# ChainlinkPriceProvider

## Overview

#### License: MIT

```solidity
contract ChainlinkPriceProvider is PriceProvider, Initializable, AccessControlUpgradeable
```

The ChainlinkPriceProvider contract is the contract that provides the functionality for getting the price of a token using Chainlink.

## Structs info

### ChainlinkMetadata

```solidity
struct ChainlinkMetadata {
	bool isActive;
	address[] aggregatorPath;
}
```

## Events info

### SetTokenAndAggregator

```solidity
event SetTokenAndAggregator(address indexed token, address[] aggregatorPath)
```

Emitted when a token and its corresponding Chainlink aggregator path are set.

Parameters:

| Name           | Type       | Description                                                                     |
| -------------- | ---------- | ------------------------------------------------------------------------------- |
| token          | address    | The address of the token.                                                       |
| aggregatorPath | address\[] | The array of Chainlink aggregator addresses used to get the price of the token. |

### ChangeActive

```solidity
event ChangeActive(address indexed token, bool active)
```

Emitted when the active status of a token is changed.

Parameters:

| Name   | Type    | Description                                              |
| ------ | ------- | -------------------------------------------------------- |
| token  | address | The address of the token whose active status is changed. |
| active | bool    | The new active status of the token.                      |

### SetTimeOut

```solidity
event SetTimeOut(address indexed aggregatorPath, uint256 newTimeOut)
```

Emitted when the time out for a Chainlink aggregator path is set.

Parameters:

| Name           | Type    | Description                                   |
| -------------- | ------- | --------------------------------------------- |
| aggregatorPath | address | The address of the Chainlink aggregator path. |
| newTimeOut     | uint256 | The new time out value in seconds.            |

### SetTokenDecimals

```solidity
event SetTokenDecimals(uint8 newTokenDecimals)
```

Emitted when the token decimals is set.

Parameters:

| Name             | Type  | Description             |
| ---------------- | ----- | ----------------------- |
| newTokenDecimals | uint8 | The new token decimals. |

## Constants info

### MODERATOR\_ROLE (0x797669c9)

```solidity
bytes32 constant MODERATOR_ROLE = keccak256("MODERATOR_ROLE")
```

### DESCRIPTION (0xf1ae8856)

```solidity
string constant DESCRIPTION = "Price provider that uses chainlink"
```

### MAX\_PRICE\_PATH\_LENGTH (0x01a9a5d3)

```solidity
uint8 constant MAX_PRICE_PATH_LENGTH = 5
```

## State variables info

### tokenDecimals (0x3b97e856)

```solidity
uint8 tokenDecimals
```

### timeOuts (0x2a6377a9)

```solidity
mapping(address => uint256) timeOuts
```

### chainlinkMetadata (0x8cc19163)

```solidity
mapping(address => struct ChainlinkPriceProvider.ChainlinkMetadata) chainlinkMetadata
```

## Modifiers info

### onlyModerator

```solidity
modifier onlyModerator()
```

Modifier to restrict access to functions to only the contract's moderator.

## Functions info

### initialize (0x8129fc1c)

```solidity
function initialize() public initializer
```

Initializes the contract by setting up the access control roles and assigning them to the contract deployer. The `DEFAULT_ADMIN_ROLE` and `MODERATOR_ROLE` roles are set up with the contract deployer as the initial role bearer. `decimals` is set to 8.

### setTokenDecimals (0xf2cf47be)

```solidity
function setTokenDecimals(uint8 newTokenDecimals) public onlyModerator
```

Sets the number of decimals used by the token. Only the moderator can call this function.

Parameters:

| Name             | Type  | Description                                   |
| ---------------- | ----- | --------------------------------------------- |
| newTokenDecimals | uint8 | The new number of decimals used by the token. |

### setTimeOut (0x60c74154)

```solidity
function setTimeOut(
    address aggregatorPath,
    uint256 newTimeOut
) external onlyModerator
```

Sets the timeout value corresponding to the aggregatorPath.

Example: ETH/USD have a new answer is written when the off-chain data moves more than the 0.5% deviation threshold or 3600 seconds have passed since the last answer was written on-chain. So, the timeOut value for each aggregator will be equal to the heartbeat threshold value plus a period of time to make the transaction update the price, that time period can be 60s or a little more.

Parameters:

| Name                                                                                                             | Type    | Description                                                                                 |
| ---------------------------------------------------------------------------------------------------------------- | ------- | ------------------------------------------------------------------------------------------- |
| aggregatorPath                                                                                                   | address | The address of chainlink aggregator contract.                                               |
| newTimeOut                                                                                                       | uint256 | It is the amount of time it takes for a new round of aggregation to start after a specified |
| amount of time since the last update plus a period of time waiting for new price update transactions to execute. |         |                                                                                             |

### setTokenAndAggregator (0xedc607b0)

```solidity
function setTokenAndAggregator(
    address token,
    address[] memory aggregatorPath
) public onlyModerator
```

Set token and aggregator path.

Parameters:

| Name           | Type       | Description                         |
| -------------- | ---------- | ----------------------------------- |
| token          | address    | The address of the token.           |
| aggregatorPath | address\[] | The address of the aggregator path. |

### changeActive (0x258a4532)

```solidity
function changeActive(address token, bool active) public override onlyModerator
```

Change active status of token.

Parameters:

| Name   | Type    | Description                 |
| ------ | ------- | --------------------------- |
| token  | address | The address of the token.   |
| active | bool    | The active status of token. |

### isListed (0xf794062e)

```solidity
function isListed(address token) public view override returns (bool)
```

Returns the is listed status of token.

Parameters:

| Name  | Type    | Description           |
| ----- | ------- | --------------------- |
| token | address | the address of token. |

Return values:

| Name | Type | Description                             |
| ---- | ---- | --------------------------------------- |
| \[0] | bool | isListed the is listed status of token. |

### isActive (0x9f8a13d7)

```solidity
function isActive(address token) public view override returns (bool)
```

Returns the is active status of token.

Parameters:

| Name  | Type    | Description           |
| ----- | ------- | --------------------- |
| token | address | the address of token. |

Return values:

| Name | Type | Description                             |
| ---- | ---- | --------------------------------------- |
| \[0] | bool | isActive the is active status of token. |

### getLatestPrice (0x16345f18)

```solidity
function getLatestPrice(
    address aggregatorPath
) public view virtual returns (uint256)
```

ReturnS the latest price after performing sanity check and staleness check.

Parameters:

| Name           | Type    | Description                                   |
| -------------- | ------- | --------------------------------------------- |
| aggregatorPath | address | The address of chainlink aggregator contract. |

Return values:

| Name | Type    | Description                |
| ---- | ------- | -------------------------- |
| \[0] | uint256 | The latest price (answer). |

### getPrice (0x41976e09)

```solidity
function getPrice(
    address token
) public view override returns (uint256 priceMantissa, uint8 priceDecimals)
```

Returns the latest asset price mantissa and price decimals.

\[price] = USD/token

* First step is get priceMantissa with priceDecimals by this formula: price = 1 \* 10 \*\* tokenDecimals \* (chainlinkPrice\_1 / 10 \*\* priceDecimals\_1) \* ... \* (chainlinkPrice\_n / 10 \*\* priceDecimals\_n) = = 10 \*\* tokenDecimals (chainlinkPrice\_1 \* ... \* chainlinkPrice\_n) / 10 \*\* (priceDecimals\_1 + ... + priceDecimals\_n)
* Second step is scale priceMantissa to usdDecimals.

Parameters:

| Name  | Type    | Description        |
| ----- | ------- | ------------------ |
| token | address | the token address. |

### getPriceDecimals (0x1b30aafc)

```solidity
function getPriceDecimals() public view override returns (uint8)
```

Returns the number of decimals used for the price provided by the Chainlink oracle.

Return values:

| Name | Type  | Description                                |
| ---- | ----- | ------------------------------------------ |
| \[0] | uint8 | The number of decimals used for the price. |

### getChainlinkMetadata (0xd718fc11)

```solidity
function getChainlinkMetadata(
    address token
) public view returns (ChainlinkPriceProvider.ChainlinkMetadata memory)
```

Returns the metadata set up for token.

Parameters:

| Name  | Type    | Description               |
| ----- | ------- | ------------------------- |
| token | address | The address of the token. |

Return values:

| Name | Type                                            | Description                                                                                                                           |
| ---- | ----------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------- |
| \[0] | struct ChainlinkPriceProvider.ChainlinkMetadata | metadata The metadata includes active status of token and array of Chainlink aggregator addresses used to get the price of the token. |