From 32100bda9a38d626723050ea744fc22b9513446f Mon Sep 17 00:00:00 2001
From: mmontin <o.montin@gmail.com>
Date: Thu, 11 Jul 2024 17:51:46 +0200
Subject: [PATCH] logging of unused collateral option

---
 CHANGELOG.md                       |  3 +++
 src/Cooked/MockChain/Balancing.hs  | 19 ++++++++++---------
 src/Cooked/MockChain/BlockChain.hs |  5 ++++-
 src/Cooked/Pretty/Cooked.hs        |  8 ++++++++
 4 files changed, 25 insertions(+), 10 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index f1a349d8..91d90340 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -30,10 +30,13 @@
   * it is now a component of `MonadBlockChainBalancing`
   * it can be turned on/off in skeleton options
   * it now displays the discarding of utxos during balancing.
+  * it now displays when the users specifies useless collateral utxos
 
 ### Fixed
 
 - All kinds of scripts can now be used as reference scripts.
+- Transactions that do not involve script are now properly generated without any
+  collateral.
 
 ## [[4.0.0]](https://github.com/tweag/cooked-validators/releases/tag/v4.0.0) - 2024-06-28
 
diff --git a/src/Cooked/MockChain/Balancing.hs b/src/Cooked/MockChain/Balancing.hs
index da0ad120..26ff46af 100644
--- a/src/Cooked/MockChain/Balancing.hs
+++ b/src/Cooked/MockChain/Balancing.hs
@@ -79,15 +79,16 @@ balanceTxSkel skelUnbal@TxSkel {..} = do
     -- We retrieve the various kinds of scripts
     spendingScripts <- txSkelInputValidators skelUnbal
     -- The transaction will only require collaterals when involving scripts
-    if Map.null txSkelMints && null (mapMaybe txSkelProposalWitness txSkelProposals) && Map.null spendingScripts
-      then return Nothing
-      else
-        Just <$> case txOptCollateralUtxos txSkelOpts of
-          CollateralUtxosFromBalancingWallet -> case balancingWallet of
-            Nothing -> fail "Can't select collateral utxos from a balancing wallet because it does not exist."
-            Just bWallet -> (,bWallet) . Set.fromList . map fst <$> runUtxoSearch (onlyValueOutputsAtSearch bWallet)
-          CollateralUtxosFromWallet cWallet -> (,cWallet) . Set.fromList . map fst <$> runUtxoSearch (onlyValueOutputsAtSearch cWallet)
-          CollateralUtxosFromSet utxos rWallet -> return (utxos, rWallet)
+    let noScriptInvolved = Map.null txSkelMints && null (mapMaybe txSkelProposalWitness txSkelProposals) && Map.null spendingScripts
+    case (noScriptInvolved, txOptCollateralUtxos txSkelOpts) of
+      (True, CollateralUtxosFromSet utxos _) -> publish (MCLogUnusedCollaterals $ Right utxos) >> return Nothing
+      (True, CollateralUtxosFromWallet cWallet) -> publish (MCLogUnusedCollaterals $ Left cWallet) >> return Nothing
+      (True, CollateralUtxosFromBalancingWallet) -> return Nothing
+      (False, CollateralUtxosFromSet utxos rWallet) -> return $ Just (utxos, rWallet)
+      (False, CollateralUtxosFromWallet cWallet) -> Just . (,cWallet) . Set.fromList . map fst <$> runUtxoSearch (onlyValueOutputsAtSearch cWallet)
+      (False, CollateralUtxosFromBalancingWallet) -> case balancingWallet of
+        Nothing -> fail "Can't select collateral utxos from a balancing wallet because it does not exist."
+        Just bWallet -> Just . (,bWallet) . Set.fromList . map fst <$> runUtxoSearch (onlyValueOutputsAtSearch bWallet)
 
   -- At this point, the presence (or absence) of balancing wallet dictates
   -- whether the transaction should be automatically balanced or not.
diff --git a/src/Cooked/MockChain/BlockChain.hs b/src/Cooked/MockChain/BlockChain.hs
index a57026aa..33c3ce26 100644
--- a/src/Cooked/MockChain/BlockChain.hs
+++ b/src/Cooked/MockChain/BlockChain.hs
@@ -126,8 +126,11 @@ data MockChainLogEntry where
   -- successfully sent for validation.
   MCLogNewTx :: Api.TxId -> MockChainLogEntry
   -- | Logging the fact that utxos provided by the user for balancing have to be
-  -- discarded for a specific reason.
+  -- discarded for a given reason.
   MCLogDiscardedUtxos :: Integer -> String -> MockChainLogEntry
+  -- | Logging the fact that utxos provided as collaterals will not be used
+  -- because the transaction does not need involve scripts.
+  MCLogUnusedCollaterals :: Either Wallet (Set Api.TxOutRef) -> MockChainLogEntry
 
 -- | Contains methods needed for balancing.
 class (MonadFail m, MonadError MockChainError m) => MonadBlockChainBalancing m where
diff --git a/src/Cooked/Pretty/Cooked.hs b/src/Cooked/Pretty/Cooked.hs
index eb22e88d..646b37ce 100644
--- a/src/Cooked/Pretty/Cooked.hs
+++ b/src/Cooked/Pretty/Cooked.hs
@@ -152,6 +152,14 @@ instance PrettyCooked MockChainLogEntry where
             ]
   prettyCookedOpt opts (MCLogNewTx txId) = "New transaction:" <+> prettyCookedOpt opts txId
   prettyCookedOpt opts (MCLogDiscardedUtxos n s) = prettyCookedOpt opts n <+> "balancing utxos were discarded:" <+> PP.pretty s
+  prettyCookedOpt opts (MCLogUnusedCollaterals (Left cWallet)) =
+    "Specific request to fetch collateral utxos from"
+      <+> prettyCookedOpt opts (walletPKHash cWallet)
+      <+> "has been disregarded because the transaction does not require collaterals"
+  prettyCookedOpt opts (MCLogUnusedCollaterals (Right (length -> n))) =
+    "Specific request to fetch collateral utxos from the given set of"
+      <+> prettyCookedOpt opts n
+      <+> "elements has been disregarded because the transaction does not require collaterals"
 
 prettyTxSkel :: PrettyCookedOpts -> SkelContext -> TxSkel -> DocCooked
 prettyTxSkel opts skelContext (TxSkel lbl txopts mints signers validityRange ins insReference outs proposals) =