# Pool Management

The Lending Pool contract handles updating pool status and asset parameters.

## Pool Status

Pool status is updated using either a permissionless function, `update_status()` , or a permissioned (admin-only) function `set_status()`. These set the pool to one of the following statuses:

* `Admin_Active` (enum 0): The pool is functioning normally.
* `Active` (enum 1): The pool is functioning normally.
* `Admin_On_Ice` (enum 2): Borrowing and auction cancellations are disabled.
* `On_Ice` (enum 3): Borrowing and auction cancellations are disabled.
* `Admin_Frozen` (enum 4): Borrowing, depositing, and auction cancellations are disabled.
* `Frozen` (enum 5): Borrowing, depositing, and auction cancellations are disabled.

### Permissionless Updates

Anyone can update pool status permissionlessly by calling `update_status()`. This function checks the backstop state and sets the status based on the current percentage of backstop deposits allocated to the pool that are queued-for-withdrawal(q4w).

The status is set as follows:

{% @mermaid/diagram content="flowchart LR
A\[update\_status] --> B{status==6}
B --------->|Yes| C\[\[PANIC!]]
B -->|No| D{status==4}
D -->|Yes| C
D -->|No| E{status==2}
E -->|Yes| F{q4w>=75%}
F ------>|Yes| G\[\["SET
status=5"]]
E -->|No| H{status==0}
F -->|No| H
H -->|Yes| I{"q4w>=50%
or
!threshold\_met"}
I -->|Yes| J\[\["SET
status=3"]]
I -->|No| K{q4w>=60%}
H -->|No| K
K -->|Yes| G
K -->|No| L{"q4w>=30%
or
!threshold\_met"}
L -->|Yes| J
L -->|No| M\[\["SET
status=1"]]" %}

### Permissioned Updates

Pool admins can update pool status by calling `set_status()`. This takes a `status` parameter and sets it after validating it with the following logic:

{% @mermaid/diagram content="flowchart TB
A\[set\_status] --> B\[status\_param=0]
A --> C\[status\_param=2]
A --> D\[status\_param=3]
A --> E\[status\_param=4]
A --> F\[status\_param=other]
F --> G\[\[PANIC!]]
B --> H{"!threshold\_met
or
q4w>=50%"}
H -->|Yes| G
H -->|No| I\[\["SET
status=0"]]
C --> J{q4w>=75%}
J -->|Yes| G
J -->|No| K\[\["SET
status=2"]]
D --> L{q4w>=75%}
L -->|Yes| G
L -->|No| M\[\["SET
status=3"]]
E ---> N\[\["SET
status=4"]]
" %}

## Asset Parameters

Asset parameters can only be updated by the pool admin. They're updated in a two-step process that involves a 7-day queue to prevent admins from suddenly adding unsafe assets or parameters. The process is as follows:

1. The admin calls `queue_set_reserve()` with the new parameters. This stores a queued reserve update in a hashmap with the address of the asset being added or updated as the key and a `QueuedReserveInit` struct as the value 

```rust
pub struct QueuedReserveInit {
    pub new_config: ReserveConfig,
    pub unlock_time: u64, // block timestamp after which the queued reserve config can be added
}
```

```rust
pub struct ReserveConfig {
    pub index: u32,      // the index of the reserve in the list
    pub decimals: u32,   // the decimals used in both the bToken and underlying contract
    pub c_factor: u32,   // the collateral factor for the reserve scaled expressed in 7 decimals
    pub l_factor: u32,   // the liability factor for the reserve scaled expressed in 7 decimals
    pub util: u32,       // the target utilization rate scaled expressed in 7 decimals
    pub max_util: u32,   // the maximum allowed utilization rate scaled expressed in 7 decimals
    pub r_one: u32,      // the R1 value in the interest rate formula scaled expressed in 7 decimals
    pub r_two: u32,      // the R2 value in the interest rate formula scaled expressed in 7 decimals
    pub r_three: u32,    // the R3 value in the interest rate formula scaled expressed in 7 decimals
    pub reactivity: u32, // the reactivity constant for the reserve scaled expressed in 7 decimals
}
```

{% hint style="info" %}
The queued reserve modification (or addition) can be canceled at any point by the admin using `cancel_set_reserve()`
{% endhint %}

2. After 7 days have passed the admin calls `set_reserve()` which sets the asset parameters to the queued metadata.