// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.8.12;

import "./UserOperation.sol";

/**
 * Aggregated Signatures validator.
 */
interface IAggregator {

    /**
     * validate aggregated signature.
     * revert if the aggregated signature does not match the given list of operations.
     */
    function validateSignatures(UserOperation[] calldata userOps, bytes calldata signature) external view;

    /**
     * validate signature of a single userOp
     * This method is should be called by bundler after EntryPoint.simulateValidation() returns (reverts) with ValidationResultWithAggregation
     * First it validates the signature over the userOp. Then it returns data to be used when creating the handleOps.
     * @param userOp the userOperation received from the user.
     * @return sigForUserOp the value to put into the signature field of the userOp when calling handleOps.
     *    (usually empty, unless account and aggregator support some kind of "multisig"
     */
    function validateUserOpSignature(UserOperation calldata userOp)
    external view returns (bytes memory sigForUserOp);

    /**
     * aggregate multiple signatures into a single value.
     * This method is called off-chain to calculate the signature to pass with handleOps()
     * bundler MAY use optimized custom code perform this aggregation
     * @param userOps array of UserOperations to collect the signatures from.
     * @return aggregatedSignature the aggregated signature
     */
    function aggregateSignatures(UserOperation[] calldata userOps) external view returns (bytes memory aggregatedSignature);
}