# `Improv.Supervisor`
[🔗](https://github.com/bbangert/improv/blob/v0.1.1/lib/improv/supervisor.ex#L1)

Supervises the Improv provisioning processes as a `:one_for_all` group.

The children are mutually dependent — the `Improv` manager registers and drives
the `GattServer` + `Advert` D-Bus exporters (off-loop via the `Task.Supervisor`)
— so a crash of any one must restart all of them together. Under the parent
`Bluez` supervisor's `:rest_for_one`, the manager (started last)
crashing would otherwise leave `GattServer`/`Advert` running: the cleartext GATT
app + advertisement would stay exported with no session timers or disarm logic.

Restarting the whole group instead drops the exporters' own `rebus` connections,
which makes `bluetoothd` auto-unregister the GATT application + advertisement,
and the manager re-evaluates connectivity from a clean slate.

## Mounting contract

Improv is a *consumer* of the `Bluez` subtree, not part of it: mount this
supervisor in `Bluez`'s `extra_children:` slot, appended **last**. Under the
`Bluez` parent's `:rest_for_one` strategy that position means a
`bluetoothd`/`Bluez.Client` restart rebuilds the whole Improv group (whose
exporters hold now-stale D-Bus registrations), while an Improv fault never
disturbs anything before it — the host's scanning/GATT or audio stacks.
The child spec's opts are also where the host passes the manager's options
(`pubsub:`, `network_type:`, `ifname:`, `identify_fun:`, `device_info:`, …)
and the advert branding (`name_prefix:` / `local_name:`):

    {Bluez,
     client: [...],
     extra_children: [
       {Improv.Supervisor,
        [
          pubsub: MyApp.PubSub,
          network_type: &MyApp.Network.type/0,
          name_prefix: "My Device",
          identify_fun: &MyApp.Identify.blink/0,
          device_info: [
            firmware_name: "My Firmware",
            firmware_version: "1.2.3",
            hardware: "Raspberry Pi 3 Model B Plus",
            device_name: "My Device 507f"
          ]
        ]}
     ]}

# `child_spec`

Returns a specification to start this module under a supervisor.

See `Supervisor`.

# `start_link`

---

*Consult [api-reference.md](api-reference.md) for complete listing*