From 311fd05b116497be9eabbb13da844e654b0754a4 Mon Sep 17 00:00:00 2001
From: Gregory Gerasev <uhbif19@gmail.com>
Date: Wed, 29 May 2024 00:30:43 +0700
Subject: [PATCH] Add `getAllSpecSigners` util

---
 src/Cardano/CEM.hs | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/Cardano/CEM.hs b/src/Cardano/CEM.hs
index f1b5f36..eeaa045 100644
--- a/src/Cardano/CEM.hs
+++ b/src/Cardano/CEM.hs
@@ -125,6 +125,15 @@ data TransitionSpec script = MkTransitionSpec
   }
   deriving stock (Show)
 
+-- | List of all signing keys required for transition spec
+getAllSpecSigners :: TransitionSpec script -> [PubKeyHash]
+getAllSpecSigners spec = signers spec ++ txInPKHs
+  where
+    txInPKHs = mapMaybe getPubKey $ filter ((Prelude.== In) . txFanCKind) $ constraints spec
+    getPubKey c = case address (txFanCFilter c) of
+      ByPubKey key -> Just key
+      _ -> Nothing
+
 {- | Static part of CEMScript datum.
 Datatype is actually used only by off-chain code due to Plutus limitations.
 -}