android_ble/

adapter.rs

// Some portions of this code is orginally written by <https://github.com/Dirbaio>.

use std::collections::HashMap;
use std::sync::{Arc, OnceLock};

use futures_core::Stream;
use futures_lite::{stream, StreamExt};
use java_spaghetti::{ByteArray, Env, Global, Local, Null, Ref};
use log::{debug, warn};
use uuid::Uuid;

use super::async_util::StreamUntil;
use super::bindings::android::bluetooth::le::{
    ScanCallback, ScanFilter_Builder, ScanResult, ScanSettings, ScanSettings_Builder,
};
use super::bindings::android::bluetooth::{
    BluetoothAdapter, BluetoothDevice, BluetoothGattCallback, BluetoothManager, BluetoothProfile,
};
use super::bindings::android::content::Context as AndroidContext;
use super::bindings::android::os::ParcelUuid;
use super::bindings::java::lang::String as JString;
use super::bindings::java::util::Map_Entry;
use super::bindings::java::{self};
use super::device::Device;
use super::error::ErrorKind;
use super::event_receiver::{EventReceiver, GlobalEvent};
use super::gatt_tree::{BluetoothGattCallbackProxy, CachedWeak, GattTree};
use super::jni::{ByteArrayExt, Monitor, VM};
use super::vm_context::{
    android_api_level, android_context, android_has_permission, jni_get_vm, jni_set_vm,
    jni_with_env,
};
use crate::util::{defer, JavaIterator, OptionExt, UuidExt};
use crate::{
    AdapterEvent, AdvertisementData, AdvertisingDevice, ConnectionEvent, DeviceId, Error,
    ManufacturerData, Result,
};

/// The system’s Bluetooth adapter interface.
#[derive(Clone)]
pub struct Adapter {
    inner: Arc<AdapterInner>,
}

struct AdapterInner {
    #[allow(unused)]
    manager: Global<BluetoothManager>,
    adapter: Global<BluetoothAdapter>,
    global_event_receiver: Arc<EventReceiver>,
    request_mtu_on_connect: bool,
    allow_multiple_connections: bool,
}

static CONN_MUTEX: async_lock::Mutex<()> = async_lock::Mutex::new(());

/// Configuration for creating an interface to the default Bluetooth adapter of the system.
///
/// By deafult, [ndk-context](https://docs.rs/ndk-context/0.1.1/ndk_context) is used for
/// obtaining the JNI `JavaVM` pointer.
pub struct AdapterConfig {
    /// - `vm` must be a valid JNI `JavaVM` pointer to a VM that will stay alive for the current
    ///   native library's lifetime. This is true for any library used by an Android application.
    vm: *mut java_spaghetti::sys::JavaVM,
    /// `manager` must be a valid global reference to an `android.bluetooth.BluetoothManager`
    /// instance, from the `java_vm` VM.
    manager: java_spaghetti::sys::jobject,

    request_mtu_on_connect: bool,
    allow_multiple_connections: bool,
}

impl AdapterConfig {
    /// Creates a config for the default Bluetooth adapter for the system.
    ///
    /// You do not need to do this if you are using the `android_activity` crate for a native application.
    ///
    /// # Safety
    ///
    /// - `java_vm` must be a valid JNI `JavaVM` pointer to a VM that will stay alive for the current native
    ///   library's lifetime. This is true for any library used by an Android application.
    /// - `bluetooth_manager` must be a valid global reference to an `android.bluetooth.BluetoothManager`
    ///   instance, from the `java_vm` VM.
    /// - The `Adapter` takes ownership of the global reference and will delete it with the `DeleteGlobalRef`
    ///   JNI call when dropped. You must not do that yourself.
    pub unsafe fn new(
        java_vm: *mut java_spaghetti::sys::JavaVM,
        bluetooth_manager: java_spaghetti::sys::jobject,
    ) -> Self {
        Self {
            vm: java_vm,
            manager: bluetooth_manager,
            request_mtu_on_connect: true,
            allow_multiple_connections: true,
        }
    }

    /// If enabled, this library will request the BLE ATT MTU to 517 bytes during [Adapter::connect_device].
    /// See <https://developer.android.com/about/versions/14/behavior-changes-all#mtu-set-to-517>.
    ///
    /// If disabled, [crate::Characteristic::max_write_len] may always return `18`.
    ///
    /// This is enabled by default; disable it if the firmware of the device to be connected is problematic.
    pub fn request_mtu_on_connect(mut self, enabled: bool) -> Self {
        self.request_mtu_on_connect = enabled;
        self
    }

    /// If enabled, connections with devices already connected outside this library instance will
    /// be permitted. Note that another `android.bluetooth.BluetoothGatt` object will not be created
    /// if the device is already connected in the current library instance.
    ///
    /// This is enabled by default; this should be okay on well-implemented Android API implementations,
    /// but disabling it might improve Android compatibility.
    pub fn allow_multiple_connections(mut self, enabled: bool) -> Self {
        self.allow_multiple_connections = enabled;
        self
    }
}

impl Default for AdapterConfig {
    fn default() -> Self {
        jni_with_env(|env| {
            let context = android_context().as_local(env);
            let service_name = JString::from_env_str(env, AndroidContext::BLUETOOTH_SERVICE);
            let manager = context
                .getSystemService_String(service_name)
                .unwrap()
                .expect("Context.getSystemService() returned null for BLUETOOTH_SERVICE")
                .cast::<BluetoothManager>()?
                .as_global();
            let config = unsafe { Self::new(jni_get_vm().as_raw(), manager.into_raw()) };
            Ok::<_, Box<dyn std::error::Error>>(config)
        })
        .unwrap()
    }
}

fn check_scan_permission() -> Result<(), crate::Error> {
    let has_perm = if android_api_level() >= 31 {
        if android_has_permission("android.permission.BLUETOOTH_SCAN") {
            if !android_has_permission("android.permission.ACCESS_FINE_LOCATION") {
                warn!("Please ensure `neverForLocation` is included in `android:usesPermissionFlags`.")
            }
            true // XXX
        } else {
            false
        }
    } else if android_api_level() >= 29 {
        android_has_permission("android.permission.ACCESS_FINE_LOCATION")
            && android_has_permission("android.permission.BLUETOOTH_ADMIN")
    } else {
        (android_has_permission("android.permission.ACCESS_COARSE_LOCATION")
            || android_has_permission("android.permission.ACCESS_FINE_LOCATION"))
            && android_has_permission("android.permission.BLUETOOTH_ADMIN")
    };
    if !has_perm {
        return Err(crate::Error::new(
            ErrorKind::NotAuthorized,
            None,
            "Bluetooth scanning permission is not granted",
        ));
    }
    Ok(())
}

fn check_connection_permission() -> Result<(), crate::Error> {
    if !android_has_permission(if android_api_level() >= 31 {
        "android.permission.BLUETOOTH_CONNECT"
    } else {
        "android.permission.BLUETOOTH"
    }) {
        return Err(crate::Error::new(
            ErrorKind::NotAuthorized,
            None,
            "Bluetooth connection permission is not granted",
        ));
    }
    Ok(())
}

impl Adapter {
    /// Creates an interface to a Bluetooth adapter using the default config.
    pub async fn default() -> Result<Self> {
        Adapter::with_config(AdapterConfig::default()).await
    }

    /// Creates an interface to a Bluetooth adapter. The `vm` pointer will be ignored
    /// if this has been called previously.
    pub async fn with_config(config: AdapterConfig) -> Result<Self> {
        unsafe {
            let vm = VM::from_raw(config.vm);
            let _ = jni_set_vm(vm);

            let manager: Global<BluetoothManager> = Global::from_raw(vm.into(), config.manager);

            jni_with_env(|env| {
                let local_manager = manager.as_ref(env);
                let adapter = local_manager.getAdapter()?.non_null()?;
                Ok(Self {
                    inner: Arc::new(AdapterInner {
                        adapter: adapter.as_global(),
                        manager: manager.clone(),
                        global_event_receiver: EventReceiver::build()?,
                        request_mtu_on_connect: config.request_mtu_on_connect,
                        allow_multiple_connections: config.allow_multiple_connections,
                    }),
                })
            })
        }
    }

    /// A stream of [AdapterEvent] which allows the application to identify when the adapter is enabled or disabled.
    pub async fn events(
        &self,
    ) -> Result<impl Stream<Item = Result<AdapterEvent>> + Send + Unpin + '_> {
        Ok(self
            .inner
            .global_event_receiver
            .subscribe()
            .await?
            .filter_map(|event| {
                if let GlobalEvent::AdapterStateChanged(val) = event {
                    match val {
                        BluetoothAdapter::STATE_ON => Some(AdapterEvent::Available),
                        BluetoothAdapter::STATE_OFF => Some(AdapterEvent::Unavailable),
                        _ => None, // XXX: process "turning on" and "turning off" events
                    }
                } else {
                    None
                }
            })
            .map(Ok))
    }

    /// Asynchronously blocks until the adapter is available.
    pub async fn wait_available(&self) -> Result<()> {
        while !self.is_available().await? {
            let mut events = self.events().await?;
            while let Some(Ok(event)) = events.next().await {
                if event == AdapterEvent::Available {
                    return Ok(());
                }
            }
        }
        Ok(())
    }

    /// Check if the adapter is available.
    pub async fn is_available(&self) -> Result<bool> {
        jni_with_env(|env| {
            let adapter = self.inner.adapter.as_local(env);
            adapter.isEnabled().map_err(|e| {
                Error::new(ErrorKind::Internal, None, format!("isEnabled threw: {e:?}"))
            })
        })
    }

    /// Attempts to create the device identified by `id`.
    pub async fn open_device(&self, id: &DeviceId) -> Result<Device> {
        if let Some(dev) = self
            .connected_devices()
            .await?
            .into_iter()
            .find(|d| &d.id() == id)
        {
            return Ok(dev);
        }
        jni_with_env(|env| {
            let adapter = self.inner.adapter.as_local(env);
            let device = adapter
                .getRemoteDevice_String(JString::from_env_str(env, &id.0))
                .map_err(|e| {
                    Error::new(
                        ErrorKind::Internal,
                        None,
                        format!("getRemoteDevice threw: {e:?}"),
                    )
                })?
                .non_null()?;
            Ok(Device {
                id: id.clone(),
                device: device.as_global(),
                connection: CachedWeak::new(),
                once_connected: Arc::new(OnceLock::new()),
            })
        })
    }

    /// Finds all connected Bluetooth LE devices.
    ///
    /// NOTE: there might be BLE devices connected outside this library.
    /// If [AdapterConfig::allow_multiple_connections] is set to true, this method will call
    /// `BluetoothManager.getConnectedDevices()` and ensure GATT connections are created
    /// for them in this library instance.
    pub async fn connected_devices(&self) -> Result<Vec<Device>> {
        check_connection_permission()?;
        if self.inner.allow_multiple_connections {
            let mut device_items = Vec::new();
            jni_with_env(|env| {
                let manager = self.inner.manager.as_ref(env);
                let devices = manager
                    .getConnectedDevices(BluetoothProfile::GATT)?
                    .non_null()?;
                let iter_devices = JavaIterator(devices.iterator()?.non_null()?);

                for device in iter_devices.filter_map(|dev| dev.cast::<BluetoothDevice>().ok()) {
                    let id = DeviceId(
                        device
                            .getAddress()?
                            .non_null()?
                            .to_string_lossy()
                            .trim()
                            .to_string(),
                    );
                    let device_item = Device {
                        id,
                        device: device.as_global(),
                        connection: CachedWeak::new(),
                        // NOTE: this makes the `connect_device` called later to discover services as if it's reconnected.
                        once_connected: Arc::new(OnceLock::from(())),
                    };
                    device_items.push(device_item);
                }
                Ok::<_, crate::Error>(())
            })?;
            for device_item in &device_items {
                if GattTree::find_connection(&device_item.id).is_none() {
                    self.connect_device(device_item).await?;
                }
            }
            Ok(device_items)
        } else {
            GattTree::registered_devices()
        }
    }

    /// Finds all connected devices providing any service in `service_ids`.
    pub async fn connected_devices_with_services(
        &self,
        service_ids: &[Uuid],
    ) -> Result<Vec<Device>> {
        let mut devices_found = Vec::new();
        for device in self.connected_devices().await? {
            device.discover_services().await?;
            let device_services = device.services().await?;
            if service_ids
                .iter()
                .any(|&id| device_services.iter().any(|serv| serv.uuid() == id))
            {
                devices_found.push(device);
            }
        }
        Ok(devices_found)
    }

    /// Starts scanning for Bluetooth advertising packets.
    ///
    /// Returns a stream of [`AdvertisingDevice`] structs which contain the data from the advertising packet and the
    /// [`Device`] which sent it. Scanning is automatically stopped when the stream is dropped. Inclusion of duplicate
    /// packets is a platform-specific implementation detail.
    ///
    /// If `service_ids` is not empty, returns advertisements including at least one GATT service with a UUID in
    /// `services`. Otherwise returns all advertisements.
    pub async fn scan<'a>(
        &'a self,
        service_ids: &'a [Uuid],
    ) -> Result<impl Stream<Item = AdvertisingDevice> + Send + Unpin + 'a> {
        check_scan_permission()?;
        let (start_receiver, stream) = jni_with_env(|env| {
            let (start_sender, start_receiver) = async_channel::bounded(1);
            let (device_sender, device_receiver) = async_channel::bounded(16);

            let callback = ScanCallback::new_proxy(
                env,
                Arc::new(ScanCallbackProxy {
                    device_sender,
                    start_sender,
                }),
            )?;
            let callback_global = callback.as_global();

            let adapter = self.inner.adapter.as_ref(env);
            let adapter_global = adapter.as_global();
            let adapter = Monitor::new(&adapter);
            let scanner = adapter.getBluetoothLeScanner()?.non_null()?;
            let scanner_global = scanner.as_global();

            let settings_builder = ScanSettings_Builder::new(env)?;
            settings_builder.setScanMode(ScanSettings::SCAN_MODE_LOW_LATENCY)?;
            let settings = settings_builder.build()?.non_null()?;

            if !service_ids.is_empty() {
                let filter_builder = ScanFilter_Builder::new(env)?;
                let filter_list = java::util::ArrayList::new(env)?;
                for uuid in service_ids {
                    let uuid_string = JString::from_env_str(env, uuid.to_string());
                    let parcel_uuid = ParcelUuid::fromString(env, uuid_string)?;
                    filter_builder.setServiceUuid_ParcelUuid(parcel_uuid)?;
                    let filter = filter_builder.build()?.non_null()?;
                    filter_list.add_Object(filter)?;
                }
                scanner.startScan_List_ScanSettings_ScanCallback(
                    filter_list,
                    settings,
                    callback,
                )?;
            } else {
                scanner.startScan_List_ScanSettings_ScanCallback(Null, settings, callback)?;
            };

            let guard = defer(move || {
                jni_with_env(|env| {
                    let callback = callback_global.as_ref(env);
                    let scanner = scanner_global.as_ref(env);
                    if adapter_global.as_ref(env).isEnabled().unwrap_or(false) {
                        match scanner.stopScan_ScanCallback(callback) {
                            Ok(()) => debug!("stopped scan"),
                            Err(e) => warn!("failed to stop scan: {:?}", e),
                        };
                    }
                });
            });

            Ok::<_, crate::Error>((
                start_receiver,
                Box::pin(device_receiver).map(move |adv_dev| {
                    let _guard = &guard;
                    adv_dev
                }),
            ))
        })?;

        #[rustfmt::skip]
        let stream = StreamUntil::create(
            stream,
            self.inner.global_event_receiver.subscribe().await?,
            |event| {
                matches!(
                    event,
                    GlobalEvent::DiscoveryFinished
                        | GlobalEvent::AdapterStateChanged(BluetoothAdapter::STATE_OFF)
                )
            }
        );

        // Wait for scan started or failed.
        match start_receiver.recv().await {
            Ok(Ok(())) => Ok(stream),
            Ok(Err(e)) => Err(e),
            Err(e) => Err(Error::new(
                ErrorKind::Internal,
                None,
                format!("receiving failed while waiting for start: {e:?}"),
            )),
        }
    }

    /// Finds Bluetooth devices providing any service in `services`.
    ///
    /// Returns a stream of [`Device`] structs with matching connected devices returned first. If the stream is not
    /// dropped before all matching connected devices are consumed then scanning will begin for devices advertising any
    /// of the `services`. Scanning will continue until the stream is dropped. Inclusion of duplicate devices is a
    /// platform-specific implementation detail.
    pub async fn discover_devices<'a>(
        &'a self,
        services: &'a [Uuid],
    ) -> Result<impl Stream<Item = Result<Device>> + Send + Unpin + 'a> {
        let connected = stream::iter(self.connected_devices_with_services(services).await?).map(Ok);

        // try_unfold is used to ensure we do not start scanning until the connected devices have been consumed
        let advertising = Box::pin(stream::try_unfold(None, |state| async {
            let mut stream = match state {
                Some(stream) => stream,
                None => self.scan(services).await?,
            };
            Ok(stream.next().await.map(|x| (x.device, Some(stream))))
        }));

        Ok(connected.chain(advertising))
    }

    /// Connects to the [`Device`].
    pub async fn connect_device(&self, device: &Device) -> Result<()> {
        check_connection_permission()?;
        let _conn_lock = CONN_MUTEX.lock().await;
        if device.is_connected().await {
            return Ok(());
        }
        if !self.inner.allow_multiple_connections && self.is_actually_connected(&device.id())? {
            return Err(Error::new(
                ErrorKind::ConnectionFailed,
                None,
                "device is connected outside the current `android_ble` library",
            ));
        }
        let callback_hdl = BluetoothGattCallbackProxy::new(device.id());
        jni_with_env(|env| {
            let adapter = self.inner.adapter.as_ref(env);
            let _lock = Monitor::new(&adapter);
            let device_obj = device.device.as_local(env);
            let proxy = BluetoothGattCallback::new_proxy(env, callback_hdl.clone())?;
            let gatt = device_obj
                .connectGatt_Context_boolean_BluetoothGattCallback(
                    android_context().as_ref(env),
                    false,
                    proxy,
                )
                .map_err(|e| {
                    Error::new(
                        ErrorKind::Internal,
                        None,
                        format!("connectGatt threw: {e:?}"),
                    )
                })?
                .non_null()?
                .as_global();
            GattTree::register_connection(
                &device.id(),
                gatt,
                &callback_hdl,
                &self.inner.global_event_receiver,
            );
            Ok::<_, crate::Error>(())
        })?;
        if !self.is_actually_connected(&device.id())? {
            GattTree::wait_connection_available(&device.id()).await?;
        }
        if self.inner.request_mtu_on_connect {
            let conn = GattTree::check_connection(&device.id())?;
            let mtu_lock = conn.mtu_changed_received.lock().await;
            jni_with_env(|env| {
                let gatt = conn.gatt.as_ref(env);
                let gatt = Monitor::new(&gatt);
                gatt.requestMtu(517)?;
                Ok::<_, crate::Error>(())
            })?;
            let _ = mtu_lock.wait_unlock().await;
        }
        // validates GATT tree API objects again upon reconnection
        if device.once_connected.get().is_some() {
            let _ = device.discover_services().await?;
        }
        let _ = device.once_connected.set(());
        Ok(())
    }

    /// Disconnects from the [`Device`].
    ///
    /// XXX: manage to call this internally when all API wrapper objects for the device are dropped.
    pub async fn disconnect_device(&self, device: &Device) -> Result<()> {
        let _conn_lock = CONN_MUTEX.lock().await;
        let Ok(conn) = device.get_connection() else {
            return Ok(());
        };
        jni_with_env(|env| {
            let adapter = self.inner.adapter.as_ref(env);
            let _lock = Monitor::new(&adapter);
            let gatt = &conn.gatt.as_ref(env);
            let gatt = Monitor::new(gatt);
            gatt.disconnect().map_err(|e| {
                Error::new(
                    ErrorKind::Internal,
                    None,
                    format!("BluetoothGatt.disconnect() threw: {e:?}"),
                )
            })?;
            Ok::<_, crate::Error>(())
        })?;
        GattTree::deregister_connection(&device.id());
        Ok(())
    }

    /// Monitors a device for connection/disconnection events.
    ///
    /// This monitors only devices connected/disconnected in this library instance,
    /// even if [AdapterConfig::allow_multiple_connections] is set to true.
    ///
    /// This does not work with random address devices.
    pub async fn device_connection_events<'a>(
        &'a self,
        device: &'a Device,
    ) -> Result<impl Stream<Item = ConnectionEvent> + Send + Unpin + 'a> {
        Ok(StreamUntil::create(
            GattTree::connection_events()
                .await
                .filter_map(|(dev_id, ev)| {
                    if dev_id == device.id() {
                        Some(ev)
                    } else {
                        None
                    }
                }),
            self.events().await?,
            |e| matches!(e, Ok(AdapterEvent::Unavailable)),
        ))
    }

    // NOTE: this returns true even if the device is connected outside this crate.
    pub(crate) fn is_actually_connected(&self, dev_id: &DeviceId) -> Result<bool> {
        jni_with_env(|env| {
            let manager = self.inner.manager.as_ref(env);
            let devices = manager
                .getConnectedDevices(BluetoothProfile::GATT)?
                .non_null()?;
            let iter_devices = JavaIterator(devices.iterator()?.non_null()?);
            for device in iter_devices.filter_map(|dev| dev.cast::<BluetoothDevice>().ok()) {
                if dev_id.0 == device.getAddress()?.non_null()?.to_string_lossy().trim() {
                    return Ok(true);
                }
            }
            Ok(false)
        })
    }
}

impl PartialEq for Adapter {
    fn eq(&self, _other: &Self) -> bool {
        true
    }
}

impl Eq for Adapter {}

impl std::hash::Hash for Adapter {
    fn hash<H: std::hash::Hasher>(&self, _state: &mut H) {}
}

impl std::fmt::Debug for Adapter {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.debug_tuple("Adapter").finish()
    }
}

struct ScanCallbackProxy {
    start_sender: async_channel::Sender<Result<()>>,
    device_sender: async_channel::Sender<AdvertisingDevice>,
}

impl super::callback::ScanCallbackProxy for ScanCallbackProxy {
    fn onScanFailed<'env>(&self, _env: Env<'env>, error_code: i32) {
        let e = Error::new(
            ErrorKind::Internal,
            None,
            format!("Scan failed to start with error code {error_code}"),
        );
        if let Err(e) = self.start_sender.try_send(Err(e)) {
            warn!("onScanFailed failed to send error: {e:?}");
        }
    }

    fn onBatchScanResults<'env>(
        &self,
        env: Env<'env>,
        scan_results: Option<Ref<'env, super::bindings::java::util::List>>,
    ) {
        let Some(scan_results) = scan_results else {
            warn!("onBatchScanResults: ignoring null scan_results");
            return;
        };

        if let Err(e) = self.on_scan_result_list(env, &scan_results) {
            warn!("onBatchScanResults failed: {e:?}");
        }
    }

    fn onScanResult<'env>(
        &self,
        env: Env<'env>,
        _callback_type: i32,
        scan_result: Option<Ref<'env, ScanResult>>,
    ) {
        let Some(scan_result) = scan_result else {
            warn!("onScanResult: ignoring null scan_result");
            return;
        };

        if let Err(e) = self.on_scan_result(env, &scan_result) {
            warn!("onScanResult failed: {e:?}");
        }
    }
}

impl ScanCallbackProxy {
    fn on_scan_result_list(
        &self,
        env: Env<'_>,
        scan_results: &Ref<super::bindings::java::util::List>,
    ) -> Result<()> {
        for scan_result in JavaIterator(scan_results.iterator()?.non_null()?) {
            let scan_result: Local<ScanResult> = scan_result.cast()?;
            self.on_scan_result(env, &scan_result.as_ref())?;
        }
        Ok(())
    }

    fn on_scan_result(&self, _env: Env<'_>, scan_result: &Ref<ScanResult>) -> Result<()> {
        let scan_record = scan_result.getScanRecord()?.non_null()?;
        let device = scan_result.getDevice()?.non_null()?;

        let address = device
            .getAddress()?
            .non_null()?
            .to_string_lossy()
            .trim()
            .to_string();
        let rssi = scan_result.getRssi()?;
        let is_connectable = if android_api_level() >= 26 {
            scan_result.isConnectable()?
        } else {
            true // XXX: try to check `eventType` via `ScanResult.toString()`
        };
        let local_name = scan_record.getDeviceName()?.map(|s| s.to_string_lossy());
        let tx_power_level = scan_record.getTxPowerLevel()?;

        // Services
        let mut services = Vec::new();
        if let Some(uuids) = scan_record.getServiceUuids()? {
            for uuid in JavaIterator(uuids.iterator()?.non_null()?) {
                services.push(Uuid::from_andriod_parcel(uuid.cast()?)?)
            }
        }

        // Service data
        let mut service_data = HashMap::new();
        let sd = scan_record.getServiceData()?.non_null()?;
        let sd = sd.entrySet()?.non_null()?;
        for entry in JavaIterator(sd.iterator()?.non_null()?) {
            let entry: Local<Map_Entry> = entry.cast()?;
            let key: Local<ParcelUuid> = entry.getKey()?.non_null()?.cast()?;
            let val: Local<ByteArray> = entry.getValue()?.non_null()?.cast()?;
            service_data.insert(Uuid::from_andriod_parcel(key)?, val.as_vec_u8());
        }

        // Manufacturer data
        let mut manufacturer_data = None;
        let msd = scan_record.getManufacturerSpecificData()?.non_null()?;
        // TODO: there can be multiple manufacturer data entries, but the API (compatible with bluest)
        // only supports one. So grab just the first.
        if msd.size()? != 0 {
            let val: Local<'_, ByteArray> = msd.valueAt(0)?.non_null()?.cast()?;
            manufacturer_data = Some(ManufacturerData {
                company_id: msd.keyAt(0)? as _,
                data: val.as_vec_u8(),
            });
        }

        let device_id = DeviceId(address);

        let d = AdvertisingDevice {
            device: Device {
                id: device_id.clone(),
                device: device.as_global(),
                connection: CachedWeak::new(),
                once_connected: Arc::new(if GattTree::find_connection(&device_id).is_none() {
                    OnceLock::new()
                } else {
                    OnceLock::from(()) // NOTE: this is unlikely to happen
                }),
            },
            adv_data: AdvertisementData {
                is_connectable,
                local_name,
                manufacturer_data, // TODO, SparseArray is cursed.
                service_data,
                services,
                tx_power_level: Some(tx_power_level as _),
            },
            rssi: Some(rssi as _),
        };

        self.start_sender.try_send(Ok(())).ok();
        self.device_sender.try_send(d).ok();

        Ok(())
    }
}