refactor: simplify device_provider — remove legacy polling, use reactive native reconnect

[mdmohsin7]

Summary

• Remove Dart-side 15s polling reconnection timer that raced with NativeBleTransport auto-reconnect (iOS CoreBluetooth / Android CompanionDeviceService)
• Replace periodicConnect with initiateConnection — single ensureConnection call, native handles retries
• Simplify scanAndConnectToDevice — direct connection, no fragile 2s delays or redundant queries
• Fix prepareDFU to use setFirmwareUpdateInProgress instead of _reconnectAt DateTime hack that only suppressed polling for 30s
• Fix transport BleBridge registration leak when replacing stale connections in DeviceService._connectToDevice
• Fix OmiGlass OTA page not resetting _isFirmwareUpdateInProgress in dispose()
• Keep discovery-only timer for onboarding (scanning for new devices every 10s)

Test plan

• Cold start with paired device — connects via native auto-reconnect
• Device goes out of range — shows disconnected, reconnects when back in range
• Manual disconnect from device info — no reconnect attempt
• DFU firmware update — disconnect, update, auto-reconnect after reboot
• OmiGlass OTA — firmware flag resets when leaving page
• Onboarding — devices discovered even if turned on after page loads
• flutter test passes (191/197, 6 pre-existing failures in unrelated widget tests)

🤖 Generated with Claude Code

[greptile-apps]

Greptile Summary

This PR removes the Dart-side 15-second polling/reconnection timer (periodicConnect / _reconnectionTimer) and replaces it with a single initiateConnection call that delegates reconnection entirely to the native BLE layer (iOS CoreBluetooth / Android CompanionDeviceService). It also fixes a BleBridge registration leak in DeviceService._connectToDevice, fixes prepareDFU to use the proper setFirmwareUpdateInProgress flag instead of a 30-second _reconnectAt DateTime hack, and fixes the OmiGlass OTA page not resetting _isFirmwareUpdateInProgress on dispose().

Key changes:

• periodicConnect → initiateConnection: single ensureConnection(force: true) call; native handles all retries
• _startDiscoveryScanning / _runDiscoveryScan: retained as a 10-second periodic scan only for onboarding (no paired device)
• _manualDisconnect flag: suppresses the 30-second disconnect notification for deliberate disconnects (DFU, user-initiated) — but see P1 comment: the flag is set before the await ensureConnection call, so a null-connection early return leaves it permanently true
• DeviceService._connectToDevice: now calls transport.dispose() on the stale connection before replacing it, preventing leaked BleBridge callbacks
• OmiGlassOtaUpdate.dispose(): now calls resetFirmwareUpdateState(), fixing a pre-existing state leak

Confidence Score: 4/5

• Safe to merge after addressing the _manualDisconnect early-reset bug; all other issues are minor style/edge-case concerns.
• The overall architecture is sound — native auto-reconnect is the right approach, the BleBridge leak fix is correct, and the OmiGlass dispose fix is clean. The one P1 bug (_manualDisconnect set before awaiting ensureConnection) is a small ordering fix that prevents a missed disconnect notification in a failure edge case. The discovery timer leak is a P2 that was equivalent in behavior to the old polling timer. No data-loss or security risks are introduced.
• app/lib/providers/device_provider.dart — _bleDisconnectDevice flag ordering (P1) and _discoveryTimer cancellation on onboarding exit (P2).

Important Files Changed

Filename	Overview
app/lib/providers/device_provider.dart	Core refactor: replaces 15s polling timer with a single initiateConnection call + native auto-reconnect. Has three issues: _manualDisconnect not reset on null connection (P1), _discoveryTimer leaks if onboarding is abandoned (P2), and inconsistent navigator key reference (P2).
app/lib/services/devices.dart	Fixes transport BleBridge registration leak: now calls _connection!.transport.dispose() before nulling _connection, ensuring callbacks are unregistered even for non-connected stale transports.
app/lib/pages/home/omiglass_ota_update.dart	Adds resetFirmwareUpdateState() call in dispose(), ensuring _isFirmwareUpdateInProgress is cleared when leaving the OTA page — fixes a pre-existing state leak.
app/lib/pages/home/page.dart	Trivial rename: periodicConnect → initiateConnection at the HomePageWrapper call site.
app/lib/pages/onboarding/find_device/found_devices.dart	Renames call from periodicConnect to initiateConnection; minor formatting fix to a ternary chain.
app/lib/providers/onboarding_provider.dart	Single-line rename: periodicConnect → initiateConnection; no logic changes.

Sequence Diagram

sequenceDiagram
    participant App as Flutter App
    participant DP as DeviceProvider
    participant DS as DeviceService
    participant NT as NativeBleTransport
    participant OS as iOS/Android BLE

    Note over App,OS: Cold start / HomePageWrapper init
    App->>DP: initiateConnection('HomePageWrapper')
    DP->>DS: ensureConnection(pairedId, force: true)
    DS->>DS: _connectToDevice(id)<br/>dispose old transport first
    DS->>NT: connect(onConnectionStateChanged)
    NT->>OS: native connect request
    OS-->>NT: connected callback
    NT-->>DS: onDeviceConnectionStateChanged(connected)
    DS-->>DP: onDeviceConnectionStateChanged(connected)
    DP->>DP: _handleDeviceConnected → _onDeviceConnected

    Note over App,OS: Device goes out of range
    OS-->>NT: disconnected callback
    NT-->>DS: onDeviceConnectionStateChanged(disconnected)
    DS-->>DP: onDeviceConnectionStateChanged(disconnected)
    DP->>DP: onDeviceDisconnected<br/>[_manualDisconnect=false → schedule 30s notification]
    OS->>NT: native auto-reconnect (no Dart polling)
    NT-->>DS: onDeviceConnectionStateChanged(connected)
    DS-->>DP: _handleDeviceConnected

    Note over App,OS: User-initiated disconnect / DFU
    App->>DP: prepareDFU()
    DP->>DP: setFirmwareUpdateInProgress(true)
    DP->>DP: _bleDisconnectDevice → _manualDisconnect=true
    DP->>DS: ensureConnection + disconnect()
    DS-->>DP: onDeviceConnectionStateChanged(disconnected)
    DP->>DP: onDeviceDisconnected<br/>[_manualDisconnect=true → return early, no notification]

    Note over App,OS: Onboarding (no paired device)
    App->>DP: initiateConnection('FoundDevices')
    DP->>DP: _startDiscoveryScanning()<br/>Timer.periodic 10s
    DP->>DS: discover() every 10s
    DS-->>DP: onDevices(foundDevices)

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Comments Outside Diff (3)

1. app/lib/providers/device_provider.dart, line 103-110 (link)

   _manualDisconnect not reset when connection is null

   _manualDisconnect is set to true synchronously at the top of _bleDisconnectDevice. If ensureConnection returns null (e.g., the transport can't locate the device), the function returns early without ever calling disconnect(), so no disconnect event fires. _manualDisconnect is therefore left as true indefinitely.

   The next time the device disconnects unexpectedly (e.g., goes out of range), onDeviceDisconnected will see _manualDisconnect == true, reset it to false, and return early — silently swallowing the 30-second "device disconnected" notification for an involuntary disconnect.

2. app/lib/providers/device_provider.dart, line 362-363 (link)

   Inconsistent navigator key reference

   This line uses MyApp.navigatorKey.currentContext while the rest of device_provider.dart (lines 167, 447, 489) consistently uses globalNavigatorKey.currentContext. MyApp.navigatorKey is a getter that delegates to globalNavigatorKey (confirmed in main.dart), so they are functionally identical — but mixing the two styles within the same file creates unnecessary confusion.

3. app/lib/providers/device_provider.dart, line 254-273 (link)

   _discoveryTimer leaks if user exits onboarding without pairing

   _startDiscoveryScanning() is triggered by initiateConnection('FoundDevices') (and initiateConnection('Onboarding')) when no device is paired. The timer calls deviceService.discover() every 10 seconds. _runDiscoveryScan self-cancels only when btDevice.id.isNotEmpty || isConnected.

   If the user opens the onboarding/found-devices page and then navigates away without ever pairing a device, neither cancellation condition is met and the timer continues firing indefinitely — running a 5-second BLE scan every 10 seconds in the background.

   Consider also cancelling _discoveryTimer when the provider receives an explicit signal that the user has left onboarding, or expose a stopDiscovery() method that the onboarding page can call in its own dispose().

_{Reviews (2): Last reviewed commit: "Merge branch 'main' into fix/skip-reconn..." | Re-trigger Greptile}

[mdmohsin7]

@greptile-apps re-review