wip: Uniswap V4 hooks

Refers #389

contracts/src/lib.rs

@@ -46,4 +46,5 @@ extern crate alloc;
 
 pub mod access;
 pub mod token;
+pub mod uniswap;
 pub mod utils;

contracts/src/uniswap/mod.rs

@@ -0,0 +1,3 @@
+//! Contracts implementing Uniswap mechanisms.
+pub mod v4;
+pub use v4::*;

contracts/src/uniswap/v4/hooks.rs

@@ -0,0 +1,259 @@
+//! Uniswap V4 Hooks Interface.
+//!
+//! V4 decides whether to invoke specific hooks by inspecting the least
+//! significant bits of the address that the hooks contract is deployed to.
+//! For example, a hooks contract deployed to address:
+//! 0x0000000000000000000000000000000000002400
+//! has the lowest bits '10 0100 0000 0000' which would cause
+//! the 'before initialize' and 'after add liquidity' hooks to be used.
+//!
+//! See the Hooks library for the full spec.
+//!
+//! Should only be callable by the v4 PoolManager.
+
+use alloy_primitives::{Address, Bytes, FixedBytes, U160};
+use stylus_sdk::stylus_proc::SolidityError;
+
+use crate::uniswap::v4::{
+    BalanceDelta, BeforeSwapDelta, ModifyLiquidityParams, PoolKey, SwapParams,
+    I24, U24,
+};
+
+/// An Uniswap V4 Hook error.
+#[derive(SolidityError, Debug)]
+pub enum Error {}
+
+/// Uniswap V4 Hooks Interface.
+pub trait IHooks {
+    /// The hook called before the state of a pool is initialized.
+    ///
+    /// Returns the function selector for the hook.
+    ///
+    /// # Arguments
+    ///
+    /// * `&mut self` - Write access to the contract's state.
+    /// * `sender` -The initial msg::sender() for the initialize call.
+    /// * `key` - The key for the pool being initialized.
+    /// * `sqrt_price_x96` - The sqrt(price) of the pool as a Q64.96.
+    ///
+    /// # Errors
+    ///
+    /// May return an [`Error`].
+    fn before_initialize(
+        &mut self,
+        sender: Address,
+        key: PoolKey,
+        sqrt_price_x96: U160,
+    ) -> Result<FixedBytes<4>, Error>;
+
+    /// The hook called after the state of a pool is initialized.
+    ///
+    /// Returns the function selector for the hook.
+    ///
+    /// # Arguments
+    ///
+    /// * `&mut self` - Write access to the contract's state.
+    /// * `sender` - The initial msg::sender() for the initialize call.
+    /// * `key` - The key for the pool being initialized.
+    /// * `sqrt_price_x96` -  The sqrt(price) of the pool as a Q64.96.
+    /// * `tick` - The current tick after the state of a pool is initialized.
+    ///
+    /// # Errors
+    ///
+    /// May return an [`Error`].
+    fn after_initialize(
+        &mut self,
+        sender: Address,
+        key: PoolKey,
+        sqrt_price_x96: U160,
+        tick: I24,
+    ) -> Result<FixedBytes<4>, Error>;
+
+    /// The hook called before liquidity is added.
+    ///
+    /// Returns the function selector for the hook.
+    ///
+    /// # Arguments
+    ///
+    /// * `&mut self` - Write access to the contract's state.
+    /// * `sender` - The initial msg::sender() for the add liquidity call.
+    /// * `key` - The key for the pool.
+    /// * `params` - The parameters for adding liquidity.
+    /// *` hook_data` - Arbitrary data handed into the Pool Manager by the
+    ///    liquidity provider to be passed on to the hook.
+    ///
+    /// # Errors
+    ///
+    /// May return an [`Error`].
+    fn before_add_liquidity(
+        &mut self,
+        sender: Address,
+        key: PoolKey,
+        params: ModifyLiquidityParams,
+        hook_data: Bytes,
+    ) -> Result<FixedBytes<4>, Error>;
+
+    /// The hook called after liquidity is added
+    ///
+    /// Returns tuple containing the function selector for the hook, and
+    /// the hook's delta in token0 and token1.
+    /// Positive: the hook is owed/took currency.
+    /// Negative: the hook owes/sent currency.
+    ///
+    /// # Arguments
+    ///
+    /// * `&mut self` - Write access to the contract's state.
+    /// * `sender` - The initial msg::sender() for the add liquidity call.
+    /// * `key` - The key for the pool.
+    /// * `params` - The parameters for adding liquidity.
+    /// * `delta` - The caller's balance delta after adding liquidity; the sum
+    ///   of principal delta, fees accrued, and hook delta.
+    /// * `fees_accrued` - The fees accrued since the last time fees were
+    ///   collected from this position.
+    /// * `hook_data` - Arbitrary data handed into the Pool Manager by the
+    ///   liquidity provider to be passed on to the hook.
+    ///
+    /// # Errors
+    ///
+    /// May return an [`Error`].
+    fn after_add_liquidity(
+        &mut self,
+        sender: Address,
+        key: PoolKey,
+        params: ModifyLiquidityParams,
+        delta: BalanceDelta,
+        fees_accrued: BalanceDelta,
+        hook_data: Bytes,
+    ) -> Result<(FixedBytes<4>, BalanceDelta), Error>;
+
+    /// The hook called before liquidity is removed.
+    ///
+    /// Returns the function selector for the hook.
+    ///
+    /// # Arguments
+    ///
+    /// * `&mut self` - Write access to the contract's state.
+    /// * `sender` - The initial msg::sender() for the remove liquidity call.
+    /// * `key` -  The key for the pool.
+    /// * `params` - The parameters for removing liquidity.
+    /// * `hook_data` - Arbitrary data handed into the Pool Manager by the
+    ///   liquidity provider to be be passed on to the hook.
+    ///
+    /// # Errors
+    ///
+    /// May return an [`Error`].
+    fn before_remove_liquidity(
+        &mut self,
+        sender: Address,
+        key: PoolKey,
+        params: ModifyLiquidityParams,
+        hook_data: Bytes,
+    ) -> Result<FixedBytes<4>, Error>;
+
+    /// The hook called after liquidity is removed.
+    ///
+    /// Returns tuple containing the function selector for the hook, and
+    /// the hook's delta in token0 and token1.
+    /// Positive: the hook is owed/took currency.
+    /// Negative: the hook owes/sent currency.
+    ///
+    /// # Arguments
+    ///
+    /// * `&mut self` - Write access to the contract's state.
+    /// * `sender` - The initial msg::sender() for the remove liquidity call.
+    /// * `key` - The key for the pool.
+    /// * `params` - The parameters for removing liquidity.
+    /// * `delta` - The caller's balance delta after removing liquidity; the sum
+    ///   of principal delta, fees accrued, and hook delta.
+    /// * `fees_accrued` - The fees accrued since the last time fees were
+    ///   collected from this position.
+    /// * `hook_data` - Arbitrary data handed into the Pool Manager by the
+    ///   liquidity provider to be be passed on to the hook.
+    ///
+    /// # Errors
+    ///
+    /// May return an [`Error`].
+    fn after_remove_liquidity(
+        &mut self,
+        sender: Address,
+        key: PoolKey,
+        params: ModifyLiquidityParams,
+        delta: BalanceDelta,
+        fees_accrued: BalanceDelta,
+        hook_data: Bytes,
+    ) -> Result<(FixedBytes<4>, BalanceDelta), Error>;
+
+    /// The hook called before a swap.
+    ///
+    /// Returns tuple containing the function selector for the hook, and
+    /// the hook's delta in specified and unspecified currencies, and
+    /// optionally override the lp fee, only used if three conditions are met:
+    /// 1. the Pool has a dynamic fee,
+    /// 2. the value's 2nd highest bit is set (23rd bit, 0x400000), and
+    /// 3. the value is less than or equal to the maximum fee (1 million).
+    ///
+    /// # Arguments
+    ///
+    /// * `&mut self` - Write access to the contract's state.
+    /// * `sender` - The initial msg::sender() for the swap call.
+    /// * `key` - The key for the pool.
+    /// * `params` - The parameters for the swap.
+    /// * `hook_data` - Arbitrary data handed into the Pool Manager by the
+    ///   swapper to be be passed on to the hook.
+    /// # Errors
+    ///
+    /// May return an [`Error`].
+    fn before_swap(
+        sender: Address,
+        key: PoolKey,
+        params: SwapParams,
+        hookData: Bytes,
+    ) -> Result<(FixedBytes<4>, BeforeSwapDelta, U24), Error>;
+    /*
+    /// @notice The hook called after a swap
+    /// @param sender The initial msg.sender for the swap call
+    /// @param key The key for the pool
+    /// @param params The parameters for the swap
+    /// @param delta The amount owed to the caller (positive) or owed to the pool (negative)
+    /// @param hookData Arbitrary data handed into the PoolManager by the swapper to be be passed on to the hook
+    /// @return bytes4 The function selector for the hook
+    /// @return int128 The hook's delta in unspecified currency. Positive: the hook is owed/took currency, negative: the hook owes/sent currency
+    function afterSwap(
+        address sender,
+        PoolKey calldata key,
+        IPoolManager.SwapParams calldata params,
+        BalanceDelta delta,
+        bytes calldata hookData
+    ) external returns (bytes4, int128);
+
+    /// @notice The hook called before donate
+    /// @param sender The initial msg.sender for the donate call
+    /// @param key The key for the pool
+    /// @param amount0 The amount of token0 being donated
+    /// @param amount1 The amount of token1 being donated
+    /// @param hookData Arbitrary data handed into the PoolManager by the donor to be be passed on to the hook
+    /// @return bytes4 The function selector for the hook
+    function beforeDonate(
+        address sender,
+        PoolKey calldata key,
+        uint256 amount0,
+        uint256 amount1,
+        bytes calldata hookData
+    ) external returns (bytes4);
+
+    /// @notice The hook called after donate
+    /// @param sender The initial msg.sender for the donate call
+    /// @param key The key for the pool
+    /// @param amount0 The amount of token0 being donated
+    /// @param amount1 The amount of token1 being donated
+    /// @param hookData Arbitrary data handed into the PoolManager by the donor to be be passed on to the hook
+    /// @return bytes4 The function selector for the hook
+    function afterDonate(
+        address sender,
+        PoolKey calldata key,
+        uint256 amount0,
+        uint256 amount1,
+        bytes calldata hookData
+    ) external returns (bytes4);
+    */
+}

contracts/src/uniswap/v4/mod.rs

@@ -0,0 +1,9 @@
+//! Contracts implementing Uniswap V4 mechanisms.
+pub mod hooks;
+pub mod types;
+
+pub use hooks::IHooks;
+pub use types::{
+    BalanceDelta, BeforeSwapDelta, Currency, ModifyLiquidityParams, PoolKey,
+    SwapParams, I24, U24,
+};