agora/agora/Agora/Proposal/Scripts.hs
2022-10-05 00:13:10 +08:00

737 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 (
PStakeDatum,
pextractVoteOption,
pgetStakeRole,
pisIrrelevant,
pisPureCreator,
pisVoter,
)
import Agora.Utils (
plistEqualsBy,
pmapMaybe,
)
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 "liqwid-plutarch-extra" Plutarch.Extra.List (pfindJust)
import Plutarch.Extra.Map (pupdate)
import Plutarch.Extra.Maybe (
passertPJust,
pisJust,
pjust,
pmaybe,
pnothing,
)
import Plutarch.Extra.Ord (pallUnique, pfromOrdBy, psort, ptryMergeBy)
import Plutarch.Extra.Record (mkRecordConstr, (.&), (.=))
import Plutarch.Extra.ScriptContext (
pfindTxInByTxOutRef,
pfromOutputDatum,
pisTokenSpent,
ptryFromOutputDatum,
)
import Plutarch.Extra.Sum (PSum (PSum))
import "liqwid-plutarch-extra" Plutarch.Extra.TermCont (
pguardC,
pletC,
pletFieldsC,
pmatchC,
ptryFromC,
)
import Plutarch.Extra.Traversable (pfoldMap)
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
-- | @since 1.0.0
newtype PStakeInputsContext (s :: S) = PStakeInputsContext
{ inputStakes :: Term s (PList PStakeDatum)
}
deriving stock
( -- | @since 1.0.0
Generic
)
deriving anyclass
( -- | @since 1.0.0
PlutusType
)
-- | @since 1.0.0
instance DerivePlutusType PStakeInputsContext where
type DPTStrat _ = PlutusTypeNewtype
{- | 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'.
Note that only one proposal per transaction is supported.
=== 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
ctxF <- pletAllC ctx
txInfo <- pletC $ pfromData ctxF.txInfo
txInfoF <-
pletFieldsC
@'[ "referenceInputs"
, "inputs"
, "outputs"
, "mint"
, "datums"
, "signatories"
, "validRange"
]
txInfo
currentTime <- pletC $ currentProposalTime # txInfoF.validRange
authorizedBy <- pletC $ pauthorizedBy # authorizationContext txInfoF
----------------------------------------------------------------------------
PSpending ((pfield @"_0" #) -> propsalInputRef) <-
pmatchC $ pfromData ctxF.purpose
let proposalInput =
pfield @"resolved"
#$ passertPJust
# "Own input should present"
#$ pfindTxInByTxOutRef
# propsalInputRef
# txInfoF.inputs
proposalInputF <- pletFieldsC @'["address", "value"] proposalInput
proposalInputDatum <- pfromData . fst <$> ptryFromC @(PAsData PProposalDatum) datum
proposalInputDatumF <- pletAllC $ pto proposalInputDatum
thresholdsF <- pletAllC proposalInputDatumF.thresholds
currentStatus <- pletC $ pfromData $ proposalInputDatumF.status
-- 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 can handle only one proposal under current design.
proposalOutputDatum <-
pletC $
passertPJust # "proposal input should present"
#$ pfindJust
# plam
( flip pletAll $ \outputF ->
let pstSymbol = pconstant $ proposalSTSymbol as
isProposalUTxO =
foldl1
(#&&)
[ ptraceIfFalse "Own by proposal validator" $
outputF.address #== proposalInputF.address
, ptraceIfFalse "Has proposal ST" $
psymbolValueOf # pstSymbol # outputF.value #== 1
]
handleProposalUTxO =
-- Using inline datum to avoid O(n^2) lookup.
pfromData $
ptrace "Resolve proposal datum" $
pfromOutputDatum @(PAsData PProposalDatum)
# outputF.datum
# txInfoF.datums
in pif
isProposalUTxO
(pjust # handleProposalUTxO)
pnothing
)
# pfromData txInfoF.outputs
--------------------------------------------------------------------------
let AssetClass (sstSymbol, sstName) = stakeSTAssetClass as
sstAssetClass <-
pletC $
passetClass
# pconstant sstSymbol
# pconstant sstName
-- Handle stake inputs/outputs.
-- Reslove stake datum if the given UTxO is a stake UTxO.
getStakeDatum :: Term _ (PTxOut :--> PMaybe PStakeDatum) <-
pletC $
plam $
flip (pletFields @'["value", "datum"]) $ \txOutF ->
let isStakeUTxO =
-- A stake UTxO is a UTxO that carries SST.
passetClassValueOf
# txOutF.value
# sstAssetClass
#== 1
stake =
pfromData $
-- If we can't resolve the stake datum, error out.
passertPJust # "Stake datum should present"
-- Use inline datum to avoid extra map lookup.
#$ ptryFromOutputDatum @(PAsData PStakeDatum)
# txOutF.datum
# txInfoF.datums
in pif isStakeUTxO (pjust # stake) pnothing
spendStakes' :: Term _ ((PStakeInputsContext :--> PUnit) :--> PUnit) <-
pletC $
plam $
let stakeInputs =
pmapMaybe
# plam ((getStakeDatum #) . (pfield @"resolved" #))
# pfromData txInfoF.inputs
ctx = pcon $ PStakeInputsContext stakeInputs
in (# ctx)
let spendStakes ::
( PStakeInputsContext _ ->
TermCont _ ()
) ->
Term _ POpaque
spendStakes c = popaque $
spendStakes' #$ plam $ \sctx ->
unTermCont $ pmatchC sctx >>= c >> pure (pconstant ())
-- Witness stakes in reference inputs.
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) ->
let stakeDatum = getStakeDatum # txOut
updateCtx' = updateCtx # ctx'
in pmaybe # ctx' # updateCtx' # stakeDatum
sortOwners =
plam $
flip pmatch $
\ctxF ->
pcon $
ctxF
{ orderedOwners = psort # ctxF.orderedOwners
}
initialCtx = pcon $ PWitnessMultipleStakeContext 0 pnil
ctx =
sortOwners
#$ pfoldl
# f
# initialCtx
# txInfoF.referenceInputs
in plam (# ctx)
let witnessStakes ::
( PWitnessMultipleStakeContext _ ->
TermCont _ ()
) ->
Term _ POpaque
witnessStakes c = popaque $
witnessStakes' #$ plam $ \sctxF ->
unTermCont $ pmatchC sctxF >>= c >> pure (pconstant ())
----------------------------------------------------------------------------
proposalRedeemer <- fst <$> ptryFromC @PProposalRedeemer redeemer
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
-- Assuming that new signatures encoded in the redeemer and exsiting
-- cosigners are sorted in ascending order, the new list of
-- signatures will be ordered.
updatedSigs <-
pletC $
ptryMergeBy # (pfromOrdBy # plam pfromData)
# newSigs
# proposalInputDatumF.cosigners
pguardC "Less cosigners than maximum limit" $
plength # updatedSigs #< pconstant maximumCosigners
-- assuming sigs are sorted
PJust cosUnique <- pmatchC $ pallUnique #$ pmap # plam pfromData # updatedSigs
pguardC "Cosigners are unique" cosUnique
pguardC "All new cosigners are witnessed by their Stake datums" $
-- Also, this ensures that the cosigners field in the output
-- propopsal datum is ordered.
plistEqualsBy
# plam (\x (pfromData -> y) -> x #== y)
# sctxF.orderedOwners
# newSigs
let expectedDatum =
mkRecordConstr
PProposalDatum
( #proposalId .= proposalInputDatumF.proposalId
.& #effects .= proposalInputDatumF.effects
.& #status .= proposalInputDatumF.status
.& #cosigners .= pdata updatedSigs
.& #thresholds .= proposalInputDatumF.thresholds
.& #votes .= proposalInputDatumF.votes
.& #timingConfig .= proposalInputDatumF.timingConfig
.& #startingTime .= proposalInputDatumF.startingTime
)
pguardC "Signatures are correctly added to cosignature list" $
proposalOutputDatum #== expectedDatum
----------------------------------------------------------------------
PVote r -> spendStakes $ \sctxF -> do
let totalStakeAmount =
pto $
pfoldMap
# plam
( \stake -> unTermCont $ do
stakeF <- pletFieldsC @'["stakedAmount", "lockedBy"] stake
pguardC "Same stake shouldn't vote on the same proposal twice" $
pnot
#$ pisVoter
#$ pgetStakeRole
# proposalInputDatumF.proposalId
# stakeF.lockedBy
pure $ pcon $ PSum $ pfromData stakeF.stakedAmount
)
# sctxF.inputStakes
-- TODO(Connor): check minimum stake amount?
pguardC "Input proposal must be in VotingReady state" $
currentStatus #== pconstant VotingReady
pguardC "Proposal time should be wthin the voting period" $
isVotingPeriod # proposalInputDatumF.timingConfig
# proposalInputDatumF.startingTime
#$ passertPJust
# "Should be able to get current time"
# currentTime
-- Ensure the transaction is voting to a valid 'ResultTag'(outcome).
PProposalVotes voteMap <- pmatchC proposalInputDatumF.votes
voteFor <- pletC $ pfromData $ pfield @"resultTag" # r
pguardC "Vote option should be valid" $
pisJust #$ plookup # voteFor # voteMap
let -- The amount of new votes should be the 'stakedAmount'.
-- Update the vote counter of the proposal, and leave other stuff as is.
expectedNewVotes =
pcon $
PProposalVotes $
pupdate
# plam
( \votes -> unTermCont $ do
PDiscrete v <- pmatchC totalStakeAmount
pure $ pcon $ PJust $ votes + (pextract # v)
)
# voteFor
# pto (pfromData proposalInputDatumF.votes)
expectedProposalOut =
mkRecordConstr
PProposalDatum
( #proposalId .= proposalInputDatumF.proposalId
.& #effects .= proposalInputDatumF.effects
.& #status .= proposalInputDatumF.status
.& #cosigners .= proposalInputDatumF.cosigners
.& #thresholds .= proposalInputDatumF.thresholds
.& #votes .= pdata expectedNewVotes
.& #timingConfig .= proposalInputDatumF.timingConfig
.& #startingTime .= proposalInputDatumF.startingTime
)
pguardC "Output proposal should be valid" $
proposalOutputDatum #== expectedProposalOut
-- Note that the output stake locks validation now happens in the
-- stake validator.
----------------------------------------------------------------------
PUnlock _ -> spendStakes $ \sctxF -> do
let expectedVotes =
pfoldl
# plam
( \votes stake -> unTermCont $ do
stakeF <-
pletFieldsC
@'["stakedAmount", "lockedBy"]
stake
stakeRole <-
pletC $
pgetStakeRole
# proposalInputDatumF.proposalId
# stakeF.lockedBy
pguardC "Stake input should be relevant" $
pnot #$ pisIrrelevant # stakeRole
let canRetractVotes =
pnot #$ pisPureCreator # stakeRole
voteCount =
pextract
#$ pto
$ pfromData stakeF.stakedAmount
newVotes =
pretractVotes
# (pextractVoteOption # stakeRole)
# voteCount
# votes
pure $ pif canRetractVotes newVotes votes
)
# proposalInputDatumF.votes
# sctxF.inputStakes
currentTime' =
passertPJust
# "Should be able to get current time"
# currentTime
inVotingPeriod =
isVotingPeriod # proposalInputDatumF.timingConfig
# proposalInputDatumF.startingTime
# currentTime'
-- The votes can only change when the proposal still allows voting.
shouldUpdateVotes =
currentStatus #== pconstant VotingReady
#&& inVotingPeriod
pguardC "Proposal output correct" $
pif
shouldUpdateVotes
( let -- Remove votes and leave other parts of the proposal as it.
expectedProposalOut =
mkRecordConstr
PProposalDatum
( #proposalId .= proposalInputDatumF.proposalId
.& #effects .= proposalInputDatumF.effects
.& #status .= proposalInputDatumF.status
.& #cosigners .= proposalInputDatumF.cosigners
.& #thresholds .= proposalInputDatumF.thresholds
.& #votes .= pdata expectedVotes
.& #timingConfig .= proposalInputDatumF.timingConfig
.& #startingTime .= proposalInputDatumF.startingTime
)
in ptraceIfFalse "Update votes" $
expectedProposalOut #== proposalOutputDatum
)
-- No change to the proposal is allowed.
( ptraceIfFalse "Proposal unchanged" $
proposalOutputDatum #== proposalInputDatum
)
----------------------------------------------------------------------
PAdvanceProposal _ -> unTermCont $ do
currentTime' <-
pletC $
passertPJust
# "Should be able to get current time"
# currentTime
applyIs <- pletC $
plam $ \f ->
f
# proposalInputDatumF.timingConfig
# proposalInputDatumF.startingTime
# currentTime'
let inDraftPeriod = applyIs # isDraftPeriod
inVotingPeriod = applyIs # isVotingPeriod
inExecutionPeriod = applyIs # isExecutionPeriod
inLockedPeriod <- pletC $ applyIs # isLockingPeriod
proposalOutputStatus <-
pletC $
pfromData $
pfield @"status" # pto proposalOutputDatum
pguardC "Only status changes in the output proposal" $
let expectedProposalOutputDatum =
mkRecordConstr
PProposalDatum
( #proposalId .= proposalInputDatumF.proposalId
.& #effects .= proposalInputDatumF.effects
.& #status .= pdata proposalOutputStatus
.& #cosigners .= proposalInputDatumF.cosigners
.& #thresholds .= proposalInputDatumF.thresholds
.& #votes .= proposalInputDatumF.votes
.& #timingConfig .= proposalInputDatumF.timingConfig
.& #startingTime .= proposalInputDatumF.startingTime
)
in proposalOutputDatum #== expectedProposalOutputDatum
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
# proposalInputDatumF.cosigners
-- 'Draft' -> 'VotingReady'
pguardC "Proposal status set to VotingReady" $
proposalOutputStatus #== pconstant VotingReady
-- Too late: failed proposal, status set to 'Finished'.
PFalse ->
pguardC "Proposal should fail: not on time" $
proposalOutputStatus #== 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" $
proposalOutputStatus #== pconstant Locked
pguardC "Winner outcome not found" $
pisJust #$ pwinner' # proposalInputDatumF.votes
#$ punsafeCoerce
$ pfromData thresholdsF.execute
-- Too late: failed proposal, status set to 'Finished'.
PFalse ->
pguardC "Proposal should fail: not on time" $
proposalOutputStatus #== 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" $
proposalOutputStatus #== 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"