smom-dbis-138/contracts/emoney/RailTriggerRegistry.sol

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

import "@openzeppelin/contracts/access/AccessControl.sol";
import "./interfaces/IRailTriggerRegistry.sol";
import "./libraries/RailTypes.sol";

/**
 * @title RailTriggerRegistry
 * @notice Canonical registry of payment rails, message types, and trigger lifecycle
 * @dev Manages trigger state machine and enforces idempotency by instructionId
 */
contract RailTriggerRegistry is IRailTriggerRegistry, AccessControl {
    bytes32 public constant RAIL_OPERATOR_ROLE = keccak256("RAIL_OPERATOR_ROLE");
    bytes32 public constant RAIL_ADAPTER_ROLE = keccak256("RAIL_ADAPTER_ROLE");

    uint256 private _nextTriggerId;
    mapping(uint256 => Trigger) private _triggers;
    mapping(bytes32 => uint256) private _triggerByInstructionId; // instructionId => triggerId

    /**
     * @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 Creates a new trigger
     * @dev Requires RAIL_OPERATOR_ROLE. Enforces idempotency by instructionId.
     * @param t Trigger struct with all required fields
     * @return id The assigned trigger ID
     */
    function createTrigger(Trigger calldata t) external override onlyRole(RAIL_OPERATOR_ROLE) returns (uint256 id) {
        require(t.token != address(0), "RailTriggerRegistry: zero token");
        require(t.amount > 0, "RailTriggerRegistry: zero amount");
        require(t.accountRefId != bytes32(0), "RailTriggerRegistry: zero accountRefId");
        require(t.instructionId != bytes32(0), "RailTriggerRegistry: zero instructionId");
        require(t.state == RailTypes.State.CREATED, "RailTriggerRegistry: invalid initial state");

        // Enforce idempotency: check if instructionId already exists
        require(!instructionIdExists(t.instructionId), "RailTriggerRegistry: duplicate instructionId");

        id = _nextTriggerId++;
        uint64 timestamp = uint64(block.timestamp);

        _triggers[id] = Trigger({
            id: id,
            rail: t.rail,
            msgType: t.msgType,
            accountRefId: t.accountRefId,
            walletRefId: t.walletRefId,
            token: t.token,
            amount: t.amount,
            currencyCode: t.currencyCode,
            instructionId: t.instructionId,
            state: RailTypes.State.CREATED,
            createdAt: timestamp,
            updatedAt: timestamp
        });

        _triggerByInstructionId[t.instructionId] = id;

        emit TriggerCreated(
            id,
            uint8(t.rail),
            t.msgType,
            t.instructionId,
            t.accountRefId,
            t.token,
            t.amount
        );
    }

    /**
     * @notice Updates the state of a trigger
     * @dev Requires RAIL_ADAPTER_ROLE. Enforces valid state transitions.
     * @param id The trigger ID
     * @param newState The new state
     * @param reason Optional reason code for the state change
     */
    function updateState(
        uint256 id,
        RailTypes.State newState,
        bytes32 reason
    ) external override onlyRole(RAIL_ADAPTER_ROLE) {
        require(triggerExists(id), "RailTriggerRegistry: trigger not found");

        Trigger storage trigger = _triggers[id];
        RailTypes.State oldState = trigger.state;

        // Validate state transition
        require(isValidStateTransition(oldState, newState), "RailTriggerRegistry: invalid state transition");

        trigger.state = newState;
        trigger.updatedAt = uint64(block.timestamp);

        emit TriggerStateUpdated(id, uint8(oldState), uint8(newState), reason);
    }

    /**
     * @notice Returns a trigger by ID
     * @param id The trigger ID
     * @return The trigger struct
     */
    function getTrigger(uint256 id) external view override returns (Trigger memory) {
        require(triggerExists(id), "RailTriggerRegistry: trigger not found");
        return _triggers[id];
    }

    /**
     * @notice Returns a trigger by instructionId
     * @param instructionId The instruction ID
     * @return The trigger struct
     */
    function getTriggerByInstructionId(bytes32 instructionId) external view override returns (Trigger memory) {
        uint256 id = _triggerByInstructionId[instructionId];
        require(id != 0 || _triggers[id].instructionId == instructionId, "RailTriggerRegistry: trigger not found");
        return _triggers[id];
    }

    /**
     * @notice Checks if a trigger exists
     * @param id The trigger ID
     * @return true if trigger exists
     */
    function triggerExists(uint256 id) public view override returns (bool) {
        return _triggers[id].id == id && _triggers[id].instructionId != bytes32(0);
    }

    /**
     * @notice Checks if an instructionId already exists
     * @param instructionId The instruction ID to check
     * @return true if instructionId exists
     */
    function instructionIdExists(bytes32 instructionId) public view override returns (bool) {
        uint256 id = _triggerByInstructionId[instructionId];
        // Check if trigger exists and has matching instructionId
        // Note: We can't use id != 0 check because first trigger has ID 0
        return _triggers[id].id == id && _triggers[id].instructionId == instructionId;
    }

    /**
     * @notice Validates a state transition
     * @param from Current state
     * @param to Target state
     * @return true if transition is valid
     */
    function isValidStateTransition(
        RailTypes.State from,
        RailTypes.State to
    ) internal pure returns (bool) {
        // Cannot transition to CREATED
        if (to == RailTypes.State.CREATED) {
            return false;
        }

        // Terminal states cannot transition
        if (
            from == RailTypes.State.SETTLED ||
            from == RailTypes.State.REJECTED ||
            from == RailTypes.State.CANCELLED ||
            from == RailTypes.State.RECALLED
        ) {
            return false;
        }

        // Valid transitions
        if (from == RailTypes.State.CREATED) {
            return to == RailTypes.State.VALIDATED || to == RailTypes.State.REJECTED || to == RailTypes.State.CANCELLED;
        }

        if (from == RailTypes.State.VALIDATED) {
            return (
                to == RailTypes.State.SUBMITTED_TO_RAIL ||
                to == RailTypes.State.REJECTED ||
                to == RailTypes.State.CANCELLED
            );
        }

        if (from == RailTypes.State.SUBMITTED_TO_RAIL) {
            return (
                to == RailTypes.State.PENDING ||
                to == RailTypes.State.REJECTED ||
                to == RailTypes.State.CANCELLED ||
                to == RailTypes.State.RECALLED
            );
        }

        if (from == RailTypes.State.PENDING) {
            return (
                to == RailTypes.State.SETTLED ||
                to == RailTypes.State.REJECTED ||
                to == RailTypes.State.CANCELLED ||
                to == RailTypes.State.RECALLED
            );
        }

        return false;
    }
}