Introduce NetworkVersions module and parse networks.json

Signed-off-by: Sasha Bogicevic <[email protected]>

Author: v0d1ch

hydra-node/hydra-node.cabal

@@ -86,6 +86,7 @@ library
     Hydra.Network.Authenticate
     Hydra.Network.Etcd
     Hydra.Network.Message
+    Hydra.NetworkVersions
     Hydra.Node
     Hydra.Node.DepositPeriod
     Hydra.Node.EmbedTH

hydra-node/src/Hydra/NetworkVersions.hs

@@ -0,0 +1,57 @@
+{-# LANGUAGE DerivingStrategies #-}
+{-# LANGUAGE TemplateHaskell #-}
+
+module Hydra.NetworkVersions where
+
+import Hydra.Prelude hiding (encodeUtf8)
+
+import Control.Lens ((^@..))
+import Data.Aeson (Value (..))
+import Data.Aeson.Key qualified as Key
+import Data.Aeson.KeyMap qualified as KeyMap
+import Data.Aeson.Lens (members, _Object)
+import Data.FileEmbed (embedFile)
+import Data.List qualified as List
+import Data.Text (splitOn)
+import Data.Text.Encoding (encodeUtf8)
+import Hydra.Cardano.Api (NetworkId (..), NetworkMagic (..), TxId, deserialiseFromRawBytesHex)
+
+networkVersionsFile :: ByteString
+networkVersionsFile = $(embedFile "./../networks.json")
+
+data ParseError
+  = ExpectedStringForTxId
+  | FailedToParseTextToTxId Text
+  | UnknownNetwork Text
+  deriving stock (Eq, Show)
+
+instance Exception ParseError
+
+parseNetworkVersions :: ByteString -> IO [(NetworkId, [TxId])]
+parseNetworkVersions bs = do
+  let info = bs ^@.. members . _Object
+  fmap catMaybes <$> forM info $ \(n, t) -> do
+    let textKey = Key.toText n
+    case textKey of
+      "mainnet" -> do
+        txids <- getLastTxId t
+        pure $ Just (Mainnet, txids)
+      "preview" -> do
+        txids <- getLastTxId t
+        pure $ Just (Testnet $ NetworkMagic 2, txids)
+      "preprod" -> do
+        txids <- getLastTxId t
+        pure $ Just (Testnet $ NetworkMagic 1, txids)
+      _ -> pure Nothing
+ where
+  getLastTxId t = do
+    lastTxIds <-
+      case List.last $ KeyMap.elems t of
+        String s -> pure s
+        _ -> throwIO ExpectedStringForTxId
+    mapM parseToTxId (splitOn "," lastTxIds)
+
+  parseToTxId textTxId = do
+    case deserialiseFromRawBytesHex $ encodeUtf8 textTxId of
+      Left _ -> throwIO $ FailedToParseTextToTxId textTxId
+      Right txid -> pure txid