateralType) // TODO: remove before production
 			continue
 		}
 
 		for _, globalRewardIndex := range globalRewardIndexes {
 			userRewardIndex, foundUserRewardIndex := userRewardIndexes.RewardIndexes.GetRewardIndex(globalRewardIndex.CollateralType)
 			if !foundUserRewardIndex {
-				continue
+				userRewardIndex = types.NewRewardIndex(globalRewardIndex.CollateralType, sdk.ZeroDec())
+				userRewardIndexes.RewardIndexes = append(userRewardIndexes.RewardIndexes, userRewardIndex)
+				claim.SupplyRewardIndexes[userRewardIndexIndex].RewardIndexes = append(claim.SupplyRewardIndexes[userRewardIndexIndex].RewardIndexes, userRewardIndex)
 			}
 
 			globalRewardFactor := globalRewardIndex.RewardFactor
@@ -705,7 +725,7 @@ func (k Keeper) SimulateHardSynchronization(ctx sdk.Context, claim types.HardLiq
 
 			factorIndex, foundFactorIndex := userRewardIndexes.RewardIndexes.GetFactorIndex(globalRewardIndex.CollateralType)
 			if !foundFactorIndex {
-				fmt.Printf("[LOG]: factor index for %s should always be found", ri.CollateralType) // TODO: remove before production
+				fmt.Printf("[LOG]: userRewardIndexes.RewardIndexes.GetFactorIndex for %s should always be found", globalRewardIndex.CollateralType) // TODO: remove before production
 				continue
 			}
 			claim.SupplyRewardIndexes[userRewardIndexIndex].RewardIndexes[factorIndex].RewardFactor = globalRewardIndex.RewardFactor
@@ -728,14 +748,16 @@ func (k Keeper) SimulateHardSynchronization(ctx sdk.Context, claim types.HardLiq
 
 		userRewardIndexIndex, foundUserRewardIndexIndex := claim.BorrowRewardIndexes.GetRewardIndexIndex(ri.CollateralType)
 		if !foundUserRewardIndexIndex {
-			fmt.Printf("\n[LOG]: factor index for %s should always be found", ri.CollateralType) // TODO: remove before production
+			fmt.Printf("\n[LOG]: claim.BorrowRewardIndexes.GetRewardIndexIndex for %s should always be found", ri.CollateralType) // TODO: remove before production
 			continue
 		}
 
 		for _, globalRewardIndex := range globalRewardIndexes {
 			userRewardIndex, foundUserRewardIndex := userRewardIndexes.RewardIndexes.GetRewardIndex(globalRewardIndex.CollateralType)
 			if !foundUserRewardIndex {
-				continue
+				userRewardIndex = types.NewRewardIndex(globalRewardIndex.CollateralType, sdk.ZeroDec())
+				userRewardIndexes.RewardIndexes = append(userRewardIndexes.RewardIndexes, userRewardIndex)
+				claim.BorrowRewardIndexes[userRewardIndexIndex].RewardIndexes = append(claim.BorrowRewardIndexes[userRewardIndexIndex].RewardIndexes, userRewardIndex)
 			}
 
 			globalRewardFactor := globalRewardIndex.RewardFactor
@@ -755,7 +777,7 @@ func (k Keeper) SimulateHardSynchronization(ctx sdk.Context, claim types.HardLiq
 
 			factorIndex, foundFactorIndex := userRewardIndexes.RewardIndexes.GetFactorIndex(globalRewardIndex.CollateralType)
 			if !foundFactorIndex {
-				fmt.Printf("[LOG]: factor index for %s should always be found", ri.CollateralType) // TODO: remove before production
+				fmt.Printf("[LOG]: userRewardIndexes.RewardIndexes.GetFactorIndex for %s should always be found", globalRewardIndex.CollateralType) // TODO: remove before production
 				continue
 			}
 			claim.BorrowRewardIndexes[userRewardIndexIndex].RewardIndexes[factorIndex].RewardFactor = globalRewardIndex.RewardFactor

x/incentive/types/claims.go

@@ -264,9 +264,101 @@ func (cs HardLiquidityProviderClaims) Validate() error {
 	return nil
 }
 
-// -------------- Subcomponents of Custom Claim Types --------------
+// ---------------------- Reward periods are used by the params ----------------------
 
-// TODO: refactor RewardPeriod name from 'collateralType' to 'denom'
+// MultiRewardPeriod supports multiple reward types
+type MultiRewardPeriod struct {
+	Active           bool      `json:"active" yaml:"active"`
+	CollateralType   string    `json:"collateral_type" yaml:"collateral_type"`
+	Start            time.Time `json:"start" yaml:"start"`
+	End              time.Time `json:"end" yaml:"end"`
+	RewardsPerSecond sdk.Coins `json:"rewards_per_second" yaml:"rewards_per_second"` // per second reward payouts
+}
+
+// String implements fmt.Stringer
+func (mrp MultiRewardPeriod) String() string {
+	return fmt.Sprintf(`Reward Period:
+	Collateral Type: %s,
+	Start: %s,
+	End: %s,
+	Rewards Per Second: %s,
+	Active %t,
+	`, mrp.CollateralType, mrp.Start, mrp.End, mrp.RewardsPerSecond, mrp.Active)
+}
+
+// NewMultiRewardPeriod returns a new MultiRewardPeriod
+func NewMultiRewardPeriod(active bool, collateralType string, start time.Time, end time.Time, reward sdk.Coins) MultiRewardPeriod {
+	return MultiRewardPeriod{
+		Active:           active,
+		CollateralType:   collateralType,
+		Start:            start,
+		End:              end,
+		RewardsPerSecond: reward,
+	}
+}
+
+// Validate performs a basic check of a MultiRewardPeriod.
+func (mrp MultiRewardPeriod) Validate() error {
+	if mrp.Start.IsZero() {
+		return errors.New("reward period start time cannot be 0")
+	}
+	if mrp.End.IsZero() {
+		return errors.New("reward period end time cannot be 0")
+	}
+	if mrp.Start.After(mrp.End) {
+		return fmt.Errorf("end period time %s cannot be before start time %s", mrp.End, mrp.Start)
+	}
+	if !mrp.RewardsPerSecond.IsValid() {
+		return fmt.Errorf("invalid reward amount: %s", mrp.RewardsPerSecond)
+	}
+	if strings.TrimSpace(mrp.CollateralType) == "" {
+		return fmt.Errorf("reward period collateral type cannot be blank: %s", mrp)
+	}
+	return nil
+}
+
+// MultiRewardPeriods array of MultiRewardPeriod
+type MultiRewardPeriods []MultiRewardPeriod
+
+// GetMultiRewardPeriod fetches a MultiRewardPeriod from an array of MultiRewardPeriods by its denom
+func (mrps MultiRewardPeriods) GetMultiRewardPeriod(denom string) (MultiRewardPeriod, bool) {
+	for _, rp := range mrps {
+		if rp.CollateralType == denom {
+			return rp, true
+		}
+	}
+	return MultiRewardPeriod{}, false
+}
+
+// GetMultiRewardPeriodIndex returns the index of a MultiRewardPeriod inside array MultiRewardPeriods
+func (mrps MultiRewardPeriods) GetMultiRewardPeriodIndex(denom string) (int, bool) {
+	for i, rp := range mrps {
+		if rp.CollateralType == denom {
+			return i, true
+		}
+	}
+	return -1, false
+}
+
+// Validate checks if all the RewardPeriods are valid and there are no duplicated
+// entries.
+func (mrps MultiRewardPeriods) Validate() error {
+	seenPeriods := make(map[string]bool)
+	for _, rp := range mrps {
+		if seenPeriods[rp.CollateralType] {
+			return fmt.Errorf("duplicated reward period with collateral type %s", rp.CollateralType)
+		}
+
+		if err := rp.Validate(); err != nil {
+			return err
+		}
+		seenPeriods[rp.CollateralType] = true
+	}
+
+	return nil
+}
+
+// ---------------------- Reward indexes are used internally in the store ----------------------
 
 // RewardIndex stores reward accumulation information
 type RewardIndex struct {
@@ -330,80 +422,6 @@ func (ris RewardIndexes) Validate() error {
 	return nil
 }
 
-// -------------------------------------------------------------------------
-
-// MultiRewardPeriod supports multiple reward types
-type MultiRewardPeriod struct {
-	Active           bool      `json:"active" yaml:"active"`
-	CollateralType   string    `json:"collateral_type" yaml:"collateral_type"`
-	Start            time.Time `json:"start" yaml:"start"`
-	End              time.Time `json:"end" yaml:"end"`
-	RewardsPerSecond sdk.Coins `json:"rewards_per_second" yaml:"rewards_per_second"` // per second reward payouts
-}
-
-// String implements fmt.Stringer
-func (mrp MultiRewardPeriod) String() string {
-	return fmt.Sprintf(`Reward Period:
-	Collateral Type: %s,
-	Start: %s,
-	End: %s,
-	Rewards Per Second: %s,
-	Active %t,
-	`, mrp.CollateralType, mrp.Start, mrp.End, mrp.RewardsPerSecond, mrp.Active)
-}
-
-// NewMultiRewardPeriod returns a new MultiRewardPeriod
-func NewMultiRewardPeriod(active bool, collateralType string, start time.Time, end time.Time, reward sdk.Coins) MultiRewardPeriod {
-	return MultiRewardPeriod{
-		Active:           active,
-		CollateralType:   collateralType,
-		Start:            start,
-		End:              end,
-		RewardsPerSecond: reward,
-	}
-}
-
-// Validate performs a basic check of a MultiRewardPeriod.
-func (mrp MultiRewardPeriod) Validate() error {
-	if mrp.Start.IsZero() {
-		return errors.New("reward period start time cannot be 0")
-	}
-	if mrp.End.IsZero() {
-		return errors.New("reward period end time cannot be 0")
-	}
-	if mrp.Start.After(mrp.End) {
-		return fmt.Errorf("end period time %s cannot be before start time %s", mrp.End, mrp.Start)
-	}
-	if !mrp.RewardsPerSecond.IsValid() {
-		return fmt.Errorf("invalid reward amount: %s", mrp.RewardsPerSecond)
-	}
-	if strings.TrimSpace(mrp.CollateralType) == "" {
-		return fmt.Errorf("reward period collateral type cannot be blank: %s", mrp)
-	}
-	return nil
-}
-
-// MultiRewardPeriods array of MultiRewardPeriod
-type MultiRewardPeriods []MultiRewardPeriod
-
-// Validate checks if all the RewardPeriods are valid and there are no duplicated
-// entries.
-func (mrps MultiRewardPeriods) Validate() error {
-	seenPeriods := make(map[string]bool)
-	for _, rp := range mrps {
-		if seenPeriods[rp.CollateralType] {
-			return fmt.Errorf("duplicated reward period with collateral type %s", rp.CollateralType)
-		}
-
-		if err := rp.Validate(); err != nil {
-			return err
-		}
-		seenPeriods[rp.CollateralType] = true
-	}
-
-	return nil
-}
-
 // MultiRewardIndex stores reward accumulation information on multiple reward types
 type MultiRewardIndex struct {
 	CollateralType string        `json:"collateral_type" yaml:"collateral_type"`