// SPDX-License-Identifier: MIT
pragma solidity 0.8.23;

import {ERC721} from "@openzeppelin/contracts/token/ERC721/ERC721.sol";
import {ERC721URIStorage} from "@openzeppelin/contracts/token/ERC721/extensions/ERC721URIStorage.sol";
import {EIP712} from "@openzeppelin/contracts/utils/cryptography/EIP712.sol";
import {SignatureChecker} from "@openzeppelin/contracts/utils/cryptography/SignatureChecker.sol";

/**
 * @title AereIdentityRegistry8004V2 — ERC-8004 Identity Registry, to the letter of the draft.
 *
 * @notice Every function, event, argument order and event indexing here is transcribed from the
 *         ERC-8004 draft text (eips.ethereum.org/EIPS/eip-8004, "Identity Registry" section, read
 *         2026-09-02), not from our earlier adapter. The adapter deployed in Wave A
 *         (AereIdentityRegistry8004, 0x5C65105E) predates the draft's ERC-721 form and fails 10 of
 *         10 identity checks of our own conformance suite; this contract is the one meant to pass
 *         them, and the suite can be run against a local deployment of it before anyone deploys.
 *
 * @dev    Surface (ERC-721 + URIStorage, plus the ERC-8004 additions):
 *           register(string,(string,bytes)[]) / register(string) / register()
 *           setAgentURI(uint256,string)                     -> URIUpdated
 *           getMetadata(uint256,string) / setMetadata(uint256,string,bytes) -> MetadataSet
 *           setAgentWallet(uint256,address,uint256,bytes) / getAgentWallet / unsetAgentWallet
 *         The reserved key `agentWallet` is initialised to the owner at registration, cannot be set
 *         through setMetadata or the register metadata array, is cleared on transfer, and can only
 *         be changed with an EIP-712 signature of the NEW wallet (EOA) or an ERC-1271 approval
 *         (contract wallet), bound to (agentId, newWallet, owner, deadline) under this registry's
 *         domain. `agentCount` is kept for the operational check POP-1 of the suite.
 *         Agent ids start at 1 and never repeat. No owner, no admin, no upgrade.
 */
contract AereIdentityRegistry8004V2 is ERC721URIStorage, EIP712 {
    struct MetadataEntry {
        string metadataKey;
        bytes metadataValue;
    }

    event Registered(uint256 indexed agentId, string agentURI, address indexed owner);
    event URIUpdated(uint256 indexed agentId, string newURI, address indexed updatedBy);
    event MetadataSet(uint256 indexed agentId, string indexed indexedMetadataKey, string metadataKey, bytes metadataValue);

    error NotAgentOwnerOrOperator(uint256 agentId, address caller);
    error ReservedMetadataKey();
    error DeadlinePassed(uint256 deadline, uint256 nowTs);
    error InvalidWalletSignature(address newWallet);
    error ZeroWallet();

    bytes32 private constant AGENT_WALLET_KEY_HASH = keccak256("agentWallet");
    string private constant AGENT_WALLET_KEY = "agentWallet";
    /// @dev EIP-712 type the NEW wallet signs to prove control; `owner` binds it to the current holder.
    bytes32 public constant AGENT_WALLET_TYPEHASH = keccak256("AgentWalletSet(uint256 agentId,address newWallet,address owner,uint256 deadline)");

    uint256 private _nextId = 1;
    uint256 public agentCount;
    mapping(uint256 => mapping(bytes32 => bytes)) private _metadata;
    mapping(uint256 => address) private _agentWallet;

    constructor() ERC721("AERE Agent Identity", "AGENT") EIP712("ERC8004IdentityRegistry", "1") {}

    // ------------------------------------------------------------------ registration

    function register(string calldata agentURI, MetadataEntry[] calldata metadata) external returns (uint256 agentId) {
        agentId = _register(agentURI);
        for (uint256 i = 0; i < metadata.length; i++) {
            _setMetadata(agentId, metadata[i].metadataKey, metadata[i].metadataValue);
        }
        emit Registered(agentId, agentURI, msg.sender);
    }

    function register(string calldata agentURI) external returns (uint256 agentId) {
        agentId = _register(agentURI);
        emit Registered(agentId, agentURI, msg.sender);
    }

    function register() external returns (uint256 agentId) {
        agentId = _register("");
        emit Registered(agentId, "", msg.sender);
    }

    function _register(string memory agentURI) internal returns (uint256 agentId) {
        agentId = _nextId++;
        agentCount += 1;
        _safeMint(msg.sender, agentId);
        if (bytes(agentURI).length != 0) _setTokenURI(agentId, agentURI);
        // the reserved key is initialised to the owner's address (spec: "initially set to the owner's address")
        _agentWallet[agentId] = msg.sender;
        emit MetadataSet(agentId, AGENT_WALLET_KEY, AGENT_WALLET_KEY, abi.encode(msg.sender));
    }

    // ------------------------------------------------------------------ agentURI

    function setAgentURI(uint256 agentId, string calldata newURI) external {
        _requireOwnerOrOperator(agentId);
        _setTokenURI(agentId, newURI);
        emit URIUpdated(agentId, newURI, msg.sender);
    }

    // ------------------------------------------------------------------ metadata

    function getMetadata(uint256 agentId, string memory metadataKey) external view returns (bytes memory) {
        if (keccak256(bytes(metadataKey)) == AGENT_WALLET_KEY_HASH) return abi.encode(_agentWallet[agentId]);
        return _metadata[agentId][keccak256(bytes(metadataKey))];
    }

    function setMetadata(uint256 agentId, string memory metadataKey, bytes memory metadataValue) external {
        _requireOwnerOrOperator(agentId);
        _setMetadata(agentId, metadataKey, metadataValue);
    }

    function _setMetadata(uint256 agentId, string memory metadataKey, bytes memory metadataValue) internal {
        bytes32 k = keccak256(bytes(metadataKey));
        if (k == AGENT_WALLET_KEY_HASH) revert ReservedMetadataKey();
        _metadata[agentId][k] = metadataValue;
        emit MetadataSet(agentId, metadataKey, metadataKey, metadataValue);
    }

    // ------------------------------------------------------------------ agent wallet

    function setAgentWallet(uint256 agentId, address newWallet, uint256 deadline, bytes calldata signature) external {
        _requireOwnerOrOperator(agentId);
        if (newWallet == address(0)) revert ZeroWallet();
        if (block.timestamp > deadline) revert DeadlinePassed(deadline, block.timestamp);
        bytes32 digest = _hashTypedDataV4(keccak256(abi.encode(AGENT_WALLET_TYPEHASH, agentId, newWallet, ownerOf(agentId), deadline)));
        if (!SignatureChecker.isValidSignatureNow(newWallet, digest, signature)) revert InvalidWalletSignature(newWallet);
        _agentWallet[agentId] = newWallet;
        emit MetadataSet(agentId, AGENT_WALLET_KEY, AGENT_WALLET_KEY, abi.encode(newWallet));
    }

    function getAgentWallet(uint256 agentId) external view returns (address) {
        return _agentWallet[agentId];
    }

    function unsetAgentWallet(uint256 agentId) external {
        _requireOwnerOrOperator(agentId);
        _clearWallet(agentId);
    }

    function _clearWallet(uint256 agentId) internal {
        _agentWallet[agentId] = address(0);
        emit MetadataSet(agentId, AGENT_WALLET_KEY, AGENT_WALLET_KEY, abi.encode(address(0)));
    }

    /// @dev spec: "When the agent is transferred, agentWallet is automatically cleared".
    function _afterTokenTransfer(address from, address to, uint256 firstTokenId, uint256 batchSize) internal override {
        super._afterTokenTransfer(from, to, firstTokenId, batchSize);
        if (from != address(0) && to != address(0) && from != to) _clearWallet(firstTokenId);
    }

    // ------------------------------------------------------------------ helpers

    function _requireOwnerOrOperator(uint256 agentId) internal view {
        if (!_isApprovedOrOwner(msg.sender, agentId)) revert NotAgentOwnerOrOperator(agentId, msg.sender);
    }

    /// @notice True when `who` is the owner, the approved address, or an operator of `agentId`.
    function isOwnerOrOperator(uint256 agentId, address who) external view returns (bool) {
        return _isApprovedOrOwner(who, agentId);
    }

    /// @notice EIP-712 domain separator, for wallets that build the AgentWalletSet signature.
    function domainSeparator() external view returns (bytes32) {
        return _domainSeparatorV4();
    }
}