From e910b831dd401dd0086d8adac760256ace659925 Mon Sep 17 00:00:00 2001
From: Sebastian Nagel <sebastian.nagel@ncoding.at>
Date: Wed, 30 Nov 2022 10:38:05 +0100
Subject: [PATCH 1/2] Add ToJSON/FromJSON instances for ChainPoint

There is already a ToJSON instance for ChainTip so we figured we could
upstream this from hydra-cardano-api.
---
 cardano-api/src/Cardano/Api/Block.hs | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/cardano-api/src/Cardano/Api/Block.hs b/cardano-api/src/Cardano/Api/Block.hs
index f91229d615c..0c557deb214 100644
--- a/cardano-api/src/Cardano/Api/Block.hs
+++ b/cardano-api/src/Cardano/Api/Block.hs
@@ -358,6 +358,24 @@ instance Ord ChainPoint where
   compare _ ChainPointAtGenesis = GT
   compare (ChainPoint sn _) (ChainPoint sn' _) = compare sn sn'
 
+instance ToJSON ChainPoint where
+  toJSON = \case
+    ChainPointAtGenesis -> object ["tag" .= String "ChainPointAtGenesis"]
+    ChainPoint slot blockHash ->
+      object
+        [ "tag" .= String "ChainPoint"
+        , "slot" .= toJSON slot
+        , "blockHash" .= toJSON blockHash
+        ]
+
+instance FromJSON ChainPoint where
+  parseJSON = withObject "ChainPoint" $ \o -> do
+    tag <- o .: "tag"
+    case tag :: Text of
+      "ChainPointAtGenesis" -> pure ChainPointAtGenesis
+      "ChainPoint" -> ChainPoint <$> o .: "slot" <*> o .: "blockHash"
+      _ -> fail "Expected tag to be ChainPointAtGenesis | ChainPoint"
+
 toConsensusPointInMode :: ConsensusMode mode
                        -> ChainPoint
                        -> Consensus.Point (ConsensusBlockForMode mode)

From 3b01002f548a7fdbe847c7997cdcba20edb75c90 Mon Sep 17 00:00:00 2001
From: Sebastian Nagel <sebastian.nagel@ncoding.at>
Date: Wed, 30 Nov 2022 12:23:38 +0100
Subject: [PATCH 2/2] Add LambdaCase pragma

---
 cardano-api/src/Cardano/Api/Block.hs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/cardano-api/src/Cardano/Api/Block.hs b/cardano-api/src/Cardano/Api/Block.hs
index 0c557deb214..51917d04b49 100644
--- a/cardano-api/src/Cardano/Api/Block.hs
+++ b/cardano-api/src/Cardano/Api/Block.hs
@@ -2,6 +2,7 @@
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE GADTs #-}
+{-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE NamedFieldPuns #-}
 {-# LANGUAGE PatternSynonyms #-}
 {-# LANGUAGE RankNTypes #-}