# VAIController

## VAI Comptroller

This is the implementation contract for the VAIUnitroller proxy

## Solidity API

#### INITIAL\_VAI\_MINT\_INDEX

Initial index used in interest computations

```solidity
uint256 INITIAL_VAI_MINT_INDEX
```

***

#### CORE\_POOL\_ID

poolId for core Pool

```solidity
uint96 CORE_POOL_ID
```

***

#### mintVAI

The mintVAI function mints and transfers VAI from the protocol to the user, and adds a borrow balance. The amount minted must be less than the user's Account Liquidity and the mint vai limit.

```solidity
function mintVAI(uint256 mintVAIAmount) external returns (uint256)
```

**Parameters**

| Name          | Type    | Description                         |
| ------------- | ------- | ----------------------------------- |
| mintVAIAmount | uint256 | The amount of the VAI to be minted. |

**Return Values**

| Name | Type    | Description                           |
| ---- | ------- | ------------------------------------- |
| \[0] | uint256 | 0 on success, otherwise an error code |

***

#### repayVAI

The repay function transfers VAI interest into the protocol and burns the rest, reducing the borrower's borrow balance. Before repaying VAI, users must first approve VAIController to access their VAI balance.

```solidity
function repayVAI(uint256 amount) external returns (uint256, uint256)
```

**Parameters**

| Name   | Type    | Description                     |
| ------ | ------- | ------------------------------- |
| amount | uint256 | The amount of VAI to be repaid. |

**Return Values**

| Name | Type    | Description                                                        |
| ---- | ------- | ------------------------------------------------------------------ |
| \[0] | uint256 | Error code (0=success, otherwise a failure, see ErrorReporter.sol) |
| \[1] | uint256 | Actual repayment amount                                            |

***

#### repayVAIBehalf

The repay on behalf function transfers VAI interest into the protocol and burns the rest, reducing the borrower's borrow balance. Borrowed VAIs are repaid by another user (possibly the borrower). Before repaying VAI, the payer must first approve VAIController to access their VAI balance.

```solidity
function repayVAIBehalf(address borrower, uint256 amount) external returns (uint256, uint256)
```

**Parameters**

| Name     | Type    | Description                        |
| -------- | ------- | ---------------------------------- |
| borrower | address | The account to repay the debt for. |
| amount   | uint256 | The amount of VAI to be repaid.    |

**Return Values**

| Name | Type    | Description                                                        |
| ---- | ------- | ------------------------------------------------------------------ |
| \[0] | uint256 | Error code (0=success, otherwise a failure, see ErrorReporter.sol) |
| \[1] | uint256 | Actual repayment amount                                            |

***

#### liquidateVAI

The sender liquidates the vai minters collateral. The collateral seized is transferred to the liquidator.

```solidity
function liquidateVAI(address borrower, uint256 repayAmount, contract VTokenInterface vTokenCollateral) external returns (uint256, uint256)
```

**Parameters**

| Name             | Type                     | Description                                               |
| ---------------- | ------------------------ | --------------------------------------------------------- |
| borrower         | address                  | The borrower of vai to be liquidated                      |
| repayAmount      | uint256                  | The amount of the underlying borrowed asset to repay      |
| vTokenCollateral | contract VTokenInterface | The market in which to seize collateral from the borrower |

**Return Values**

| Name | Type    | Description                                                        |
| ---- | ------- | ------------------------------------------------------------------ |
| \[0] | uint256 | Error code (0=success, otherwise a failure, see ErrorReporter.sol) |
| \[1] | uint256 | Actual repayment amount                                            |

***

#### \_setComptroller

Sets a new comptroller

```solidity
function _setComptroller(contract ComptrollerInterface comptroller_) external returns (uint256)
```

**Return Values**

| Name | Type    | Description                                                                |
| ---- | ------- | -------------------------------------------------------------------------- |
| \[0] | uint256 | uint256 0=success, otherwise a failure (see ErrorReporter.sol for details) |

***

#### setPrimeToken

Set the prime token contract address

```solidity
function setPrimeToken(address prime_) external
```

**Parameters**

| Name    | Type    | Description                                 |
| ------- | ------- | ------------------------------------------- |
| prime\_ | address | The new address of the prime token contract |

***

#### setVAIToken

Set the VAI token contract address

```solidity
function setVAIToken(address vai_) external
```

**Parameters**

| Name  | Type    | Description                               |
| ----- | ------- | ----------------------------------------- |
| vai\_ | address | The new address of the VAI token contract |

***

#### toggleOnlyPrimeHolderMint

Toggle mint only for prime holder

```solidity
function toggleOnlyPrimeHolderMint() external returns (uint256)
```

**Return Values**

| Name | Type    | Description                                                                |
| ---- | ------- | -------------------------------------------------------------------------- |
| \[0] | uint256 | uint256 0=success, otherwise a failure (see ErrorReporter.sol for details) |

***

```solidity
struct AccountAmountLocalVars {
  uint256 oErr;
  enum CarefulMath.MathError mErr;
  uint256 sumSupply;
  uint256 marketSupply;
  uint256 sumBorrowPlusEffects;
  uint256 vTokenBalance;
  uint256 borrowBalance;
  uint256 exchangeRateMantissa;
  uint256 oraclePriceMantissa;
  struct ExponentialNoError.Exp exchangeRate;
  struct ExponentialNoError.Exp oraclePrice;
  struct ExponentialNoError.Exp tokensToDenom;
}
```

#### getMintableVAI

Function that returns the amount of VAI a user can mint based on their account liquidy and the VAI mint rate If mintEnabledOnlyForPrimeHolder is true, only Prime holders are able to mint VAI

```solidity
function getMintableVAI(address minter) public view returns (uint256, uint256)
```

**Parameters**

| Name   | Type    | Description                       |
| ------ | ------- | --------------------------------- |
| minter | address | The account to check mintable VAI |

**Return Values**

| Name | Type    | Description                                                                    |
| ---- | ------- | ------------------------------------------------------------------------------ |
| \[0] | uint256 | Error code (0=success, otherwise a failure, see ErrorReporter.sol for details) |
| \[1] | uint256 | Mintable amount (with 18 decimals)                                             |

***

#### \_setTreasuryData

Update treasury data

```solidity
function _setTreasuryData(address newTreasuryGuardian, address newTreasuryAddress, uint256 newTreasuryPercent) external returns (uint256)
```

**Parameters**

| Name                | Type    | Description                                                     |
| ------------------- | ------- | --------------------------------------------------------------- |
| newTreasuryGuardian | address | New Treasury Guardian address                                   |
| newTreasuryAddress  | address | New Treasury Address                                            |
| newTreasuryPercent  | uint256 | New fee percentage for minting VAI that is sent to the treasury |

***

#### getVAIRepayRate

Gets yearly VAI interest rate based on the VAI price

```solidity
function getVAIRepayRate() public view returns (uint256)
```

**Return Values**

| Name | Type    | Description                      |
| ---- | ------- | -------------------------------- |
| \[0] | uint256 | uint256 Yearly VAI interest rate |

***

#### getVAIRepayRatePerBlock

Get interest rate per block

```solidity
function getVAIRepayRatePerBlock() public view returns (uint256)
```

**Return Values**

| Name | Type    | Description                    |
| ---- | ------- | ------------------------------ |
| \[0] | uint256 | uint256 Interest rate per bock |

***

#### getVAIMinterInterestIndex

Get the last updated interest index for a VAI Minter

```solidity
function getVAIMinterInterestIndex(address minter) public view returns (uint256)
```

**Parameters**

| Name   | Type    | Description           |
| ------ | ------- | --------------------- |
| minter | address | Address of VAI minter |

**Return Values**

| Name | Type    | Description                                          |
| ---- | ------- | ---------------------------------------------------- |
| \[0] | uint256 | uint256 Returns the interest rate index for a minter |

***

#### getVAIRepayAmount

Get the current total VAI a user needs to repay

```solidity
function getVAIRepayAmount(address account) public view returns (uint256)
```

**Parameters**

| Name    | Type    | Description                     |
| ------- | ------- | ------------------------------- |
| account | address | The address of the VAI borrower |

**Return Values**

| Name | Type    | Description                                               |
| ---- | ------- | --------------------------------------------------------- |
| \[0] | uint256 | (uint256) The total amount of VAI the user needs to repay |

***

#### getVAICalculateRepayAmount

Calculate how much VAI the user needs to repay

```solidity
function getVAICalculateRepayAmount(address borrower, uint256 repayAmount) public view returns (uint256, uint256, uint256)
```

**Parameters**

| Name        | Type    | Description                      |
| ----------- | ------- | -------------------------------- |
| borrower    | address | The address of the VAI borrower  |
| repayAmount | uint256 | The amount of VAI being returned |

**Return Values**

| Name | Type    | Description                                             |
| ---- | ------- | ------------------------------------------------------- |
| \[0] | uint256 | Amount of VAI to be burned                              |
| \[1] | uint256 | Amount of VAI the user needs to pay in current interest |
| \[2] | uint256 | Amount of VAI the user needs to pay in past interest    |

***

#### accrueVAIInterest

Accrue interest on outstanding minted VAI

```solidity
function accrueVAIInterest() public
```

***

#### setAccessControl

Sets the address of the access control of this contract

```solidity
function setAccessControl(address newAccessControlAddress) external
```

**Parameters**

| Name                    | Type    | Description                        |
| ----------------------- | ------- | ---------------------------------- |
| newAccessControlAddress | address | New address for the access control |

***

#### setBaseRate

Set VAI borrow base rate

```solidity
function setBaseRate(uint256 newBaseRateMantissa) external
```

**Parameters**

| Name                | Type    | Description                          |
| ------------------- | ------- | ------------------------------------ |
| newBaseRateMantissa | uint256 | the base rate multiplied by 10\*\*18 |

***

#### setFloatRate

Set VAI borrow float rate

```solidity
function setFloatRate(uint256 newFloatRateMantissa) external
```

**Parameters**

| Name                 | Type    | Description                               |
| -------------------- | ------- | ----------------------------------------- |
| newFloatRateMantissa | uint256 | the VAI float rate multiplied by 10\*\*18 |

***

#### setReceiver

Set VAI stability fee receiver address

```solidity
function setReceiver(address newReceiver) external
```

**Parameters**

| Name        | Type    | Description                         |
| ----------- | ------- | ----------------------------------- |
| newReceiver | address | the address of the VAI fee receiver |

***

#### setMintCap

Set VAI mint cap

```solidity
function setMintCap(uint256 _mintCap) external
```

**Parameters**

| Name      | Type    | Description                          |
| --------- | ------- | ------------------------------------ |
| \_mintCap | uint256 | the amount of VAI that can be minted |

***

#### getVAIAddress

Return the address of the VAI token

```solidity
function getVAIAddress() public view virtual returns (address)
```

**Return Values**

| Name | Type    | Description        |
| ---- | ------- | ------------------ |
| \[0] | address | The address of VAI |

***


---

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