IDefiBridge.sol

// SPDX-License-Identifier: Apache-2.0
// Copyright 2022 Aztec
pragma solidity >=0.8.4;

import {AztecTypes} from "rollup-encoder/libraries/AztecTypes.sol";

interface IDefiBridge {
    /**
     * @notice A function which converts input assets to output assets.
     * @param _inputAssetA A struct detailing the first input asset
     * @param _inputAssetB A struct detailing the second input asset
     * @param _outputAssetA A struct detailing the first output asset
     * @param _outputAssetB A struct detailing the second output asset
     * @param _totalInputValue An amount of input assets transferred to the bridge (Note: "total" is in the name
     *                         because the value can represent summed/aggregated token amounts of users actions on L2)
     * @param _interactionNonce A globally unique identifier of this interaction/`convert(...)` call.
     * @param _auxData Bridge specific data to be passed into the bridge contract (e.g. slippage, nftID etc.)
     * @return outputValueA An amount of `_outputAssetA` returned from this interaction.
     * @return outputValueB An amount of `_outputAssetB` returned from this interaction.
     * @return isAsync A flag indicating if the interaction is async.
     * @dev This function is called from the RollupProcessor contract via the DefiBridgeProxy. Before this function is
     *      called _RollupProcessor_ contract will have sent you all the assets defined by the input params. This
     *      function is expected to convert input assets to output assets (e.g. on Uniswap) and return the amounts
     *      of output assets to be received by the _RollupProcessor_. If output assets are ERC20 tokens the bridge has
     *      to _RollupProcessor_ as a spender before the interaction is finished. If some of the output assets is ETH
     *      it has to be sent to _RollupProcessor_ via the `receiveEthFromBridge(uint256 _interactionNonce)` method
     *      inside before the `convert(...)` function call finishes.
     * @dev If there are two input assets, equal amounts of both assets will be transferred to the bridge before this
     *      method is called.
     * @dev **BOTH** output assets could be virtual but since their `assetId` is currently assigned as
     *      `_interactionNonce` it would simply mean that more of the same virtual asset is minted.
     * @dev If this interaction is async the function has to return `(0,0 true)`. Async interaction will be finalised at
     *      a later time and its output assets will be returned in a `IDefiBridge.finalise(...)` call.
     *
     */
    function convert(
        AztecTypes.AztecAsset calldata _inputAssetA,
        AztecTypes.AztecAsset calldata _inputAssetB,
        AztecTypes.AztecAsset calldata _outputAssetA,
        AztecTypes.AztecAsset calldata _outputAssetB,
        uint256 _totalInputValue,
        uint256 _interactionNonce,
        uint64 _auxData,
        address _rollupBeneficiary
    ) external payable returns (uint256 outputValueA, uint256 outputValueB, bool isAsync);

    /**
     * @notice A function that finalises asynchronous interaction.
     * @param _inputAssetA A struct detailing the first input asset
     * @param _inputAssetB A struct detailing the second input asset
     * @param _outputAssetA A struct detailing the first output asset
     * @param _outputAssetB A struct detailing the second output asset
     * @param _interactionNonce A globally unique identifier of this interaction/`convert(...)` call.
     * @param _auxData Bridge specific data to be passed into the bridge contract (e.g. slippage, nftID etc.)
     * @return outputValueA An amount of `_outputAssetA` returned from this interaction.
     * @return outputValueB An amount of `_outputAssetB` returned from this interaction.
     * @dev This function should use the `BridgeBase.onlyRollup()` modifier to ensure it can only be called from
     *      the `RollupProcessor.processAsyncDefiInteraction(uint256 _interactionNonce)` method.
     *
     */
    function finalise(
        AztecTypes.AztecAsset calldata _inputAssetA,
        AztecTypes.AztecAsset calldata _inputAssetB,
        AztecTypes.AztecAsset calldata _outputAssetA,
        AztecTypes.AztecAsset calldata _outputAssetB,
        uint256 _interactionNonce,
        uint64 _auxData
    ) external payable returns (uint256 outputValueA, uint256 outputValueB, bool interactionComplete);
}