pragma solidity >=0.4.24;

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


interface IIssuer {
    // Views
    function anySynthOrOKSRateIsStale() external view returns (bool anyRateStale);

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

    function availableSynthCount() external view returns (uint);

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

    function burnSynthsForLiquidation(
        address burnForAddress,
        address liquidator,
        uint amount,
        uint existingDebt,
        uint totalDebtIssued
    ) external ;

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

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

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

    function collateralisationRatioAndAnyRatesStale(address _issuer)
        external
        view
        returns (uint cratio, bool anyRateIsStale);

    function debtBalanceOf(address issuer, bytes32 currencyKey) external view returns (uint debtBalance);

    function debtBalanceOfAndTotalDebt(address _issuer)
        external
        view
        returns (
            uint debtBalance,
            uint totalSystemValue,
            bool anyRateIsStale
        );
    
    function lastIssueEvent(address account) external view returns (uint);

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

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

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

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

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

    function totalIssuedSynths(bytes32 currencyKey, bool excludeEtherCollateral) external view returns (uint);

    function transferableOikosAndAnyRateIsStale(address account, uint balance)
        external
        view
        returns (uint transferable, bool anyRateIsStale);

    // Restricted: used internally to Oikos
    function issueSynths(address from, uint amount) external;

    function issueSynthsOnBehalf(
        address issueFor,
        address from,
        uint amount
    ) external;

    function issueMaxSynths(address from) external;

    function issueMaxSynthsOnBehalf(address issueFor, address from) external;

    function burnSynths(address from, uint amount) external;

    function burnSynthsOnBehalf(
        address burnForAddress,
        address from,
        uint amount
    ) external;

    function burnSynthsToTarget(address from) external;

    function burnSynthsToTargetOnBehalf(address burnForAddress, address from) external;

    function liquidateDelinquentAccount(address account, uint susdAmount, address liquidator) external returns (uint totalRedeemed, uint amountToLiquidate);
}