Homework2.hs

{-# LANGUAGE DataKinds           #-}
{-# LANGUAGE DeriveAnyClass      #-}
{-# LANGUAGE DeriveGeneric       #-}
{-# LANGUAGE FlexibleContexts    #-}
{-# LANGUAGE NoImplicitPrelude   #-}
{-# LANGUAGE OverloadedStrings   #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE TemplateHaskell     #-}
{-# LANGUAGE TypeApplications    #-}
{-# LANGUAGE TypeFamilies        #-}
{-# LANGUAGE TypeOperators       #-}

{-# OPTIONS_GHC -fno-warn-unused-imports #-}

module Week02.Homework2 where

import           Control.Monad        hiding (fmap)
import           Data.Aeson           (FromJSON, ToJSON)
import           Data.Map             as Map
import           Data.Text            (Text)
import           Data.Void            (Void)
import           GHC.Generics         (Generic)
import           Plutus.Contract
import qualified PlutusTx
import           PlutusTx.Prelude     hiding (Semigroup(..), unless)
import           Ledger               hiding (singleton)
import           Ledger.Constraints   as Constraints
import qualified Ledger.Typed.Scripts as Scripts
import           Ledger.Ada           as Ada
import           Playground.Contract  (printJson, printSchemas, ensureKnownCurrencies, stage, ToSchema)
import           Playground.TH        (mkKnownCurrencies, mkSchemaDefinitions)
import           Playground.Types     (KnownCurrency (..))
import           Prelude              (IO, Semigroup (..), String, undefined)
import           Text.Printf          (printf)

data MyRedeemer = MyRedeemer
    { flag1 :: Bool
    , flag2 :: Bool
    } deriving (Generic, FromJSON, ToJSON, ToSchema)

PlutusTx.unstableMakeIsData ''MyRedeemer

{-# INLINABLE mkValidator #-}
-- This should validate if and only if the two Booleans in the redeemer are equal!
mkValidator :: () -> MyRedeemer -> ScriptContext -> Bool
mkValidator _ r _ = case r of 
    MyRedeemer { flag1 = True, flag2 = True } -> True
    MyRedeemer { flag1 = False, flag2 = False } -> True
    _ -> traceIfFalse "Both flags in redeemer must match." False

data Typed
instance Scripts.ValidatorTypes Typed where
  type instance DatumType Typed = ()
  type instance RedeemerType Typed = MyRedeemer

typedValidator :: Scripts.TypedValidator Typed
typedValidator = Scripts.mkTypedValidator @Typed
    $$(PlutusTx.compile [|| mkValidator ||])
    $$(PlutusTx.compile [|| wrap ||])
  where
    wrap = Scripts.wrapValidator @() @MyRedeemer

validator :: Validator
validator = Scripts.validatorScript typedValidator

valHash :: Ledger.ValidatorHash
valHash = Scripts.validatorHash typedValidator

scrAddress :: Ledger.Address
scrAddress = scriptAddress validator

type GiftSchema =
            Endpoint "give" Integer
        .\/ Endpoint "grab" MyRedeemer

give :: AsContractError e => Integer -> Contract w s e ()
give amount = do
    let tx = mustPayToTheScript () $ Ada.lovelaceValueOf amount
    ledgerTx <- submitTxConstraints typedValidator tx
    void $ awaitTxConfirmed $ getCardanoTxId ledgerTx
    logInfo @String $ printf "made a gift of %d lovelace" amount

grab :: forall w s e. AsContractError e => MyRedeemer -> Contract w s e ()
grab r = do
    utxos <- utxosAt scrAddress
    let orefs   = fst <$> Map.toList utxos
        lookups = Constraints.unspentOutputs utxos      <>
                  Constraints.otherScript validator
        tx :: TxConstraints Void Void
        tx      = mconcat [mustSpendScriptOutput oref $ Redeemer $ PlutusTx.toBuiltinData r | oref <- orefs]
    ledgerTx <- submitTxConstraintsWith @Void lookups tx
    void $ awaitTxConfirmed $ getCardanoTxId ledgerTx
    logInfo @String $ "collected gifts"

endpoints :: Contract () GiftSchema Text ()
endpoints = awaitPromise (give' `select` grab') >> endpoints
  where
    give' = endpoint @"give" give
    grab' = endpoint @"grab" grab

mkSchemaDefinitions ''GiftSchema

mkKnownCurrencies []