// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

import "./UniversalCCIPBridge.sol";

/**
 * @title CommodityCCIPBridge
 * @notice Specialized bridge for commodity-backed tokens (gold, oil, etc.)
 * @dev Includes certificate validation and physical delivery coordination
 */
contract CommodityCCIPBridge is UniversalCCIPBridge {
    
    // Certificate registry (authenticity verification)
    mapping(address => mapping(bytes32 => bool)) public validCertificates;
    mapping(address => mapping(bytes32 => CertificateInfo)) public certificates;
    
    struct CertificateInfo {
        bytes32 certificateHash;
        address custodian;
        uint256 quantity;
        string commodityType;
        uint256 issuedAt;
        uint256 expiresAt;
        bool isValid;
    }
    
    // Custodian registry
    mapping(address => address) public tokenCustodians;
    mapping(address => bool) public approvedCustodians;
    
    // Physical delivery tracking
    struct DeliveryRequest {
        bytes32 messageId;
        address token;
        uint256 amount;
        address requester;
        string deliveryAddress;
        uint256 requestedAt;
        DeliveryStatus status;
    }
    
    enum DeliveryStatus {
        Requested,
        Confirmed,
        InTransit,
        Delivered,
        Cancelled
    }
    
    mapping(bytes32 => DeliveryRequest) public deliveryRequests;
    bytes32[] public deliveryIds;

    event CertificateRegistered(
        address indexed token,
        bytes32 indexed certificateHash,
        address custodian
    );
    
    event PhysicalDeliveryRequested(
        bytes32 indexed deliveryId,
        bytes32 indexed messageId,
        address token,
        uint256 amount
    );
    
    event DeliveryStatusUpdated(
        bytes32 indexed deliveryId,
        DeliveryStatus status
    );

    /**
     * @notice Bridge commodity token with certificate validation
     */
    function bridgeCommodity(
        address token,
        uint256 amount,
        uint64 destinationChain,
        address recipient,
        bytes32 certificateHash,
        bytes calldata custodianSignature
    ) external nonReentrant returns (bytes32 messageId) {
        // Verify asset is Commodity type
        UniversalAssetRegistry.UniversalAsset memory asset = assetRegistry.getAsset(token);
        require(asset.assetType == UniversalAssetRegistry.AssetType.Commodity, "Not commodity");
        require(asset.isActive, "Asset not active");
        
        // Verify certificate
        require(validCertificates[token][certificateHash], "Invalid certificate");
        
        CertificateInfo memory cert = certificates[token][certificateHash];
        require(cert.isValid, "Certificate not valid");
        require(block.timestamp < cert.expiresAt, "Certificate expired");
        require(cert.quantity >= amount, "Certificate insufficient");
        
        // Verify custodian
        require(approvedCustodians[cert.custodian], "Custodian not approved");
        
        // Verify custodian signature
        _verifyCustodianSignature(token, amount, certificateHash, custodianSignature, cert.custodian);
        
        // Execute bridge
        BridgeOperation memory op = BridgeOperation({
            token: token,
            amount: amount,
            destinationChain: destinationChain,
            recipient: recipient,
            assetType: bytes32(uint256(UniversalAssetRegistry.AssetType.Commodity)),
            usePMM: true, // Commodities can use PMM
            useVault: false,
            complianceProof: abi.encode(certificateHash),
            vaultInstructions: ""
        });
        
        messageId = this.bridge(op);
        
        return messageId;
    }

    /**
     * @notice Initiate physical delivery of commodity
     */
    function initiatePhysicalDelivery(
        bytes32 messageId,
        string calldata deliveryAddress
    ) external returns (bytes32 deliveryId) {
        require(messageId != bytes32(0), "Invalid message ID");
        
        deliveryId = keccak256(abi.encode(messageId, msg.sender, block.timestamp));
        
        // This would integrate with off-chain logistics systems
        deliveryRequests[deliveryId] = DeliveryRequest({
            messageId: messageId,
            token: address(0), // Would be fetched from bridge record
            amount: 0,         // Would be fetched from bridge record
            requester: msg.sender,
            deliveryAddress: deliveryAddress,
            requestedAt: block.timestamp,
            status: DeliveryStatus.Requested
        });
        
        deliveryIds.push(deliveryId);
        
        emit PhysicalDeliveryRequested(deliveryId, messageId, address(0), 0);
        
        return deliveryId;
    }

    /**
     * @notice Update physical delivery status
     */
    function updateDeliveryStatus(
        bytes32 deliveryId,
        DeliveryStatus status
    ) external onlyRole(BRIDGE_OPERATOR_ROLE) {
        require(deliveryRequests[deliveryId].requestedAt > 0, "Delivery not found");
        
        deliveryRequests[deliveryId].status = status;
        
        emit DeliveryStatusUpdated(deliveryId, status);
    }

    /**
     * @notice Verify custodian signature
     */
    function _verifyCustodianSignature(
        address /* token */,
        uint256 /* amount */,
        bytes32 certificateHash,
        bytes memory signature,
        address custodian
    ) internal view {
        // In production, this would use EIP-712 signature verification
        // For now, simplified check
        require(signature.length > 0, "Missing signature");
        require(custodian != address(0), "Invalid custodian");
    }

    // Admin functions
    
    function registerCertificate(
        address token,
        bytes32 certificateHash,
        address custodian,
        uint256 quantity,
        string calldata commodityType,
        uint256 expiresAt
    ) external onlyRole(BRIDGE_OPERATOR_ROLE) {
        validCertificates[token][certificateHash] = true;
        
        certificates[token][certificateHash] = CertificateInfo({
            certificateHash: certificateHash,
            custodian: custodian,
            quantity: quantity,
            commodityType: commodityType,
            issuedAt: block.timestamp,
            expiresAt: expiresAt,
            isValid: true
        });
        
        emit CertificateRegistered(token, certificateHash, custodian);
    }

    function approveCustodian(address custodian, bool approved) external onlyRole(DEFAULT_ADMIN_ROLE) {
        approvedCustodians[custodian] = approved;
    }

    function revokeCertificate(address token, bytes32 certificateHash) 
        external onlyRole(BRIDGE_OPERATOR_ROLE) {
        validCertificates[token][certificateHash] = false;
        certificates[token][certificateHash].isValid = false;
    }
}