# Orderbook

## Overview

The `Orderbook` contains modified order-book functionality, matching lenders to borrower within the `BloomPool` .

## Contract API

### `openDepth`

```solidity
function openDepth(uint256 amount) external;
```

Returns the current total depth of open orders in terms of `asset` tokens.

### `amountOpen`

```solidity
function amountOpen(address account) external view returns (uint256);
```

Returns the total amount of underlying `asset`s in open orders for a users `account`.

### `lendOrder`

```solidity
function lendOrder(uint256 amount) external;
```

Opens a lend order for a user.

{% hint style="info" %}
Users have the right at anytime to cancel their lend order and withdraw their assets.
{% endhint %}

{% hint style="warning" %}
Assets will be transferred to the `BloomPool` contract when executing this function, but no receipt token will be given. `TBY`s are only minted after orders have been matched and market makers have performed their swaps.
{% endhint %}

### `killOpenOrder`

```solidity
function killOpenOrder(uint256 amount) external;
```

Allows users to cancel their open lend order and withdraw their underlying assets.

### `matchedDepth`

```solidity
function matchedDepth() external view returns (uint256);
```

Returns the current total depth of matched orders.

### `amountMatched`

```solidity
function amountMatched(address account) external view returns (uint256 amount);
```

Returns the total `amount` of underlying assets in matched orders for a users `account`.

### `matchedOrder`

```solidity
function matchedOrder(address account, uint256 index) external view returns (MatchOrder memory);
```

Returns the matched order details for a users `account` in the form of a `MatchOrder` struct. 

```solidity
/**
 * @notice Struct to store the details of a lend order that has been matched.
 * @param lCollateral The amount of underlying assets the lender used as collateral.
 * @param bCollateral The amount of underlying assets the borrower used as collateral.
 * @param borrower The address of the borrower who filled the order.
*/
struct MatchOrder {
   uint128 lCollateral;
   uint128 bCollateral;
   address borrower;
}
```

### `matchedOrderCount`

```solidity
function matchedOrderCount(address account) external view returns (uint256);
```

Returns the number of matched orders for a users `account`.

### `killMatchOrder`

```solidity
function killMatchOrder(uint256 amount) external returns (uint256 totalRemoved);
```

Allows users to cancel their match lend orders and withdraw their underlying assets. 

Returns the `totalRemoved` amount in terms of `asset` tokens.

### `killBorrowerMatch`

```solidity
function killBorrowerMatch(address lender) external returns (uint256 lenderAmount, uint256 borrowerReturn);
```

Allows borrowers to cancel their match orders and withdraw their underlying assets

Returns the `lenderAmount` and `borrowerReturn` in terms of underlying assets that were returned to the various users.

### `fillOrder`

{% hint style="info" %}
This is a permissioned function. Only KYCed borrowers can call this function.
{% endhint %}

```solidity
function fillOrder(address account, uint256 amount) external returns (uint256 filled);
```

Allows borrowers to fill a single `account`s lend order with a specified `amount` of underlying assets.

Returns the amount of liquidity filled in terms of `asset` tokens.

### `fillOrders`

{% hint style="info" %}
This is a permissioned function. Only KYCed borrowers can call this function.
{% endhint %}

```solidity
function fillOrders(address[] calldata accounts, uint256 amount) external returns (uint256 filled);
```

Allows borrowers to fill a multiple `account`s lend orders with a specified `amount` of underlying assets.

Returns the amount of liquidity filled in terms of `asset` tokens.

### `idleCapital`

```solidity
function idleCapital(address account) external view returns (uint256);
```

Returns the idle capital of the borrower.

### `withdrawIdleCapital`

```solidity
function withdrawIdleCapital(uint256 amount) external;
```

Allows borrowers to withdraw idle capital from the system.