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

import {AccessControl} from "@openzeppelin/contracts/access/AccessControl.sol";
import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";

contract H11XPegOracle is AccessControl {
    bytes32 public constant GOVERNOR_ROLE = keccak256("GOVERNOR_ROLE");
    string public constant REFERENCE_BOUNDARY =
        "Internal protocol reference only; not fiat backing, redemption rights, banking functionality, or market price.";
    IERC20 public immutable h11xToken;

    uint256 private constant H11X_DECIMALS = 11;
    uint256 private constant H11X_UNIT = 10 ** H11X_DECIMALS;

    uint256 private priceUsd18;
    bool public pegEnabled;

    event PegConfigured(uint256 priceUsd18, bool enabled);

    error ZeroAddress();
    error InvalidPrice();

    constructor(address h11xTokenAddress, address initialGovernor) {
        if (h11xTokenAddress == address(0) || initialGovernor == address(0)) {
            revert ZeroAddress();
        }

        h11xToken = IERC20(h11xTokenAddress);
        _grantRole(DEFAULT_ADMIN_ROLE, msg.sender);
        _grantRole(GOVERNOR_ROLE, initialGovernor);

        priceUsd18 = 1e18;
        pegEnabled = false;

        emit PegConfigured(priceUsd18, pegEnabled);
    }

    function priceUsd() external view returns (uint256) {
        return priceUsd18;
    }

    function setPriceUsd(uint256 newPriceUsd18) external onlyRole(GOVERNOR_ROLE) {
        if (newPriceUsd18 == 0) {
            revert InvalidPrice();
        }
        priceUsd18 = newPriceUsd18;
        emit PegConfigured(priceUsd18, pegEnabled);
    }

    function setPegEnabled(bool enabled) external onlyRole(GOVERNOR_ROLE) {
        pegEnabled = enabled;
        emit PegConfigured(priceUsd18, pegEnabled);
    }

    function grantGovernor(address account) external onlyRole(DEFAULT_ADMIN_ROLE) {
        _grantRole(GOVERNOR_ROLE, account);
    }

    function revokeGovernor(address account) external onlyRole(DEFAULT_ADMIN_ROLE) {
        _revokeRole(GOVERNOR_ROLE, account);
    }

    function usdValue(uint256 h11xUnits) external view returns (uint256) {
        if (!pegEnabled) {
            return 0;
        }

        uint256 whole = h11xUnits / H11X_UNIT;
        uint256 remainder = h11xUnits % H11X_UNIT;
        return whole * priceUsd18 + (remainder * priceUsd18) / H11X_UNIT;
    }

    function h11xUnitsForUsd(uint256 usdValue18) external view returns (uint256) {
        if (!pegEnabled) {
            return 0;
        }

        return (usdValue18 * H11X_UNIT) / priceUsd18;
    }
}