agora/agora/Agora/Proposal/Scripts.hs
2022-09-13 20:24:32 +08:00

747 lines
26 KiB
Haskell

{- |
Module : Agora.Proposal.Scripts
Maintainer : emi@haskell.fyi
Description: Plutus Scripts for Proposals.
Plutus Scripts for Proposals.
-}
module Agora.Proposal.Scripts (
proposalValidator,
proposalPolicy,
) where
import Agora.Credential (authorizationContext, pauthorizedBy)
import Agora.Proposal (
PProposalDatum (PProposalDatum),
PProposalRedeemer (PAdvanceProposal, PCosign, PUnlock, PVote),
PProposalStatus (PDraft, PFinished, PLocked, PVotingReady),
PProposalVotes (PProposalVotes),
ProposalStatus (Draft, Finished, Locked, VotingReady),
pretractVotes,
pwinner',
)
import Agora.Proposal.Time (
currentProposalTime,
isDraftPeriod,
isExecutionPeriod,
isLockingPeriod,
isVotingPeriod,
)
import Agora.Scripts (AgoraScripts, governorSTSymbol, proposalSTSymbol, stakeSTAssetClass)
import Agora.Stake (
PProposalLock (PVoted),
PStakeDatum (PStakeDatum),
pextractVoteOption,
pgetStakeRole,
pisCreator,
pisIrrelevant,
pisPureCreator,
pisVoter,
)
import Agora.Utils (
plistEqualsBy,
pltAsData,
)
import Plutarch.Api.V1 (PCredential)
import Plutarch.Api.V1.AssocMap (plookup)
import Plutarch.Api.V2 (
PMintingPolicy,
PScriptContext (PScriptContext),
PScriptPurpose (PMinting, PSpending),
PTxInInfo,
PTxInfo (PTxInfo),
PTxOut,
PValidator,
)
import Plutarch.Extra.AssetClass (passetClass, passetClassValueOf)
import Plutarch.Extra.Category (PCategory (pidentity))
import Plutarch.Extra.Comonad (pextract)
import Plutarch.Extra.Field (pletAll, pletAllC)
import Plutarch.Extra.Functor (pfmap)
import Plutarch.Extra.List (pfirstJust, pisUniq', pmergeBy, pmsort)
import Plutarch.Extra.Map (pupdate)
import Plutarch.Extra.Maybe (
passertPJust,
pfromJust,
pfromMaybe,
pisJust,
pjust,
pnothing,
)
import Plutarch.Extra.Record (mkRecordConstr, (.&), (.=))
import Plutarch.Extra.ScriptContext (
pfindTxInByTxOutRef,
pfromOutputDatum,
pisTokenSpent,
ptryFromOutputDatum,
)
import Plutarch.Extra.TermCont (
pguardC,
pletC,
pletFieldsC,
pmatchC,
ptryFromC,
)
import Plutarch.Extra.Value (psymbolValueOf)
import Plutarch.SafeMoney (PDiscrete (PDiscrete))
import Plutarch.Unsafe (punsafeCoerce)
import PlutusLedgerApi.V1.Value (AssetClass (AssetClass))
{- | Policy for Proposals.
== What this policy does
=== For minting:
- Governor is happy with mint.
* The governor must do most of the checking for the validity of the
transaction. For example, the governor must check that the datum
is correct, and that the ST is correctly paid to the right validator.
- Exactly 1 token is minted.
=== For burning:
- This policy cannot be burned.
@since 0.1.0
-}
proposalPolicy ::
-- | The assetclass of GST, see 'Agora.Governor.Scripts.governorPolicy'.
AssetClass ->
ClosedTerm PMintingPolicy
proposalPolicy (AssetClass (govCs, govTn)) =
plam $ \_redeemer ctx' -> unTermCont $ do
PScriptContext ctx' <- pmatchC ctx'
ctx <- pletAllC ctx'
PTxInfo txInfo' <- pmatchC $ pfromData ctx.txInfo
txInfo <- pletFieldsC @'["inputs", "mint"] txInfo'
PMinting ownSymbol' <- pmatchC $ pfromData ctx.purpose
let mintedProposalST =
passetClassValueOf
# pfromData txInfo.mint
# (passetClass # (pfield @"_0" # ownSymbol') # pconstant "")
pguardC "Governance state-thread token must move" $
pisTokenSpent
# (passetClass # pconstant govCs # pconstant govTn)
# txInfo.inputs
pguardC "Minted exactly one proposal ST" $
mintedProposalST #== 1
pure $ popaque (pconstant ())
{- | Validation context for redeemers which witness multiple stake in the reference
inputs.
@since 1.0.0
-}
data PWitnessMultipleStakeContext (s :: S) = PWitnessMultipleStakeContext
{ totalAmount :: Term s PInteger
, orderedOwners :: Term s (PList PCredential)
}
deriving stock
( -- | @since 1.0.0
Generic
)
deriving anyclass
( -- | @since 1.0.0
PlutusType
)
-- | @since 1.0.0
instance DerivePlutusType PWitnessMultipleStakeContext where
type DPTStrat _ = PlutusTypeScott
{- | Validation context for redeemers which need to modify a single stake.
@since 1.0.0
-}
data PSpendSingleStakeContext (s :: S) = PSpendSingleStakeContext
{ inputStake :: Term s PStakeDatum
, outputStake :: Term s PStakeDatum
}
deriving stock
( -- | @since 1.0.0
Generic
)
deriving anyclass
( -- | @since 1.0.0
PlutusType
)
-- | @since 1.0.0
instance DerivePlutusType PSpendSingleStakeContext where
type DPTStrat _ = PlutusTypeScott
{- | The validator for Proposals.
The documentation for various of the redeemers lives at 'Agora.Proposal.ProposalRedeemer'.
== What this validator does
=== Voting/unlocking
When voting and unlocking, the proposal must witness a state transition
occuring in the relevant Stake. This transition must place a lock on
the stake that is tagged with the right 'Agora.Proposal.ResultTag', and 'Agora.Proposal.ProposalId'.
=== Periods
Most redeemers are time-sensitive.
A list of all time-sensitive redeemers and their requirements:
- 'Agora.Proposal.Vote' can only be used when both the status is in 'Agora.Proposal.VotingReady',
and 'Agora.Proposal.Time.isVotingPeriod' is true.
- 'Agora.Proposal.Cosign' can only be used when both the status is in 'Agora.Proposal.Draft',
and 'Agora.Proposal.Time.isDraftPeriod' is true.
- 'Agora.Proposal.AdvanceProposal' can only be used when the status can be advanced
(see 'Agora.Proposal.AdvanceProposal' docs).
- 'Agora.Proposal.Unlock' is always valid.
@since 0.1.0
-}
proposalValidator ::
-- | Lazy precompiled scripts.
AgoraScripts ->
-- | See 'Agora.Governor.Governor.maximumCosigners'.
Integer ->
ClosedTerm PValidator
proposalValidator as maximumCosigners =
plam $ \datum redeemer ctx' -> unTermCont $ do
PScriptContext ctx' <- pmatchC ctx'
ctx <- pletFieldsC @'["txInfo", "purpose"] ctx'
txInfo <- pletC $ pfromData ctx.txInfo
PTxInfo txInfo' <- pmatchC txInfo
txInfoF <-
pletFieldsC
@'[ "referenceInputs"
, "inputs"
, "outputs"
, "mint"
, "datums"
, "signatories"
, "validRange"
]
txInfo'
PSpending ((pfield @"_0" #) -> txOutRef) <- pmatchC $ pfromData ctx.purpose
PJust ((pfield @"resolved" #) -> txOut) <-
pmatchC $
pfindTxInByTxOutRef
# txOutRef
# txInfoF.inputs
txOutF <- pletFieldsC @'["address", "value"] $ txOut
proposalDatum <- pfromData . fst <$> ptryFromC @(PAsData PProposalDatum) datum
proposalRedeemer <- fst <$> ptryFromC @PProposalRedeemer redeemer
proposalF <- pletAllC $ pto proposalDatum
ownAddress <- pletC $ txOutF.address
thresholdsF <- pletAllC proposalF.thresholds
currentStatus <- pletC $ pfromData $ proposalF.status
let stCurrencySymbol = pconstant $ proposalSTSymbol as
authorizedBy <- pletC $ pauthorizedBy # authorizationContext txInfoF
currentTime <- pletC $ currentProposalTime # txInfoF.validRange
-- Own output is an output that
-- * is sent to the address of the proposal validator
-- * has an PST
-- * has the same proposal id as the proposal input
--
-- We match the proposal id here so that we can support multiple
-- proposal inputs in one thansaction.
proposalOut <-
pletC $
passertPJust
# "Own output should be present"
#$ pfirstJust
# plam
( flip pletAll $ \outputF ->
let isProposalUTxO =
foldl1
(#&&)
[ ptraceIfFalse "Own by proposal validator" $
outputF.address #== ownAddress
, ptraceIfFalse "Has proposal ST" $
psymbolValueOf # stCurrencySymbol # outputF.value #== 1
]
handleProposalUTxO = unTermCont $ do
-- Using inline datum to avoid O(n^2) lookup.
datum <-
pletC $
pfromData $
pfromOutputDatum @(PAsData PProposalDatum)
# outputF.datum
# txInfoF.datums
pure $
pif
( pfield @"proposalId" # pto datum
#== proposalF.proposalId
)
(pjust # datum)
pnothing
in pif
isProposalUTxO
handleProposalUTxO
pnothing
)
# pfromData txInfoF.outputs
proposalUnchanged <- pletC $ proposalOut #== proposalDatum
proposalOutStatus <-
pletC $
pfromData $
pfield @"status" # pto proposalOut
onlyStatusChanged <-
pletC $
-- Only the status of proposals is updated.
proposalOut
#== mkRecordConstr
PProposalDatum
( #proposalId .= proposalF.proposalId
.& #effects .= proposalF.effects
.& #status .= pdata proposalOutStatus
.& #cosigners .= proposalF.cosigners
.& #thresholds .= proposalF.thresholds
.& #votes .= proposalF.votes
.& #timingConfig .= proposalF.timingConfig
.& #startingTime .= proposalF.startingTime
)
--------------------------------------------------------------------------
-- Find the stake inputs/outputs by SST.
getStakeDatum :: Term _ (PTxOut :--> PMaybe PStakeDatum) <-
pletC $
plam $
flip (pletFields @'["value", "datum"]) $ \txOutF ->
let AssetClass (stakeSym, _) = stakeSTAssetClass as
isStakeUTxO =
psymbolValueOf
# pconstant stakeSym
# txOutF.value
#== 1
stake =
pfromData $
pfromJust
-- Use inline datum to avoid extra map lookup.
#$ ptryFromOutputDatum @(PAsData PStakeDatum)
# txOutF.datum
# txInfoF.datums
in pif isStakeUTxO (pjust # stake) pnothing
witnessStakes' ::
Term
s
( (PWitnessMultipleStakeContext :--> PUnit) :--> PUnit
) <-
pletC $
let updateCtx = plam $ \ctx' stake -> unTermCont $ do
ctxF <- pmatchC ctx'
stakeF <-
pletFieldsC @'["stakedAmount", "owner"] $
pto stake
pure $
pcon $
PWitnessMultipleStakeContext
{ totalAmount =
ctxF.totalAmount
+ punsafeCoerce
(pfromData stakeF.stakedAmount)
, orderedOwners =
pcons # stakeF.owner
# ctxF.orderedOwners
}
f :: Term _ (_ :--> PTxInInfo :--> _)
f = plam $ \ctx' ((pfield @"resolved" #) -> txOut) ->
pfromMaybe # ctx'
#$ (pfmap # (updateCtx # ctx') #$ getStakeDatum # txOut)
sortOwners = plam $
flip pmatch $ \ctxF ->
pcon $
PWitnessMultipleStakeContext
{ totalAmount = ctxF.totalAmount
, orderedOwners = pmsort # ctxF.orderedOwners
}
ctx =
sortOwners
#$ pfoldl
# f
# pcon (PWitnessMultipleStakeContext 0 pnil)
# txInfoF.referenceInputs
in plam (# ctx)
let witnessStakes ::
( PWitnessMultipleStakeContext _ ->
TermCont _ ()
) ->
Term _ POpaque
witnessStakes c = popaque $
witnessStakes' #$ plam $ \sctxF ->
unTermCont $ pmatchC sctxF >>= c >> pure (pconstant ())
spendSingleStake' ::
Term
s
((PSpendSingleStakeContext :--> PUnit) :--> PUnit) <-
pletC $
let singleInput ::
Term
_
( PMaybe PStakeDatum
:--> PTxInInfo
:--> PMaybe PStakeDatum
)
singleInput = plam $ \l ((pfield @"resolved" #) -> txOut) ->
unTermCont $ do
lF <- pmatchC l
t <- pletC $ getStakeDatum # txOut
tF <- pmatchC t
pure $ case (lF, tF) of
(PJust _, PJust _) ->
ptraceError "Can only deal with one stake"
(PNothing, _) -> t
(_, PNothing) -> l
stakeInput =
passertPJust # "Stake input not found"
#$ pfoldl # singleInput # pnothing # txInfoF.inputs
stakeOutput =
pfromJust
#$ pfirstJust # getStakeDatum # txInfoF.outputs
ctx = pcon $ PSpendSingleStakeContext stakeInput stakeOutput
in plam (# ctx)
let spendSingleStake ::
( PSpendSingleStakeContext _ ->
TermCont _ ()
) ->
Term _ POpaque
spendSingleStake c = popaque $
spendSingleStake' #$ plam $ \sctx ->
unTermCont $ pmatchC sctx >>= c >> pure (pconstant ())
pure $
popaque $
pmatch proposalRedeemer $ \case
PCosign r -> witnessStakes $ \sctxF -> do
pguardC "Should be in draft state" $
currentStatus #== pconstant Draft
newSigs <- pletC $ pfield @"newCosigners" # r
pguardC "Signed by all new cosigners" $
pall # plam ((authorizedBy #) . pfromData) # newSigs
updatedSigs <-
pletC $
pmergeBy # pltAsData
# newSigs
# proposalF.cosigners
pguardC "Less cosigners than maximum limit" $
plength # updatedSigs #< pconstant maximumCosigners
pguardC "Cosigners are unique" $
pisUniq' # updatedSigs
pguardC "All new cosigners are witnessed by their Stake datums" $
plistEqualsBy
# plam (\x (pfromData -> y) -> x #== y)
# sctxF.orderedOwners
# newSigs
let expectedDatum =
mkRecordConstr
PProposalDatum
( #proposalId .= proposalF.proposalId
.& #effects .= proposalF.effects
.& #status .= proposalF.status
.& #cosigners .= pdata updatedSigs
.& #thresholds .= proposalF.thresholds
.& #votes .= proposalF.votes
.& #timingConfig .= proposalF.timingConfig
.& #startingTime .= proposalF.startingTime
)
pguardC "Signatures are correctly added to cosignature list" $
proposalOut #== expectedDatum
----------------------------------------------------------------------
PVote r -> spendSingleStake $ \sctxF -> do
stakeInF <- pletAllC $ pto sctxF.inputStake
pguardC "Input proposal must be in VotingReady state" $
currentStatus #== pconstant VotingReady
pguardC "Proposal time should be wthin the voting period" $
isVotingPeriod # proposalF.timingConfig
# proposalF.startingTime
#$ pfromJust
# currentTime
-- Ensure the transaction is voting to a valid 'ResultTag'(outcome).
PProposalVotes voteMap <- pmatchC proposalF.votes
voteFor <- pletC $ pfromData $ pfield @"resultTag" # r
pguardC "Vote option should be valid" $
pisJust #$ plookup # voteFor # voteMap
-- Ensure that no lock with the current proposal id has been put on the stake.
pguardC "Same stake shouldn't vote on the same proposal twice" $
pnot #$ pisVoter #$ pgetStakeRole # proposalF.proposalId # stakeInF.lockedBy
let -- The amount of new votes should be the 'stakedAmount'.
-- Update the vote counter of the proposal, and leave other stuff as is.
expectedNewVotes = pmatch (pfromData proposalF.votes) $ \(PProposalVotes m) ->
pcon $
PProposalVotes $
pupdate
# plam
( \votes -> unTermCont $ do
PDiscrete v <- pmatchC stakeInF.stakedAmount
pure $ pcon $ PJust $ votes + (pextract # v)
)
# voteFor
# m
expectedProposalOut =
mkRecordConstr
PProposalDatum
( #proposalId .= proposalF.proposalId
.& #effects .= proposalF.effects
.& #status .= proposalF.status
.& #cosigners .= proposalF.cosigners
.& #thresholds .= proposalF.thresholds
.& #votes .= pdata expectedNewVotes
.& #timingConfig .= proposalF.timingConfig
.& #startingTime .= proposalF.startingTime
)
pguardC "Output proposal should be valid" $ proposalOut #== expectedProposalOut
-- We validate the output stake datum here as well: We need the vote option
-- to create a valid 'ProposalLock', however the vote option is encoded
-- in the proposal redeemer, which is invisible for the stake validator.
let newProposalLock =
mkRecordConstr
PVoted
( #votedOn .= proposalF.proposalId
.& #votedFor .= pdata voteFor
)
-- Prepend the new lock to existing locks
expectedProposalLocks =
pcons
# pdata newProposalLock
# pfromData stakeInF.lockedBy
expectedStakeOut =
mkRecordConstr
PStakeDatum
( #stakedAmount .= stakeInF.stakedAmount
.& #owner .= stakeInF.owner
.& #delegatedTo .= stakeInF.delegatedTo
.& #lockedBy .= pdata expectedProposalLocks
)
pguardC "Output stake should be locked by the proposal" $ expectedStakeOut #== sctxF.outputStake
----------------------------------------------------------------------
PUnlock _ -> spendSingleStake $ \sctxF -> do
stakeInF <- pletAllC $ pto sctxF.inputStake
stakeRole <- pletC $ pgetStakeRole # proposalF.proposalId # stakeInF.lockedBy
pguardC "Stake input should be relevant" $
pnot #$ pisIrrelevant # stakeRole
retractCount <-
pletC $
pmatch stakeInF.stakedAmount $ \(PDiscrete v) -> pextract # v
-- The votes can only change when the proposal still allows voting.
let shouldUpdateVotes =
currentStatus #== pconstant VotingReady
#&& pnot # (pisPureCreator # stakeRole)
allowRemovingCreatorLock =
currentStatus #== pconstant Finished
isCreator = pisCreator # stakeRole
-- If the stake has been used for creating the proposal,
-- the creator lock can only be removed when the proposal
-- is finished.
--
-- In other cases, all the locks related to this
-- proposal should be removed.
validateOutputLocks = plam $ \locks ->
plet
( pgetStakeRole # proposalF.proposalId # locks
)
$ \newStakeRole ->
pif
(isCreator #&& pnot # allowRemovingCreatorLock)
(pisPureCreator # newStakeRole)
(pisIrrelevant # newStakeRole)
pguardC "Proposal output correct" $
pif
shouldUpdateVotes
( let -- Remove votes and leave other parts of the proposal as it.
expectedVotes = pretractVotes # (pextractVoteOption # stakeRole) # retractCount # proposalF.votes
expectedProposalOut =
mkRecordConstr
PProposalDatum
( #proposalId .= proposalF.proposalId
.& #effects .= proposalF.effects
.& #status .= proposalF.status
.& #cosigners .= proposalF.cosigners
.& #thresholds .= proposalF.thresholds
.& #votes .= pdata expectedVotes
.& #timingConfig .= proposalF.timingConfig
.& #startingTime .= proposalF.startingTime
)
in ptraceIfFalse "Update votes" $
expectedProposalOut #== proposalOut
)
-- No change to the proposal is allowed.
$ ptraceIfFalse "Proposal unchanged" proposalUnchanged
-- At last, we ensure that all locks belong to this proposal will be removed.
stakeOutputLocks <- pletC $ pfield @"lockedBy" # pto sctxF.outputStake
let templateStakeOut =
mkRecordConstr
PStakeDatum
( #stakedAmount .= stakeInF.stakedAmount
.& #owner .= stakeInF.owner
.& #delegatedTo .= stakeInF.delegatedTo
.& #lockedBy .= pdata stakeOutputLocks
)
pguardC "Only locks updated in the output stake" $
templateStakeOut #== sctxF.outputStake
pguardC "All relevant locks removed from the stake" $
validateOutputLocks # stakeOutputLocks
----------------------------------------------------------------------
PAdvanceProposal _ -> unTermCont $ do
currentTime' <- pletC $ pfromJust # currentTime
let inDraftPeriod = isDraftPeriod # proposalF.timingConfig # proposalF.startingTime # currentTime'
inVotingPeriod = isVotingPeriod # proposalF.timingConfig # proposalF.startingTime # currentTime'
inExecutionPeriod = isExecutionPeriod # proposalF.timingConfig # proposalF.startingTime # currentTime'
inLockedPeriod <- pletC $ isLockingPeriod # proposalF.timingConfig # proposalF.startingTime # currentTime'
pguardC "Only status changes in the output proposal" onlyStatusChanged
pure $
pmatch currentStatus $ \case
PDraft ->
witnessStakes $ \sctxF -> do
let notTooLate = inDraftPeriod
pmatchC notTooLate >>= \case
PTrue -> do
pguardC "More cosigns than minimum amount" $
punsafeCoerce (pfromData thresholdsF.vote) #< sctxF.totalAmount
pguardC "All new cosigners are witnessed by their Stake datums" $
plistEqualsBy
# plam (\x (pfromData -> y) -> x #== y)
# sctxF.orderedOwners
# proposalF.cosigners
-- 'Draft' -> 'VotingReady'
pguardC "Proposal status set to VotingReady" $
proposalOutStatus #== pconstant VotingReady
-- Too late: failed proposal, status set to 'Finished'.
PFalse ->
pguardC "Proposal should fail: not on time" $
proposalOutStatus #== pconstant Finished
PVotingReady -> unTermCont $ do
let notTooLate = inLockedPeriod
notTooEarly = pnot # inVotingPeriod
pguardC "Cannot advance ahead of time" notTooEarly
pmatchC notTooLate >>= \case
PTrue -> do
-- 'VotingReady' -> 'Locked'
pguardC "Proposal status set to Locked" $
proposalOutStatus #== pconstant Locked
pguardC "Winner outcome not found" $
pisJust #$ pwinner' # proposalF.votes
#$ punsafeCoerce
$ pfromData thresholdsF.execute
-- Too late: failed proposal, status set to 'Finished'.
PFalse ->
pguardC "Proposal should fail: not on time" $
proposalOutStatus #== pconstant Finished
pure $ popaque $ pconstant ()
PLocked -> unTermCont $ do
let notTooLate = inExecutionPeriod
notTooEarly = pnot # inLockedPeriod
pguardC "Not too early" notTooEarly
pguardC "Proposal status set to Finished" $
proposalOutStatus #== pconstant Finished
let gstSymbol = pconstant $ governorSTSymbol as
gstMoved =
pany
# plam
( \( (pfield @"value" #)
. (pfield @"resolved" #) ->
value
) ->
psymbolValueOf # gstSymbol # value #== 1
)
# pfromData txInfoF.inputs
pguardC "GST not moved if too late, moved otherwise" $
pif
notTooLate
-- Not too late: GST should moved
pidentity
-- Not too late: GST should not moved
pnot
# gstMoved
pure $ popaque $ pconstant ()
PFinished -> ptraceError "Finished proposals cannot be advanced"