// 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 called by EntryPoint.simulateUserOperation() if the wallet has an aggregator.
     * First it validates the signature over the userOp. then it return data to be used when creating the handleOps:
     * @param userOp the userOperation received from the user.
     * @param offChainSigCheck if true, don't check signature, and leave it for the Bundler to use an off-chain native library.
     * @return sigForUserOp the value to put into the signature field of the userOp when calling handleOps.
     *    (usually empty, unless wallet and aggregator support some kind of "multisig"
     * @return sigForAggregation the value to pass (for all wallets) to aggregateSignatures()
     * @return offChainSigInfo in case offChainSigCheck is true, this value should be used by the off-chain signature code (e.g. it contains the sender's publickey)
     */
    function validateUserOpSignature(UserOperation calldata userOp, bool offChainSigCheck)
    external view returns (bytes memory sigForUserOp, bytes memory sigForAggregation, bytes memory offChainSigInfo);

    /**
     * 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 sigsForAggregation array of values returned by validateUserOpSignature() for each op
   * @return aggregatesSignature the aggregated signature
   */
    function aggregateSignatures(bytes[] calldata sigsForAggregation) external view returns (bytes memory aggregatesSignature);
}