# Fund Flow Controller

The `FundFlowController` manages deposits and withdrawals for Chainlink staking vaults in the `OperatorVCS` and `CommunityVCS`. Specifcally, it calculates vault deposit/withdrawal order, calculates the current state of accounting across vault groups, and periodically unbonds vaults in the Chainlink staking contract to ensure there are always funds available to withdraw.

## View Functions

### operatorVCS

Returns the address of the Operator VCS

```solidity
function operatorVCS() public view returns (address)
```

#### Return Values

| Name        | Type    | Description             |
| ----------- | ------- | ----------------------- |
| operatorVCS | address | Address of Operator VCS |

### communityVCS

Returns the address of the Community VCS

```solidity
function communityVCS() public view returns (address)
```

#### Return Values

| Name         | Type    | Description              |
| ------------ | ------- | ------------------------ |
| communityVCS | address | Address of Community VCS |

### unbondingPeriod

Returns the duration of the unbonding period in the Chainlink staking contract

```solidity
function unbondingPeriod() public view returns (uint64)
```

#### Return Values

| Name            | Type   | Description      |
| --------------- | ------ | ---------------- |
| unbondingPeriod | uint64 | Unbonding period |

### claimPeriod

Returns the duration of the claim period in the Chainlink staking contract

```solidity
function claimPeriod() public view returns (uint64)
```

#### Return Values

| Name        | Type   | Description  |
| ----------- | ------ | ------------ |
| claimPeriod | uint64 | Claim period |

### numVaultGroups

Returns the total number of vault groups

```solidity
function numVaultGroups() public view returns (uint64)
```

#### Return Values

| Name           | Type   | Description            |
| -------------- | ------ | ---------------------- |
| numVaultGroups | uint64 | Number of vault groups |

### curUnbondedVaultGroup

Returns the index of current unbonded vault group

```solidity
function curUnbondedVaultGroup() public view returns (uint64)
```

#### Return Values

| Name                  | Type   | Description                  |
| --------------------- | ------ | ---------------------------- |
| curUnbondedVaultGroup | uint64 | Current unbonded vault group |

### timeOfLastUpdateByGroup

Returns the time that a vault group was last unbonded

```solidity
function timeOfLastUpdateByGroup() public view returns (uint64)
```

#### Parameters

| Name       | Type   | Description          |
| ---------- | ------ | -------------------- |
| vaultGroup | uint64 | Index of vault group |

#### Return Values

| Name             | Type   | Description                            |
| ---------------- | ------ | -------------------------------------- |
| timeOfLastUpdate | uint64 | Time of last update for selected group |

### getDepositData

Returns encoded vault deposit order for each strategy

*Return data should be passed to the priority pool when depositing into the staking pool*

```solidity
function getDepositData(uint256 _toDeposit) external view returns (bytes[])
```

#### Parameters

| Name        | Type    | Description       |
| ----------- | ------- | ----------------- |
| \_toDeposit | uint256 | amount to deposit |

#### Return Values

| Name        | Type     | Description                        |
| ----------- | -------- | ---------------------------------- |
| depositData | bytes\[] | list of encoded vault deposit data |

### getWithdrawalData

Returns encoded vault withdrawal order for each strategy

*Return data should be passed to the priority pool when withdrawing from the staking pool*

```solidity
function getWithdrawalData(uint256 _toWithdraw) external view returns (bytes[])
```

#### Parameters

| Name         | Type    | Description        |
| ------------ | ------- | ------------------ |
| \_toWithdraw | uint256 | amount to withdraw |

#### Return Values

| Name           | Type     | Description                           |
| -------------- | -------- | ------------------------------------- |
| withdrawalData | bytes\[] | list of encoded vault withdrawal data |

### claimPeriodActive

Returns whether claim period is active

*Funds can only be withdrawn while the claim period is active*

```solidity
function claimPeriodActive() external view returns (bool)
```

#### Return Values

| Name     | Type | Description                                     |
| -------- | ---- | ----------------------------------------------- |
| isActive | bool | true if claim period is active, false otherwise |

### shouldUpdateVaultGroups

Returns whether vault groups should be updated.

```solidity
function shouldUpdateVaultGroups() external view returns (bool)
```

#### Return Values

| Name         | Type | Description                                             |
| ------------ | ---- | ------------------------------------------------------- |
| shouldUpdate | bool | true if vault groups should be updated, false otherwise |

## Write Functions

### updateVaultGroups

Executes a vault group update

*Re-unbonds all vaults in the current vault group and increments the current vault group*\
\&#xNAN;*to the next one which will have just entered the claim period*\
\&#xNAN;*an update is needed once per claim period right after the claim period expires for the*\
\&#xNAN;*current vault group*

```solidity
function updateVaultGroups() external
```

### updateOperatorVaultGroupAccounting

Calculates and updates totalDepositRoom and totalUnbonded for a list of operator vault groups

*Used to correct minor accounting errors that result from the removal or slashing*\
\&#xNAN;*of operators in the Chainlink staking contract*

```solidity
function updateOperatorVaultGroupAccounting(uint256[] _vaultGroups) external
```

#### Parameters

| Name          | Type       | Description          |
| ------------- | ---------- | -------------------- |
| \_vaultGroups | uint256\[] | list of vault groups |

### delegateVaults

Delegates to an address for a group of vaults.

```solidity
function delegateVaults(address[] _vaults, address _to, bytes32 _rights, bool _enable) external
```

#### Parameters

| Name     | Type       | Description                            |
| -------- | ---------- | -------------------------------------- |
| \_vaults | address\[] | List of vault addresses                |
| \_to     | address    | Address to delegate to                 |
| \_rights | bytes32    | Rights to grant                        |
| \_enable | bool       | Whether to enable or revoke delegation |

### withdrawTokenRewards

Withdraws non-LINK token rewards from a group of vaults.

```solidity
function withdrawTokenRewards(address[] _vaults, address[] _tokens) external
```

#### Parameters

| Name     | Type       | Description                |
| -------- | ---------- | -------------------------- |
| \_vaults | address\[] | List of vault addresses    |
| \_tokens | address\[] | List of tokens to withdraw |

### setNonLINKRewardReceiver

Sets the address of reward receiver for non-LINK vault rewards.

```solidity
function setNonLINKRewardReceiver(address _nonLINKRewardReceiver) external
```

#### Parameters

| Name                    | Type    | Description                |
| ----------------------- | ------- | -------------------------- |
| \_nonLINKRewardReceiver | address | Address of reward receiver |


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