{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE EmptyDataDeriving #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE TypeFamilies #-}

module Cardano.Protocol.TPraos.Rules.Updn (
  UPDN,
  UpdnEnv (..),
  UpdnState (..),
  PredicateFailure,
  UpdnPredicateFailure,
) where

import Cardano.Ledger.BaseTypes
import Cardano.Ledger.Slot
import Cardano.Protocol.Crypto
import Control.Monad.Trans.Reader (asks)
import Control.State.Transition
import GHC.Generics (Generic)
import NoThunks.Class (NoThunks (..))

data UPDN c

newtype UpdnEnv
  = -- | New nonce
    UpdnEnv
      Nonce

data UpdnState = UpdnState Nonce Nonce
  deriving (Int -> UpdnState -> ShowS
[UpdnState] -> ShowS
UpdnState -> String
(Int -> UpdnState -> ShowS)
-> (UpdnState -> String)
-> ([UpdnState] -> ShowS)
-> Show UpdnState
forall a.
(Int -> a -> ShowS) -> (a -> String) -> ([a] -> ShowS) -> Show a
$cshowsPrec :: Int -> UpdnState -> ShowS
showsPrec :: Int -> UpdnState -> ShowS
$cshow :: UpdnState -> String
show :: UpdnState -> String
$cshowList :: [UpdnState] -> ShowS
showList :: [UpdnState] -> ShowS
Show, UpdnState -> UpdnState -> Bool
(UpdnState -> UpdnState -> Bool)
-> (UpdnState -> UpdnState -> Bool) -> Eq UpdnState
forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
$c== :: UpdnState -> UpdnState -> Bool
== :: UpdnState -> UpdnState -> Bool
$c/= :: UpdnState -> UpdnState -> Bool
/= :: UpdnState -> UpdnState -> Bool
Eq)

data UpdnPredicateFailure c -- No predicate failures
  deriving ((forall x.
 UpdnPredicateFailure c -> Rep (UpdnPredicateFailure c) x)
-> (forall x.
    Rep (UpdnPredicateFailure c) x -> UpdnPredicateFailure c)
-> Generic (UpdnPredicateFailure c)
forall x. Rep (UpdnPredicateFailure c) x -> UpdnPredicateFailure c
forall x. UpdnPredicateFailure c -> Rep (UpdnPredicateFailure c) x
forall a.
(forall x. a -> Rep a x) -> (forall x. Rep a x -> a) -> Generic a
forall c x.
Rep (UpdnPredicateFailure c) x -> UpdnPredicateFailure c
forall c x.
UpdnPredicateFailure c -> Rep (UpdnPredicateFailure c) x
$cfrom :: forall c x.
UpdnPredicateFailure c -> Rep (UpdnPredicateFailure c) x
from :: forall x. UpdnPredicateFailure c -> Rep (UpdnPredicateFailure c) x
$cto :: forall c x.
Rep (UpdnPredicateFailure c) x -> UpdnPredicateFailure c
to :: forall x. Rep (UpdnPredicateFailure c) x -> UpdnPredicateFailure c
Generic, Int -> UpdnPredicateFailure c -> ShowS
[UpdnPredicateFailure c] -> ShowS
UpdnPredicateFailure c -> String
(Int -> UpdnPredicateFailure c -> ShowS)
-> (UpdnPredicateFailure c -> String)
-> ([UpdnPredicateFailure c] -> ShowS)
-> Show (UpdnPredicateFailure c)
forall c. Int -> UpdnPredicateFailure c -> ShowS
forall c. [UpdnPredicateFailure c] -> ShowS
forall c. UpdnPredicateFailure c -> String
forall a.
(Int -> a -> ShowS) -> (a -> String) -> ([a] -> ShowS) -> Show a
$cshowsPrec :: forall c. Int -> UpdnPredicateFailure c -> ShowS
showsPrec :: Int -> UpdnPredicateFailure c -> ShowS
$cshow :: forall c. UpdnPredicateFailure c -> String
show :: UpdnPredicateFailure c -> String
$cshowList :: forall c. [UpdnPredicateFailure c] -> ShowS
showList :: [UpdnPredicateFailure c] -> ShowS
Show, UpdnPredicateFailure c -> UpdnPredicateFailure c -> Bool
(UpdnPredicateFailure c -> UpdnPredicateFailure c -> Bool)
-> (UpdnPredicateFailure c -> UpdnPredicateFailure c -> Bool)
-> Eq (UpdnPredicateFailure c)
forall c. UpdnPredicateFailure c -> UpdnPredicateFailure c -> Bool
forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
$c== :: forall c. UpdnPredicateFailure c -> UpdnPredicateFailure c -> Bool
== :: UpdnPredicateFailure c -> UpdnPredicateFailure c -> Bool
$c/= :: forall c. UpdnPredicateFailure c -> UpdnPredicateFailure c -> Bool
/= :: UpdnPredicateFailure c -> UpdnPredicateFailure c -> Bool
Eq)

instance NoThunks (UpdnPredicateFailure c)

newtype UpdnEvent c = NewEpoch EpochNo

instance
  Crypto c =>
  STS (UPDN c)
  where
  type State (UPDN c) = UpdnState
  type Signal (UPDN c) = SlotNo
  type Environment (UPDN c) = UpdnEnv
  type BaseM (UPDN c) = ShelleyBase
  type PredicateFailure (UPDN c) = UpdnPredicateFailure c
  type Event (UPDN c) = UpdnEvent c
  initialRules :: [InitialRule (UPDN c)]
initialRules =
    [ UpdnState -> F (Clause (UPDN c) 'Initial) UpdnState
forall a. a -> F (Clause (UPDN c) 'Initial) a
forall (f :: * -> *) a. Applicative f => a -> f a
pure
        ( Nonce -> Nonce -> UpdnState
UpdnState
            Nonce
initialNonce
            Nonce
initialNonce
        )
    ]
    where
      initialNonce :: Nonce
initialNonce = Word64 -> Nonce
mkNonceFromNumber Word64
0
  transitionRules :: [TransitionRule (UPDN c)]
transitionRules = [TransitionRule (UPDN c)
forall c. Crypto c => TransitionRule (UPDN c)
updTransition]

updTransition :: Crypto c => TransitionRule (UPDN c)
updTransition :: forall c. Crypto c => TransitionRule (UPDN c)
updTransition = do
  TRC (UpdnEnv eta, UpdnState eta_v eta_c, s) <- Rule (UPDN c) 'Transition (RuleContext 'Transition (UPDN c))
F (Clause (UPDN c) 'Transition) (TRC (UPDN c))
forall sts (rtype :: RuleType).
Rule sts rtype (RuleContext rtype sts)
judgmentContext
  ei <- liftSTS $ asks epochInfoPure
  sp <- liftSTS $ asks stabilityWindow
  let curEpochNo = HasCallStack => EpochInfo Identity -> SlotNo -> EpochNo
EpochInfo Identity -> SlotNo -> EpochNo
epochInfoEpoch EpochInfo Identity
ei SlotNo
Signal (UPDN c)
s
      nextEpochNo = EpochNo -> EpochInterval -> EpochNo
addEpochInterval EpochNo
curEpochNo (Word32 -> EpochInterval
EpochInterval Word32
1)
      firstSlotNextEpoch = HasCallStack => EpochInfo Identity -> EpochNo -> SlotNo
EpochInfo Identity -> EpochNo -> SlotNo
epochInfoFirst EpochInfo Identity
ei EpochNo
nextEpochNo
  tellEvent $ NewEpoch nextEpochNo
  pure $
    UpdnState
      (eta_v ⭒ eta)
      ( if s +* Duration sp < firstSlotNextEpoch
          then eta_v ⭒ eta
          else eta_c
      )