function to store all remaining Mana on an output

builder/transaction_builder.go

@@ -157,6 +157,36 @@ func (b *TransactionBuilder) AddTaggedDataPayload(payload *iotago.TaggedData) *T
 // TransactionFunc is a function which receives a SignedTransaction as its parameter.
 type TransactionFunc func(tx *iotago.SignedTransaction)
 
+func (b *TransactionBuilder) StoreRemainingManaInOutput(targetSlot iotago.SlotIndex, blockIssuerAccountID iotago.AccountID, storedManaOutputIndex int) *TransactionBuilder {
+	setBuildError := func(err error) *TransactionBuilder {
+		b.occurredBuildErr = err
+		return b
+	}
+
+	if storedManaOutputIndex >= len(b.transaction.Outputs) {
+		return setBuildError(ierrors.Errorf("given storedManaOutputIndex does not exist: %d", storedManaOutputIndex))
+	}
+
+	unboundManaInputsLeftoverBalance, err := b.calculateAvailableManaLeftover(targetSlot, 0, blockIssuerAccountID)
+	if err != nil {
+		return setBuildError(err)
+	}
+
+	// move the remaining mana to stored mana on the specified output index
+	switch output := b.transaction.Outputs[storedManaOutputIndex].(type) {
+	case *iotago.BasicOutput:
+		output.Mana += unboundManaInputsLeftoverBalance
+	case *iotago.AccountOutput:
+		output.Mana += unboundManaInputsLeftoverBalance
+	case *iotago.NFTOutput:
+		output.Mana += unboundManaInputsLeftoverBalance
+	default:
+		return setBuildError(ierrors.Wrapf(iotago.ErrUnknownOutputType, "output type %T does not support stored mana", output))
+	}
+
+	return b
+}
+
 func (b *TransactionBuilder) AllotRequiredManaAndStoreRemainingManaInOutput(targetSlot iotago.SlotIndex, rmc iotago.Mana, blockIssuerAccountID iotago.AccountID, storedManaOutputIndex int) *TransactionBuilder {
 	setBuildError := func(err error) *TransactionBuilder {
 		b.occurredBuildErr = err