cow-settlement-client 0.2.0

//! Instruction builders for the settlement program.
//!
//! A single place for client callers to reach for instruction constructors.
//! The instruction builders are the same as those in the interface, but they
//! provide a simplified interface at the price of more computation done
//! by the function, making it more suitable for off-chain use.

use cow_settlement_interface::{
    data::intent::{EncodedOrderIntent, OrderIntent},
    pda::{buffer::find_buffer_pda, order::find_order_pda, state::find_state_pda},
    Instruction, Pubkey,
};

// Reexport the instruction builders that don't change from the interface.
// We want the client to provide all instruction builders.
pub use cow_settlement_interface::instruction::settle::Pull;

/// An order ready to be settled, together with the funds to pull from it:
/// `intent` identifies the order and `pulls` lists the [`Pull`]s to make from
/// its sell token account.
pub struct InitializedIntent<'a> {
    pub intent: &'a OrderIntent,
    pub pulls: &'a [Pull],
}

/// Builder for a `BeginSettle` instruction settling the given orders.
pub struct BeginSettle<'a> {
    pub program_id: Pubkey,
    pub finalize_ix_index: u16,
    /// The off-chain auction this settlement executes, carried so it can be tied
    /// back to its auction off-chain.
    pub auction_id: i64,
    pub orders: &'a [InitializedIntent<'a>],
}

impl From<BeginSettle<'_>> for Instruction {
    fn from(builder: BeginSettle<'_>) -> Self {
        let mut order_pdas = Vec::with_capacity(builder.orders.len());
        let mut sell_token_accounts = Vec::with_capacity(builder.orders.len());
        let mut pull_lists: Vec<&[Pull]> = Vec::with_capacity(builder.orders.len());
        for order in builder.orders {
            let (order_pda, _bump) = find_order_pda(&builder.program_id, &order.intent.uid());
            order_pdas.push(order_pda);
            sell_token_accounts.push(order.intent.sell_token_account);
            pull_lists.push(order.pulls);
        }
        let (state_pda, _bump) = find_state_pda(&builder.program_id);
        cow_settlement_interface::instruction::settle::BeginSettle {
            program_id: builder.program_id,
            state_pda,
            finalize_ix_index: builder.finalize_ix_index,
            auction_id: builder.auction_id,
            order_pdas: &order_pdas,
            sell_token_accounts: &sell_token_accounts,
            pulls: &pull_lists,
        }
        .into()
    }
}

/// A settled order whose proceeds are pushed to it: `intent` identifies the
/// order (its `buy_token_account` is the push destination), `mint` selects the
/// canonical source buffer, and `amount` is the quantity to push.
/// Technically the mint is already included in the intent, but for that we need
/// to read the sell account data on-chain, which makes the builder harder to
/// use.
pub struct FinalizedIntent<'a> {
    pub intent: &'a OrderIntent,
    pub mint: Pubkey,
    pub amount: u64,
}

/// Builder for a `FinalizeSettle` instruction pushing each order's proceeds to
/// its buy token account.
///
/// The destination is the order intent's `buy_token_account` and the source is
/// the canonical buffer PDA for `mint` (see [`find_buffer_pda`]). The orders are
/// sorted by their canonical order PDA (the same key [`BeginSettle`] orders its
/// settled-order list by) so the two instructions present the orders in the
/// same order and their lists line up.
pub struct FinalizeSettle<'a> {
    pub program_id: Pubkey,
    pub begin_ix_index: u16,
    pub orders: &'a [FinalizedIntent<'a>],
}

impl From<FinalizeSettle<'_>> for Instruction {
    fn from(builder: FinalizeSettle<'_>) -> Self {
        // Sort the orders by their canonical order PDA, the key `BeginSettle`
        // lays its settled orders out by, so the two instruction lists align.
        // For BeginSettle, sorting can take place in the interface. But the
        // order PDAs don't appear in the actual FinalizeSettle instruction, so
        // the sorting can only happen here.
        let num_orders = builder.orders.len();
        let mut orders: Vec<usize> = (0..num_orders).collect();
        orders.sort_by_key(|&i| {
            find_order_pda(&builder.program_id, &builder.orders[i].intent.uid()).0
        });

        let mut source_buffers: Vec<Pubkey> = Vec::with_capacity(num_orders);
        let mut destinations = Vec::with_capacity(num_orders);
        let mut bumps = Vec::with_capacity(num_orders);
        let mut amounts = Vec::with_capacity(num_orders);
        for &i in &orders {
            let (buffer_pda, bump) = find_buffer_pda(&builder.program_id, &builder.orders[i].mint);
            source_buffers.push(buffer_pda);
            destinations.push(builder.orders[i].intent.buy_token_account);
            bumps.push(bump);
            amounts.push(builder.orders[i].amount);
        }
        let (state_pda, _bump) = find_state_pda(&builder.program_id);
        cow_settlement_interface::instruction::settle::FinalizeSettle {
            program_id: builder.program_id,
            state_pda,
            begin_ix_index: builder.begin_ix_index,
            source_buffers: &source_buffers,
            destinations: &destinations,
            bumps: &bumps,
            amounts: &amounts,
        }
        .into()
    }
}

pub struct CreateOrder<'a> {
    pub program_id: Pubkey,
    pub owner: Pubkey,
    pub created_by: Pubkey,
    pub intent: &'a OrderIntent,
}

impl From<CreateOrder<'_>> for Instruction {
    fn from(builder: CreateOrder<'_>) -> Self {
        let encoded = EncodedOrderIntent::from(builder.intent);
        let (order_pda, _bump) = find_order_pda(&builder.program_id, &encoded.hash());
        let intent_bytes: [u8; EncodedOrderIntent::SIZE] = (&encoded).into();
        cow_settlement_interface::instruction::create_order::CreateOrder {
            program_id: builder.program_id,
            owner: builder.owner,
            created_by: builder.created_by,
            order_pda,
            intent_bytes,
        }
        .into()
    }
}

pub struct CreateBuffers<'a> {
    pub program_id: Pubkey,
    pub payer: Pubkey,
    pub mints: &'a [Pubkey],
}

impl From<CreateBuffers<'_>> for Instruction {
    fn from(builder: CreateBuffers<'_>) -> Self {
        let buffers: Vec<(Pubkey, Pubkey)> = builder
            .mints
            .iter()
            .map(|mint| (find_buffer_pda(&builder.program_id, mint).0, *mint))
            .collect();
        cow_settlement_interface::instruction::create_buffer::CreateBuffers {
            program_id: builder.program_id,
            payer: builder.payer,
            buffers: &buffers,
        }
        .into()
    }
}

pub struct Initialize {
    pub program_id: Pubkey,
    pub payer: Pubkey,
    pub manager: Pubkey,
    pub reclaim_authority: Pubkey,
}

impl From<Initialize> for Instruction {
    fn from(builder: Initialize) -> Self {
        let (state_pda, _bump) = find_state_pda(&builder.program_id);
        cow_settlement_interface::instruction::initialize::Initialize {
            program_id: builder.program_id,
            payer: builder.payer,
            state_pda,
            manager: builder.manager,
            reclaim_authority: builder.reclaim_authority,
        }
        .into()
    }
}

/// Builder for a `ReclaimBuffer` instruction closing the buffer for each of
/// `mints` and sending their rent lamports to `reclaim_recipient`, which
/// `reclaim_authority` picks freely and may set to itself.
///
/// A buffer that still holds a token balance is silently skipped rather than
/// closed, so a successful instruction is no guarantee that any buffer went
/// away. This is done to prevent accidental loss of funds.
pub struct ReclaimBuffer<'a> {
    pub program_id: Pubkey,
    pub reclaim_authority: Pubkey,
    pub reclaim_recipient: Pubkey,
    pub mints: &'a [Pubkey],
}

impl From<ReclaimBuffer<'_>> for Instruction {
    fn from(builder: ReclaimBuffer<'_>) -> Self {
        let (state_pda, _bump) = find_state_pda(&builder.program_id);
        let buffers: Vec<(Pubkey, Pubkey)> = builder
            .mints
            .iter()
            .map(|mint| {
                let (buffer_pda, _bump) = find_buffer_pda(&builder.program_id, mint);
                (buffer_pda, *mint)
            })
            .collect();
        cow_settlement_interface::instruction::reclaim_buffer::ReclaimBuffer {
            program_id: builder.program_id,
            state_pda,
            reclaim_authority: builder.reclaim_authority,
            reclaim_recipient: builder.reclaim_recipient,
            buffers: &buffers,
        }
        .into()
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use ::proptest::{prelude::*, test_runner::TestCaseError};
    use cow_settlement_interface::{
        data::intent::fixtures::arb_order_intent,
        instruction::{
            fixtures::fake_account_from_array,
            settle::{
                BeginSettleInput, FinalizeSettleInput, INSTRUCTIONS_SYSVAR_ID, SPL_TOKEN_PROGRAM_ID,
            },
            InstructionInputParsing,
        },
        pda::order::find_order_pda,
    };

    proptest! {
        // `BeginSettle` derives each order's PDA from its intent and forwards to
        // the interface builder so that the on-chain parser recovers exactly
        // those orders.
        #[test]
        fn begin_settle_derives_orders_from_intents(
            finalize_ix_index in any::<u16>(),
            intents in prop::collection::vec(arb_order_intent(), 1..=5),
        ) {
            let program_id = Pubkey::new_unique();
            // No pulls here: this test only checks that orders are derived and
            // laid out correctly.
            let orders: Vec<InitializedIntent> = intents
                .iter()
                .map(|intent| InitializedIntent { intent, pulls: &[] })
                .collect();
            let ix = Instruction::from(BeginSettle {
                program_id,
                finalize_ix_index,
                auction_id: 0,
                orders: &orders,
            });

            // Expected orders: each intent's canonical PDA paired with its sell
            // token account, sorted by PDA address (the builder's order).
            let mut expected: Vec<(Pubkey, Pubkey)> = intents
                .iter()
                .map(|intent| {
                    let (order_pda, _bump) = find_order_pda(&program_id, &intent.uid());
                    (order_pda, intent.sell_token_account)
                })
                .collect();
            expected.sort_by_key(|(order_pda, _)| *order_pda);

            let accounts: Vec<_> = ix
                .accounts
                .iter()
                .map(|meta| fake_account_from_array(meta.pubkey.to_bytes()))
                .collect();
            let parsed = BeginSettleInput::parse(&ix.data, &accounts)
                .map_err(|e| TestCaseError::fail(format!("parse failed: {e:?}")))?;

            prop_assert_eq!(parsed.finalize_ix_index, finalize_ix_index);
            prop_assert_eq!(
                parsed.instructions_sysvar_account.address(),
                &INSTRUCTIONS_SYSVAR_ID,
            );

            let actual: Vec<(Pubkey, Pubkey)> = parsed
                .orders
                .iter()
                .map(|order| {
                    (
                        *order.order_pda.address(),
                        *order.sell_token_account.address(),
                    )
                })
                .collect();
            prop_assert_eq!(actual, expected);
        }

        // `FinalizeSettle` derives each order's source buffer from its mint and
        // destination from the intent, sorting by canonical order PDA like
        // `BeginSettle` so the on-chain parser recovers exactly those pushes in
        // that order.
        #[test]
        fn finalize_settle_derives_buffers_from_mints(
            begin_ix_index in any::<u16>(),
            cases in prop::collection::vec(
                (arb_order_intent(), any::<[u8; 32]>(), any::<u64>()),
                1..=5,
            ),
        ) {
            let program_id = Pubkey::new_unique();
            let orders: Vec<FinalizedIntent> = cases
                .iter()
                .map(|(intent, mint, amount)| FinalizedIntent {
                    intent,
                    mint: Pubkey::new_from_array(*mint),
                    amount: *amount,
                })
                .collect();
            let ix = Instruction::from(FinalizeSettle {
                program_id,
                begin_ix_index,
                orders: &orders,
            });

            // Expected pushes: each order's buffer PDA (and its canonical bump),
            // buy token account, and amount, sorted by the order's canonical PDA
            // (the builder's order).
            struct ExpectedPush {
                order_pda: Pubkey,
                buffer: Pubkey,
                bump: u8,
                destination: Pubkey,
                amount: u64,
            }
            let mut expected: Vec<ExpectedPush> = orders
                .iter()
                .map(|order| {
                    let (order_pda, _bump) = find_order_pda(&program_id, &order.intent.uid());
                    let (buffer, bump) = find_buffer_pda(&program_id, &order.mint);
                    ExpectedPush {
                        order_pda,
                        buffer,
                        bump,
                        destination: order.intent.buy_token_account,
                        amount: order.amount,
                    }
                })
                .collect();
            expected.sort_by_key(|push| push.order_pda);

            let accounts: Vec<_> = ix
                .accounts
                .iter()
                .map(|meta| fake_account_from_array(meta.pubkey.to_bytes()))
                .collect();
            let parsed = FinalizeSettleInput::parse(&ix.data, &accounts)
                .map_err(|e| TestCaseError::fail(format!("parse failed: {e:?}")))?;

            prop_assert_eq!(parsed.begin_ix_index, begin_ix_index);
            prop_assert_eq!(
                parsed.instructions_sysvar_account.address(),
                &INSTRUCTIONS_SYSVAR_ID,
            );
            let (state_pda, _bump) = find_state_pda(&program_id);
            prop_assert_eq!(parsed.state_pda_account.address(), &state_pda);
            prop_assert_eq!(
                parsed.token_program_account.address(),
                &SPL_TOKEN_PROGRAM_ID,
            );

            let parsed_pushes: Vec<_> = parsed.pushes.iter().collect();
            prop_assert_eq!(parsed_pushes.len(), expected.len());
            for (push, expected) in parsed_pushes.iter().zip(&expected) {
                prop_assert_eq!(push.source_buffer.address(), &expected.buffer);
                prop_assert_eq!(push.destination.address(), &expected.destination);
                prop_assert_eq!(push.bump, expected.bump);
                prop_assert_eq!(push.amount, expected.amount);
            }
        }
    }
}