// File: /contracts/AccessControl.sol



// SPDX-License-Identifier: MIT
// Tells the Solidity compiler to compile only from v0.8.13 to v0.9.0
pragma solidity ^0.8.0;

import "@openzeppelin/contracts/utils/math/SafeMath.sol";

contract AccessControl {    

    address public owner;
    address public auditor;
    address public settlementContract;

    bool public definedContract = false;

    mapping(address => bool) private custodianAddresses; 
    mapping(address => uint8) private custodianCategory; // 1 - Big custodians  2 - Individuals 10 - Marked as releasable
    mapping(address => bool) private allowableTokens;

    event CustodianAdded(address custodianAddress, uint8 custodianCategory);


    constructor(address auditorAddress){
        checkZeroAddress(auditorAddress);
        auditor = auditorAddress;
        owner = msg.sender;
    }

    function onlyOwner (address sentAddress) private view {
        require(sentAddress == owner, "Not contract owner");
        return;
    }

    function checkZeroAddress(address _address) internal pure {
        require (_address != address(0), "Invalid address");
    }

    function onlySettlementAndAuditor(address settlementContractOrAuditorAddress) private view {
        require((settlementContractOrAuditorAddress == auditor) || (settlementContractOrAuditorAddress == settlementContract), "No permission to release");
        return;
    }

     function onlySettlement(address settlementContractOrAuditorAddress) private view {
        require((settlementContractOrAuditorAddress == settlementContract), "No permission to lock");
        return;
    }

    function onlyAllowed (address sentAddress) external view {
        require(custodianAddresses[sentAddress] == true || sentAddress == auditor, "Address not allowed");
        return;
    }

    function onlyAllowedToken(address tokenAddress) external view {
        require(allowableTokens[tokenAddress] == true, "Token not allowed");
        return;
    }

    function isAuditor(address auditorAddress) external view returns (bool) {
        require(auditor == auditorAddress, "Address is not the auditor");
        return true;
    }

    function markAsRelease(address custodianAddress) public {
        onlySettlementAndAuditor(msg.sender);
        require (custodianCategory[custodianAddress] == 2, "Wrong custodian category");
        custodianCategory[custodianAddress] = 10;
    }

    function setMultipleCustodiansAllowable(address[] calldata newCustodianAddresses, uint8[] calldata custodianCategories) external {
        require(newCustodianAddresses.length == custodianCategories.length);
        onlyOwner(msg.sender);
        for (uint8 i = 0; i< newCustodianAddresses.length; i++){
            setCustodianAllowable(newCustodianAddresses[i], custodianCategories[i]);
        }
    }

    function setCustodianAllowable(address custodianAddress, uint8 custodianCategoryValue) public {
        onlyOwner(msg.sender);
        checkZeroAddress(custodianAddress);
        custodianAddresses[custodianAddress] = true;
        custodianCategory[custodianAddress] = custodianCategoryValue;
        emit CustodianAdded(custodianAddress, custodianCategoryValue);
    }

    function getCustodianAllowable(address custodianAddress) external view returns (bool, uint8) {
        return (custodianAddresses[custodianAddress], custodianCategory[custodianAddress]);
    }

    function isVirtualCustodian(address custodianAddress) external view returns (bool) {
        return 2 == custodianCategory[custodianAddress];
    }
    function isBrickAndMortar(address custodianAddress) external view returns (bool){
        return 1 == custodianCategory[custodianAddress];
    }

    function isReleased(address custodianAddress) external view returns (bool) {
        return 10 == custodianCategory[custodianAddress];
    }

    function relockForVC(address custodianAddress) external {
        onlySettlement(msg.sender);
        if(custodianCategory[custodianAddress] == 10) custodianCategory[custodianAddress] = 2; //relocks custodian after marked for release
        require(custodianCategory[custodianAddress] == 2, "Custodian category cannot lock funds");
        return;
    }

    function validateSettlement(address creditor, address debtor, bool releaseCreditor, bool releaseDebtor, address[] calldata tokenAddresses) external view{
        require ((custodianAddresses[creditor] && custodianAddresses[debtor]), "Invalid creditor/debtor");
        bool inconsistent = false;
        if (releaseCreditor && custodianCategory[creditor]!= 2){
            inconsistent = true;
        }
        if (releaseDebtor && custodianCategory[debtor]!= 2){
            inconsistent = true;
        }
        require(!inconsistent, "Creditor/debtor is not a VC to be released");
        for(uint index = 0; index < tokenAddresses.length; index++) {
            require(allowableTokens[tokenAddresses[index]], "Invalid token used");
        }        
    }

    function removeCustodianAllowable(address custodianAddress) external {
        onlyOwner(msg.sender);
        custodianAddresses[custodianAddress] = false;
    }    

    function setTokenAllowable(address tokenAddress) external {
        onlyOwner(msg.sender);
        allowableTokens[tokenAddress] = true;
    }

    function removeTokenAllowable(address tokenAddress) external {
        onlyOwner(msg.sender);
        allowableTokens[tokenAddress] = false;
    }

    function getTokenAllowable(address tokenAddress) public view returns (bool) {
        return allowableTokens[tokenAddress];
    }

    function changeOwnership(address ownerAddress) external {
        onlyOwner(msg.sender);
        checkZeroAddress(ownerAddress);
        owner = ownerAddress;
    }

    function addSettlementContractAddress(address settlementAddress) public {
        onlyOwner(msg.sender);
        require (definedContract == false, "Cannot redefine linked settlement contract");
        checkZeroAddress(settlementAddress);
        settlementContract = settlementAddress;
        definedContract = true;
    }
}

// File: @openzeppelin/contracts/utils/math/SafeMath.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (utils/math/SafeMath.sol)

pragma solidity ^0.8.0;

// CAUTION
// This version of SafeMath should only be used with Solidity 0.8 or later,
// because it relies on the compiler's built in overflow checks.

/**
 * @dev Wrappers over Solidity's arithmetic operations.
 *
 * NOTE: `SafeMath` is generally not needed starting with Solidity 0.8, since the compiler
 * now has built in overflow checking.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            uint256 c = a + b;
            if (c < a) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b > a) return (false, 0);
            return (true, a - b);
        }
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
            // benefit is lost if 'b' is also tested.
            // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
            if (a == 0) return (true, 0);
            uint256 c = a * b;
            if (c / a != b) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a / b);
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a % b);
        }
    }

    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        return a + b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return a - b;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        return a * b;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator.
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return a % b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b <= a, errorMessage);
            return a - b;
        }
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a / b;
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a % b;
        }
    }
}