ISuperToken.sol

// SPDX-License-Identifier: MIT
pragma solidity >= 0.8.11;

import { ISuperfluidToken } from "./ISuperfluidToken.sol";
import { IERC20, IERC20Metadata } from "@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol";
import { IERC20Permit } from "@openzeppelin/contracts/token/ERC20/extensions/IERC20Permit.sol";
import { IERC5267 } from "@openzeppelin/contracts/interfaces/IERC5267.sol";
import { IERC777 } from "@openzeppelin/contracts/token/ERC777/IERC777.sol";
import { IPoolAdminNFT } from "../agreements/gdav1/IPoolAdminNFT.sol";
import { IPoolMemberNFT } from "../agreements/gdav1/IPoolMemberNFT.sol";

/**
 * @title Super token (Superfluid Token + ERC20 + ERC777) interface
 * @author Superfluid
 */
interface ISuperToken is ISuperfluidToken, IERC20Metadata, IERC777, IERC20Permit, IERC5267 {

    /**************************************************************************
     * Errors
     *************************************************************************/
    error SUPER_TOKEN_CALLER_IS_NOT_OPERATOR_FOR_HOLDER();                   // 0xf7f02227
    error SUPER_TOKEN_NOT_ERC777_TOKENS_RECIPIENT();                         // 0xfe737d05
    error SUPER_TOKEN_INFLATIONARY_DEFLATIONARY_NOT_SUPPORTED();             // 0xe3e13698
    error SUPER_TOKEN_NO_UNDERLYING_TOKEN();                                 // 0xf79cf656
    error SUPER_TOKEN_ONLY_SELF();                                           // 0x7ffa6648
    error SUPER_TOKEN_ONLY_ADMIN();                                          // 0x0484acab
    error SUPER_TOKEN_ONLY_GOV_OWNER();                                      // 0xd9c7ed08
    error SUPER_TOKEN_APPROVE_FROM_ZERO_ADDRESS();                           // 0x81638627
    error SUPER_TOKEN_APPROVE_TO_ZERO_ADDRESS();                             // 0xdf070274
    error SUPER_TOKEN_BURN_FROM_ZERO_ADDRESS();                              // 0xba2ab184
    error SUPER_TOKEN_MINT_TO_ZERO_ADDRESS();                                // 0x0d243157
    error SUPER_TOKEN_TRANSFER_FROM_ZERO_ADDRESS();                          // 0xeecd6c9b
    error SUPER_TOKEN_TRANSFER_TO_ZERO_ADDRESS();                            // 0xe219bd39
    error SUPER_TOKEN_NFT_PROXY_ADDRESS_CHANGED();                           // 0xef1b6ddf
    error SUPER_TOKEN_PERMIT_EXPIRED_SIGNATURE(uint256 deadline);            // 0x6e72b90f
    error SUPER_TOKEN_PERMIT_INVALID_SIGNER(address signer, address owner);  // 0xb6422105

    /**
     * @dev Initialize the contract
     */
    function initialize(
        IERC20 underlyingToken,
        uint8 underlyingDecimals,
        string calldata n,
        string calldata s
    ) external;

    /**
     * @dev Initialize the contract with an admin
     */
    function initializeWithAdmin(
        IERC20 underlyingToken,
        uint8 underlyingDecimals,
        string calldata n,
        string calldata s,
        address admin
    ) external;

    /**
     * @notice Changes the admin for the SuperToken
     * @dev Only the current admin can call this function
     * if admin is address(0), it is implicitly the host address
     * @param newAdmin New admin address
     */
    function changeAdmin(address newAdmin) external;

    event AdminChanged(address indexed oldAdmin, address indexed newAdmin);

    /**
     * @dev Returns the admin address for the SuperToken
     */
    function getAdmin() external view returns (address admin);

    /**************************************************************************
    * Immutable variables
    *************************************************************************/

    // solhint-disable-next-line func-name-mixedcase
    function POOL_ADMIN_NFT() external view returns (IPoolAdminNFT);
    // solhint-disable-next-line func-name-mixedcase
    function POOL_MEMBER_NFT() external view returns (IPoolMemberNFT);

    /**************************************************************************
    * IERC20Metadata & ERC777
    *************************************************************************/

    /**
     * @dev Returns the name of the token.
     */
    function name() external view override(IERC777, IERC20Metadata) returns (string memory);

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() external view override(IERC777, IERC20Metadata) returns (string memory);

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5,05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the value {ERC20} uses, unless {_setupDecimals} is
     * called.
     *
     * @custom:note SuperToken always uses 18 decimals.
     *
     * This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() external view override(IERC20Metadata) returns (uint8);

    /**************************************************************************
    * ERC20 & ERC777
    *************************************************************************/

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() external view override(IERC777, IERC20) returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by an account (`owner`).
     */
    function balanceOf(address account) external view override(IERC777, IERC20) returns(uint256 balance);

    /**************************************************************************
    * ERC20
    *************************************************************************/

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * @return Returns Success a boolean value indicating whether the operation succeeded.
     *
     * @custom:emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount) external override(IERC20) returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     *         allowed to spend on behalf of `owner` through {transferFrom}. This is
     *         zero by default.
     *
     * @notice This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external override(IERC20) view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * @return Returns Success a boolean value indicating whether the operation succeeded.
     *
     * @custom:note Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * @custom:emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external override(IERC20) returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     *         allowance mechanism. `amount` is then deducted from the caller's
     *         allowance.
     *
     * @return Returns Success a boolean value indicating whether the operation succeeded.
     *
     * @custom:emits a {Transfer} event.
     */
    function transferFrom(address sender, address recipient, uint256 amount) external override(IERC20) returns (bool);

    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * @custom:emits an {Approval} event indicating the updated allowance.
     *
     * @custom:requirements
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) external returns (bool);

    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * @custom:emits an {Approval} event indicating the updated allowance.
     *
     * @custom:requirements
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
     function decreaseAllowance(address spender, uint256 subtractedValue) external returns (bool);

    /**************************************************************************
    * ERC777
    *************************************************************************/

    /**
     * @dev Returns the smallest part of the token that is not divisible. This
     *         means all token operations (creation, movement and destruction) must have
     *         amounts that are a multiple of this number.
     *
     * @custom:note For super token contracts, this value is always 1
     */
    function granularity() external view override(IERC777) returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * @dev If send or receive hooks are registered for the caller and `recipient`,
     *      the corresponding functions will be called with `userData` and empty
     *      `operatorData`. See {IERC777Sender} and {IERC777Recipient}.
     *
     * @custom:emits a {Sent} event.
     *
     * @custom:requirements
     * - the caller must have at least `amount` tokens.
     * - `recipient` cannot be the zero address.
     * - if `recipient` is a contract, it must implement the {IERC777Recipient}
     * interface.
     */
    function send(address recipient, uint256 amount, bytes calldata userData) external override(IERC777);

    /**
     * @dev Destroys `amount` tokens from the caller's account, reducing the
     * total supply and transfers the underlying token to the caller's account.
     *
     * If a send hook is registered for the caller, the corresponding function
     * will be called with `userData` and empty `operatorData`. See {IERC777Sender}.
     *
     * @custom:emits a {Burned} event.
     *
     * @custom:requirements
     * - the caller must have at least `amount` tokens.
     */
    function burn(uint256 amount, bytes calldata userData) external override(IERC777);

    /**
     * @dev Returns true if an account is an operator of `tokenHolder`.
     * Operators can send and burn tokens on behalf of their owners. All
     * accounts are their own operator.
     *
     * See {operatorSend} and {operatorBurn}.
     */
    function isOperatorFor(address operator, address tokenHolder) external override(IERC777) view returns (bool);

    /**
     * @dev Make an account an operator of the caller.
     *
     * See {isOperatorFor}.
     *
     * @custom:emits an {AuthorizedOperator} event.
     *
     * @custom:requirements
     * - `operator` cannot be calling address.
     */
    function authorizeOperator(address operator) external override(IERC777);

    /**
     * @dev Revoke an account's operator status for the caller.
     *
     * See {isOperatorFor} and {defaultOperators}.
     *
     * @custom:emits a {RevokedOperator} event.
     *
     * @custom:requirements
     * - `operator` cannot be calling address.
     */
    function revokeOperator(address operator) external override(IERC777);

    /**
     * @dev Returns the list of default operators. These accounts are operators
     * for all token holders, even if {authorizeOperator} was never called on
     * them.
     *
     * This list is immutable, but individual holders may revoke these via
     * {revokeOperator}, in which case {isOperatorFor} will return false.
     */
    function defaultOperators() external override(IERC777) view returns (address[] memory);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient`. The caller must
     * be an operator of `sender`.
     *
     * If send or receive hooks are registered for `sender` and `recipient`,
     * the corresponding functions will be called with `userData` and
     * `operatorData`. See {IERC777Sender} and {IERC777Recipient}.
     *
     * @custom:emits a {Sent} event.
     *
     * @custom:requirements
     * - `sender` cannot be the zero address.
     * - `sender` must have at least `amount` tokens.
     * - the caller must be an operator for `sender`.
     * - `recipient` cannot be the zero address.
     * - if `recipient` is a contract, it must implement the {IERC777Recipient}
     * interface.
     */
    function operatorSend(
        address sender,
        address recipient,
        uint256 amount,
        bytes calldata userData,
        bytes calldata operatorData
    ) external override(IERC777);

    /**
     * @dev Destroys `amount` tokens from `account`, reducing the total supply.
     * The caller must be an operator of `account`.
     *
     * If a send hook is registered for `account`, the corresponding function
     * will be called with `userData` and `operatorData`. See {IERC777Sender}.
     *
     * @custom:emits a {Burned} event.
     *
     * @custom:requirements
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     * - the caller must be an operator for `account`.
     */
    function operatorBurn(
        address account,
        uint256 amount,
        bytes calldata userData,
        bytes calldata operatorData
    ) external override(IERC777);

    /**************************************************************************
     * SuperToken custom token functions
     *************************************************************************/

    /**
     * @dev Mint new tokens for the account
     * If `userData` is not empty, the `tokensReceived` hook is invoked according to ERC777 semantics.
     *
     * @custom:modifiers
     *  - onlySelf
     */
    function selfMint(
        address account,
        uint256 amount,
        bytes memory userData
    ) external;

   /**
    * @dev Burn existing tokens for the account
    * If `userData` is not empty, the `tokensToSend` hook is invoked according to ERC777 semantics.
    *
    * @custom:modifiers
    *  - onlySelf
    */
   function selfBurn(
       address account,
       uint256 amount,
       bytes memory userData
   ) external;

   /**
    * @dev Transfer `amount` tokens from the `sender` to `recipient`.
    * If `spender` isn't the same as `sender`, checks if `spender` has allowance to
    * spend tokens of `sender`.
    *
    * @custom:modifiers
    *  - onlySelf
    */
   function selfTransferFrom(
        address sender,
        address spender,
        address recipient,
        uint256 amount
   ) external;

   /**
    * @dev Give `spender`, `amount` allowance to spend the tokens of
    * `account`.
    *
    * @custom:modifiers
    *  - onlySelf
    */
   function selfApproveFor(
        address account,
        address spender,
        uint256 amount
   ) external;

    /**************************************************************************
     * SuperToken extra functions
     *************************************************************************/

    /**
     * @dev Transfer all available balance from `msg.sender` to `recipient`
     */
    function transferAll(address recipient) external;

    /**************************************************************************
     * ERC20 wrapping
     *************************************************************************/

    /**
     * @dev Return the underlying token contract
     * @return tokenAddr Underlying token address
     */
    function getUnderlyingToken() external view returns(address tokenAddr);

    /**
     * @dev Return the underlying token decimals
     * @return underlyingDecimals Underlying token decimals
     */
    function getUnderlyingDecimals() external view returns (uint8 underlyingDecimals);

    /**
     * @dev Return the underlying token conversion rate
     * @param amount Number of tokens to be upgraded (in 18 decimals)
     * @return underlyingAmount The underlying token amount after scaling
     * @return adjustedAmount The super token amount after scaling
     */
    function toUnderlyingAmount(uint256 amount)
        external
        view
        returns (uint256 underlyingAmount, uint256 adjustedAmount);

    /**
     * @dev Upgrade ERC20 to SuperToken.
     * @param amount Number of tokens to be upgraded (in 18 decimals)
     *
     * @custom:note It will use `transferFrom` to get tokens. Before calling this
     * function you should `approve` this contract
     */
    function upgrade(uint256 amount) external;

    /**
     * @dev Upgrade ERC20 to SuperToken and transfer immediately
     * @param to The account to receive upgraded tokens
     * @param amount Number of tokens to be upgraded (in 18 decimals)
     * @param userData User data for the TokensRecipient callback
     *
     * @custom:note It will use `transferFrom` to get tokens. Before calling this
     * function you should `approve` this contract
     *
     * @custom:warning
     * - there is potential of reentrancy IF the "to" account is a registered ERC777 recipient.
     * @custom:requirements
     * - if `userData` is NOT empty AND `to` is a contract, it MUST be a registered ERC777 recipient
     *   otherwise it reverts.
     */
    function upgradeTo(address to, uint256 amount, bytes calldata userData) external;

    /**
     * @dev Token upgrade event
     * @param account Account where tokens are upgraded to
     * @param amount Amount of tokens upgraded (in 18 decimals)
     */
    event TokenUpgraded(
        address indexed account,
        uint256 amount
    );

    /**
     * @dev Downgrade SuperToken to ERC20.
     * @dev It will call transfer to send tokens
     * @param amount Number of tokens to be downgraded
     */
    function downgrade(uint256 amount) external;

    /**
     * @dev Downgrade SuperToken to ERC20 and transfer immediately
     * @param to The account to receive downgraded tokens
     * @param amount Number of tokens to be downgraded (in 18 decimals)
     */
    function downgradeTo(address to, uint256 amount) external;

    /**
     * @dev Token downgrade event
     * @param account Account whose tokens are downgraded
     * @param amount Amount of tokens downgraded
     */
    event TokenDowngraded(
        address indexed account,
        uint256 amount
    );

    /**************************************************************************
    * Batch Operations
    *************************************************************************/

    /**
    * @dev Perform ERC20 approve by host contract.
    * @param account The account owner to be approved.
    * @param spender The spender of account owner's funds.
    * @param amount Number of tokens to be approved.
    *
    * @custom:modifiers
    *  - onlyHost
    */
    function operationApprove(
        address account,
        address spender,
        uint256 amount
    ) external;

    function operationIncreaseAllowance(
        address account,
        address spender,
        uint256 addedValue
    ) external;

    function operationDecreaseAllowance(
        address account,
        address spender,
        uint256 subtractedValue
    ) external;

    /**
    * @dev Perform ERC20 transferFrom by host contract.
    * @param account The account to spend sender's funds.
    * @param spender The account where the funds is sent from.
    * @param recipient The recipient of the funds.
    * @param amount Number of tokens to be transferred.
    *
    * @custom:modifiers
    *  - onlyHost
    */
    function operationTransferFrom(
        address account,
        address spender,
        address recipient,
        uint256 amount
    ) external;

    /**
    * @dev Perform ERC777 send by host contract.
    * @param spender The account where the funds is sent from.
    * @param recipient The recipient of the funds.
    * @param amount Number of tokens to be transferred.
    * @param userData Arbitrary user inputted data
    *
    * @custom:modifiers
    *  - onlyHost
    */
    function operationSend(
        address spender,
        address recipient,
        uint256 amount,
        bytes memory userData
    ) external;

    /**
    * @dev Upgrade ERC20 to SuperToken by host contract.
    * @param account The account to be changed.
    * @param amount Number of tokens to be upgraded (in 18 decimals)
    *
    * @custom:modifiers
    *  - onlyHost
    */
    function operationUpgrade(address account, uint256 amount) external;

    /**
    * @dev Downgrade ERC20 to SuperToken by host contract.
    * @param account The account to be changed.
    * @param amount Number of tokens to be downgraded (in 18 decimals)
    *
    * @custom:modifiers
    *  - onlyHost
    */
    function operationDowngrade(address account, uint256 amount) external;

    /**
    * @dev Upgrade ERC20 to SuperToken by host contract and transfer immediately.
    * @param account The account to be changed.
    * @param to The account to receive upgraded tokens
    * @param amount Number of tokens to be upgraded (in 18 decimals)
    *
    * @custom:modifiers
    *  - onlyHost
    */
    function operationUpgradeTo(address account, address to, uint256 amount) external;

    /**
    * @dev Downgrade ERC20 to SuperToken by host contract and transfer immediately.
    * @param account The account to be changed.
    * @param to The account to receive downgraded tokens
    * @param amount Number of tokens to be downgraded (in 18 decimals)
    *
    * @custom:modifiers
    *  - onlyHost
    */
    function operationDowngradeTo(address account, address to, uint256 amount) external;

    /**
     * @dev Pool Admin NFT proxy created event
     * @param poolAdminNFT pool admin nft address
     */
    event PoolAdminNFTCreated(
        IPoolAdminNFT indexed poolAdminNFT
    );

    /**
     * @dev Pool Member NFT proxy created event
     * @param poolMemberNFT pool member nft address
     */
    event PoolMemberNFTCreated(
        IPoolMemberNFT indexed poolMemberNFT
    );

    /**************************************************************************
    * 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 the contract itself
    //modifier onlySelf() virtual

}