// SPDX-License-Identifier: MIT
pragma solidity ^0.8.19;

import "@openzeppelin/contracts/access/AccessControl.sol";
import "./interfaces/IPacketRegistry.sol";

/**
 * @title PacketRegistry
 * @notice Records packet lifecycle events for non-scheme participants
 * @dev Tracks packet generation, dispatch, and acknowledgment linked to ChainID 138 triggers
 *      Provides tamper-evident audit trail for instruction packets sent via secure email, AS4, or PDF
 */
contract PacketRegistry is IPacketRegistry, AccessControl {
    bytes32 public constant PACKET_OPERATOR_ROLE = keccak256("PACKET_OPERATOR_ROLE");

    // triggerId => latest packet info
    mapping(uint256 => PacketInfo) private _packets;

    struct PacketInfo {
        bytes32 payloadHash;
        bytes32 mode;
        bytes32 channel;
        bytes32 messageRef;
        bytes32 receiptRef;
        bytes32 status;
        bool generated;
        bool dispatched;
        bool acknowledged;
    }

    /**
     * @notice Initializes the registry with an admin address
     * @param admin Address that will receive DEFAULT_ADMIN_ROLE
     */
    constructor(address admin) {
        _grantRole(DEFAULT_ADMIN_ROLE, admin);
    }

    /**
     * @notice Records that a packet has been generated
     * @dev Requires PACKET_OPERATOR_ROLE
     * @param triggerId The trigger ID from RailTriggerRegistry
     * @param payloadHash SHA-256 hash of the packet payload
     * @param mode Transmission mode (e.g., "PDF", "EMAIL", "AS4")
     */
    function recordGenerated(
        uint256 triggerId,
        bytes32 payloadHash,
        bytes32 mode
    ) external override onlyRole(PACKET_OPERATOR_ROLE) {
        require(triggerId > 0, "PacketRegistry: zero triggerId");
        require(payloadHash != bytes32(0), "PacketRegistry: zero payloadHash");
        require(mode != bytes32(0), "PacketRegistry: zero mode");
        require(!_packets[triggerId].generated, "PacketRegistry: already generated");

        _packets[triggerId].payloadHash = payloadHash;
        _packets[triggerId].mode = mode;
        _packets[triggerId].generated = true;

        emit PacketGenerated(triggerId, payloadHash, mode);
    }

    /**
     * @notice Records that a packet has been dispatched via a channel
     * @dev Requires PACKET_OPERATOR_ROLE. Packet must have been generated first.
     * @param triggerId The trigger ID from RailTriggerRegistry
     * @param channel The dispatch channel (e.g., "EMAIL", "AS4", "PORTAL")
     * @param messageRef The message reference ID from the transport layer
     */
    function recordDispatched(
        uint256 triggerId,
        bytes32 channel,
        bytes32 messageRef
    ) external override onlyRole(PACKET_OPERATOR_ROLE) {
        require(triggerId > 0, "PacketRegistry: zero triggerId");
        require(channel != bytes32(0), "PacketRegistry: zero channel");
        require(messageRef != bytes32(0), "PacketRegistry: zero messageRef");
        require(_packets[triggerId].generated, "PacketRegistry: not generated");
        require(!_packets[triggerId].dispatched, "PacketRegistry: already dispatched");

        _packets[triggerId].channel = channel;
        _packets[triggerId].messageRef = messageRef;
        _packets[triggerId].dispatched = true;

        emit PacketDispatched(triggerId, channel, messageRef);
    }

    /**
     * @notice Records that a packet has been acknowledged by the recipient
     * @dev Requires PACKET_OPERATOR_ROLE. Packet must have been dispatched first.
     * @param triggerId The trigger ID from RailTriggerRegistry
     * @param receiptRef The receipt reference ID from the recipient
     * @param status The acknowledgment status (e.g., "RECEIVED", "ACCEPTED", "REJECTED")
     */
    function recordAcknowledged(
        uint256 triggerId,
        bytes32 receiptRef,
        bytes32 status
    ) external override onlyRole(PACKET_OPERATOR_ROLE) {
        require(triggerId > 0, "PacketRegistry: zero triggerId");
        require(receiptRef != bytes32(0), "PacketRegistry: zero receiptRef");
        require(status != bytes32(0), "PacketRegistry: zero status");
        require(_packets[triggerId].dispatched, "PacketRegistry: not dispatched");
        require(!_packets[triggerId].acknowledged, "PacketRegistry: already acknowledged");

        _packets[triggerId].receiptRef = receiptRef;
        _packets[triggerId].status = status;
        _packets[triggerId].acknowledged = true;

        emit PacketAcknowledged(triggerId, receiptRef, status);
    }

    /**
     * @notice Returns packet information for a trigger
     * @param triggerId The trigger ID
     * @return payloadHash The payload hash
     * @return mode The transmission mode
     * @return channel The dispatch channel
     * @return messageRef The message reference
     * @return receiptRef The receipt reference
     * @return status The acknowledgment status
     * @return generated Whether packet was generated
     * @return dispatched Whether packet was dispatched
     * @return acknowledged Whether packet was acknowledged
     */
    function getPacketInfo(
        uint256 triggerId
    )
        external
        view
        returns (
            bytes32 payloadHash,
            bytes32 mode,
            bytes32 channel,
            bytes32 messageRef,
            bytes32 receiptRef,
            bytes32 status,
            bool generated,
            bool dispatched,
            bool acknowledged
        )
    {
        PacketInfo memory info = _packets[triggerId];
        return (
            info.payloadHash,
            info.mode,
            info.channel,
            info.messageRef,
            info.receiptRef,
            info.status,
            info.generated,
            info.dispatched,
            info.acknowledged
        );
    }
}