From 8b447dce2e8f9a49e1143120b2944209cba115ad Mon Sep 17 00:00:00 2001
From: Sebastian Nagel <sebastian.nagel@ncoding.at>
Date: Tue, 21 Sep 2021 10:27:17 +0200
Subject: [PATCH] Progress in running abort validator with hash workaround

Seems that the Plutus ValidatorHash contains a different hash than
produced by `hashScript` of the ledger. Or the serialization of
`initialScript` is wrong. Work around to see if it runs.
---
 hydra-node/src/Hydra/Chain/Direct/Tx.hs      | 37 ++++++++++++++------
 hydra-node/test/Hydra/Chain/Direct/TxSpec.hs |  5 +--
 2 files changed, 29 insertions(+), 13 deletions(-)

diff --git a/hydra-node/src/Hydra/Chain/Direct/Tx.hs b/hydra-node/src/Hydra/Chain/Direct/Tx.hs
index 0e7a75145ec..20ec829348c 100644
--- a/hydra-node/src/Hydra/Chain/Direct/Tx.hs
+++ b/hydra-node/src/Hydra/Chain/Direct/Tx.hs
@@ -10,15 +10,17 @@ module Hydra.Chain.Direct.Tx where
 
 import Hydra.Prelude
 
-import Cardano.Crypto.Hash (hashFromBytes)
+import Cardano.Binary (serialize)
+import Cardano.Crypto.Hash (Hash, hashFromBytes)
 import Cardano.Ledger.Address (Addr (Addr))
-import Cardano.Ledger.Alonzo (AlonzoEra)
+import Cardano.Ledger.Alonzo (AlonzoEra, Script)
 import Cardano.Ledger.Alonzo.Data (Data (Data), hashData)
 import Cardano.Ledger.Alonzo.Scripts (ExUnits (..), Script (PlutusScript), Tag (Spend))
 import Cardano.Ledger.Alonzo.Tx (IsValid (IsValid), ValidatedTx (..))
 import Cardano.Ledger.Alonzo.TxBody (TxBody (..), TxOut (TxOut))
 import Cardano.Ledger.Alonzo.TxWitness (RdmrPtr (RdmrPtr), Redeemers (..), TxDats (..), TxWitness (..), unTxDats)
 import Cardano.Ledger.Crypto (ADDRHASH, StandardCrypto)
+import Cardano.Ledger.Hashes (EraIndependentScript)
 import Cardano.Ledger.ShelleyMA.Timelocks (ValidityInterval (..))
 import Cardano.Ledger.Val (inject)
 import qualified Data.Map as Map
@@ -29,7 +31,7 @@ import Hydra.Contract.Head (State (Initial))
 import Hydra.Data.ContestationPeriod (contestationPeriodFromDiffTime, contestationPeriodToDiffTime)
 import Hydra.Data.Party (partyFromVerKey, partyToVerKey)
 import Hydra.Party (anonymousParty, vkey)
-import Plutus.V1.Ledger.Api (ValidatorHash (ValidatorHash), fromBuiltin, fromData, toBuiltinData, toData)
+import Plutus.V1.Ledger.Api (ValidatorHash (ValidatorHash), fromBuiltin, fromData, toData)
 import Shelley.Spec.Ledger.API (
   Coin (..),
   Credential (ScriptHashObj),
@@ -64,7 +66,7 @@ constructTx txIn = \case
 -- which will be used as unique parameter for minting NFTs.
 initTx :: HeadParameters -> TxIn StandardCrypto -> ValidatedTx Era
 initTx HeadParameters{contestationPeriod, parties} txIn =
-  mkUnsignedTx body dats mempty
+  mkUnsignedTx body dats mempty mempty
  where
   body =
     TxBody
@@ -107,7 +109,7 @@ initTx HeadParameters{contestationPeriod, parties} txIn =
 
 abortTx :: TxIn StandardCrypto -> ValidatedTx Era
 abortTx txIn =
-  mkUnsignedTx body mempty redeemers
+  mkUnsignedTx body mempty redeemers scripts
  where
   body =
     TxBody
@@ -132,6 +134,16 @@ abortTx txIn =
   -- TODO(SN): This should be 'Abort' or so
   redeemerData = Data $ toData ()
 
+  scripts = Map.singleton initialScriptHash initialScript
+
+  -- FIXME(SN): Ideally use the ledgers `hashScript` here, but it seems to be
+  -- different from what the Plutus ValidatorHash wraps and fails lookup
+  initialScriptHash = case validatorHashToHash Initial.validatorHash of
+    Nothing -> error "ValidatorHash does not hold a proper hash" -- should not happen^TM
+    Just h -> ScriptHash h
+
+  initialScript = PlutusScript . toShort . fromLazy $ serialize Initial.validatorScript
+
 --
 
 -- * Observe Hydra Head transactions
@@ -165,15 +177,16 @@ mkUnsignedTx ::
   TxBody Era ->
   TxDats Era ->
   Map RdmrPtr (Data Era, ExUnits) ->
+  Map (ScriptHash StandardCrypto) (Script Era) ->
   ValidatedTx Era
-mkUnsignedTx body datums redeemers =
+mkUnsignedTx body datums redeemers scripts =
   ValidatedTx
     { body
     , wits =
         TxWitness
           { txwitsVKey = mempty
           , txwitsBoot = mempty
-          , txscripts = mempty
+          , txscripts = scripts
           , txdats = datums
           , txrdmrs = Redeemers redeemers
           }
@@ -183,15 +196,17 @@ mkUnsignedTx body datums redeemers =
 
 -- | Convert a plutus address to its ledger representation.
 validatorHashToAddr :: ValidatorHash -> Addr StandardCrypto
-validatorHashToAddr (ValidatorHash builtinByteString) =
+validatorHashToAddr vh =
   Addr
     network
     (ScriptHashObj $ ScriptHash hash)
     -- REVIEW(SN): stake head funds?
     StakeRefNull
  where
-  hash = case hashFromBytes @(ADDRHASH StandardCrypto) bytes of
-    Nothing -> error $ "ValidatorHash is not (the right) hash: " <> show bytes
+  hash = case validatorHashToHash vh of
+    Nothing -> error $ "ValidatorHash is not (the right) hash: " <> show vh
     Just h -> h
 
-  bytes = fromBuiltin builtinByteString
+validatorHashToHash :: ValidatorHash -> Maybe (Hash (ADDRHASH StandardCrypto) EraIndependentScript)
+validatorHashToHash (ValidatorHash builtinByteString) =
+  hashFromBytes @(ADDRHASH StandardCrypto) (fromBuiltin builtinByteString)
diff --git a/hydra-node/test/Hydra/Chain/Direct/TxSpec.hs b/hydra-node/test/Hydra/Chain/Direct/TxSpec.hs
index ff8138b925c..9bf89d1bc44 100644
--- a/hydra-node/test/Hydra/Chain/Direct/TxSpec.hs
+++ b/hydra-node/test/Hydra/Chain/Direct/TxSpec.hs
@@ -95,9 +95,10 @@ spec =
             initialValue = inject (Coin 0)
             initialDatumHash = hashData @Era . Data . toData $ PubKeyHash "not a PubKeyHash"
             results = validateTxScriptsUnlimited tx utxo
-         in -- TODO(SN): are the RdmrPtr keys useful?
-            1 == length (rights $ Map.elems results)
+         in 1 == length (rights $ Map.elems results)
               & counterexample ("Evaluation results: " <> show results)
+              & counterexample ("Tx: " <> show tx)
+              & counterexample ("Input utxo: " <> show utxo)
 
 isImplemented :: PostChainTx tx -> Bool
 isImplemented = \case