// SPDX-License-Identifier: MIT
pragma solidity ^0.8.21;

import {Initializable} from "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";

import {ECDSA384} from "@solarity/solidity-lib/libs/crypto/ECDSA384.sol";

import {ICertificateSigner} from "../../interfaces/signers/ICertificateSigner.sol";

import {SHA384} from "../../utils/SHA384.sol";

contract CECDSA384Signer is ICertificateSigner, Initializable {
    using ECDSA384 for *;
    using SHA384 for *;

    enum Curve {
        secp384r1,
        brainpoolP384r1
    }

    enum HF {
        sha256,
        sha384
    }

    ECDSA384.Parameters internal _secp384r1CurveParams =
        ECDSA384.Parameters({
            a: hex"fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffeffffffff0000000000000000fffffffc",
            b: hex"b3312fa7e23ee7e4988e056be3f82d19181d9c6efe8141120314088f5013875ac656398d8a2ed19d2a85c8edd3ec2aef",
            gx: hex"aa87ca22be8b05378eb1c71ef320ad746e1d3b628ba79b9859f741e082542a385502f25dbf55296c3a545e3872760ab7",
            gy: hex"3617de4a96262c6f5d9e98bf9292dc29f8f41dbd289a147ce9da3113b5f0b8c00a60b1ce1d7e819d7a431d7c90ea0e5f",
            p: hex"fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffeffffffff0000000000000000ffffffff",
            n: hex"ffffffffffffffffffffffffffffffffffffffffffffffffc7634d81f4372ddf581a0db248b0a77aecec196accc52973"
        });

    ECDSA384.Parameters internal _brainpoolP384r1CurveParams =
        ECDSA384.Parameters({
            a: hex"7bc382c63d8c150c3c72080ace05afa0c2bea28e4fb22787139165efba91f90f8aa5814a503ad4eb04a8c7dd22ce2826",
            b: hex"04a8c7dd22ce28268b39b55416f0447c2fb77de107dcd2a62e880ea53eeb62d57cb4390295dbc9943ab78696fa504c11",
            gx: hex"1d1c64f068cf45ffa2a63a81b7c13f6b8847a3e77ef14fe3db7fcafe0cbd10e8e826e03436d646aaef87b2e247d4af1e",
            gy: hex"8abe1d7520f9c2a45cb1eb8e95cfd55262b70b29feec5864e19c054ff99129280e4646217791811142820341263c5315",
            p: hex"8cb91e82a3386d280f5d6f7e50e641df152f7109ed5456b412b1da197fb71123acd3a729901d1a71874700133107ec53",
            n: hex"8cb91e82a3386d280f5d6f7e50e641df152f7109ed5456b31f166e6cac0425a7cf3ab6af6b7fc3103b883202e9046565"
        });

    Curve public curve;
    HF public hashFunction;

    function __CECDSA384Signer_init(Curve curve_, HF hashFunction_) external initializer {
        curve = curve_;
        hashFunction = hashFunction_;
    }

    function verifyICAOSignature(
        bytes memory x509SignedAttributes_,
        bytes memory icaoMemberSignature_,
        bytes memory icaoMemberKey_
    ) external view returns (bool) {
        ECDSA384.Parameters memory curveParams_;
        function(bytes memory) internal view returns (bytes memory) hasher_;

        if (curve == Curve.secp384r1) {
            curveParams_ = _secp384r1CurveParams;
        } else if (curve == Curve.brainpoolP384r1) {
            curveParams_ = _brainpoolP384r1CurveParams;
        }

        if (hashFunction == HF.sha256) {
            hasher_ = _sha2;
        } else if (hashFunction == HF.sha384) {
            hasher_ = SHA384.sha384;
        }

        return
            curveParams_.verify(
                hasher_(x509SignedAttributes_),
                icaoMemberSignature_,
                icaoMemberKey_
            );
    }

    function _sha2(bytes memory message) internal pure returns (bytes memory) {
        return abi.encodePacked(sha256(message));
    }
}