agora/agora/Agora/Proposal/Scripts.hs
2022-06-20 18:45:56 +08:00

561 lines
21 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.Proposal (
PProposalDatum (PProposalDatum),
PProposalRedeemer (..),
PProposalStatus (..),
PProposalVotes (PProposalVotes),
Proposal (governorSTAssetClass, stakeSTAssetClass),
ProposalStatus (..),
pretractVotes,
)
import Agora.Proposal.Time (
currentProposalTime,
isDraftPeriod,
isExecutionPeriod,
isLockingPeriod,
isVotingPeriod,
)
import Agora.Stake (
PProposalLock (..),
PStakeDatum (..),
PStakeUsage (..),
findStakeOwnedBy,
pgetStakeUsage,
)
import Agora.Utils (
findTxOutByTxOutRef,
getMintingPolicySymbol,
mustBePJust,
mustFindDatum',
)
import Plutarch.Api.V1 (
PMintingPolicy,
PScriptContext (PScriptContext),
PScriptPurpose (PMinting, PSpending),
PTxInfo (PTxInfo),
PValidator,
)
import Plutarch.Api.V1.AssetClass (passetClass, passetClassValueOf)
import Plutarch.Api.V1.ScriptContext (
pisTokenSpent,
ptxSignedBy,
pvalueSpent,
)
import "liqwid-plutarch-extra" Plutarch.Api.V1.Value (psymbolValueOf)
import Plutarch.Extra.Comonad (pextract)
import Plutarch.Extra.List (pisUniqBy)
import Plutarch.Extra.Map (plookup, pupdate)
import Plutarch.Extra.Maybe (pisJust)
import Plutarch.Extra.Record (mkRecordConstr, (.&), (.=))
import Plutarch.Extra.TermCont (
pguardC,
pletC,
pletFieldsC,
pmatchC,
ptryFromC,
)
import Plutarch.SafeMoney (PDiscrete (..))
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.
-}
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 <- tcont $ pletFields @'["txInfo", "purpose"] ctx'
PTxInfo txInfo' <- pmatchC $ pfromData ctx.txInfo
txInfo <- tcont $ pletFields @'["inputs", "mint"] txInfo'
PMinting _ownSymbol <- pmatchC $ pfromData ctx.purpose
let inputs = txInfo.inputs
mintedValue = pfromData txInfo.mint
PMinting ownSymbol' <- pmatchC $ pfromData ctx.purpose
let mintedProposalST =
passetClassValueOf
# mintedValue
# (passetClass # (pfield @"_0" # ownSymbol') # pconstant "")
pguardC "Governance state-thread token must move" $
pisTokenSpent
# (passetClass # pconstant govCs # pconstant govTn)
# inputs
pguardC "Minted exactly one proposal ST" $
mintedProposalST #== 1
pure $ popaque (pconstant ())
{- | 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.
-}
proposalValidator :: Proposal -> ClosedTerm PValidator
proposalValidator proposal =
plam $ \datum redeemer ctx' -> unTermCont $ do
PScriptContext ctx' <- pmatchC ctx'
ctx <- tcont $ pletFields @'["txInfo", "purpose"] ctx'
txInfo <- pletC $ pfromData ctx.txInfo
PTxInfo txInfo' <- pmatchC txInfo
txInfoF <-
tcont $
pletFields
@'[ "inputs"
, "outputs"
, "mint"
, "datums"
, "signatories"
, "validRange"
]
txInfo'
PSpending ((pfield @"_0" #) -> txOutRef) <- pmatchC $ pfromData ctx.purpose
PJust txOut <- pmatchC $ findTxOutByTxOutRef # txOutRef # txInfoF.inputs
txOutF <- tcont $ pletFields @'["address", "value"] $ txOut
(pfromData -> proposalDatum, _) <-
ptryFromC @(PAsData PProposalDatum) datum
(pfromData -> proposalRedeemer, _) <-
ptryFromC @(PAsData PProposalRedeemer) redeemer
proposalF <-
tcont $
pletFields
@'[ "proposalId"
, "effects"
, "status"
, "cosigners"
, "thresholds"
, "votes"
, "timingConfig"
, "startingTime"
]
proposalDatum
ownAddress <- pletC $ txOutF.address
let stCurrencySymbol =
pconstant $ getMintingPolicySymbol (proposalPolicy proposal.governorSTAssetClass)
valueSpent <- pletC $ pvalueSpent # txInfoF.inputs
signedBy <- pletC $ ptxSignedBy # txInfoF.signatories
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.
ownOutput <-
pletC $
mustBePJust # "Own output should be present" #$ pfind
# plam
( \input -> unTermCont $ do
inputF <- tcont $ pletFields @'["address", "value", "datumHash"] input
-- TODO: this is highly inefficient: O(n) for every output,
-- Maybe we can cache the sorted datum map?
let datum =
mustFindDatum' @PProposalDatum
# inputF.datumHash
# txInfoF.datums
proposalId = pfield @"proposalId" # datum
pure $
inputF.address #== ownAddress
#&& psymbolValueOf # stCurrencySymbol # inputF.value #== 1
#&& proposalId #== proposalF.proposalId
)
# pfromData txInfoF.outputs
proposalOut <-
pletC $
mustFindDatum' @PProposalDatum
# (pfield @"datumHash" # ownOutput)
# txInfoF.datums
proposalUnchanged <- pletC $ proposalOut #== proposalDatum
--------------------------------------------------------------------------
-- Find the stake input and stake output by SST.
let AssetClass (stakeSym, stakeTn) = proposal.stakeSTAssetClass
stakeSTAssetClass <-
pletC $ passetClass # pconstant stakeSym # pconstant stakeTn
spentStakeST <-
pletC $ passetClassValueOf # valueSpent # stakeSTAssetClass
let stakeInput =
pfield @"resolved"
#$ mustBePJust
# "Stake input should be present"
#$ pfind
# plam
( \(pfromData . (pfield @"value" #) . (pfield @"resolved" #) -> value) ->
passetClassValueOf # value # stakeSTAssetClass #== 1
)
# pfromData txInfoF.inputs
stakeIn <- pletC $ mustFindDatum' @PStakeDatum # (pfield @"datumHash" # stakeInput) # txInfoF.datums
stakeInF <- pletFieldsC @'["stakedAmount", "lockedBy", "owner"] stakeIn
let stakeOutput =
mustBePJust # "Stake output should be present"
#$ pfind
# plam
( \(pfromData . (pfield @"value" #) -> value) ->
passetClassValueOf # value # stakeSTAssetClass #== 1
)
# pfromData txInfoF.outputs
stakeOut <- pletC $ mustFindDatum' @PStakeDatum # (pfield @"datumHash" # stakeOutput) # txInfoF.datums
stakeUnchanged <- pletC $ stakeIn #== stakeOut
--------------------------------------------------------------------------
pure $
pmatch proposalRedeemer $ \case
PVote r -> unTermCont $ do
pguardC "Input proposal must be in VotingReady state" $
proposalF.status #== pconstant VotingReady
pguardC "Proposal time should be wthin the voting period" $
isVotingPeriod # proposalF.timingConfig # proposalF.startingTime # 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 propsoal twice" $
pnot #$ pany
# plam
( \((pfield @"proposalTag" #) . pfromData -> pid) ->
pid #== proposalF.proposalId
)
# pfromData 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
PProposalLock
( #vote .= pdata voteFor
.& #proposalTag .= proposalF.proposalId
)
-- Prepend the new lock to existing locks
expectedProposalLocks =
pcons
# pdata newProposalLock
# pfromData stakeInF.lockedBy
expectedStakeOut =
mkRecordConstr
PStakeDatum
( #stakedAmount .= stakeInF.stakedAmount
.& #owner .= stakeInF.owner
.& #lockedBy .= pdata expectedProposalLocks
)
pguardC "Output stake should be locked by the proposal" $ expectedStakeOut #== stakeOut
pure $ popaque (pconstant ())
--------------------------------------------------------------------------
PCosign r -> unTermCont $ do
pguardC "Stake should not change" stakeUnchanged
newSigs <- pletC $ pfield @"newCosigners" # r
pguardC "Cosigners are unique" $
pisUniqBy
# phoistAcyclic (plam (#==))
# phoistAcyclic (plam $ \(pfromData -> x) (pfromData -> y) -> x #< y)
# newSigs
pguardC "Signed by all new cosigners" $
pall # signedBy # newSigs
pguardC "As many new cosigners as Stake datums" $
spentStakeST #== plength # newSigs
pguardC "All new cosigners are witnessed by their Stake datums" $
pall
# plam
( \sig ->
pmatch
( findStakeOwnedBy # stakeSTAssetClass
# pfromData sig
# txInfoF.datums
# txInfoF.inputs
)
$ \case
PNothing -> pcon PFalse
PJust _ -> pcon PTrue
)
# newSigs
let updatedSigs = pconcat # newSigs # proposalF.cosigners
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
pure $ popaque (pconstant ())
--------------------------------------------------------------------------
PUnlock r -> unTermCont $ do
-- At draft stage, the votes should be empty.
pguardC "Shouldn't retract votes from a draft propsoal" $
pnot #$ proposalF.status #== pconstantData Draft
-- This is the vote option we're retracting from.
retractFrom <- pletC $ pfield @"resultTag" # r
-- Determine if the input stake is actually locked by this proposal.
stakeUsage <- pletC $ pgetStakeUsage # stakeInF.lockedBy # proposalF.proposalId
pguardC "Stake input relevant" $
pmatch stakeUsage $ \case
PDidNothing ->
ptraceIfFalse "Stake should be relevant" $
pconstant False
PCreated ->
ptraceIfFalse "Removing creator's locks means status is Finished" $
proposalF.status #== pconstantData Finished
PVotedFor rt ->
ptraceIfFalse "Result tag should match the one given in the redeemer" $
rt #== retractFrom
-- The count of removing votes is equal to the 'stakeAmount' of input stake.
retractCount <-
pletC $
pmatch stakeInF.stakedAmount $ \(PDiscrete v) -> pextract # v
-- The votes can only change when the proposal still allows voting.
let shouldUpdateVotes =
proposalF.status #== pconstantData VotingReady
#&& pnot # (pcon PCreated #== stakeUsage)
pguardC "Proposal output correct" $
pif
shouldUpdateVotes
( let -- Remove votes and leave other parts of the proposal as it.
expectedVotes = pretractVotes # retractFrom # 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" # stakeOut
let templateStakeOut =
mkRecordConstr
PStakeDatum
( #stakedAmount .= stakeInF.stakedAmount
.& #owner .= stakeInF.owner
.& #lockedBy .= stakeOutputLocks
)
pguardC "Only locks updated in the output stake" $
templateStakeOut #== stakeOut
pguardC "All relevant locks removed from the stake" $
pgetStakeUsage # pfromData stakeOutputLocks
# proposalF.proposalId #== pcon PDidNothing
pure $ popaque (pconstant ())
--------------------------------------------------------------------------
PAdvanceProposal _r -> unTermCont $ do
pguardC "Stake should not change" stakeUnchanged
proposalOutStatus <- pletC $ pfield @"status" # proposalOut
let -- Only the status of proposals should be updated in this case.
templateProposalOut =
mkRecordConstr
PProposalDatum
( #proposalId .= proposalF.proposalId
.& #effects .= proposalF.effects
.& #status .= proposalOutStatus
.& #cosigners .= proposalF.cosigners
.& #thresholds .= proposalF.thresholds
.& #votes .= proposalF.votes
.& #timingConfig .= proposalF.timingConfig
.& #startingTime .= proposalF.startingTime
)
pguardC "Only status changes in the output proposal" $
templateProposalOut #== proposalOut
inDraftPeriod <- pletC $ isDraftPeriod # proposalF.timingConfig # proposalF.startingTime # currentTime
inVotingPeriod <- pletC $ isVotingPeriod # proposalF.timingConfig # proposalF.startingTime # currentTime
inLockedPeriod <- pletC $ isLockingPeriod # proposalF.timingConfig # proposalF.startingTime # currentTime
inExecutionPeriod <- pletC $ isExecutionPeriod # proposalF.timingConfig # proposalF.startingTime # currentTime
-- Check the timings.
let isFinished = proposalF.status #== pconstantData Finished
notTooLate = pmatch (pfromData proposalF.status) $ \case
PDraft _ -> inDraftPeriod
-- Can only advance after the voting period is over.
PVotingReady _ -> inLockedPeriod
PLocked _ -> inExecutionPeriod
_ -> pconstant False
notTooEarly = pmatch (pfromData proposalF.status) $ \case
PVotingReady _ -> pnot # inVotingPeriod
PLocked _ -> pnot # inLockedPeriod
_ -> pconstant True
pguardC "Cannot advance ahead of time" notTooEarly
pguardC "Finished proposals cannot be advanced" $ pnot # isFinished
pure $
pif
notTooLate
-- On time: advance to next status.
( pmatch (pfromData proposalF.status) $ \case
PDraft _ -> unTermCont $ do
-- TODO: Perform other necessary checks.
-- 'Draft' -> 'VotingReady'
pguardC "Proposal status set to VotingReady" $
proposalOutStatus #== pconstantData VotingReady
pure $ popaque (pconstant ())
PVotingReady _ -> unTermCont $ do
-- 'VotingReady' -> 'Locked'
pguardC "Proposal status set to Locked" $
proposalOutStatus #== pconstantData Locked
pure $ popaque (pconstant ())
PLocked _ -> unTermCont $ do
-- 'Locked' -> 'Finished'
pguardC "Proposal status set to Finished" $
proposalOutStatus #== pconstantData Finished
-- TODO: Perform other necessary checks.
pure $ popaque (pconstant ())
_ -> popaque (pconstant ())
)
-- Too late: failed proposal, status set to 'Finished'.
( popaque $
ptraceIfFalse "Proposal should fail: not on time" $
proposalOutStatus #== pconstantData Finished
-- TODO: Should check that the GST is not moved
-- if the proposal is in 'Locked' state.
)