Hanzo ID

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;

import "@hanzo/identity/IEAS.sol";
import "@hanzo/identity/ISchemaRegistry.sol";

/// @title IdentityAttestation - On-chain identity and verifiable credentials
/// @notice DID-linked attestations using Ethereum Attestation Service (EAS)
contract IdentityAttestation {
    IEAS public eas;
    ISchemaRegistry public schemaRegistry;

    // Schema UIDs for different credential types
    bytes32 public constant KYC_SCHEMA = keccak256("bool verified,uint64 expiry,string provider");
    bytes32 public constant AGE_SCHEMA = keccak256("bool ageOver18,bool ageOver21,uint64 verifiedAt");
    bytes32 public constant ACCREDITATION_SCHEMA = keccak256("string accreditationType,string jurisdiction,uint64 validUntil");

    // DID to attestation mapping
    mapping(bytes32 => bytes32[]) public didAttestations;

    event AttestationCreated(
        bytes32 indexed did,
        bytes32 indexed attestationId,
        bytes32 indexed schemaId
    );

    event CredentialRevoked(
        bytes32 indexed did,
        bytes32 indexed attestationId
    );

    constructor(address _eas, address _schemaRegistry) {
        eas = IEAS(_eas);
        schemaRegistry = ISchemaRegistry(_schemaRegistry);
    }

    // Create KYC attestation for a DID
    function attestKYC(
        bytes32 did,
        address recipient,
        bool verified,
        uint64 expiry,
        string calldata provider
    ) external returns (bytes32 attestationId) {
        bytes memory data = abi.encode(verified, expiry, provider);

        AttestationRequest memory request = AttestationRequest({
            schema: KYC_SCHEMA,
            data: AttestationRequestData({
                recipient: recipient,
                expirationTime: expiry,
                revocable: true,
                refUID: bytes32(0),
                data: data,
                value: 0
            })
        });

        attestationId = eas.attest(request);
        didAttestations[did].push(attestationId);
        emit AttestationCreated(did, attestationId, KYC_SCHEMA);
    }

    // Create age verification attestation
    function attestAge(
        bytes32 did,
        address recipient,
        bool ageOver18,
        bool ageOver21
    ) external returns (bytes32 attestationId) {
        bytes memory data = abi.encode(ageOver18, ageOver21, block.timestamp);

        AttestationRequest memory request = AttestationRequest({
            schema: AGE_SCHEMA,
            data: AttestationRequestData({
                recipient: recipient,
                expirationTime: 0, // No expiry
                revocable: true,
                refUID: bytes32(0),
                data: data,
                value: 0
            })
        });

        attestationId = eas.attest(request);
        didAttestations[did].push(attestationId);
        emit AttestationCreated(did, attestationId, AGE_SCHEMA);
    }

    // Verify an attestation is valid
    function verifyAttestation(bytes32 attestationId) external view returns (
        bool valid,
        address recipient,
        uint64 expirationTime,
        bool revoked
    ) {
        Attestation memory attestation = eas.getAttestation(attestationId);
        valid = attestation.uid != bytes32(0);
        recipient = attestation.recipient;
        expirationTime = attestation.expirationTime;
        revoked = attestation.revocationTime > 0;
    }

    // Revoke a credential
    function revokeCredential(bytes32 did, bytes32 attestationId) external {
        eas.revoke(RevocationRequest({
            schema: KYC_SCHEMA,
            data: RevocationRequestData({
                uid: attestationId,
                value: 0
            })
        }));
        emit CredentialRevoked(did, attestationId);
    }

    // Get all attestations for a DID
    function getAttestations(bytes32 did) external view returns (bytes32[] memory) {
        return didAttestations[did];
    }
}