Ignore collateral handling for simple transactions

Author: TotallyNotChase

src/BotPlutusInterface/Balance.hs

@@ -1,4 +1,5 @@
 {-# LANGUAGE AllowAmbiguousTypes #-}
+{-# LANGUAGE NamedFieldPuns #-}
 
 module BotPlutusInterface.Balance (
   balanceTxStep,
@@ -20,10 +21,10 @@ import Control.Monad.Trans.Either (EitherT, hoistEither, newEitherT, runEitherT)
 import Data.Coerce (coerce)
 import Data.Either.Combinators (rightToMaybe)
 import Data.Kind (Type)
-import Data.List (partition, (\\))
+import Data.List (partition, (\\), find)
 import Data.Map (Map)
 import Data.Map qualified as Map
-import Data.Maybe (fromMaybe, mapMaybe)
+import Data.Maybe (fromMaybe, mapMaybe, isJust)
 import Data.Set (Set)
 import Data.Set qualified as Set
 import Data.Text (Text)
@@ -280,7 +281,7 @@ balanceTxIns utxos tx = do
  (suboptimally we just pick a random utxo from the tx inputs)
 -}
 addTxCollaterals :: Map TxOutRef TxOut -> Tx -> Either Text Tx
-addTxCollaterals utxos tx = do
+addTxCollaterals utxos tx = if not $ usesScripts tx then Right tx else do
   let txIns = mapMaybe (rightToMaybe . txOutToTxIn) $ Map.toList $ filterAdaOnly utxos
   txIn <- findPubKeyTxIn txIns
   pure $ tx {txCollateral = Set.singleton txIn}
@@ -291,6 +292,12 @@ addTxCollaterals utxos tx = do
       _ : xs -> findPubKeyTxIn xs
       _ -> Left "There are no utxos to be used as collateral"
     filterAdaOnly = Map.filter (isAdaOnly . txOutValue)
+    usesScripts Tx{txInputs, txMintScripts}
+      = not (null txMintScripts)
+        || isJust
+          (find (\TxIn{txInType} -> case txInType of { Just ConsumeScriptAddress{} -> True; _ -> False })
+            $ Set.toList txInputs
+          )
 
 -- | Ensures all non ada change goes back to user
 handleNonAdaChange :: Address -> Map TxOutRef TxOut -> Tx -> Either Text Tx