diamondyhand / vault

🚩 Vault Contract Design.

Vault(FlashLender), FlashBorrow, Proxy and Proxiable contract

• FlashBorrow Contract: User's contract whiteListed Contract
• Vault Contract: Main Contract
• Proxy Contract: UUPS contract
• Proxiable Contract: UUPS contract

Vault Variables 📋

struct whiteInfo

• Contract's status and approved users.

  struct whiteInfo {
    mapping(address => bool) Users;
    bool status;  // add or remove status
  }

mapping userShares

• amount that user have shares for ERC20Tokens.

  // mapping (User address(ERC20Token(Usable) => amount of vault share)
  mapping(address => mapping(address => uint256)) public userShares;

mapping whiteList

• approved Contract's InfoList

  // mapping (Contract address => (user address => status))
  mapping(address => mapping(address => bool)) public whiteList;

mapping whiteList

• approved Contract's InfoList

  /// @notice mapping to contract to whitelist status
  mapping(address => mapping(address => bool)) public allowedContracts;

mapping totalShares

• amount of shares already created for this vault

  // mapping (ERC20Token(Usable) => currentTotal(amount of shares already created for this vault))
  mapping(address => uint256) public totalShares;

mappingg totalAmounts

• amount of the particular depoosited asset already in the vault.

  // mapping (ERC20Token(Usable) => currentUnderlyingBalance((amount of the particular depoosited asset already in the vault.)))
  mapping(address => uint256) public totalAmounts;

All Function Table 🖥️

Contract	Function name	Note	Role
FlashBorrow	onFlashLoan		Vault
FlashBorrow	flashBorrow		Vault
Vault	deposit	Main Action	User
Vault	withdraw	Main Action	WhiteList, User
Vault	transfer	Main Action	WhiteList, User
Vault	flashLoan	Main Action	User
Vault	approveContract	Main Action	User
Vault	setPause	Admin Action	Admin
Vault	emergencyWidthdraw	Admin Action	Admin
Vault	allowContract	Admin Action	Admin
Vault	updateFlashloanRate	Admin Action	Admin
Vault	toShare	Help Action	All
Vault	toUnderlying	Help Action	All
Proxiable	updateCodeAddress	Upgrade Action	All
Proxiable	proxiableUUID	Upgrade Action	All
Proxy	fallback	Upgrade Action	All

FlashBorrow Contract

function onFlashLoan()

  /**
   * @dev User use this function to flashLoan.
   * @param initator this contract address(FlashBrrow address)
   * @param token ERC20Token address
   * @param amount flashLoan amount
   * @param fee flashLoan fee amount
   * @param data option data
   */
  function onFlashLoan(
    address initiator,
    address token,
    uint256 amount,
    uint256 fee,
    bytes calldata data
  ) external returns (bytes32);

function flashBorrow()

  /**
   * @dev User call this function for flashLoan.
   * @param token ERC20Token address for flashLoan
   * @param amount flashLoan amount(amount of ERC20Token)
   */
  function flashBorrow(
    address token,
    uint256 amount
  )

Vault Contract (Main Action) 🔧

function deposit()

  /**@dev When Users deposist ERC20 Tokens, They get vault of ERC20 amount(deposit amount).
   * @param _token Token address to deposit.
   * @param _amount Amount to deposit.
   */
  function deposit(
    address token,  
    address amount,
  ) external view payable;

function withdraw()

  /**
   * @dev Users can get ERC20Token amount about their shares.
   * @notice whiteListed Contract can call this func.
   * @param token Token address to withdraw.
   * @param amount Amount of ERC20Token for withdraw
   */
  function withdraw(
    address token,
    address amount,
  ) external view payable;

function transfer()

  /**
   * @dev Users can transfer ERC20 shares to other users using this func.
   * @notice whiteListed Contract can call this func.
   * @param _user spender address to transfer
   * @param _receiver receiver address to transfer
   * @param _token token(ERC20) address to transfer
   * @param _share vault share to transfer
   */
  function transfer(
    address _user,
    address _receiver,
    address _token,
    uint256 _share
  ) external view payable;

function flashLoan()

  /**
   * @dev flashlender's main function. User can get profit using flashLoan.
   * @param receiver WhiteListed Contract
   * @param token The loan currency.
   * @param amount The amount of tokens lent.
   * @param data Option data
   */
  function flashLoan(
    IERC3156FlashBorrower _receiver,
    address _token,
    uint _amount,
    bytes calldata _data
  ) external returns (bool)

function approve()

  /**
   * @dev This function will enable or disable the whitelisted contracts 
   * to transfer or withdraw user's vault shares. In here, param v, r, s is hashString of verifyingContract and signer. EIP712 hashing and signing method.
   * @param _user user's address
   * @param _contract user's approved contract(whiteList) == FlashBorrower's address
   * @param _status enable(true) or disable
   * @param v EIP712 hashing param v
   * @param r EIP712 hashing param r
   * @param s EIP712 hashing param s
   */
  function approveContract(
    address _user,
    address _contract,
    bool _status,
    uint8 v,
    bytes32 r,
    bytes32 s
  ) external view payable;

Vault Contract (Admin Actions) 🤖

function updateCode()

  /**
   * @dev This contract is using UUPS proxy pattern and admin can upgrade using updateCode function.
   * @param newCode upgrade contract address
   */
  function updateCode(
    address newCode
  ) external view;

function setPause()

  /**
   * @dev Admin can pause/unpause all the above main functions.
   * @param _paused paused status(true: pause, false: unpause)
   */
  function setPause(
    bool _paused
  ) external;

function emergencyWidthdraw()

  /**
   * @dev when vault paused, admin can withdraw user's amount.
   * @param _user user's address for withdraw
   * @param _token ERC20token address for withdraw
   * @param _amount amount for ERC20token
   */
  function emergencyWidthdraw(
      address _user,
      address _token,
      uint _amount
  ) external;

function allowContract()

  /**
   * @dev Admin can add or remove contracts to the whitelist.
   * @param _addr contract address that you'll add or remove in whitelist.
   * @param _status add: true, remove: false
   */
  function allowContract(
    address _addr, 
    bool _status
  ) external;

function updateFalshloanRate()

  /**
   * @dev Admin can update the flashLoanfeeRate using this.
   * @param _feeRate flashLoan-feeRate that you'll update.
   */
  function updateFlashloanRate(
    uint _feeRate
  ) external;

Vault Contract (Helper Actions) 💢

function toShare()

  /**
   * @dev User can know shares from ERC20token amount.
   * @param _token ERC20Token interface for convert
   * @param _amount amount of ERC20Token
   */
  function toShare(
    IERC20 _token, 
    uint _amount
  ) external;

function toUnderlying()

  /**
   * @dev User can know ERC20Token amount from share.
   * @param _token ERC20Token interface for convert
   * @param _share share of ERC20Token
   */
  function toUnderlying(
    IERC20 _token,
    uint _share
  ) external;

Proxy Contract

You can use Proxy contract instead of Vault Contract. In other words, this contract exist for upgrade. Proxy contract only has fallback function. I use EIP-1822 proxy contract.

Proxiable Contract

You can use Proxiable contract for updateCode. updateCodeAddress and proxiableUUID function. I use EIP-1822 proxiable contract.