contract BlindAuction is ZamaEthereumConfig {
    struct Auction {
        address creator;
        uint256 biddingEndTime;
        uint256 revealEndTime;
        euint64 highestBid;        // ENCRYPTED
        address highestBidder;
        uint64 revealedHighestBid;
        bool ended;
    }

    // Phase 1: Place encrypted bid
    function placeBid(
        uint256 auctionId,
        externalEuint64 encryptedBid,
        bytes calldata inputProof
    ) external {
        euint64 bid = FHE.fromExternal(encryptedBid, inputProof);

        if (FHE.isInitialized(auction.highestBid)) {
            ebool isHigher = FHE.gt(bid, auction.highestBid);
            auction.highestBid = FHE.select(isHigher, bid, auction.highestBid);
        } else {
            auction.highestBid = bid;  // First bid
        }

        FHE.allowThis(auction.highestBid);
    }

    // Phase 2: Request reveal
    function requestReveal(uint256 auctionId) external {
        auction.highestBid = FHE.makePubliclyDecryptable(auction.highestBid);
        emit RevealRequested(auctionId, FHE.toBytes32(auction.highestBid));
    }

    // Phase 3: Settlement with proof verification
    function endAuction(
        uint256 auctionId,
        bytes memory cleartexts,
        bytes memory decryptionProof
    ) external {
        bytes32[] memory handlesList = new bytes32[](1);
        handlesList[0] = FHE.toBytes32(auction.highestBid);
        FHE.checkSignatures(handlesList, cleartexts, decryptionProof);

        auction.revealedHighestBid = abi.decode(cleartexts, (uint64));
        auction.ended = true;
    }
}

contract ERC7984Mock is ERC7984, ZamaEthereumConfig, Ownable {
    // Hook: Called on every mint / burn / transfer
    function _update(
        address from, address to, euint64 amount
    ) internal virtual override returns (euint64 transferred) {
        transferred = super._update(from, to, amount);
        // Grant owner access to total supply (for monitoring)
        FHE.allow(confidentialTotalSupply(), _OWNER);
    }

    // Mint with external encrypted input (production)
    function $_mint(
        address to, externalEuint64 encryptedAmount, bytes calldata inputProof
    ) public onlyOwner returns (euint64) {
        euint64 internalAmount = FHE.fromExternal(encryptedAmount, inputProof);
        return _mint(to, internalAmount);
    }

    // Transfer with external encrypted input
    function $_transfer(
        address from, address to,
        externalEuint64 encryptedAmount, bytes calldata inputProof
    ) public returns (euint64) {
        return _transfer(from, to, FHE.fromExternal(encryptedAmount, inputProof));
    }
}

auction.highestBid = FHE.select(isHigher, bid, auction.highestBid);
FHE.allowThis(auction.highestBid);  // REQUIRED!