chia_sdk_driver/action_system/

singleton_spends.rs

use std::fmt::Debug;

use chia_protocol::{Bytes32, Coin};
use chia_puzzles::{SETTLEMENT_PAYMENT_HASH, SINGLETON_LAUNCHER_HASH};
use chia_sdk_types::{
    conditions::{
        AssertPuzzleAnnouncement, CreateCoin, NewMetadataOutput, TransferNft, UpdateNftMetadata,
    },
    Conditions,
};
use clvm_traits::clvm_list;
use clvmr::NodePtr;

use crate::{
    Asset, Did, DidInfo, DriverError, FungibleSpend, HashedPtr, Launcher, Nft, NftInfo,
    OptionContract, OutputSet, Spend, SpendContext, SpendKind,
};

#[derive(Debug, Clone)]
pub struct SingletonSpends<A>
where
    A: SingletonAsset,
{
    pub lineage: Vec<SingletonSpend<A>>,
    pub ephemeral: bool,
}

impl<A> SingletonSpends<A>
where
    A: SingletonAsset,
{
    pub fn new(asset: A, ephemeral: bool) -> Self {
        Self {
            lineage: vec![SingletonSpend::new(asset)],
            ephemeral,
        }
    }

    pub fn last(&self) -> Result<&SingletonSpend<A>, DriverError> {
        self.lineage.last().ok_or(DriverError::NoSourceForOutput)
    }

    pub fn last_mut(&mut self) -> Result<&mut SingletonSpend<A>, DriverError> {
        self.lineage
            .last_mut()
            .ok_or(DriverError::NoSourceForOutput)
    }

    pub fn last_or_create_settlement(
        &mut self,
        ctx: &mut SpendContext,
    ) -> Result<usize, DriverError> {
        let last = self
            .lineage
            .last_mut()
            .ok_or(DriverError::NoSourceForOutput)?;

        if !last.kind.missing_singleton_output() {
            return Err(DriverError::NoSourceForOutput);
        }

        if last.kind.is_settlement() {
            return Ok(self.lineage.len() - 1);
        }

        let Some(child) = A::finalize(
            ctx,
            last,
            SETTLEMENT_PAYMENT_HASH.into(),
            SETTLEMENT_PAYMENT_HASH.into(),
        )?
        else {
            return Err(DriverError::NoSourceForOutput);
        };

        self.lineage.push(child);

        Ok(self.lineage.len() - 1)
    }

    pub fn finalize(
        &mut self,
        ctx: &mut SpendContext,
        intermediate_puzzle_hash: Bytes32,
        change_puzzle_hash: Bytes32,
    ) -> Result<Option<A>, DriverError> {
        let asset = loop {
            let last = self
                .lineage
                .last_mut()
                .ok_or(DriverError::NoSourceForOutput)?;

            if !last.kind.missing_singleton_output() {
                break None;
            }

            let Some(child) = A::finalize(ctx, last, intermediate_puzzle_hash, change_puzzle_hash)?
            else {
                break None;
            };

            if A::needs_additional_spend(&child.child_info) {
                self.lineage.push(child);
            } else {
                break Some(child.asset);
            }
        };

        Ok(asset)
    }

    pub fn intermediate_fungible_xch_spend(
        &mut self,
        ctx: &mut SpendContext,
        intermediate_puzzle_hash: Bytes32,
    ) -> Result<Option<FungibleSpend<Coin>>, DriverError> {
        let Some((index, amount)) = self.lineage.iter().enumerate().find_map(|(index, item)| {
            item.kind
                .find_amount(intermediate_puzzle_hash, &item.asset.constraints())
                .map(|amount| (index, amount))
        }) else {
            return Ok(None);
        };

        let source = &mut self.lineage[index];

        let hint = ctx.hint(intermediate_puzzle_hash)?;

        source.kind.create_intermediate_coin(CreateCoin::new(
            intermediate_puzzle_hash,
            amount,
            hint,
        ));

        let child = FungibleSpend::new(
            Coin::new(source.asset.coin_id(), intermediate_puzzle_hash, amount),
            true,
        );

        Ok(Some(child))
    }

    pub fn launcher_source(&mut self) -> Result<(usize, u64), DriverError> {
        let Some((index, amount)) = self.lineage.iter().enumerate().find_map(|(index, item)| {
            item.kind
                .find_amount(SINGLETON_LAUNCHER_HASH.into(), &item.asset.constraints())
                .map(|amount| (index, amount))
        }) else {
            return Err(DriverError::NoSourceForOutput);
        };

        Ok((index, amount))
    }

    pub fn create_launcher(
        &mut self,
        singleton_amount: u64,
    ) -> Result<(usize, Launcher), DriverError> {
        let (index, launcher_amount) = self.launcher_source()?;

        let (create_coin, launcher) =
            Launcher::create_early(self.lineage[index].asset.coin_id(), launcher_amount);

        self.lineage[index]
            .kind
            .create_intermediate_coin(create_coin);

        Ok((index, launcher.with_singleton_amount(singleton_amount)))
    }
}

#[derive(Debug, Clone)]
pub struct SingletonSpend<A>
where
    A: SingletonAsset,
{
    pub asset: A,
    pub kind: SpendKind,
    pub child_info: A::ChildInfo,
    pub payment_assertions: Vec<AssertPuzzleAnnouncement>,
}

impl<A> SingletonSpend<A>
where
    A: SingletonAsset,
{
    pub fn new(asset: A) -> Self {
        let kind = if asset.p2_puzzle_hash() == SETTLEMENT_PAYMENT_HASH.into() {
            SpendKind::settlement()
        } else {
            SpendKind::conditions()
        };
        let child_info = A::default_child_info(&asset, &kind);

        Self {
            asset,
            kind,
            child_info,
            payment_assertions: Vec::new(),
        }
    }
}

pub trait SingletonAsset: Debug + Clone + Asset {
    type ChildInfo: Debug + Clone;

    fn default_child_info(asset: &Self, spend_kind: &SpendKind) -> Self::ChildInfo;
    fn needs_additional_spend(child_info: &Self::ChildInfo) -> bool;
    fn finalize(
        ctx: &mut SpendContext,
        singleton: &mut SingletonSpend<Self>,
        intermediate_puzzle_hash: Bytes32,
        change_puzzle_hash: Bytes32,
    ) -> Result<Option<SingletonSpend<Self>>, DriverError>;
}

impl SingletonAsset for Did<HashedPtr> {
    type ChildInfo = ChildDidInfo;

    fn default_child_info(asset: &Self, spend_kind: &SpendKind) -> Self::ChildInfo {
        ChildDidInfo {
            recovery_list_hash: asset.info.recovery_list_hash,
            num_verifications_required: asset.info.num_verifications_required,
            metadata: asset.info.metadata,
            destination: None,
            new_spend_kind: spend_kind.empty_copy(),
            needs_update: false,
        }
    }

    fn needs_additional_spend(child_info: &Self::ChildInfo) -> bool {
        child_info.needs_update
    }

    fn finalize(
        ctx: &mut SpendContext,
        singleton: &mut SingletonSpend<Self>,
        _conditions_puzzle_hash: Bytes32,
        change_puzzle_hash: Bytes32,
    ) -> Result<Option<SingletonSpend<Self>>, DriverError> {
        let change_hint = ctx.hint(change_puzzle_hash)?;

        let current_info = singleton.asset.info;
        let child_info = &singleton.child_info;

        // If the DID layer has changed, we need to perform an update spend to ensure wallets can properly sync the coin.
        let needs_update = current_info.recovery_list_hash != child_info.recovery_list_hash
            || current_info.num_verifications_required != child_info.num_verifications_required
            || current_info.metadata != child_info.metadata;

        let final_destination = child_info.destination;

        let destination = if needs_update {
            let p2_puzzle_hash = current_info.p2_puzzle_hash;
            let hint = ctx.hint(p2_puzzle_hash)?;
            SingletonDestination::CreateCoin(CreateCoin::new(
                p2_puzzle_hash,
                singleton.asset.coin.amount,
                hint,
            ))
        } else {
            child_info
                .destination
                .unwrap_or(SingletonDestination::CreateCoin(CreateCoin::new(
                    change_puzzle_hash,
                    singleton.asset.coin.amount,
                    change_hint,
                )))
        };

        match destination {
            SingletonDestination::CreateCoin(destination) => {
                let child_info = DidInfo::new(
                    current_info.launcher_id,
                    child_info.recovery_list_hash,
                    child_info.num_verifications_required,
                    child_info.metadata,
                    destination.puzzle_hash,
                );

                // Create the new DID coin with the updated DID info. The DID puzzle does not automatically wrap the output.
                let create_coin = CreateCoin::new(
                    child_info.inner_puzzle_hash().into(),
                    destination.amount,
                    destination.memos,
                );
                let parent_puzzle_hash = singleton.asset.full_puzzle_hash();
                singleton.kind.create_coin_with_assertion(
                    ctx,
                    parent_puzzle_hash,
                    &mut singleton.payment_assertions,
                    create_coin,
                );

                // Create a new singleton spend with the child and the new spend kind.
                // This will only be added to the lineage if an additional spend is required.
                let mut new_spend = SingletonSpend::new(
                    singleton
                        .asset
                        .child_with(child_info, singleton.asset.coin.amount),
                );

                // Signal that an additional spend is required.
                new_spend.child_info.needs_update = needs_update;

                if needs_update {
                    new_spend.child_info.destination = final_destination;
                }

                Ok(Some(new_spend))
            }
            SingletonDestination::Melt => {
                match &mut singleton.kind {
                    SpendKind::Conditions(conditions) => {
                        conditions.add_conditions(Conditions::new().melt_singleton());
                    }
                    SpendKind::Settlement(_) => {
                        return Err(DriverError::CannotEmitConditions);
                    }
                }

                Ok(None)
            }
        }
    }
}

impl SingletonAsset for Nft<HashedPtr> {
    type ChildInfo = ChildNftInfo;

    fn default_child_info(_asset: &Self, spend_kind: &SpendKind) -> Self::ChildInfo {
        ChildNftInfo {
            metadata_update_spends: Vec::new(),
            transfer_condition: None,
            destination: None,
            new_spend_kind: spend_kind.empty_copy(),
        }
    }

    fn needs_additional_spend(child_info: &Self::ChildInfo) -> bool {
        !child_info.metadata_update_spends.is_empty() || child_info.transfer_condition.is_some()
    }

    fn finalize(
        ctx: &mut SpendContext,
        singleton: &mut SingletonSpend<Self>,
        intermediate_puzzle_hash: Bytes32,
        change_puzzle_hash: Bytes32,
    ) -> Result<Option<SingletonSpend<Self>>, DriverError> {
        if !singleton.kind.is_conditions()
            && (!singleton.child_info.metadata_update_spends.is_empty()
                || singleton.child_info.transfer_condition.is_some())
        {
            let create_coin = CreateCoin::new(
                intermediate_puzzle_hash,
                singleton.asset.coin.amount,
                ctx.hint(intermediate_puzzle_hash)?,
            );
            let parent_puzzle_hash = singleton.asset.full_puzzle_hash();
            singleton.kind.create_coin_with_assertion(
                ctx,
                parent_puzzle_hash,
                &mut singleton.payment_assertions,
                create_coin,
            );

            let new_info = NftInfo {
                p2_puzzle_hash: intermediate_puzzle_hash,
                ..singleton.asset.info
            };

            let mut spend = SingletonSpend::new(
                singleton
                    .asset
                    .child_with(new_info, singleton.asset.coin.amount),
            );

            spend.child_info = singleton.child_info.clone();

            return Ok(Some(spend));
        }

        let change_hint = ctx.hint(change_puzzle_hash)?;

        let mut new_child_info = singleton.child_info.clone();

        let metadata_update_spend = new_child_info.metadata_update_spends.pop();
        let transfer_condition = new_child_info.transfer_condition.take();
        let needs_additional_spend = Self::needs_additional_spend(&new_child_info);

        let destination = if needs_additional_spend {
            let p2_puzzle_hash = singleton.asset.info.p2_puzzle_hash;
            let hint = ctx.hint(p2_puzzle_hash)?;
            CreateCoin::new(p2_puzzle_hash, singleton.asset.coin.amount, hint)
        } else {
            new_child_info.destination.unwrap_or(CreateCoin::new(
                change_puzzle_hash,
                singleton.asset.coin.amount,
                change_hint,
            ))
        };

        let mut nft_info = singleton.asset.info;
        nft_info.p2_puzzle_hash = destination.puzzle_hash;

        // Create the new NFT coin with the updated info.
        let parent_puzzle_hash = singleton.asset.full_puzzle_hash();

        singleton.kind.create_coin_with_assertion(
            ctx,
            parent_puzzle_hash,
            &mut singleton.payment_assertions,
            destination,
        );

        let mut conditions = Conditions::new();

        if let Some(spend) = metadata_update_spend {
            conditions.push(UpdateNftMetadata::new(spend.puzzle, spend.solution));

            let metadata_updater_solution = ctx.alloc(&clvm_list!(
                singleton.asset.info.metadata,
                singleton.asset.info.metadata_updater_puzzle_hash,
                spend.solution
            ))?;
            let ptr = ctx.run(spend.puzzle, metadata_updater_solution)?;
            let output = ctx.extract::<NewMetadataOutput<HashedPtr, NodePtr>>(ptr)?;

            nft_info.metadata = output.metadata_info.new_metadata;
            nft_info.metadata_updater_puzzle_hash = output.metadata_info.new_updater_puzzle_hash;
        }

        if let Some(transfer_condition) = transfer_condition {
            nft_info.current_owner = transfer_condition.launcher_id;
            conditions.push(transfer_condition);
        }

        if !conditions.is_empty() {
            match &mut singleton.kind {
                SpendKind::Conditions(spend) => {
                    spend.add_conditions(conditions);
                }
                SpendKind::Settlement(_) => {
                    return Err(DriverError::CannotEmitConditions);
                }
            }
        }

        // Create a new singleton spend with the child and the new spend kind.
        let mut spend = SingletonSpend::new(
            singleton
                .asset
                .child_with(nft_info, singleton.asset.coin.amount),
        );

        spend.child_info = new_child_info;

        Ok(Some(spend))
    }
}

impl SingletonAsset for OptionContract {
    type ChildInfo = ChildOptionInfo;

    fn default_child_info(_asset: &Self, spend_kind: &SpendKind) -> Self::ChildInfo {
        ChildOptionInfo {
            destination: None,
            new_spend_kind: spend_kind.empty_copy(),
        }
    }

    fn needs_additional_spend(_child_info: &Self::ChildInfo) -> bool {
        false
    }

    fn finalize(
        ctx: &mut SpendContext,
        singleton: &mut SingletonSpend<Self>,
        _conditions_puzzle_hash: Bytes32,
        change_puzzle_hash: Bytes32,
    ) -> Result<Option<SingletonSpend<Self>>, DriverError> {
        let change_hint = ctx.hint(change_puzzle_hash)?;

        let default_destination = SingletonDestination::CreateCoin(CreateCoin::new(
            change_puzzle_hash,
            singleton.asset.coin.amount,
            change_hint,
        ));

        let destination = singleton
            .child_info
            .destination
            .unwrap_or(default_destination);

        match destination {
            SingletonDestination::CreateCoin(destination) => {
                // Create the new option contract coin.
                let parent_puzzle_hash = singleton.asset.full_puzzle_hash();
                singleton.kind.create_coin_with_assertion(
                    ctx,
                    parent_puzzle_hash,
                    &mut singleton.payment_assertions,
                    destination,
                );

                // Create a new singleton spend with the child and the new spend kind.
                Ok(Some(SingletonSpend::new(singleton.asset.child(
                    destination.puzzle_hash,
                    singleton.asset.coin.amount,
                ))))
            }
            SingletonDestination::Melt => {
                // We need to emit a message to the underlying coin to exercise the option and melt it.
                let message = singleton.asset.info.underlying_delegated_puzzle_hash.into();
                let data = ctx.alloc(&singleton.asset.info.underlying_coin_id)?;

                match &mut singleton.kind {
                    SpendKind::Conditions(spend) => {
                        spend.add_conditions(Conditions::new().melt_singleton().send_message(
                            23,
                            message,
                            vec![data],
                        ));
                    }
                    SpendKind::Settlement(_) => {
                        return Err(DriverError::CannotEmitConditions);
                    }
                }

                Ok(None)
            }
        }
    }
}

#[derive(Debug, Clone, Copy)]
pub enum SingletonDestination {
    CreateCoin(CreateCoin<NodePtr>),
    Melt,
}

#[derive(Debug, Clone)]
pub struct ChildDidInfo {
    pub recovery_list_hash: Option<Bytes32>,
    pub num_verifications_required: u64,
    pub metadata: HashedPtr,
    pub destination: Option<SingletonDestination>,
    pub new_spend_kind: SpendKind,
    pub needs_update: bool,
}

#[derive(Debug, Clone)]
pub struct ChildNftInfo {
    pub metadata_update_spends: Vec<Spend>,
    pub transfer_condition: Option<TransferNft>,
    pub destination: Option<CreateCoin<NodePtr>>,
    pub new_spend_kind: SpendKind,
}

#[derive(Debug, Clone)]
pub struct ChildOptionInfo {
    pub destination: Option<SingletonDestination>,
    pub new_spend_kind: SpendKind,
}