address julien's comments

x/protocolpool/README.md

@@ -112,6 +112,21 @@ The message will fail under the following conditions:
 * The number of tranches is not a positive integer.
 * The period length is not a positive integer.
 
+*Disclaimer: The behavior described here is based on the current implementation and may be subject to changes in future versions.*
+```go
+func (k MsgServer) SubmitBudgetProposal(ctx context.Context, msg *types.MsgSubmitBudgetProposal) (*types.MsgSubmitBudgetProposalResponse, error) {
+    // ... (existing code)
+
+    // Set the budget proposal in the state.
+    err = k.BudgetProposal.Set(ctx, recipient, *budgetProposal)
+    if err != nil {
+        return nil, err
+    }
+
+    // ... (rest of the code)
+}
+```
+
 ```go reference
 https://github.com/cosmos/cosmos-sdk/blob/97724493d792517ba2be8969078b5f92ad04d79c/x/protocolpool/keeper/msg_server.go#L39-l61
 ```

x/protocolpool/keeper/grpc_query.go

@@ -53,13 +53,10 @@ func (k Querier) UnclaimedBudget(ctx context.Context, req *types.QueryUnclaimedB
 	var unclaimedBudget sdk.Coin
 	if budget.ClaimedAmount == nil {
 		unclaimedBudget = *budget.TotalBudget
-	} else {
-		unclaimedBudget = budget.TotalBudget.Sub(*budget.ClaimedAmount)
-	}
-
-	if budget.ClaimedAmount == nil {
 		zeroCoin := sdk.NewCoin(budget.TotalBudget.Denom, math.ZeroInt())
 		budget.ClaimedAmount = &zeroCoin
+	} else {
+		unclaimedBudget = budget.TotalBudget.Sub(*budget.ClaimedAmount)
 	}
 
 	if budget.NextClaimFrom == nil {

x/protocolpool/keeper/keeper.go

@@ -188,13 +188,13 @@ func (k Keeper) calculateClaimableFunds(ctx context.Context, recipient sdk.AccAd
 	return amount, nil
 }
 
-func (k Keeper) validateAndUpdateBudgetProposal(ctx context.Context, bp types.MsgSubmitBudgetProposal) error {
+func (k Keeper) validateAndUpdateBudgetProposal(ctx context.Context, bp *types.MsgSubmitBudgetProposal) (*types.Budget, error) {
 	if bp.TotalBudget.IsZero() {
-		return fmt.Errorf("invalid budget proposal: total budget cannot be zero")
+		return nil, fmt.Errorf("invalid budget proposal: total budget cannot be zero")
 	}
 
 	if err := validateAmount(sdk.NewCoins(*bp.TotalBudget)); err != nil {
-		return fmt.Errorf("invalid budget proposal: %w", err)
+		return nil, fmt.Errorf("invalid budget proposal: %w", err)
 	}
 
 	currentTime := sdk.UnwrapSDKContext(ctx).BlockTime()
@@ -204,16 +204,25 @@ func (k Keeper) validateAndUpdateBudgetProposal(ctx context.Context, bp types.Ms
 
 	// if bp.StartTime < uint64(currentTime) {
 	if currentTime.After(*bp.StartTime) {
-		return fmt.Errorf("invalid budget proposal: start time cannot be less than the current block time")
+		return nil, fmt.Errorf("invalid budget proposal: start time cannot be less than the current block time")
 	}
 
 	if bp.Tranches == 0 {
-		return fmt.Errorf("invalid budget proposal: tranches must be greater than zero")
+		return nil, fmt.Errorf("invalid budget proposal: tranches must be greater than zero")
 	}
 
 	if bp.Period == nil || *bp.Period == 0 {
-		return fmt.Errorf("invalid budget proposal: period length should be greater than zero")
+		return nil, fmt.Errorf("invalid budget proposal: period length should be greater than zero")
 	}
 
-	return nil
+	// Create and return an updated budget proposal
+	updatedBudget := types.Budget{
+		RecipientAddress: bp.RecipientAddress,
+		TotalBudget:      bp.TotalBudget,
+		StartTime:        bp.StartTime,
+		Tranches:         bp.Tranches,
+		Period:           bp.Period,
+	}
+
+	return &updatedBudget, nil
 }

x/protocolpool/keeper/msg_server.go

@@ -46,12 +46,11 @@ func (k MsgServer) SubmitBudgetProposal(ctx context.Context, msg *types.MsgSubmi
 		return nil, err
 	}
 
-	if err := k.validateAndUpdateBudgetProposal(ctx, *msg); err != nil {
+	budgetProposal, err := k.validateAndUpdateBudgetProposal(ctx, msg)
+	if err != nil {
 		return nil, err
 	}
 
-	budgetProposal := types.NewBudgetProposal(msg.RecipientAddress, *msg.TotalBudget, msg.StartTime, msg.Tranches, msg.Period)
-
 	// set budget proposal in state
 	err = k.BudgetProposal.Set(ctx, recipient, *budgetProposal)
 	if err != nil {

x/protocolpool/types/msg.go

@@ -1,8 +1,6 @@
 package types
 
 import (
-	"time"
-
 	sdk "github.com/cosmos/cosmos-sdk/types"
 )
 
@@ -29,13 +27,3 @@ func NewCommunityPoolSpend(amount sdk.Coins, authority, recipient string) *MsgCo
 		Amount:    amount,
 	}
 }
-
-func NewBudgetProposal(recipient string, totalBudget sdk.Coin, startTime *time.Time, tranches uint64, period *time.Duration) *Budget {
-	return &Budget{
-		RecipientAddress: recipient,
-		TotalBudget:      &totalBudget,
-		StartTime:        startTime,
-		Tranches:         tranches,
-		Period:           period,
-	}
-}