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

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


/**
 * @title Constant Flow Agreement interface
 * @author Superfluid
 */
abstract contract IConstantFlowAgreementV1 is ISuperAgreement {

    /// @dev ISuperAgreement.agreementType implementation
    function agreementType() external override pure returns (bytes32) {
        return keccak256("org.superfluid-finance.agreements.ConstantFlowAgreement.v1");
    }

    /**
     * @notice Get the maximum flow rate allowed with the deposit
     * @dev The deposit is clipped and rounded down
     * @param deposit Deposit amount used for creating the flow
     * @return flowRate The maximum flow rate
     */
    function getMaximumFlowRateFromDeposit(
        ISuperfluidToken token,
        uint256 deposit)
        external view virtual
        returns (int96 flowRate);

    /**
     * @notice Get the deposit required for creating the flow
     * @dev Calculates the deposit based on the liquidationPeriod and flowRate
     * @param flowRate Flow rate to be tested
     * @return deposit The deposit amount based on flowRate and liquidationPeriod
     * NOTE:
     * - if calculated deposit (flowRate * liquidationPeriod) is less
     *   than the minimum deposit, we use the minimum deposit otherwise
     *   we use the calculated deposit
     */
    function getDepositRequiredForFlowRate(
        ISuperfluidToken token,
        int96 flowRate)
        external view virtual
        returns (uint256 deposit);

    /**
     * @dev Returns whether it is the patrician period based on host.getNow()
     * @param account The account we are interested in
     * @return isCurrentlyPatricianPeriod Whether it is currently the patrician period dictated by governance
     * @return timestamp The value of host.getNow()
     */
    function isPatricianPeriodNow(
        ISuperfluidToken token,
        address account)
        public view virtual
        returns (bool isCurrentlyPatricianPeriod, uint256 timestamp);

    /**
     * @dev Returns whether it is the patrician period based on timestamp
     * @param account The account we are interested in
     * @param timestamp The timestamp we are interested in observing the result of isPatricianPeriod
     * @return bool Whether it is currently the patrician period dictated by governance
     */
    function isPatricianPeriod(
        ISuperfluidToken token,
        address account,
        uint256 timestamp
    )
        public view virtual
        returns (bool);

    /**
     * @dev msgSender from `ctx` updates permissions for the `flowOperator` with `flowRateAllowance`
     * @param token Super token address
     * @param flowOperator The permission grantee address
     * @param permissions A bitmask representation of the granted permissions
     * @param flowRateAllowance The flow rate allowance the `flowOperator` is granted (only goes down)
     * @param ctx Context bytes (see ISuperfluid.sol for Context struct)
     */
    function updateFlowOperatorPermissions(
        ISuperfluidToken token,
        address flowOperator,
        uint8 permissions,
        int96 flowRateAllowance,
        bytes calldata ctx
    ) 
        external virtual
        returns(bytes memory newCtx);

    /**
     * @dev msgSender from `ctx` grants `flowOperator` all permissions with flowRateAllowance as type(int96).max
     * @param token Super token address
     * @param flowOperator The permission grantee address
     * @param ctx Context bytes (see ISuperfluid.sol for Context struct)
     */
    function authorizeFlowOperatorWithFullControl(
        ISuperfluidToken token,
        address flowOperator,
        bytes calldata ctx
    )
        external virtual
        returns(bytes memory newCtx);

     /**
     * @notice msgSender from `ctx` revokes `flowOperator` create/update/delete permissions
     * @dev `permissions` and `flowRateAllowance` will both be set to 0
     * @param token Super token address
     * @param flowOperator The permission grantee address
     * @param ctx Context bytes (see ISuperfluid.sol for Context struct)
     */
    function revokeFlowOperatorWithFullControl(
        ISuperfluidToken token,
        address flowOperator,
        bytes calldata ctx
    )
        external virtual
        returns(bytes memory newCtx);

    /**
     * @notice Get the permissions of a flow operator between `sender` and `flowOperator` for `token`
     * @param token Super token address
     * @param sender The permission granter address
     * @param flowOperator The permission grantee address
     * @return flowOperatorId The keccak256 hash of encoded string "flowOperator", sender and flowOperator
     * @return permissions A bitmask representation of the granted permissions
     * @return flowRateAllowance The flow rate allowance the `flowOperator` is granted (only goes down)
     */
    function getFlowOperatorData(
       ISuperfluidToken token,
       address sender,
       address flowOperator
    )
        public view virtual
        returns (
            bytes32 flowOperatorId,
            uint8 permissions,
            int96 flowRateAllowance
        );

    /**
     * @notice Get flow operator using flowOperatorId
     * @param token Super token address
     * @param flowOperatorId The keccak256 hash of encoded string "flowOperator", sender and flowOperator
     * @return permissions A bitmask representation of the granted permissions
     * @return flowRateAllowance The flow rate allowance the `flowOperator` is granted (only goes down)
     */
    function getFlowOperatorDataByID(
       ISuperfluidToken token,
       bytes32 flowOperatorId
    )
        external view virtual
        returns (
            uint8 permissions,
            int96 flowRateAllowance
        );

    /**
     * @notice Create a flow betwen ctx.msgSender and receiver
     * @dev flowId (agreementId) is the keccak256 hash of encoded sender and receiver
     * @param token Super token address
     * @param receiver Flow receiver address
     * @param flowRate New flow rate in amount per second
     * @param ctx Context bytes (see ISuperfluid.sol for Context struct)
     *
     * # App callbacks
     *
     * - AgreementCreated
     *   - agreementId - can be used in getFlowByID
     *   - agreementData - abi.encode(address flowSender, address flowReceiver)
     *
     * NOTE:
     * - A deposit is taken as safety margin for the solvency agents
     * - A extra gas fee may be taken to pay for solvency agent liquidations
     */
    function createFlow(
        ISuperfluidToken token,
        address receiver,
        int96 flowRate,
        bytes calldata ctx
    )
        external virtual
        returns(bytes memory newCtx);

    /**
    * @notice Create a flow between sender and receiver
    * @dev A flow created by an approved flow operator (see above for details on callbacks)
    * @param token Super token address
    * @param sender Flow sender address (has granted permissions)
    * @param receiver Flow receiver address
    * @param flowRate New flow rate in amount per second
    * @param ctx Context bytes (see ISuperfluid.sol for Context struct)
    */
    function createFlowByOperator(
        ISuperfluidToken token,
        address sender,
        address receiver,
        int96 flowRate,
        bytes calldata ctx
    )
        external virtual
        returns(bytes memory newCtx);

    /**
     * @notice Update the flow rate between ctx.msgSender and receiver
     * @dev flowId (agreementId) is the keccak256 hash of encoded sender and receiver
     * @param token Super token address
     * @param receiver Flow receiver address
     * @param flowRate New flow rate in amount per second
     * @param ctx Context bytes (see ISuperfluid.sol for Context struct)
     *
     * # App callbacks
     *
     * - AgreementUpdated
     *   - agreementId - can be used in getFlowByID
     *   - agreementData - abi.encode(address flowSender, address flowReceiver)
     *
     * NOTE:
     * - Only the flow sender may update the flow rate
     * - Even if the flow rate is zero, the flow is not deleted
     * from the system
     * - Deposit amount will be adjusted accordingly
     * - No new gas fee is charged
     */
    function updateFlow(
        ISuperfluidToken token,
        address receiver,
        int96 flowRate,
        bytes calldata ctx
    )
        external virtual
        returns(bytes memory newCtx);

    /**
    * @notice Update a flow between sender and receiver
    * @dev A flow updated by an approved flow operator (see above for details on callbacks)
    * @param token Super token address
    * @param sender Flow sender address (has granted permissions)
    * @param receiver Flow receiver address
    * @param flowRate New flow rate in amount per second
    * @param ctx Context bytes (see ISuperfluid.sol for Context struct)
    */
    function updateFlowByOperator(
        ISuperfluidToken token,
        address sender,
        address receiver,
        int96 flowRate,
        bytes calldata ctx
    )
        external virtual
        returns(bytes memory newCtx);

    /**
     * @dev Get the flow data between `sender` and `receiver` of `token`
     * @param token Super token address
     * @param sender Flow receiver
     * @param receiver Flow sender
     * @return timestamp Timestamp of when the flow is updated
     * @return flowRate The flow rate
     * @return deposit The amount of deposit the flow
     * @return owedDeposit The amount of owed deposit of the flow
     */
    function getFlow(
        ISuperfluidToken token,
        address sender,
        address receiver
    )
        external view virtual
        returns (
            uint256 timestamp,
            int96 flowRate,
            uint256 deposit,
            uint256 owedDeposit
        );

    /**
     * @notice Get flow data using agreementId
     * @dev flowId (agreementId) is the keccak256 hash of encoded sender and receiver
     * @param token Super token address
     * @param agreementId The agreement ID
     * @return timestamp Timestamp of when the flow is updated
     * @return flowRate The flow rate
     * @return deposit The deposit amount of the flow
     * @return owedDeposit The owed deposit amount of the flow
     */
    function getFlowByID(
       ISuperfluidToken token,
       bytes32 agreementId
    )
        external view virtual
        returns (
            uint256 timestamp,
            int96 flowRate,
            uint256 deposit,
            uint256 owedDeposit
        );

    /**
     * @dev Get the aggregated flow info of the account
     * @param token Super token address
     * @param account Account for the query
     * @return timestamp Timestamp of when a flow was last updated for account
     * @return flowRate The net flow rate of token for account
     * @return deposit The sum of all deposits for account's flows
     * @return owedDeposit The sum of all owed deposits for account's flows
     */
    function getAccountFlowInfo(
        ISuperfluidToken token,
        address account
    )
        external view virtual
        returns (
            uint256 timestamp,
            int96 flowRate,
            uint256 deposit,
            uint256 owedDeposit);

    /**
     * @dev Get the net flow rate of the account
     * @param token Super token address
     * @param account Account for the query
     * @return flowRate Net flow rate
     */
    function getNetFlow(
        ISuperfluidToken token,
        address account
    )
        external view virtual
        returns (int96 flowRate);

    /**
     * @notice Delete the flow between sender and receiver
     * @dev flowId (agreementId) is the keccak256 hash of encoded sender and receiver
     * @param token Super token address
     * @param ctx Context bytes (see ISuperfluid.sol for Context struct)
     * @param receiver Flow receiver address
     *
     * # App callbacks
     *
     * - AgreementTerminated
     *   - agreementId - can be used in getFlowByID
     *   - agreementData - abi.encode(address flowSender, address flowReceiver)
     *
     * NOTE:
     * - Both flow sender and receiver may delete the flow
     * - If Sender account is insolvent or in critical state, a solvency agent may
     *   also terminate the agreement
     * - Gas fee may be returned to the sender
     */
    function deleteFlow(
        ISuperfluidToken token,
        address sender,
        address receiver,
        bytes calldata ctx
    )
        external virtual
        returns(bytes memory newCtx);

    /**
     * @notice Delete the flow between sender and receiver
     * @dev A flow deleted by an approved flow operator (see above for details on callbacks)
     * @param token Super token address
     * @param ctx Context bytes (see ISuperfluid.sol for Context struct)
     * @param receiver Flow receiver address
     */
    function deleteFlowByOperator(
        ISuperfluidToken token,
        address sender,
        address receiver,
        bytes calldata ctx
    )
        external virtual
        returns(bytes memory newCtx);
     
    /**
     * @dev Flow operator updated event
     * @param token Super token address
     * @param sender Flow sender address
     * @param flowOperator Flow operator address
     * @param permissions Octo bitmask representation of permissions
     * @param flowRateAllowance The flow rate allowance the `flowOperator` is granted (only goes down)
     */
    event FlowOperatorUpdated(
        ISuperfluidToken indexed token,
        address indexed sender,
        address indexed flowOperator,
        uint8 permissions,
        int96 flowRateAllowance
    );

    /**
     * @dev Flow updated event
     * @param token Super token address
     * @param sender Flow sender address
     * @param receiver Flow recipient address
     * @param flowRate Flow rate in amount per second for this flow
     * @param totalSenderFlowRate Total flow rate in amount per second for the sender
     * @param totalReceiverFlowRate Total flow rate in amount per second for the receiver
     * @param userData The user provided data
     *
     */
    event FlowUpdated(
        ISuperfluidToken indexed token,
        address indexed sender,
        address indexed receiver,
        int96 flowRate,
        int256 totalSenderFlowRate,
        int256 totalReceiverFlowRate,
        bytes userData
    );

    /**
     * @dev Flow updated extension event
     * @param flowOperator Flow operator address - the Context.msgSender
     * @param deposit The deposit amount for the stream
     */
    event FlowUpdatedExtension(
        address indexed flowOperator,
        uint256 deposit
    );
}