[FR] - `cardano-api`'s `TxId` from `GenTxId blk`

[deepfire]

Internal

Describe the feature you'd like

Because the transaction generator runs a TxSubmission protocol peer, it has to use its type language, which includes GenTxId blk. Internally the generator uses cardano-api's TxId type.

So we need a conversion function like fromGenTxId :: Mode mode era -> GenTxId (BlockOf mode) -> TxId, paired with a BlockOf mode function, similarly to #1853 & #1861. Note that the mode-indexed GADT Mode doesn't exist in cardano-api (but does in the generator) -- some tagged GADT is needed to both bind the mode (so the block type can be computed by BlockOf) and to dispatch in the implementation.

This is currently implemented in the generator as follows:

fromGenTxId ModeShelley{}
  (HFC.project' (Proxy @(WrapGenTxId ShelleyBlock)) -> x) = shelleyTxId x
fromGenTxId ModeByron{}
  (HFC.project' (Proxy @(WrapGenTxId Byron.ByronBlock)) -> (Byron.ByronTxId i)) = fromByronTxId i
fromGenTxId ModeCardanoShelley{} (GenTxIdShelley x)  = shelleyTxId x
fromGenTxId ModeCardanoByron{}   (GenTxIdByron   (Byron.ByronTxId i))                           = fromByronTxId i

shelleyTxId :: GenTxId (BlockOf ShelleyMode) -> TxId
shelleyTxId (Shelley.ShelleyTxId (ShelleyLedger.TxId i)) = TxId (Crypto.castHash i)

fromByronTxId :: Byron.TxId -> TxId
fromByronTxId =
  maybe (error "Failed to convert Byron txid.") TxId
  . Crypto.hashFromBytes . Byron.hashToBytes

[Jimbo4350]

Closing this. If this is still relevant please re-open.