# IOfferLogic

It is an IMaker for Mangrove.

## LogIncident

```solidity
event LogIncident(bytes32 olKeyHash, uint256 offerId, bytes32 makerData, bytes32 mgvData)
```

Log incident (during post trade execution)\
By emitting this data, an indexer can keep track of what incidents has happened.

### Parameters

| Name      | Type    | Description                                                                         |
| --------- | ------- | ----------------------------------------------------------------------------------- |
| olKeyHash | bytes32 | the hash of the offer list key. This is indexed so that RPC calls can filter on it. |
| offerId   | uint256 | the Mangrove offer id. This is indexed so that RPC calls can filter on it.          |
| makerData | bytes32 | from the maker.                                                                     |
| mgvData   | bytes32 | from Mangrove.                                                                      |

## SetRouter

```solidity
event SetRouter(contract AbstractRouter router)
```

Logging change of router address\
By emitting this an indexer can keep track of what router is used.

### Parameters

| Name   | Type                    | Description             |
| ------ | ----------------------- | ----------------------- |
| router | contract AbstractRouter | the new router address. |

## setRouter

```solidity
function setRouter(contract AbstractRouter router_) external
```

sets a new router to pull outbound tokens from contract's reserve to `this` and push inbound tokens to reserve.

*new router needs to be approved by `this` to push funds to reserve (see `activate` function). It also needs to be approved by reserve to pull from it.*

### Parameters

| Name     | Type                    | Description                                                                           |
| -------- | ----------------------- | ------------------------------------------------------------------------------------- |
| router\_ | contract AbstractRouter | the new router contract that this contract should use. Use `NO_ROUTER` for no router. |

## approve

```solidity
function approve(contract IERC20 token, address spender, uint256 amount) external returns (bool)
```

Approves a spender to transfer a certain amount of tokens on behalf of `this`.

*admin may use this function to revoke specific approvals of `this` that are set after a call to `activate`.*

### Parameters

| Name    | Type            | Description              |
| ------- | --------------- | ------------------------ |
| token   | contract IERC20 | the ERC20 token contract |
| spender | address         | the approved spender     |
| amount  | uint256         | the spending amount      |

### Return Values

| Name | Type | Description               |
| ---- | ---- | ------------------------- |
| \[0] | bool | result of token approval. |

## provisionOf

```solidity
function provisionOf(struct OLKey olKey, uint256 offerId) external view returns (uint256 provision)
```

computes the amount of native tokens that can be redeemed when deprovisioning a given offer.

### Parameters

| Name    | Type         | Description                                   |
| ------- | ------------ | --------------------------------------------- |
| olKey   | struct OLKey | the offer list key.                           |
| offerId | uint256      | the identifier of the offer in the offer list |

### Return Values

| Name      | Type    | Description                                                                    |
| --------- | ------- | ------------------------------------------------------------------------------ |
| provision | uint256 | the amount of native tokens that can be redeemed when deprovisioning the offer |

## checkList

```solidity
function checkList(contract IERC20[] tokens) external view
```

verifies that this contract's current state is ready to be used to post offers on Mangrove

*throws with a reason if something (e.g. an approval) is missing.*

### Parameters

| Name   | Type               | Description                                         |
| ------ | ------------------ | --------------------------------------------------- |
| tokens | contract IERC20\[] | the list of tokens that are traded by this contract |

## activate

```solidity
function activate(contract IERC20[] tokens) external
```

performs the required approvals so as to allow `this` to interact with Mangrove on a set of assets.

### Parameters

| Name   | Type               | Description                                                                            |
| ------ | ------------------ | -------------------------------------------------------------------------------------- |
| tokens | contract IERC20\[] | the ERC20 `this` will approve to be able to trade on Mangrove's corresponding markets. |

## withdrawFromMangrove

```solidity
function withdrawFromMangrove(uint256 amount, address payable receiver) external
```

withdraws native tokens from `this` balance on Mangrove.

*Since a call is made to the `receiver`, this function is subject to reentrancy.*

### Parameters

| Name     | Type            | Description                               |
| -------- | --------------- | ----------------------------------------- |
| amount   | uint256         | the amount of WEI one wishes to withdraw. |
| receiver | address payable | the address of the receiver of the funds. |

## OfferArgs

Memory allocation for `_new/updateOffer`'s arguments.

*`owner` is required in `Forwarder` logics, when `_newOffer` or `_updateOffer` in called in a hook (`msg.sender==MGV`).*

### Parameters

```solidity
struct OfferArgs {
  struct OLKey olKey;
  Tick tick;
  uint256 gives;
  uint256 gasreq;
  uint256 gasprice;
  uint256 fund;
  bool noRevert;
}
```

## router

```solidity
function router() external view returns (contract AbstractRouter)
```

Contract's router getter.

*if contract has a no router, function returns `NO_ROUTER`.*

### Return Values

| Name | Type                    | Description |
| ---- | ----------------------- | ----------- |
| \[0] | contract AbstractRouter | the router. |

## MGV

```solidity
function MGV() external view returns (contract IMangrove)
```

Contract's Mangrove getter

### Return Values

| Name | Type               | Description            |
| ---- | ------------------ | ---------------------- |
| \[0] | contract IMangrove | the Mangrove contract. |