From da572c08f73ba04f0f98f455ecb4e0d5c684d16b Mon Sep 17 00:00:00 2001
From: Daniel Firth <daniel.firth@iohk.io>
Date: Mon, 9 Dec 2024 16:50:09 +0000
Subject: [PATCH] Add TxMintValue modifier functions

---
 cardano-api/internal/Cardano/Api/Tx/Body.hs | 28 +++++++++++++++++++++
 cardano-api/src/Cardano/Api.hs              |  3 +++
 2 files changed, 31 insertions(+)

diff --git a/cardano-api/internal/Cardano/Api/Tx/Body.hs b/cardano-api/internal/Cardano/Api/Tx/Body.hs
index 03443e391d..952a7b7449 100644
--- a/cardano-api/internal/Cardano/Api/Tx/Body.hs
+++ b/cardano-api/internal/Cardano/Api/Tx/Body.hs
@@ -66,6 +66,9 @@ module Cardano.Api.Tx.Body
   , setTxProposalProcedures
   , setTxVotingProcedures
   , setTxMintValue
+  , modTxMintValue
+  , addTxMintValue
+  , subtractTxMintValue
   , setTxScriptValidity
   , setTxCurrentTreasuryValue
   , setTxTreasuryDonation
@@ -1592,6 +1595,31 @@ setTxUpdateProposal v txBodyContent = txBodyContent{txUpdateProposal = v}
 setTxMintValue :: TxMintValue build era -> TxBodyContent build era -> TxBodyContent build era
 setTxMintValue v txBodyContent = txBodyContent{txMintValue = v}
 
+modTxMintValue
+  :: (TxMintValue build era -> TxMintValue build era)
+  -> TxBodyContent build era
+  -> TxBodyContent build era
+modTxMintValue f tx = tx{txMintValue = f (txMintValue tx)}
+
+addTxMintValue
+  :: IsMaryBasedEra era
+  => Map PolicyId [(AssetName, Quantity, BuildTxWith build (ScriptWitness WitCtxMint era))]
+  -> TxBodyContent build era
+  -> TxBodyContent build era
+addTxMintValue assets =
+  modTxMintValue
+    ( \case
+        TxMintNone -> TxMintValue maryBasedEra assets
+        TxMintValue era t -> TxMintValue era (t <> assets)
+    )
+
+subtractTxMintValue
+  :: IsMaryBasedEra era
+  => Map PolicyId [(AssetName, Quantity, BuildTxWith build (ScriptWitness WitCtxMint era))]
+  -> TxBodyContent build era
+  -> TxBodyContent build era
+subtractTxMintValue assets = addTxMintValue (fmap (fmap (\(x, y, z) -> (x, negate y, z))) assets)
+
 setTxScriptValidity :: TxScriptValidity era -> TxBodyContent build era -> TxBodyContent build era
 setTxScriptValidity v txBodyContent = txBodyContent{txScriptValidity = v}
 
diff --git a/cardano-api/src/Cardano/Api.hs b/cardano-api/src/Cardano/Api.hs
index 4c28183f30..45459c7a40 100644
--- a/cardano-api/src/Cardano/Api.hs
+++ b/cardano-api/src/Cardano/Api.hs
@@ -329,6 +329,9 @@ module Cardano.Api
   , setTxCertificates
   , setTxUpdateProposal
   , setTxMintValue
+  , modTxMintValue
+  , addTxMintValue
+  , subtractTxMintValue
   , setTxScriptValidity
   , setTxProposalProcedures
   , setTxVotingProcedures