From e98364ca56e53543912e174caea9c3f011f67d16 Mon Sep 17 00:00:00 2001
From: Franco Testagrossa <franco.testagrossa@gmail.com>
Date: Wed, 11 Sep 2024 02:26:45 +0200
Subject: [PATCH] Add new field 'inlineDatumRaw' to TxOut ToJSON instance

It contains the raw CBOR for any inline datum.

Reason:
> When building applications that need to spend from a script UTxO which has a datum attached  (like in a Hydra head),
that off-chain code needs access to the raw Datum for evaluating the transaction and calculate fees.
---
 cardano-api/internal/Cardano/Api/Tx/Body.hs | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/cardano-api/internal/Cardano/Api/Tx/Body.hs b/cardano-api/internal/Cardano/Api/Tx/Body.hs
index 0e40356f0..46baa9d21 100644
--- a/cardano-api/internal/Cardano/Api/Tx/Body.hs
+++ b/cardano-api/internal/Cardano/Api/Tx/Body.hs
@@ -211,6 +211,8 @@ import           Cardano.Api.ProtocolParameters
 import qualified Cardano.Api.ReexposeLedger as Ledger
 import           Cardano.Api.Script
 import           Cardano.Api.ScriptData
+import           Cardano.Api.ScriptData ()
+import           Cardano.Api.SerialiseCBOR
 import           Cardano.Api.SerialiseJSON
 import           Cardano.Api.SerialiseRaw
 import           Cardano.Api.Tx.Sign
@@ -263,6 +265,7 @@ import qualified Data.Aeson.Key as Aeson
 import qualified Data.Aeson.Types as Aeson
 import           Data.Bifunctor (Bifunctor (..))
 import           Data.ByteString (ByteString)
+import qualified Data.ByteString.Base16 as Base16
 import qualified Data.ByteString.Char8 as BSC
 import qualified Data.DList as DList
 import           Data.Foldable (for_)
@@ -285,6 +288,7 @@ import qualified Data.Set as Set
 import           Data.String
 import           Data.Text (Text)
 import qualified Data.Text as Text
+import qualified Data.Text.Encoding as Text
 import           Data.Type.Equality (TestEquality (..), (:~:) (Refl))
 import           Data.Word (Word16, Word32, Word64)
 import           GHC.Exts (IsList (..))
@@ -369,6 +373,7 @@ txOutToJsonValue era (TxOut addr val dat refScript) =
         , datHashJsonVal dat
         , "datum" .= datJsonVal dat
         , "inlineDatum" .= inlineDatumJsonVal dat
+        , "inlineDatumRaw" .= inlineDatumRawJsonCbor dat
         , "referenceScript" .= refScriptJsonVal refScript
         ]
     ConwayEra ->
@@ -378,6 +383,7 @@ txOutToJsonValue era (TxOut addr val dat refScript) =
         , datHashJsonVal dat
         , "datum" .= datJsonVal dat
         , "inlineDatum" .= inlineDatumJsonVal dat
+        , "inlineDatumRaw" .= inlineDatumRawJsonCbor dat
         , "referenceScript" .= refScriptJsonVal refScript
         ]
  where
@@ -409,6 +415,19 @@ txOutToJsonValue era (TxOut addr val dat refScript) =
       TxOutDatumInTx'{} -> Aeson.Null
       TxOutDatumInline _ datum -> scriptDataToJson ScriptDataJsonDetailedSchema datum
 
+  inlineDatumRawJsonCbor :: TxOutDatum ctx era -> Aeson.Value
+  inlineDatumRawJsonCbor d =
+    case d of
+      TxOutDatumNone -> Aeson.Null
+      TxOutDatumHash{} -> Aeson.Null
+      TxOutDatumInTx'{} -> Aeson.Null
+      TxOutDatumInline _ datum ->
+        Aeson.String
+          . Text.decodeUtf8
+          . Base16.encode
+          . serialiseToCBOR
+          $ datum
+
   refScriptJsonVal :: ReferenceScript era -> Aeson.Value
   refScriptJsonVal rScript =
     case rScript of