// SPDX-License-Identifier: AGPLv3
pragma solidity >= 0.8.0;

import { ISuperAgreement } from "./ISuperAgreement.sol";


/**
 * @title Superfluid token interface
 * @author Superfluid
 */
interface ISuperfluidToken {

    /**************************************************************************
     * Basic information
     *************************************************************************/

    /**
     * @dev Get superfluid host contract address
     */
    function getHost() external view returns(address host);

    /**
     * @dev Encoded liquidation type data mainly used for handling stack to deep errors
     *
     * Note:
     * - version: 1
     * - liquidationType key:
     *    - 0 = reward account receives reward (PIC period)
     *    - 1 = liquidator account receives reward (Pleb period)
     *    - 2 = liquidator account receives reward (Pirate period/bailout)
     */
    struct LiquidationTypeData {
        uint256 version;
        uint8 liquidationType;
    }

    /**************************************************************************
     * Real-time balance functions
     *************************************************************************/

    /**
    * @dev Calculate the real balance of a user, taking in consideration all agreements of the account
    * @param account for the query
    * @param timestamp Time of balance
    * @return availableBalance Real-time balance
    * @return deposit Account deposit
    * @return owedDeposit Account owed Deposit
    */
    function realtimeBalanceOf(
       address account,
       uint256 timestamp
    )
        external view
        returns (
            int256 availableBalance,
            uint256 deposit,
            uint256 owedDeposit);

    /**
     * @notice Calculate the realtime balance given the current host.getNow() value
     * @dev realtimeBalanceOf with timestamp equals to block timestamp
     * @param account for the query
     * @return availableBalance Real-time balance
     * @return deposit Account deposit
     * @return owedDeposit Account owed Deposit
     */
    function realtimeBalanceOfNow(
       address account
    )
        external view
        returns (
            int256 availableBalance,
            uint256 deposit,
            uint256 owedDeposit,
            uint256 timestamp);

    /**
    * @notice Check if account is critical
    * @dev A critical account is when availableBalance < 0
    * @param account The account to check
    * @param timestamp The time we'd like to check if the account is critical (should use future)
    * @return isCritical Whether the account is critical
    */
    function isAccountCritical(
        address account,
        uint256 timestamp
    )
        external view
        returns(bool isCritical);

    /**
    * @notice Check if account is critical now (current host.getNow())
    * @dev A critical account is when availableBalance < 0
    * @param account The account to check
    * @return isCritical Whether the account is critical
    */
    function isAccountCriticalNow(
        address account
    )
        external view
        returns(bool isCritical);

    /**
     * @notice Check if account is solvent
     * @dev An account is insolvent when the sum of deposits for a token can't cover the negative availableBalance
     * @param account The account to check
     * @param timestamp The time we'd like to check if the account is solvent (should use future)
     * @return isSolvent
     */
    function isAccountSolvent(
        address account,
        uint256 timestamp
    )
        external view
        returns(bool isSolvent);

    /**
     * @notice Check if account is solvent now
     * @dev An account is insolvent when the sum of deposits for a token can't cover the negative availableBalance
     * @param account The account to check
     * @return isSolvent
     */
    function isAccountSolventNow(
        address account
    )
        external view
        returns(bool isSolvent);

    /**
    * @notice Get a list of agreements that is active for the account
    * @dev An active agreement is one that has state for the account
    * @param account Account to query
    * @return activeAgreements List of accounts that have non-zero states for the account
    */
    function getAccountActiveAgreements(address account)
       external view
       returns(ISuperAgreement[] memory activeAgreements);


   /**************************************************************************
    * Super Agreement hosting functions
    *************************************************************************/

    /**
     * @dev Create a new agreement
     * @param id Agreement ID
     * @param data Agreement data
     */
    function createAgreement(
        bytes32 id,
        bytes32[] calldata data
    )
        external;
    /**
     * @dev Agreement created event
     * @param agreementClass Contract address of the agreement
     * @param id Agreement ID
     * @param data Agreement data
     */
    event AgreementCreated(
        address indexed agreementClass,
        bytes32 id,
        bytes32[] data
    );

    /**
     * @dev Get data of the agreement
     * @param agreementClass Contract address of the agreement
     * @param id Agreement ID
     * @return data Data of the agreement
     */
    function getAgreementData(
        address agreementClass,
        bytes32 id,
        uint dataLength
    )
        external view
        returns(bytes32[] memory data);

    /**
     * @dev Create a new agreement
     * @param id Agreement ID
     * @param data Agreement data
     */
    function updateAgreementData(
        bytes32 id,
        bytes32[] calldata data
    )
        external;
    /**
     * @dev Agreement updated event
     * @param agreementClass Contract address of the agreement
     * @param id Agreement ID
     * @param data Agreement data
     */
    event AgreementUpdated(
        address indexed agreementClass,
        bytes32 id,
        bytes32[] data
    );

    /**
     * @dev Close the agreement
     * @param id Agreement ID
     */
    function terminateAgreement(
        bytes32 id,
        uint dataLength
    )
        external;
    /**
     * @dev Agreement terminated event
     * @param agreementClass Contract address of the agreement
     * @param id Agreement ID
     */
    event AgreementTerminated(
        address indexed agreementClass,
        bytes32 id
    );

    /**
     * @dev Update agreement state slot
     * @param account Account to be updated
     *
     * NOTE
     * - To clear the storage out, provide zero-ed array of intended length
     */
    function updateAgreementStateSlot(
        address account,
        uint256 slotId,
        bytes32[] calldata slotData
    )
        external;
    /**
     * @dev Agreement account state updated event
     * @param agreementClass Contract address of the agreement
     * @param account Account updated
     * @param slotId slot id of the agreement state
     */
    event AgreementStateUpdated(
        address indexed agreementClass,
        address indexed account,
        uint256 slotId
    );

    /**
     * @dev Get data of the slot of the state of an agreement
     * @param agreementClass Contract address of the agreement
     * @param account Account to query
     * @param slotId slot id of the state
     * @param dataLength length of the state data
     */
    function getAgreementStateSlot(
        address agreementClass,
        address account,
        uint256 slotId,
        uint dataLength
    )
        external view
        returns (bytes32[] memory slotData);

    /**
     * @notice Settle balance from an account by the agreement
     * @dev The agreement needs to make sure that the balance delta is balanced afterwards
     * @param account Account to query.
     * @param delta Amount of balance delta to be settled
     *
     * Modifiers:
     *  - onlyAgreement
     */
    function settleBalance(
        address account,
        int256 delta
    )
        external;

    /**
     * @dev Make liquidation payouts (v2)
     * @param id Agreement ID
     * @param liquidationTypeData Data regarding the version of the liquidation schema and the type
     * @param liquidatorAccount Address of the executor of the liquidation
     * @param useDefaultRewardAccount Whether or not the default reward account receives the rewardAmount
     * @param targetAccount Account of the stream sender
     * @param rewardAmount The amount the reward recepient account will receive
     * @param targetAccountBalanceDelta The amount the sender account balance should change by
     *
     * - If a bailout is required (bailoutAmount > 0)
     *   - the actual reward (single deposit) goes to the executor,
     *   - while the reward account becomes the bailout account
     *   - total bailout include: bailout amount + reward amount
     *   - the targetAccount will be bailed out
     * - If a bailout is not required
     *   - the targetAccount will pay the rewardAmount
     *   - the liquidator (reward account in PIC period) will receive the rewardAmount
     *
     * Modifiers:
     *  - onlyAgreement
     */
    function makeLiquidationPayoutsV2
    (
        bytes32 id,
        bytes memory liquidationTypeData,
        address liquidatorAccount,
        bool useDefaultRewardAccount,
        address targetAccount,
        uint256 rewardAmount,
        int256 targetAccountBalanceDelta
    ) external;
    /**
     * @dev Agreement liquidation event v2 (including agent account)
     * @param agreementClass Contract address of the agreement
     * @param id Agreement ID
     * @param liquidatorAccount Address of the executor of the liquidation
     * @param targetAccount Account of the stream sender
     * @param rewardAccount Account that collects the reward or bails out insolvent accounts
     * @param rewardAmount The amount the reward recipient account balance should change by
     * @param targetAccountBalanceDelta The amount the sender account balance should change by
     * @param liquidationTypeData The encoded liquidation type data including the version (how to decode)
     *
     * NOTE:
     * Reward account rule:
     * - if the agreement is liquidated during the PIC period
     *   - the rewardAccount will get the rewardAmount (remaining deposit), regardless of the liquidatorAccount
     *   - the targetAccount will pay for the rewardAmount
     * - if the agreement is liquidated after the PIC period AND the targetAccount is solvent
     *   - the liquidatorAccount will get the rewardAmount (remaining deposit)
     *   - the targetAccount will pay for the rewardAmount
     * - if the targetAccount is insolvent
     *   - the liquidatorAccount will get the rewardAmount (single deposit)
     *   - the rewardAccount will pay for both the rewardAmount and bailoutAmount
     *   - the targetAccount will receive the bailoutAmount
     */
    event AgreementLiquidatedV2(
        address indexed agreementClass,
        bytes32 id,
        address indexed liquidatorAccount,
        address indexed targetAccount,
        address rewardAccount,
        uint256 rewardAmount,
        int256 targetAccountBalanceDelta,
        bytes liquidationTypeData
    );

    /**************************************************************************
     * Function modifiers for access control and parameter validations
     *
     * While they cannot be explicitly stated in function definitions, they are
     * listed in function definition comments instead for clarity.
     *
     * NOTE: solidity-coverage not supporting it
     *************************************************************************/

     /// @dev The msg.sender must be host contract
     //modifier onlyHost() virtual;

    /// @dev The msg.sender must be a listed agreement.
    //modifier onlyAgreement() virtual;

    /**************************************************************************
     * DEPRECATED
     *************************************************************************/

    /**
     * @dev Agreement liquidation event (DEPRECATED BY AgreementLiquidatedBy)
     * @param agreementClass Contract address of the agreement
     * @param id Agreement ID
     * @param penaltyAccount Account of the agreement to be penalized
     * @param rewardAccount Account that collect the reward
     * @param rewardAmount Amount of liquidation reward
     *
     * NOTE:
     *
     * [DEPRECATED] Use AgreementLiquidatedV2 instead
     */
    event AgreementLiquidated(
        address indexed agreementClass,
        bytes32 id,
        address indexed penaltyAccount,
        address indexed rewardAccount,
        uint256 rewardAmount
    );

    /**
     * @dev System bailout occurred (DEPRECATED BY AgreementLiquidatedBy)
     * @param bailoutAccount Account that bailout the penalty account
     * @param bailoutAmount Amount of account bailout
     *
     * NOTE:
     *
     * [DEPRECATED] Use AgreementLiquidatedV2 instead
     */
    event Bailout(
        address indexed bailoutAccount,
        uint256 bailoutAmount
    );

    /**
     * @dev Agreement liquidation event (DEPRECATED BY AgreementLiquidatedV2)
     * @param liquidatorAccount Account of the agent that performed the liquidation.
     * @param agreementClass Contract address of the agreement
     * @param id Agreement ID
     * @param penaltyAccount Account of the agreement to be penalized
     * @param bondAccount Account that collect the reward or bailout accounts
     * @param rewardAmount Amount of liquidation reward
     * @param bailoutAmount Amount of liquidation bailouot
     *
     * NOTE:
     * Reward account rule:
     * - if bailout is equal to 0, then
     *   - the bondAccount will get the rewardAmount,
     *   - the penaltyAccount will pay for the rewardAmount.
     * - if bailout is larger than 0, then
     *   - the liquidatorAccount will get the rewardAmouont,
     *   - the bondAccount will pay for both the rewardAmount and bailoutAmount,
     *   - the penaltyAccount will pay for the rewardAmount while get the bailoutAmount.
     */
    event AgreementLiquidatedBy(
        address liquidatorAccount,
        address indexed agreementClass,
        bytes32 id,
        address indexed penaltyAccount,
        address indexed bondAccount,
        uint256 rewardAmount,
        uint256 bailoutAmount
    );
}