feat(incentives): feature flag to enable/disable epoch end distribution

proto/dymensionxyz/dymension/incentives/params.proto

@@ -29,4 +29,7 @@ message Params {
     (gogoproto.nullable) = false,
     (gogoproto.customtype) = "github.com/cosmos/cosmos-sdk/types.Int"
   ];
+  // FeatureFlagEpochEndDistribution enables distribution of gauge rewards
+  // at the end of each epoch. If disabled, rewards are not distributed.
+  bool feature_flag_epoch_end_distribution = 5;
 }

x/incentives/keeper/hooks.go

@@ -14,6 +14,11 @@ func (k Keeper) BeforeEpochStart(ctx sdk.Context, epochIdentifier string, epochN
 // AfterEpochEnd is the epoch end hook.
 func (k Keeper) AfterEpochEnd(ctx sdk.Context, epochIdentifier string, epochNumber int64) error {
 	params := k.GetParams(ctx)
+
+	if !params.FeatureFlagEpochEndDistribution {
+		return nil
+	}
+
 	if epochIdentifier == params.DistrEpochIdentifier {
 		// begin distribution if it's start time
 		gauges := k.GetUpcomingGauges(ctx)

x/incentives/types/params.go

@@ -12,10 +12,11 @@ import (
 
 // Incentives parameters key store.
 var (
-	KeyDistrEpochIdentifier = []byte("DistrEpochIdentifier")
-	KeyCreateGaugeFee       = []byte("CreateGaugeFee")
-	KeyAddToGaugeFee        = []byte("AddToGaugeFee")
-	KeyAddDenomFee          = []byte("AddDenomFee")
+	KeyDistrEpochIdentifier            = []byte("DistrEpochIdentifier")
+	KeyCreateGaugeFee                  = []byte("CreateGaugeFee")
+	KeyAddToGaugeFee                   = []byte("AddToGaugeFee")
+	KeyAddDenomFee                     = []byte("AddDenomFee")
+	KeyFeatureFlagEpochEndDistribution = []byte("FeatureFlagEpochEndDistribution")
 )
 
 // ParamKeyTable returns the key table for the incentive module's parameters.
@@ -24,22 +25,24 @@ func ParamKeyTable() paramtypes.KeyTable {
 }
 
 // NewParams takes an epoch distribution identifier, then returns an incentives Params struct.
-func NewParams(distrEpochIdentifier string, createGaugeFee, addToGaugeFee, addDenomFee math.Int) Params {
+func NewParams(distrEpochIdentifier string, createGaugeFee, addToGaugeFee, addDenomFee math.Int, ffEpochEndDistribution bool) Params {
 	return Params{
-		DistrEpochIdentifier: distrEpochIdentifier,
-		CreateGaugeBaseFee:   createGaugeFee,
-		AddToGaugeBaseFee:    addToGaugeFee,
-		AddDenomFee:          addDenomFee,
+		DistrEpochIdentifier:            distrEpochIdentifier,
+		CreateGaugeBaseFee:              createGaugeFee,
+		AddToGaugeBaseFee:               addToGaugeFee,
+		AddDenomFee:                     addDenomFee,
+		FeatureFlagEpochEndDistribution: ffEpochEndDistribution,
 	}
 }
 
 // DefaultParams returns the default incentives module parameters.
 func DefaultParams() Params {
 	return Params{
-		DistrEpochIdentifier: DefaultDistrEpochIdentifier,
-		CreateGaugeBaseFee:   DefaultCreateGaugeFee,
-		AddToGaugeBaseFee:    DefaultAddToGaugeFee,
-		AddDenomFee:          DefaultAddDenomFee,
+		DistrEpochIdentifier:            DefaultDistrEpochIdentifier,
+		CreateGaugeBaseFee:              DefaultCreateGaugeFee,
+		AddToGaugeBaseFee:               DefaultAddToGaugeFee,
+		AddDenomFee:                     DefaultAddDenomFee,
+		FeatureFlagEpochEndDistribution: false,
 	}
 }
 
@@ -57,6 +60,9 @@ func (p Params) Validate() error {
 	if err := validateAddDenomFee(p.AddDenomFee); err != nil {
 		return err
 	}
+	if err := validateBool(p.FeatureFlagEpochEndDistribution); err != nil {
+		return err
+	}
 	return nil
 }
 
@@ -67,6 +73,7 @@ func (p *Params) ParamSetPairs() paramtypes.ParamSetPairs {
 		paramtypes.NewParamSetPair(KeyCreateGaugeFee, &p.CreateGaugeBaseFee, validateCreateGaugeFeeInterface),
 		paramtypes.NewParamSetPair(KeyAddToGaugeFee, &p.AddToGaugeBaseFee, validateAddToGaugeFeeInterface),
 		paramtypes.NewParamSetPair(KeyAddDenomFee, &p.AddDenomFee, validateAddDenomFee),
+		paramtypes.NewParamSetPair(KeyFeatureFlagEpochEndDistribution, &p.FeatureFlagEpochEndDistribution, validateBool),
 	}
 }
 
@@ -102,3 +109,11 @@ func validateAddDenomFee(i interface{}) error {
 	}
 	return nil
 }
+
+func validateBool(i interface{}) error {
+	_, ok := i.(bool)
+	if !ok {
+		return fmt.Errorf("invalid parameter type: %T", i)
+	}
+	return nil
+}