add sum of the deposits in a transaction event

shelley/chain-and-ledger/executable-spec/src/Shelley/Spec/Ledger/STS/Utxo.hs

@@ -18,6 +18,7 @@ module Shelley.Spec.Ledger.STS.Utxo
   ( UTXO,
     UtxoEnv (..),
     UtxoPredicateFailure (..),
+    UtxoEvent (..),
     PredicateFailure,
   )
 where
@@ -75,7 +76,7 @@ import Control.State.Transition
     trans,
     wrapEvent,
     wrapFailed,
-    (?!),
+    (?!), tellEvent
   )
 import Data.Foldable (foldl', toList)
 import Data.Map.Strict (Map)
@@ -116,6 +117,7 @@ import Shelley.Spec.Ledger.UTxO
     txouts,
     txup,
   )
+import Data.Void (Void)
 
 data UTXO era
 
@@ -128,6 +130,10 @@ data UtxoEnv era
 
 deriving instance Show (Core.PParams era) => Show (UtxoEnv era)
 
+data UtxoEvent era
+  = TotalDeposits Coin
+  | UpdateEvent (Event (Core.EraRule "PPUP" era))
+
 data UtxoPredicateFailure era
   = BadInputsUTxO
       !(Set (TxIn (Crypto era))) -- The bad transaction inputs
@@ -296,6 +302,7 @@ instance
   type Environment (UTXO era) = UtxoEnv era
   type BaseM (UTXO era) = ShelleyBase
   type PredicateFailure (UTXO era) = UtxoPredicateFailure era
+  type Event (UTXO era) = UtxoEvent era
 
   transitionRules = [utxoInductive]
 
@@ -337,6 +344,7 @@ utxoInductive ::
     State (utxo era) ~ UTxOState era,
     Signal (utxo era) ~ Tx era,
     PredicateFailure (utxo era) ~ UtxoPredicateFailure era,
+    Event (utxo era) ~ UtxoEvent era,
     Environment (Core.EraRule "PPUP" era) ~ PPUPEnv era,
     State (Core.EraRule "PPUP" era) ~ PPUPState era,
     Signal (Core.EraRule "PPUP" era) ~ Maybe (Update era),
@@ -421,7 +429,9 @@ utxoInductive = do
 
   let refunded = keyRefunds pp txb
   let txCerts = toList $ getField @"certs" txb
-  let depositChange = totalDeposits pp (`Map.notMember` stakepools) txCerts <-> refunded
+  let totalDeposits' = totalDeposits pp (`Map.notMember` stakepools) txCerts 
+  tellEvent $ TotalDeposits totalDeposits'
+  let depositChange = totalDeposits' <-> refunded
 
   pure
     UTxOState
@@ -434,9 +444,10 @@ utxoInductive = do
 instance
   ( Era era,
     STS (PPUP era),
-    PredicateFailure (Core.EraRule "PPUP" era) ~ PpupPredicateFailure era
+    PredicateFailure (Core.EraRule "PPUP" era) ~ PpupPredicateFailure era,
+    Event (Core.EraRule "PPUP" era) ~ Void
   ) =>
   Embed (PPUP era) (UTXO era)
   where
   wrapFailed = UpdateFailure
-  wrapEvent = id
+  wrapEvent = UpdateEvent