penumbra_transaction/
is_action.rs

use ark_ff::Zero;
use decaf377::Fr;
use penumbra_asset::{balance, Value};
use penumbra_auction::auction::dutch::actions::{
    view::{ActionDutchAuctionScheduleView, ActionDutchAuctionWithdrawView},
    ActionDutchAuctionEnd, ActionDutchAuctionSchedule, ActionDutchAuctionWithdraw,
};
use penumbra_community_pool::{CommunityPoolDeposit, CommunityPoolOutput, CommunityPoolSpend};
use penumbra_dex::{
    lp::{
        action::{PositionClose, PositionOpen, PositionWithdraw},
        position, LpNft,
    },
    swap::{Swap, SwapCiphertext, SwapView},
    swap_claim::{SwapClaim, SwapClaimView},
};
use penumbra_governance::{
    DelegatorVote, DelegatorVoteView, ProposalDepositClaim, ProposalSubmit, ProposalWithdraw,
    ValidatorVote, VotingReceiptToken,
};
use penumbra_ibc::IbcRelay;
use penumbra_shielded_pool::{Ics20Withdrawal, Note, Output, OutputView, Spend, SpendView};
use penumbra_stake::{Delegate, Undelegate, UndelegateClaim};

use crate::{Action, ActionView, TransactionPerspective};

// TODO: how do we have this be implemented in the component crates?
// currently can't because of txp

/// Common behavior between Penumbra actions.
pub trait IsAction {
    fn balance_commitment(&self) -> balance::Commitment;
    fn view_from_perspective(&self, txp: &TransactionPerspective) -> ActionView;
}

// foreign types

impl From<DelegatorVote> for Action {
    fn from(value: DelegatorVote) -> Self {
        Action::DelegatorVote(value)
    }
}

impl IsAction for DelegatorVote {
    fn balance_commitment(&self) -> balance::Commitment {
        Value {
            amount: self.body.unbonded_amount,
            asset_id: VotingReceiptToken::new(self.body.proposal).id(),
        }
        .commit(Fr::zero())
    }

    fn view_from_perspective(&self, txp: &TransactionPerspective) -> ActionView {
        let delegator_vote_view = match txp.spend_nullifiers.get(&self.body.nullifier) {
            Some(note) => DelegatorVoteView::Visible {
                delegator_vote: self.to_owned(),
                note: txp.view_note(note.to_owned()),
            },
            None => DelegatorVoteView::Opaque {
                delegator_vote: self.to_owned(),
            },
        };

        ActionView::DelegatorVote(delegator_vote_view)
    }
}

impl IsAction for ProposalDepositClaim {
    fn balance_commitment(&self) -> balance::Commitment {
        self.balance().commit(Fr::zero())
    }

    fn view_from_perspective(&self, _txp: &TransactionPerspective) -> ActionView {
        ActionView::ProposalDepositClaim(self.clone())
    }
}

impl IsAction for ProposalSubmit {
    fn balance_commitment(&self) -> balance::Commitment {
        self.balance().commit(Fr::zero())
    }

    fn view_from_perspective(&self, _txp: &TransactionPerspective) -> ActionView {
        ActionView::ProposalSubmit(self.to_owned())
    }
}

impl IsAction for ProposalWithdraw {
    fn balance_commitment(&self) -> balance::Commitment {
        self.balance().commit(Fr::zero())
    }

    fn view_from_perspective(&self, _txp: &TransactionPerspective) -> ActionView {
        ActionView::ProposalWithdraw(self.to_owned())
    }
}

impl IsAction for ValidatorVote {
    fn balance_commitment(&self) -> balance::Commitment {
        Default::default()
    }

    fn view_from_perspective(&self, _txp: &TransactionPerspective) -> ActionView {
        ActionView::ValidatorVote(self.to_owned())
    }
}

impl IsAction for Output {
    fn balance_commitment(&self) -> balance::Commitment {
        self.body.balance_commitment
    }

    fn view_from_perspective(&self, txp: &TransactionPerspective) -> ActionView {
        let note_commitment = self.body.note_payload.note_commitment;
        let epk = self.body.note_payload.ephemeral_key;
        // Retrieve payload key for associated note commitment
        let output_view = if let Some(payload_key) = txp.payload_keys.get(&note_commitment) {
            let decrypted_note = Note::decrypt_with_payload_key(
                &self.body.note_payload.encrypted_note,
                payload_key,
                &epk,
            );

            let decrypted_memo_key = self.body.wrapped_memo_key.decrypt_outgoing(payload_key);

            if let (Ok(decrypted_note), Ok(decrypted_memo_key)) =
                (decrypted_note, decrypted_memo_key)
            {
                // Neither decryption failed, so return the visible ActionView
                OutputView::Visible {
                    output: self.to_owned(),
                    note: txp.view_note(decrypted_note),
                    payload_key: decrypted_memo_key,
                }
            } else {
                // One or both of the note or memo key is missing, so return the opaque ActionView
                OutputView::Opaque {
                    output: self.to_owned(),
                }
            }
        } else {
            // There was no payload key found, so return the opaque ActionView
            OutputView::Opaque {
                output: self.to_owned(),
            }
        };

        ActionView::Output(output_view)
    }
}

impl IsAction for Spend {
    fn balance_commitment(&self) -> balance::Commitment {
        self.body.balance_commitment
    }

    fn view_from_perspective(&self, txp: &TransactionPerspective) -> ActionView {
        let spend_view = match txp.spend_nullifiers.get(&self.body.nullifier) {
            Some(note) => SpendView::Visible {
                spend: self.to_owned(),
                note: txp.view_note(note.to_owned()),
            },
            None => SpendView::Opaque {
                spend: self.to_owned(),
            },
        };

        ActionView::Spend(spend_view)
    }
}

impl IsAction for Delegate {
    fn balance_commitment(&self) -> balance::Commitment {
        self.balance().commit(Fr::zero())
    }

    fn view_from_perspective(&self, _txp: &TransactionPerspective) -> ActionView {
        ActionView::Delegate(self.to_owned())
    }
}

impl IsAction for Undelegate {
    fn balance_commitment(&self) -> balance::Commitment {
        self.balance().commit(Fr::zero())
    }

    fn view_from_perspective(&self, _txp: &TransactionPerspective) -> ActionView {
        ActionView::Undelegate(self.to_owned())
    }
}

impl IsAction for UndelegateClaim {
    fn balance_commitment(&self) -> balance::Commitment {
        self.body.balance_commitment
    }

    fn view_from_perspective(&self, _txp: &TransactionPerspective) -> ActionView {
        ActionView::UndelegateClaim(self.to_owned())
    }
}

impl IsAction for IbcRelay {
    fn balance_commitment(&self) -> balance::Commitment {
        Default::default()
    }

    fn view_from_perspective(&self, _txp: &TransactionPerspective) -> ActionView {
        ActionView::IbcRelay(self.clone())
    }
}

impl IsAction for Ics20Withdrawal {
    fn balance_commitment(&self) -> balance::Commitment {
        self.balance().commit(Fr::zero())
    }

    fn view_from_perspective(&self, _txp: &TransactionPerspective) -> ActionView {
        ActionView::Ics20Withdrawal(self.to_owned())
    }
}

impl IsAction for CommunityPoolDeposit {
    fn balance_commitment(&self) -> balance::Commitment {
        self.balance().commit(Fr::zero())
    }

    fn view_from_perspective(&self, _txp: &TransactionPerspective) -> ActionView {
        ActionView::CommunityPoolDeposit(self.clone())
    }
}

impl IsAction for CommunityPoolOutput {
    fn balance_commitment(&self) -> balance::Commitment {
        // Outputs from the Community Pool require value
        self.balance().commit(Fr::zero())
    }

    fn view_from_perspective(&self, _txp: &TransactionPerspective) -> ActionView {
        ActionView::CommunityPoolOutput(self.clone())
    }
}

impl IsAction for CommunityPoolSpend {
    fn balance_commitment(&self) -> balance::Commitment {
        self.balance().commit(Fr::zero())
    }

    fn view_from_perspective(&self, _txp: &TransactionPerspective) -> ActionView {
        ActionView::CommunityPoolSpend(self.clone())
    }
}

impl IsAction for PositionOpen {
    fn balance_commitment(&self) -> balance::Commitment {
        self.balance().commit(Fr::zero())
    }

    fn view_from_perspective(&self, _txp: &TransactionPerspective) -> ActionView {
        ActionView::PositionOpen(self.to_owned())
    }
}

impl IsAction for PositionClose {
    fn balance_commitment(&self) -> balance::Commitment {
        self.balance().commit(Fr::zero())
    }

    fn view_from_perspective(&self, _txp: &TransactionPerspective) -> ActionView {
        ActionView::PositionClose(self.to_owned())
    }
}

impl IsAction for PositionWithdraw {
    fn balance_commitment(&self) -> balance::Commitment {
        let prev_state_nft = if self.sequence == 0 {
            Value {
                amount: 1u64.into(),
                asset_id: LpNft::new(self.position_id, position::State::Closed).asset_id(),
            }
        } else {
            Value {
                amount: 1u64.into(),
                asset_id: LpNft::new(
                    self.position_id,
                    position::State::Withdrawn {
                        sequence: self.sequence - 1,
                    },
                )
                .asset_id(),
            }
        }
        .commit(Fr::zero());

        let next_state_nft = Value {
            amount: 1u64.into(),
            asset_id: LpNft::new(
                self.position_id,
                position::State::Withdrawn {
                    sequence: self.sequence,
                },
            )
            .asset_id(),
        }
        .commit(Fr::zero());

        // The action consumes a closed position and produces the position's reserves and a withdrawn position NFT.
        self.reserves_commitment - prev_state_nft + next_state_nft
    }

    fn view_from_perspective(&self, _txp: &TransactionPerspective) -> ActionView {
        ActionView::PositionWithdraw(self.to_owned())
    }
}

impl IsAction for Swap {
    /// Compute a commitment to the value contributed to a transaction by this swap.
    /// Will subtract (v1,t1), (v2,t2), and (f,fee_token)
    fn balance_commitment(&self) -> balance::Commitment {
        self.balance_commitment_inner()
    }

    fn view_from_perspective(&self, txp: &TransactionPerspective) -> ActionView {
        let commitment = self.body.payload.commitment;

        let plaintext = txp.payload_keys.get(&commitment).and_then(|payload_key| {
            // Decrypt swap ciphertext
            SwapCiphertext::decrypt_with_payload_key(&self.body.payload.encrypted_swap, payload_key)
                .ok()
        });

        ActionView::Swap(match plaintext {
            Some(swap_plaintext) => {
                // If we can find a matching BSOD in the TxP, use it to compute the output notes
                // for the swap.
                let bsod = txp
                    .batch_swap_output_data
                    .iter()
                    // This finds the first matching one; there should only be one
                    // per trading pair per block and we trust the TxP provider not to lie about it.
                    .find(|bsod| bsod.trading_pair == swap_plaintext.trading_pair);

                let (output_1, output_2) = match bsod.map(|bsod| swap_plaintext.output_notes(bsod))
                {
                    Some((output_1, output_2)) => {
                        (Some(txp.view_note(output_1)), Some(txp.view_note(output_2)))
                    }
                    None => (None, None),
                };

                SwapView::Visible {
                    swap: self.to_owned(),
                    swap_plaintext: swap_plaintext.clone(),
                    output_1,
                    output_2,
                    claim_tx: txp
                        .nullification_transaction_ids_by_commitment
                        .get(&commitment)
                        .cloned(),
                    batch_swap_output_data: bsod.cloned(),
                    asset_1_metadata: txp
                        .denoms
                        .get(&swap_plaintext.trading_pair.asset_1())
                        .cloned(),
                    asset_2_metadata: txp
                        .denoms
                        .get(&swap_plaintext.trading_pair.asset_2())
                        .cloned(),
                }
            }
            None => {
                // If we can find a matching BSOD in the TxP, we can use it to compute the output notes
                // for the swap.
                let bsod = txp
                    .batch_swap_output_data
                    .iter()
                    // This finds the first matching one; there should only be one
                    // per trading pair per block and we trust the TxP provider not to lie about it.
                    .find(|bsod| bsod.trading_pair == self.body.trading_pair);

                // We can get the denom metadata whether we get a BSOD or not
                let denom_1 = txp.denoms.get(&self.body.trading_pair.asset_1()).cloned();
                let denom_2 = txp.denoms.get(&self.body.trading_pair.asset_2()).cloned();

                match bsod {
                    None => {
                        // If we can't find a matching BSOD, we can't compute the output notes
                        // for the swap.
                        SwapView::Opaque {
                            swap: self.to_owned(),
                            batch_swap_output_data: None,
                            output_1: None,
                            output_2: None,
                            asset_1_metadata: denom_1.clone(),
                            asset_2_metadata: denom_2.clone(),
                        }
                    }
                    Some(bsod) => {
                        // If we can find a matching BSOD, use it to compute the output notes
                        // for the swap.
                        let (lambda_1_i, lambda_2_i) =
                            bsod.pro_rata_outputs((self.body.delta_1_i, self.body.delta_2_i));
                        SwapView::Opaque {
                            swap: self.to_owned(),
                            batch_swap_output_data: Some(bsod.clone()),
                            asset_1_metadata: denom_1.clone(),
                            asset_2_metadata: denom_2.clone(),
                            output_1: Some(
                                Value {
                                    amount: lambda_1_i,
                                    asset_id: self.body.trading_pair.asset_1(),
                                }
                                .view_with_cache(&txp.denoms),
                            ),
                            output_2: Some(
                                Value {
                                    amount: lambda_2_i,
                                    asset_id: self.body.trading_pair.asset_2(),
                                }
                                .view_with_cache(&txp.denoms),
                            ),
                        }
                    }
                }
            }
        })
    }
}

impl IsAction for SwapClaim {
    fn balance_commitment(&self) -> balance::Commitment {
        self.balance().commit(Fr::zero())
    }

    fn view_from_perspective(&self, txp: &TransactionPerspective) -> ActionView {
        // Get the advice notes for each output from the swap claim
        let output_1 = txp.advice_notes.get(&self.body.output_1_commitment);
        let output_2 = txp.advice_notes.get(&self.body.output_2_commitment);

        match (output_1, output_2) {
            (Some(output_1), Some(output_2)) => {
                let swap_claim_view = SwapClaimView::Visible {
                    swap_claim: self.to_owned(),
                    output_1: txp.view_note(output_1.to_owned()),
                    output_2: txp.view_note(output_2.to_owned()),
                    swap_tx: txp
                        .creation_transaction_ids_by_nullifier
                        .get(&self.body.nullifier)
                        .cloned(),
                };
                ActionView::SwapClaim(swap_claim_view)
            }
            _ => {
                let swap_claim_view = SwapClaimView::Opaque {
                    swap_claim: self.to_owned(),
                };
                ActionView::SwapClaim(swap_claim_view)
            }
        }
    }
}

impl IsAction for ActionDutchAuctionSchedule {
    fn balance_commitment(&self) -> balance::Commitment {
        self.balance().commit(Fr::zero())
    }

    fn view_from_perspective(&self, txp: &TransactionPerspective) -> ActionView {
        let view = ActionDutchAuctionScheduleView {
            action: self.to_owned(),
            auction_id: self.description.id(),
            input_metadata: txp.denoms.get_by_id(self.description.input.asset_id),
            output_metadata: txp.denoms.get_by_id(self.description.output_id),
        };
        ActionView::ActionDutchAuctionSchedule(view)
    }
}

impl IsAction for ActionDutchAuctionEnd {
    fn balance_commitment(&self) -> balance::Commitment {
        self.balance().commit(Fr::zero())
    }

    fn view_from_perspective(&self, _txp: &TransactionPerspective) -> ActionView {
        ActionView::ActionDutchAuctionEnd(self.to_owned())
    }
}

impl IsAction for ActionDutchAuctionWithdraw {
    fn balance_commitment(&self) -> balance::Commitment {
        self.balance_commitment()
    }

    fn view_from_perspective(&self, _txp: &TransactionPerspective) -> ActionView {
        let view = ActionDutchAuctionWithdrawView {
            action: self.to_owned(),
            reserves: vec![],
        };
        ActionView::ActionDutchAuctionWithdraw(view)
    }
}
penumbra_transaction/is_action.rs

penumbra_transaction/
is_action.rs
