IAllowanceTransfer.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import {IEIP712} from "./IEIP712.sol";

/// @title AllowanceTransfer
/// @notice Handles ERC20 token permissions through signature based allowance setting and ERC20 token transfers by checking allowed amounts
/// @dev Requires user's token approval on the Permit2 contract
interface IAllowanceTransfer is IEIP712 {
    /// @notice Thrown when an allowance on a token has expired.
    /// @param deadline The timestamp at which the allowed amount is no longer valid
    error AllowanceExpired(uint256 deadline);

    /// @notice Thrown when an allowance on a token has been depleted.
    /// @param amount The maximum amount allowed
    error InsufficientAllowance(uint256 amount);

    /// @notice Thrown when too many nonces are invalidated.
    error ExcessiveInvalidation();

    /// @notice Emits an event when the owner successfully invalidates an ordered nonce.
    event NonceInvalidation(
        address indexed owner, address indexed token, address indexed spender, uint48 newNonce, uint48 oldNonce
    );

    /// @notice Emits an event when the owner successfully sets permissions on a token for the spender.
    event Approval(
        address indexed owner, address indexed token, address indexed spender, uint160 amount, uint48 expiration
    );

    /// @notice Emits an event when the owner successfully sets permissions using a permit signature on a token for the spender.
    event Permit(
        address indexed owner,
        address indexed token,
        address indexed spender,
        uint160 amount,
        uint48 expiration,
        uint48 nonce
    );

    /// @notice Emits an event when the owner sets the allowance back to 0 with the lockdown function.
    event Lockdown(address indexed owner, address token, address spender);

    /// @notice The permit data for a token
    struct PermitDetails {
        // ERC20 token address
        address token;
        // the maximum amount allowed to spend
        uint160 amount;
        // timestamp at which a spender's token allowances become invalid
        uint48 expiration;
        // an incrementing value indexed per owner,token,and spender for each signature
        uint48 nonce;
    }

    /// @notice The permit message signed for a single token allowance
    struct PermitSingle {
        // the permit data for a single token alownce
        PermitDetails details;
        // address permissioned on the allowed tokens
        address spender;
        // deadline on the permit signature
        uint256 sigDeadline;
    }

    /// @notice The permit message signed for multiple token allowances
    struct PermitBatch {
        // the permit data for multiple token allowances
        PermitDetails[] details;
        // address permissioned on the allowed tokens
        address spender;
        // deadline on the permit signature
        uint256 sigDeadline;
    }

    /// @notice The saved permissions
    /// @dev This info is saved per owner, per token, per spender and all signed over in the permit message
    /// @dev Setting amount to type(uint160).max sets an unlimited approval
    struct PackedAllowance {
        // amount allowed
        uint160 amount;
        // permission expiry
        uint48 expiration;
        // an incrementing value indexed per owner,token,and spender for each signature
        uint48 nonce;
    }

    /// @notice A token spender pair.
    struct TokenSpenderPair {
        // the token the spender is approved
        address token;
        // the spender address
        address spender;
    }

    /// @notice Details for a token transfer.
    struct AllowanceTransferDetails {
        // the owner of the token
        address from;
        // the recipient of the token
        address to;
        // the amount of the token
        uint160 amount;
        // the token to be transferred
        address token;
    }

    /// @notice A mapping from owner address to token address to spender address to PackedAllowance struct, which contains details and conditions of the approval.
    /// @notice The mapping is indexed in the above order see: allowance[ownerAddress][tokenAddress][spenderAddress]
    /// @dev The packed slot holds the allowed amount, expiration at which the allowed amount is no longer valid, and current nonce thats updated on any signature based approvals.
    function allowance(address user, address token, address spender)
        external
        view
        returns (uint160 amount, uint48 expiration, uint48 nonce);

    /// @notice Approves the spender to use up to amount of the specified token up until the expiration
    /// @param token The token to approve
    /// @param spender The spender address to approve
    /// @param amount The approved amount of the token
    /// @param expiration The timestamp at which the approval is no longer valid
    /// @dev The packed allowance also holds a nonce, which will stay unchanged in approve
    /// @dev Setting amount to type(uint160).max sets an unlimited approval
    function approve(address token, address spender, uint160 amount, uint48 expiration) external;

    /// @notice Permit a spender to a given amount of the owners token via the owner's EIP-712 signature
    /// @dev May fail if the owner's nonce was invalidated in-flight by invalidateNonce
    /// @param owner The owner of the tokens being approved
    /// @param permitSingle Data signed over by the owner specifying the terms of approval
    /// @param signature The owner's signature over the permit data
    function permit(address owner, PermitSingle memory permitSingle, bytes calldata signature) external;

    /// @notice Permit a spender to the signed amounts of the owners tokens via the owner's EIP-712 signature
    /// @dev May fail if the owner's nonce was invalidated in-flight by invalidateNonce
    /// @param owner The owner of the tokens being approved
    /// @param permitBatch Data signed over by the owner specifying the terms of approval
    /// @param signature The owner's signature over the permit data
    function permit(address owner, PermitBatch memory permitBatch, bytes calldata signature) external;

    /// @notice Transfer approved tokens from one address to another
    /// @param from The address to transfer from
    /// @param to The address of the recipient
    /// @param amount The amount of the token to transfer
    /// @param token The token address to transfer
    /// @dev Requires the from address to have approved at least the desired amount
    /// of tokens to msg.sender.
    function transferFrom(address from, address to, uint160 amount, address token) external;

    /// @notice Transfer approved tokens in a batch
    /// @param transferDetails Array of owners, recipients, amounts, and tokens for the transfers
    /// @dev Requires the from addresses to have approved at least the desired amount
    /// of tokens to msg.sender.
    function transferFrom(AllowanceTransferDetails[] calldata transferDetails) external;

    /// @notice Enables performing a "lockdown" of the sender's Permit2 identity
    /// by batch revoking approvals
    /// @param approvals Array of approvals to revoke.
    function lockdown(TokenSpenderPair[] calldata approvals) external;

    /// @notice Invalidate nonces for a given (token, spender) pair
    /// @param token The token to invalidate nonces for
    /// @param spender The spender to invalidate nonces for
    /// @param newNonce The new nonce to set. Invalidates all nonces less than it.
    /// @dev Can't invalidate more than 2**16 nonces per transaction.
    function invalidateNonces(address token, address spender, uint48 newNonce) external;
}