Sepolia Testnet

Contract Diff Checker

Contract Name:
MultiCollateralSynthLightChain

Contract Source Code:

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @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) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    /**
     * @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) {
        require(b <= a, "SafeMath: subtraction overflow");
        uint256 c = a - b;

        return c;
    }

    /**
     * @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) {
        // 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-solidity/pull/522
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts 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) internal pure returns (uint256) {
        // Solidity only automatically asserts when dividing by 0
        require(b > 0, "SafeMath: division by zero");
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts 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) {
        require(b != 0, "SafeMath: modulo by zero");
        return a % b;
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

interface IAddressResolver {
    function getAddress(bytes32 name) external view returns (address);

    function getSynth(bytes32 key) external view returns (address);

    function getAvailableBridge(bytes32 bridgeName) external view returns (address);

    function getBridgeList() external view returns (bytes32[] memory);

    function requireAndGetAddress(bytes32 name, string calldata reason) external view returns (address);
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

interface IERC20 {
    // ERC20 Optional Views
    function name() external view returns (string memory);

    function symbol() external view returns (string memory);

    function decimals() external view returns (uint8);

    // Views
    function totalSupply() external view returns (uint256);

    function balanceOf(address owner) external view returns (uint256);

    function allowance(address owner, address spender) external view returns (uint256);

    // Mutative functions
    function transfer(address to, uint256 value) external returns (bool);

    function approve(address spender, uint256 value) external returns (bool);

    function transferFrom(address from, address to, uint256 value) external returns (bool);

    // Events
    event Transfer(address indexed from, address indexed to, uint256 value);

    event Approval(address indexed owner, address indexed spender, uint256 value);
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

interface IExchanger {
    struct ExchangeEntrySettlement {
        bytes32 src;
        uint256 amount;
        bytes32 dest;
        uint256 reclaim;
        uint256 rebate;
        uint256 srcRoundIdAtPeriodEnd;
        uint256 destRoundIdAtPeriodEnd;
        uint256 timestamp;
    }

    struct ExchangeEntry {
        uint256 sourceRate;
        uint256 destinationRate;
        uint256 destinationAmount;
        uint256 exchangeFeeRate;
        uint256 exchangeDynamicFeeRate;
        uint256 roundIdForSrc;
        uint256 roundIdForDest;
    }

    struct ExchangeArgs {
        address fromAccount;
        address destAccount;
        bytes32 sourceCurrencyKey;
        bytes32 destCurrencyKey;
        uint256 sourceAmount;
        uint256 destAmount;
        uint256 fee;
        uint256 reclaimed;
        uint256 refunded;
        uint16 destChainId;
        bool erc20Payment;
    }

    // Views
    function calculateAmountAfterSettlement(
        address from,
        bytes32 currencyKey,
        uint256 amount,
        uint256 refunded
    ) external view returns (uint256 amountAfterSettlement);

    function isSynthRateInvalid(bytes32 currencyKey) external view returns (bool);

    function maxSecsLeftInWaitingPeriod(address account, bytes32 currencyKey) external view returns (uint256);

    function settlementOwing(
        address account,
        bytes32 currencyKey
    ) external view returns (uint256 reclaimAmount, uint256 rebateAmount, uint256 numEntries);

    // function hasWaitingPeriodOrSettlementOwing(address account, bytes32 currencyKey) external view returns (bool);

    function feeRateForExchange(bytes32 sourceCurrencyKey, bytes32 destinationCurrencyKey) external view returns (uint256);

    function dynamicFeeRateForExchange(
        bytes32 sourceCurrencyKey,
        bytes32 destinationCurrencyKey
    ) external view returns (uint256 feeRate, bool tooVolatile);

    function getAmountsForExchange(
        uint256 sourceAmount,
        bytes32 sourceCurrencyKey,
        bytes32 destinationCurrencyKey
    ) external view returns (uint256 amountReceived, uint256 fee, uint256 exchangeFeeRate);

    // function priceDeviationThresholdFactor() external view returns (uint256);

    // function waitingPeriodSecs() external view returns (uint256);

    // function lastExchangeRate(bytes32 currencyKey) external view returns (uint256);

    // Mutative functions
    function exchange(ExchangeArgs calldata args, bytes32 bridgeName) external payable returns (uint256 amountReceived);

    function exchangeAtomically(
        uint256 minAmount,
        ExchangeArgs calldata args,
        bytes32 bridgeName
    ) external payable returns (uint256 amountReceived);

    function settle(address from, bytes32 currencyKey) external returns (uint256 reclaimed, uint256 refunded, uint256 numEntries);

    function suspendSynthWithInvalidRate(bytes32 currencyKey) external;

    function updateDestinationForExchange(address recipient, bytes32 destinationKey, uint256 destinationAmount) external;
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "../interfaces/ISynth.sol";

interface IIssuer {
    // Views

    function allNetworksDebtInfo() external view returns (uint256 debt, uint256 sharesSupply);

    function availableCurrencyKeys() external view returns (bytes32[] memory);

    function availableSynthCount() external view returns (uint256);

    function availableSynths(uint256 index) external view returns (ISynth);

    function canBurnSynths(address account) external view returns (bool);

    function collateral(address account) external view returns (uint256);

    function collateralisationRatio(address issuer) external view returns (uint256);

    function collateralisationRatioAndAnyRatesInvalid(
        address _issuer
    ) external view returns (uint256 cratio, bool anyRateIsInvalid);

    function debtBalanceOf(address issuer) external view returns (uint256 debtBalance);

    function issuanceRatio() external view returns (uint256);

    function lastIssueEvent(address account) external view returns (uint256);

    function maxIssuableSynths(address issuer) external view returns (uint256 maxIssuable);

    function minimumStakeTime() external view returns (uint256);

    function remainingIssuableSynths(
        address issuer
    ) external view returns (uint256 maxIssuable, uint256 alreadyIssued, uint256 totalSystemDebt);

    function synths(bytes32 currencyKey) external view returns (ISynth);

    function getSynths(bytes32[] calldata currencyKeys) external view returns (ISynth[] memory);

    function synthsByAddress(address synthAddress) external view returns (bytes32);

    function totalIssuedSynths(bytes32 currencyKey) external view returns (uint256);

    function checkFreeCollateral(
        address _issuer,
        bytes32 _collateralKey,
        uint16 _chainId
    ) external view returns (uint256 withdrawableSynthr);

    function issueSynths(
        address from,
        uint256 amount,
        uint256 destChainId
    ) external returns (uint256 synthAmount, uint256 debtShare);

    function issueMaxSynths(address from, uint256 destChainId) external returns (uint256 synthAmount, uint256 debtShare);

    function burnSynths(
        address from,
        bytes32 synthKey,
        uint256 amount
    ) external returns (uint256 synthAmount, uint256 debtShare, uint256 reclaimed, uint256 refunded);

    function burnSynthsToTarget(
        address from,
        bytes32 synthKey
    ) external returns (uint256 synthAmount, uint256 debtShare, uint256 reclaimed, uint256 refunded);

    function burnForRedemption(address deprecatedSynthProxy, address account, uint256 balance) external;

    function burnSynthsWithoutDebt(bytes32 currencyKey, address from, uint amount) external returns (uint256 burnAmount);

    function synthIssueFromSynthrSwap(address _account, bytes32 _synthKey, uint256 _synthAmount) external;

    function liquidateAccount(
        address account,
        bytes32 collateralKey,
        uint16 chainId,
        bool isSelfLiquidation
    ) external returns (uint256 totalRedeemed, uint256 amountToLiquidate, uint256 sharesToRemove);

    function destIssue(address _account, bytes32 _synthKey, uint256 _synthAmount) external;

    function destBurn(address _account, bytes32 _synthKey, uint256 _synthAmount) external returns (uint256);

    function transferMargin(address account, uint256 marginDelta) external returns (uint256);

    function destTransferMargin(address _account, uint256 _marginDelta, bytes32 _marketKey) external returns (bool);

    function setCurrentPeriodId(uint128 periodId) external;
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "./IExchanger.sol";

interface IOffChainExchanger {
    // Views
    function offchainPriceMaxAge(bytes32 _currencyKey) external view returns (uint256);

    function offchainPriceMinAge(bytes32 _currencyKey) external view returns (uint256);

    function offchainPriceDivergence(bytes32 _currencyKey) external view returns (uint256);

    function feeRateForOffChainExchange(
        bytes32 sourceCurrencyKey,
        bytes32 destinationCurrencyKey
    ) external view returns (uint256);

    function getAmountsForOffChainExchangeMinusFees(
        bytes32 _sourceKey,
        bytes32 _destKey,
        uint256 _destAmount
    ) external view returns (uint256 amountReceived, uint256 fee);

    // Mutative functions
    function exchange(
        IExchanger.ExchangeArgs calldata args,
        bytes32 bridgeName,
        bytes[] calldata priceUpdateData
    ) external payable returns (uint256 amountReceived);

    function updateDestinationForExchange(address recipient, bytes32 destinationKey, uint256 destinationAmount) external;

    function exchangeForDexAggregation(
        address _account,
        bytes32 _sourceKey,
        bytes32 _destKey,
        uint256 _sourceAmount,
        bytes[] memory _priceUpdateData,
        uint16 _destChainId
    ) external payable returns (uint256 destAmount, uint256 fee);
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

interface ISynth {
    // Views
    function balanceOf(address _account) external view returns (uint256);

    function currencyKey() external view returns (bytes32);

    function transferableSynths(address account) external view returns (uint256);

    // Mutative functions
    function transferAndSettle(address to, uint256 value) external payable returns (bool);

    function transferFromAndSettle(address from, address to, uint256 value) external payable returns (bool);

    function burn(address account, uint256 amount) external;

    function issue(address account, uint256 amount) external;
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

interface ISystemStatus {
    struct Status {
        bool canSuspend;
        bool canResume;
    }

    struct Suspension {
        bool suspended;
        // reason is an integer code,
        // 0 => no reason, 1 => upgrading, 2+ => defined by system usage
        uint248 reason;
    }

    // Views
    function accessControl(bytes32 section, address account) external view returns (bool canSuspend, bool canResume);

    function requireSystemActive() external view;

    function systemSuspended() external view returns (bool);

    function requireIssuanceActive() external view;

    function requireExchangeActive() external view;

    function requireFuturesActive() external view;

    function requireFuturesMarketActive(bytes32 marketKey) external view;

    function requireExchangeBetweenSynthsAllowed(bytes32 sourceCurrencyKey, bytes32 destinationCurrencyKey) external view;

    function requireSynthActive(bytes32 currencyKey) external view;

    function synthSuspended(bytes32 currencyKey) external view returns (bool);

    function requireSynthsActive(bytes32 sourceCurrencyKey, bytes32 destinationCurrencyKey) external view;

    function systemSuspension() external view returns (bool suspended, uint248 reason);

    function issuanceSuspension() external view returns (bool suspended, uint248 reason);

    function exchangeSuspension() external view returns (bool suspended, uint248 reason);

    function futuresSuspension() external view returns (bool suspended, uint248 reason);

    function synthExchangeSuspension(bytes32 currencyKey) external view returns (bool suspended, uint248 reason);

    function synthSuspension(bytes32 currencyKey) external view returns (bool suspended, uint248 reason);

    function futuresMarketSuspension(bytes32 marketKey) external view returns (bool suspended, uint248 reason);

    function getSynthExchangeSuspensions(
        bytes32[] calldata synths
    ) external view returns (bool[] memory exchangeSuspensions, uint256[] memory reasons);

    function getSynthSuspensions(
        bytes32[] calldata synths
    ) external view returns (bool[] memory suspensions, uint256[] memory reasons);

    function getFuturesMarketSuspensions(
        bytes32[] calldata marketKeys
    ) external view returns (bool[] memory suspensions, uint256[] memory reasons);

    // Restricted functions
    function suspendIssuance(uint256 reason) external;

    function suspendSynth(bytes32 currencyKey, uint256 reason) external;

    function suspendFuturesMarket(bytes32 marketKey, uint256 reason) external;

    function updateAccessControl(bytes32 section, address account, bool canSuspend, bool canResume) external;
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

// Inheritance
import "./Owned.sol";
import "../interfaces/IAddressResolver.sol";

// Internal references
import "../interfaces/IIssuer.sol";
import "./MixinResolver.sol";

contract AddressResolverLightChain is Owned, IAddressResolver {
    mapping(bytes32 => address) public repository;
    mapping(bytes32 => address) public availableBridge;
    mapping(address => bool) public isBridge;

    bytes32[] public bridgeList;

    constructor(address _owner) Owned(_owner) {}

    /* ========== RESTRICTED FUNCTIONS ========== */

    function importAddresses(bytes32[] calldata names, address[] calldata destinations) external onlyOwner {
        require(names.length == destinations.length, "Input lengths must match");

        for (uint256 i = 0; i < names.length; i++) {
            bytes32 name = names[i];
            address destination = destinations[i];
            repository[name] = destination;
            emit AddressImported(name, destination);
        }
    }

    function addAvailableBridge(bytes32 bridgeName, address bridgeAddress) external onlyOwner {
        _addAvailableBridge(bridgeName, bridgeAddress);
    }

    function removeAvailableBridge(bytes32 bridgeName) external onlyOwner {
        _removeAvailableBridge(bridgeName);
    }

    /* ========= PUBLIC FUNCTIONS ========== */

    function rebuildCaches(MixinResolver[] calldata destinations) external {
        for (uint256 i = 0; i < destinations.length; i++) {
            destinations[i].rebuildCache();
        }
    }

    /* ========== PRIVATE FUNCTIONS ========== */
    function _addAvailableBridge(bytes32 bridgeName, address bridgeAddress) private {
        if (availableBridge[bridgeName] != address(0)) {
            _removeAvailableBridge(bridgeName);
        }
        availableBridge[bridgeName] = bridgeAddress;
        isBridge[bridgeAddress] = true;
        bridgeList.push(bridgeName);
        emit AddBridge(bridgeName, bridgeAddress);
    }

    function _removeAvailableBridge(bytes32 bridgeName) private {
        require(availableBridge[bridgeName] != address(0), "The bridge no exist.");
        uint lastBridgeNumber = bridgeList.length - 1;
        for (uint ii = 0; ii <= lastBridgeNumber; ii++) {
            if (bridgeList[ii] == bridgeName) {
                bridgeList[ii] = bridgeList[lastBridgeNumber];
                bridgeList.pop();
                break;
            }
        }
        address bridgeToRemove = availableBridge[bridgeName];
        delete availableBridge[bridgeName];
        delete isBridge[bridgeToRemove];
        emit RemoveBridge(bridgeName, bridgeToRemove);
    }

    /* ========== VIEWS ========== */

    function areAddressesImported(bytes32[] calldata names, address[] calldata destinations) external view returns (bool) {
        for (uint256 i = 0; i < names.length; i++) {
            if (repository[names[i]] != destinations[i]) {
                return false;
            }
        }
        return true;
    }

    function getAddress(bytes32 name) external view returns (address) {
        return repository[name];
    }

    function requireAndGetAddress(bytes32 name, string calldata reason) external view returns (address) {
        address _foundAddress = repository[name];
        require(_foundAddress != address(0), reason);
        return _foundAddress;
    }

    function getSynth(bytes32 key) external view returns (address) {
        IIssuer issuer = IIssuer(repository["Issuer"]);
        require(address(issuer) != address(0), "Cannot find Issuer address");
        return address(issuer.synths(key));
    }

    function getAvailableBridge(bytes32 bridgeName) external view returns (address) {
        return availableBridge[bridgeName];
    }

    function getBridgeList() external view returns (bytes32[] memory) {
        return bridgeList;
    }

    /* ========== EVENTS ========== */

    event AddressImported(bytes32 name, address destination);
    event AddBridge(bytes32 indexed bridgeName, address bridgeAddress);
    event RemoveBridge(bytes32 indexed bridgeName, address bridgeAddress);
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

// Inheritance
import "./Owned.sol";
// Libraries
import "./SafeDecimalMath.sol";

// Internal references
import "./TokenStateLightChain.sol";

contract ExternStateToken is Owned {
    using SafeMath for uint256;
    using SafeDecimalMath for uint256;

    /* ========== STATE VARIABLES ========== */

    /* Stores balances and allowances. */
    TokenStateLightChain public tokenState;

    /* Other ERC20 fields. */
    string public name;
    string public symbol;
    uint8 public decimals;

    constructor(
        TokenStateLightChain _tokenState,
        string memory _name,
        string memory _symbol,
        uint8 _decimals,
        address _owner
    ) Owned(_owner) {
        tokenState = _tokenState;

        name = _name;
        symbol = _symbol;
        decimals = _decimals;
    }

    /* ========== VIEWS ========== */

    /**
     * @notice Returns the ERC20 allowance of one party to spend on behalf of another.
     * @param owner The party authorising spending of their funds.
     * @param spender The party spending tokenOwner's funds.
     */
    function allowance(address owner, address spender) public view returns (uint256) {
        return tokenState.allowance(owner, spender);
    }

    /**
     * @notice Returns the ERC20 token balance of a given account.
     */
    function balanceOf(address account) external view returns (uint256) {
        return tokenState.balanceOf(account);
    }

    function totalSupply() external view returns (uint256) {
        return tokenState.totalSupply();
    }

    /* ========== MUTATIVE FUNCTIONS ========== */

    /**
     * @notice Set the address of the TokenState contract.
     * @dev This can be used to "pause" transfer functionality, by pointing the tokenState at 0x000..
     * as balances would be unreachable.
     */
    function setTokenState(TokenStateLightChain _tokenState) external onlyOwner {
        tokenState = _tokenState;
        emit TokenStateUpdated(address(_tokenState));
    }

    function _internalTransfer(address from, address to, uint256 value) internal virtual returns (bool) {
        /* Disallow transfers to irretrievable-addresses. */
        require(to != address(0) && to != address(this), "Cannot transfer to this address");

        // Insufficient balance will be handled by the safe subtraction.
        tokenState.setBalanceOf(from, tokenState.balanceOf(from).sub(value));
        tokenState.setBalanceOf(to, tokenState.balanceOf(to).add(value));

        // Emit a standard ERC20 transfer event
        emit Transfer(from, to, value);

        return true;
    }

    /**
     * @dev Perform an ERC20 token transfer. Designed to be called by transfer functions possessing
     * the onlyProxy or optionalProxy modifiers.
     */
    function _transferByProxy(address from, address to, uint256 value) internal returns (bool) {
        return _internalTransfer(from, to, value);
    }

    /*
     * @dev Perform an ERC20 token transferFrom. Designed to be called by transferFrom functions
     * possessing the optionalProxy or optionalProxy modifiers.
     */
    function _transferFromByProxy(address sender, address from, address to, uint256 value) internal returns (bool) {
        /* Insufficient allowance will be handled by the safe subtraction. */
        tokenState.setAllowance(from, sender, tokenState.allowance(from, sender).sub(value));
        return _internalTransfer(from, to, value);
    }

    /**
     * @notice Approves spender to transfer on the message sender's behalf.
     */
    function approve(address spender, uint256 value) public returns (bool) {
        address sender = msg.sender;

        tokenState.setAllowance(sender, spender, value);
        emit Approval(sender, spender, value);
        return true;
    }

    /* ========== EVENTS ========== */
    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(address indexed owner, address indexed spender, uint256 value);
    event TokenStateUpdated(address newTokenState);
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

// Internal references
import "./AddressResolverLightChain.sol";

contract MixinResolver {
    AddressResolverLightChain public resolver;

    mapping(bytes32 => address) private addressCache;

    constructor(address _resolver) {
        resolver = AddressResolverLightChain(_resolver);
    }

    /* ========== INTERNAL FUNCTIONS ========== */

    function combineArrays(bytes32[] memory first, bytes32[] memory second) internal pure returns (bytes32[] memory combination) {
        combination = new bytes32[](first.length + second.length);

        for (uint256 i = 0; i < first.length; i++) {
            combination[i] = first[i];
        }

        for (uint256 j = 0; j < second.length; j++) {
            combination[first.length + j] = second[j];
        }
    }

    /* ========== PUBLIC FUNCTIONS ========== */

    // Note: this function is public not external in order for it to be overridden and invoked via super in subclasses
    function resolverAddressesRequired() public view virtual returns (bytes32[] memory addresses) {}

    function rebuildCache() public {
        bytes32[] memory requiredAddresses = resolverAddressesRequired();
        // The resolver must call this function whenver it updates its state
        for (uint256 i = 0; i < requiredAddresses.length; i++) {
            bytes32 name = requiredAddresses[i];
            // Note: can only be invoked once the resolver has all the targets needed added
            address destination = resolver.requireAndGetAddress(
                name,
                string(abi.encodePacked("Resolver missing target: ", name))
            );
            addressCache[name] = destination;
            emit CacheUpdated(name, destination);
        }
    }

    /* ========== VIEWS ========== */

    function isResolverCached() external view returns (bool) {
        bytes32[] memory requiredAddresses = resolverAddressesRequired();
        for (uint256 i = 0; i < requiredAddresses.length; i++) {
            bytes32 name = requiredAddresses[i];
            // false if our cache is invalid or if the resolver doesn't have the required address
            if (resolver.getAddress(name) != addressCache[name] || addressCache[name] == address(0)) {
                return false;
            }
        }

        return true;
    }

    /* ========== INTERNAL FUNCTIONS ========== */

    function requireAndGetAddress(bytes32 name) internal view returns (address) {
        address _foundAddress = addressCache[name];
        require(_foundAddress != address(0), string(abi.encodePacked("Missing address: ", name)));
        return _foundAddress;
    }

    /* ========== EVENTS ========== */

    event CacheUpdated(bytes32 name, address destination);
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
// Inheritance
import "./Synth.sol";

contract MultiCollateralSynthLightChain is Synth {
    // bytes32 public constant CONTRACT_NAME = "MultiCollateralSynth";

    /* ========== CONSTRUCTOR ========== */

    constructor(
        TokenStateLightChain _tokenState,
        string memory _tokenName,
        string memory _tokenSymbol,
        address _owner,
        bytes32 _currencyKey,
        address _resolver
    ) Synth(_tokenState, _tokenName, _tokenSymbol, _owner, _currencyKey, _resolver) {}

    /* ========== VIEWS ======================= */

    /* ========== MUTATIVE FUNCTIONS ========== */

    /**
     * @notice Function that allows multi Collateral to issue a certain number of synths from an account.
     * @param account Account to issue synths to
     * @param amount Number of synths
     */
    function issue(address account, uint256 amount) external override onlyInternalContracts {
        super._internalIssue(account, amount);
    }

    /**
     * @notice Function that allows multi Collateral to burn a certain number of synths from an account.
     * @param account Account to burn synths from
     * @param amount Number of synths
     */
    function burn(address account, uint256 amount) external override onlyInternalContracts {
        super._internalBurn(account, amount);
    }

    /* ========== MODIFIERS ========== */

    // overriding modifier from super to add more internal contracts and checks
    function _isInternalContract(address account) internal view override returns (bool) {
        return super._isInternalContract(account);
        // || wrapperFactory().isWrapper(account);
        //  || (account == address(etherWrapper()))
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

contract Owned {
    address public owner;
    address public nominatedOwner;

    constructor(address _owner) {
        require(_owner != address(0), "Owner address cannot be 0");
        owner = _owner;
        emit OwnerChanged(address(0), _owner);
    }

    function nominateNewOwner(address _owner) external onlyOwner {
        nominatedOwner = _owner;
        emit OwnerNominated(_owner);
    }

    function acceptOwnership() external {
        require(msg.sender == nominatedOwner, "You must be nominated before you can accept ownership");
        emit OwnerChanged(owner, nominatedOwner);
        owner = nominatedOwner;
        nominatedOwner = address(0);
    }

    modifier onlyOwner() {
        _onlyOwner();
        _;
    }

    function _onlyOwner() private view {
        require(msg.sender == owner, "Only the contract owner may perform this action");
    }

    event OwnerNominated(address newOwner);
    event OwnerChanged(address oldOwner, address newOwner);
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

// Libraries
// import "openzeppelin-solidity-2.3.0/contracts/math/SafeMath.sol";
import "../externals/openzeppelin/SafeMath.sol";

library SafeDecimalMath {
    using SafeMath for uint256;

    /* Number of decimal places in the representations. */
    uint8 public constant decimals = 18;
    uint8 public constant highPrecisionDecimals = 27;

    /* The number representing 1.0. */
    uint256 public constant UNIT = 10 ** uint256(decimals);

    /* The number representing 1.0 for higher fidelity numbers. */
    uint256 public constant PRECISE_UNIT = 10 ** uint256(highPrecisionDecimals);
    uint256 private constant UNIT_TO_HIGH_PRECISION_CONVERSION_FACTOR = 10 ** uint256(highPrecisionDecimals - decimals);

    /**
     * @return Provides an interface to UNIT.
     */
    function unit() external pure returns (uint256) {
        return UNIT;
    }

    /**
     * @return Provides an interface to PRECISE_UNIT.
     */
    function preciseUnit() external pure returns (uint256) {
        return PRECISE_UNIT;
    }

    /**
     * @return The result of multiplying x and y, interpreting the operands as fixed-point
     * decimals.
     *
     * @dev A unit factor is divided out after the product of x and y is evaluated,
     * so that product must be less than 2**256. As this is an integer division,
     * the internal division always rounds down. This helps save on gas. Rounding
     * is more expensive on gas.
     */
    function multiplyDecimal(uint256 x, uint256 y) internal pure returns (uint256) {
        /* Divide by UNIT to remove the extra factor introduced by the product. */
        return x.mul(y) / UNIT;
    }

    /**
     * @return The result of safely multiplying x and y, interpreting the operands
     * as fixed-point decimals of the specified precision unit.
     *
     * @dev The operands should be in the form of a the specified unit factor which will be
     * divided out after the product of x and y is evaluated, so that product must be
     * less than 2**256.
     *
     * Unlike multiplyDecimal, this function rounds the result to the nearest increment.
     * Rounding is useful when you need to retain fidelity for small decimal numbers
     * (eg. small fractions or percentages).
     */
    function _multiplyDecimalRound(uint256 x, uint256 y, uint256 precisionUnit) private pure returns (uint256) {
        /* Divide by UNIT to remove the extra factor introduced by the product. */
        uint256 quotientTimesTen = x.mul(y) / (precisionUnit / 10);

        if (quotientTimesTen % 10 >= 5) {
            quotientTimesTen += 10;
        }

        return quotientTimesTen / 10;
    }

    /**
     * @return The result of safely multiplying x and y, interpreting the operands
     * as fixed-point decimals of a precise unit.
     *
     * @dev The operands should be in the precise unit factor which will be
     * divided out after the product of x and y is evaluated, so that product must be
     * less than 2**256.
     *
     * Unlike multiplyDecimal, this function rounds the result to the nearest increment.
     * Rounding is useful when you need to retain fidelity for small decimal numbers
     * (eg. small fractions or percentages).
     */
    function multiplyDecimalRoundPrecise(uint256 x, uint256 y) internal pure returns (uint256) {
        return _multiplyDecimalRound(x, y, PRECISE_UNIT);
    }

    /**
     * @return The result of safely multiplying x and y, interpreting the operands
     * as fixed-point decimals of a standard unit.
     *
     * @dev The operands should be in the standard unit factor which will be
     * divided out after the product of x and y is evaluated, so that product must be
     * less than 2**256.
     *
     * Unlike multiplyDecimal, this function rounds the result to the nearest increment.
     * Rounding is useful when you need to retain fidelity for small decimal numbers
     * (eg. small fractions or percentages).
     */
    function multiplyDecimalRound(uint256 x, uint256 y) internal pure returns (uint256) {
        return _multiplyDecimalRound(x, y, UNIT);
    }

    /**
     * @return The result of safely dividing x and y. The return value is a high
     * precision decimal.
     *
     * @dev y is divided after the product of x and the standard precision unit
     * is evaluated, so the product of x and UNIT must be less than 2**256. As
     * this is an integer division, the result is always rounded down.
     * This helps save on gas. Rounding is more expensive on gas.
     */
    function divideDecimal(uint256 x, uint256 y) internal pure returns (uint256) {
        /* Reintroduce the UNIT factor that will be divided out by y. */
        return x.mul(UNIT).div(y);
    }

    /**
     * @return The result of safely dividing x and y. The return value is as a rounded
     * decimal in the precision unit specified in the parameter.
     *
     * @dev y is divided after the product of x and the specified precision unit
     * is evaluated, so the product of x and the specified precision unit must
     * be less than 2**256. The result is rounded to the nearest increment.
     */
    function _divideDecimalRound(uint256 x, uint256 y, uint256 precisionUnit) private pure returns (uint256) {
        uint256 resultTimesTen = x.mul(precisionUnit * 10).div(y);

        if (resultTimesTen % 10 >= 5) {
            resultTimesTen += 10;
        }

        return resultTimesTen / 10;
    }

    /**
     * @return The result of safely dividing x and y. The return value is as a rounded
     * standard precision decimal.
     *
     * @dev y is divided after the product of x and the standard precision unit
     * is evaluated, so the product of x and the standard precision unit must
     * be less than 2**256. The result is rounded to the nearest increment.
     */
    function divideDecimalRound(uint256 x, uint256 y) internal pure returns (uint256) {
        return _divideDecimalRound(x, y, UNIT);
    }

    /**
     * @return The result of safely dividing x and y. The return value is as a rounded
     * high precision decimal.
     *
     * @dev y is divided after the product of x and the high precision unit
     * is evaluated, so the product of x and the high precision unit must
     * be less than 2**256. The result is rounded to the nearest increment.
     */
    function divideDecimalRoundPrecise(uint256 x, uint256 y) internal pure returns (uint256) {
        return _divideDecimalRound(x, y, PRECISE_UNIT);
    }

    /**
     * @dev Convert a standard decimal representation to a high precision one.
     */
    function decimalToPreciseDecimal(uint256 i) internal pure returns (uint256) {
        return i.mul(UNIT_TO_HIGH_PRECISION_CONVERSION_FACTOR);
    }

    /**
     * @dev Convert a high precision decimal to a standard decimal representation.
     */
    function preciseDecimalToDecimal(uint256 i) internal pure returns (uint256) {
        uint256 quotientTimesTen = i / (UNIT_TO_HIGH_PRECISION_CONVERSION_FACTOR / 10);

        if (quotientTimesTen % 10 >= 5) {
            quotientTimesTen += 10;
        }

        return quotientTimesTen / 10;
    }

    // Computes `a - b`, setting the value to 0 if b > a.
    function floorsub(uint256 a, uint256 b) internal pure returns (uint256) {
        return b >= a ? 0 : a - b;
    }

    /* ---------- Utilities ---------- */
    /*
     * Absolute value of the input, returned as a signed number.
     */
    function signedAbs(int256 x) internal pure returns (int256) {
        return x < 0 ? -x : x;
    }

    /*
     * Absolute value of the input, returned as an unsigned number.
     */
    function abs(int256 x) internal pure returns (uint256) {
        return uint256(signedAbs(x));
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

// Inheritance
import "./Owned.sol";

contract State is Owned {
    // the address of the contract that can modify variables
    // this can only be changed by the owner of this contract
    address public associatedContract;

    constructor(address _owner, address _associatedContract) Owned(_owner) {
        // This contract is abstract, and thus cannot be instantiated directly
        require(owner != address(0), "Owner must be set");

        associatedContract = _associatedContract;
        emit AssociatedContractUpdated(_associatedContract);
    }

    /* ========== SETTERS ========== */

    // Change the associated contract to a new address
    function setAssociatedContract(address _associatedContract) external onlyOwner {
        associatedContract = _associatedContract;
        emit AssociatedContractUpdated(_associatedContract);
    }

    /* ========== MODIFIERS ========== */

    modifier onlyAssociatedContract() {
        require(msg.sender == associatedContract, "Only the associated contract can perform this action");
        _;
    }

    /* ========== EVENTS ========== */

    event AssociatedContractUpdated(address associatedContract);
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

// Inheritance
import "./Owned.sol";
import "./ExternStateToken.sol";
import "./MixinResolver.sol";
import "../interfaces/ISynth.sol";
import "../interfaces/IERC20.sol";

// Internal references
import "../interfaces/ISystemStatus.sol";
import "../interfaces/IExchanger.sol";
import "../interfaces/IOffChainExchanger.sol";
import "../interfaces/IIssuer.sol";
import "./SafeDecimalMath.sol";

contract Synth is Owned, ExternStateToken, MixinResolver {
    using SafeMath for uint256;
    using SafeDecimalMath for uint256;

    bytes32 public constant CONTRACT_NAME = "Synth";

    /* ========== STATE VARIABLES ========== */

    // Currency key which identifies this Synth to the Synthr system
    bytes32 public currencyKey;
    address private syAggregator;

    uint8 public constant DECIMALS = 18;

    // Where fees are pooled in sUSD
    address public constant FEE_ADDRESS = 0xfeEFEEfeefEeFeefEEFEEfEeFeefEEFeeFEEFEeF;

    /* ========== ADDRESS RESOLVER CONFIGURATION ========== */

    bytes32 private constant CONTRACT_SYSTEMSTATUS = "SystemStatus";
    bytes32 private constant CONTRACT_EXCHANGER = "Exchanger";
    bytes32 private constant CONTRACT_OFF_CHAIN_EXCHANGER = "OffChainExchanger";
    bytes32 private constant CONTRACT_ISSUER = "Issuer";

    /* ========== CONSTRUCTOR ========== */

    constructor(
        TokenStateLightChain _tokenState,
        string memory _tokenName,
        string memory _tokenSymbol,
        address _owner,
        bytes32 _currencyKey,
        address _resolver
    ) ExternStateToken(_tokenState, _tokenName, _tokenSymbol, DECIMALS, _owner) MixinResolver(_resolver) {
        require(_owner != address(0), "_owner cannot be 0");

        currencyKey = _currencyKey;
    }

    /* ========== VIEWS ========== */

    // Note: use public visibility so that it can be invoked in a subclass
    function resolverAddressesRequired() public view virtual override returns (bytes32[] memory addresses) {
        addresses = new bytes32[](4);
        addresses[0] = CONTRACT_SYSTEMSTATUS;
        addresses[1] = CONTRACT_EXCHANGER;
        addresses[2] = CONTRACT_ISSUER;
        addresses[3] = CONTRACT_OFF_CHAIN_EXCHANGER;
    }

    function systemStatus() internal view returns (ISystemStatus) {
        return ISystemStatus(requireAndGetAddress(CONTRACT_SYSTEMSTATUS));
    }

    function exchanger() internal view returns (IExchanger) {
        return IExchanger(requireAndGetAddress(CONTRACT_EXCHANGER));
    }

    function offChainExchanger() internal view returns (IOffChainExchanger) {
        return IOffChainExchanger(requireAndGetAddress(CONTRACT_OFF_CHAIN_EXCHANGER));
    }

    function issuer() internal view returns (IIssuer) {
        return IIssuer(requireAndGetAddress(CONTRACT_ISSUER));
    }

    function _ensureCanTransfer(address from, uint256 value) internal view {
        require(exchanger().maxSecsLeftInWaitingPeriod(from, currencyKey) == 0, "Cannot transfer during waiting period");
        require(transferableSynths(from) >= value, "Insufficient balance after any settlement owing");
        systemStatus().requireSynthActive(currencyKey);
    }

    function transferableSynths(address account) public view returns (uint256) {
        (uint256 reclaimAmount, , ) = exchanger().settlementOwing(account, currencyKey);

        // Note: ignoring rebate amount here because a settle() is required in order to
        // allow the transfer to actually work

        uint256 balance = tokenState.balanceOf(account);

        if (reclaimAmount > balance) {
            return 0;
        } else {
            return balance.sub(reclaimAmount);
        }
    }

    /* ========== MUTATIVE FUNCTIONS ========== */
    function transfer(address to, uint256 value) public payable returns (bool) {
        _ensureCanTransfer(msg.sender, value);

        // transfers to 0x address will be burned
        if (to == address(0)) {
            return _internalBurn(msg.sender, value);
        }

        return _internalTransfer(msg.sender, to, value);
    }

    function transferAndSettle(address to, uint256 value) public payable returns (bool) {
        // Exchanger.settle ensures synth is active
        (, , uint256 numEntriesSettled) = exchanger().settle(msg.sender, currencyKey);

        // Save gas instead of calling transferableSynths
        uint256 balanceAfter = value;

        if (numEntriesSettled > 0) {
            balanceAfter = tokenState.balanceOf(msg.sender);
        }

        // Reduce the value to transfer if balance is insufficient after reclaimed
        value = value > balanceAfter ? balanceAfter : value;

        return _internalTransfer(msg.sender, to, value);
    }

    function transferFrom(address from, address to, uint256 value) public payable returns (bool) {
        _ensureCanTransfer(from, value);

        return _internalTransferFrom(from, to, value);
    }

    function transferFromAndSettle(address from, address to, uint256 value) public payable returns (bool) {
        // Exchanger.settle() ensures synth is active
        (, , uint256 numEntriesSettled) = exchanger().settle(from, currencyKey);

        // Save gas instead of calling transferableSynths
        uint256 balanceAfter = value;

        if (numEntriesSettled > 0) {
            balanceAfter = tokenState.balanceOf(from);
        }

        // Reduce the value to transfer if balance is insufficient after reclaimed
        value = value >= balanceAfter ? balanceAfter : value;

        return _internalTransferFrom(from, to, value);
    }

    function issue(address account, uint256 amount) external virtual onlyInternalContracts {
        _internalIssue(account, amount);
    }

    function burn(address account, uint256 amount) external virtual onlyInternalContracts {
        _internalBurn(account, amount);
    }

    function _internalIssue(address account, uint256 amount) internal {
        tokenState.setBalanceOf(account, tokenState.balanceOf(account).add(amount));
        tokenState.setTotalSupply(tokenState.totalSupply().add(amount));
        emit Transfer(address(0), account, amount);
        // emit Issued(account, amount);
    }

    function _internalBurn(address account, uint256 amount) internal returns (bool) {
        tokenState.setBalanceOf(account, tokenState.balanceOf(account).sub(amount));
        tokenState.setTotalSupply(tokenState.totalSupply().sub(amount));
        emit Transfer(account, address(0), amount);
        // emit Burned(account, amount);

        return true;
    }

    // Allow owner to set the total supply on import.
    function setTotalSupply(uint256 amount) external onlyOwner {
        tokenState.setTotalSupply(amount);
    }

    /* ========== INTERNAL FUNCTIONS ========== */

    function _internalTransferFrom(address from, address to, uint256 value) internal returns (bool) {
        // Skip allowance update in case of infinite allowance
        if (tokenState.allowance(from, msg.sender) != type(uint256).max) {
            // Reduce the allowance by the amount we're transferring.
            // The safeSub call will handle an insufficient allowance.
            tokenState.setAllowance(from, msg.sender, tokenState.allowance(from, msg.sender).sub(value));
        }
        return super._internalTransfer(from, to, value);
    }

    function _internalTransfer(address from, address to, uint256 value) internal override returns (bool) {
        return super._internalTransfer(from, to, value);
    }

    /* ========== MODIFIERS ========== */

    function _isInternalContract(address account) internal view virtual returns (bool) {
        return account == address(exchanger()) || account == address(issuer()) || account == address(offChainExchanger());
    }

    modifier onlyInternalContracts() {
        require(_isInternalContract(msg.sender), "Only internal contracts allowed");
        _;
    }

    /* ========== EVENTS ========== */
    // event Issued(address indexed account, uint256 value);

    // event Burned(address indexed account, uint256 value);
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

// Inheritance
import "./State.sol";

contract TokenStateLightChain is State {
    /* ERC20 fields. */
    mapping(address => uint256) public balanceOf;
    mapping(address => mapping(address => uint256)) public allowance;
    uint256 public totalSupply;

    constructor(address _owner, address _associatedContract, uint256 _totalSupply) State(_owner, _associatedContract) {}

    /* ========== SETTERS ========== */

    /**
     * @notice Set ERC20 allowance.
     * @dev Only the associated contract may call this.
     * @param tokenOwner The authorising party.
     * @param spender The authorised party.
     * @param value The total value the authorised party may spend on the
     * authorising party's behalf.
     */
    function setAllowance(address tokenOwner, address spender, uint256 value) external onlyAssociatedContract {
        allowance[tokenOwner][spender] = value;
    }

    /**
     * @notice Set the balance in a given account
     * @dev Only the associated contract may call this.
     * @param account The account whose value to set.
     * @param value The new balance of the given account.
     */
    function setBalanceOf(address account, uint256 value) external onlyAssociatedContract {
        balanceOf[account] = value;
    }

    function setTotalSupply(uint256 _amount) external onlyAssociatedContract {
        totalSupply = _amount;
    }
}

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