# Notifications

Background polling that surfaces new bank activity as system notifications, plus an in-app bottom sheet for reading them. Opt-in only — the polling service is started from [Settings → Notifications](27-settings-notifications.md).

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## Foreground Service — `NotificationPollingService`

File: `service/NotificationPollingService.kt`. Runs as a foreground service while the user has notifications enabled. Polls every **30 seconds** (`POLL_INTERVAL_MS = 30_000L`) on a `SupervisorJob` IO scope.

### Lifecycle

1. `onCreate`: creates the service channel (low importance, no badge), calls `startForeground(SERVICE_NOTIF_ID, ...)` with a persistent low-priority notification, then starts the polling loop
2. `onStartCommand`: returns `START_STICKY` so Android relaunches the service after kills
3. `onDestroy`: cancels the coroutine scope

### Poll Cycle

Each tick calls `pollBml()` and `pollMib()` sequentially. Both share the same shape:

| Step | Description |
|---|---|
| 1 | For every active session in `app.bmlSessions` / `app.mibSessions`, fetch the latest activity page |
| 2 | Compare with `NotificationsCache.loadBml(loginId)` / `loadMib(loginId, readIds)` |
| 3 | If the cache is empty (first run), persist the page silently — no system notifications are emitted on first sync |
| 4 | Otherwise, find IDs not in the cache, persist the merged list, and post a system notification per new item |

MIB activity is fetched via `MibActivityHistoryClient.fetchActivity(session, loginId, 1, 100)`. BML uses `BmlNotificationsClient.fetchNotifications(session, loginId, page = 1)`. Errors are caught per-loginId so one bad session does not block the rest.

### Channels

`ensureLoginChannel(bank, loginId)` lazily creates a `NotificationChannel` named `bank_{bank}_{loginId}` with `IMPORTANCE_DEFAULT`. The channel display name uses the profile's `name` from `bmlProfilesMap` / `mibProfilesMap` ("BML · Personal Name" etc.), falling back to the bare login id. This gives the user per-bank-per-profile channel control in system settings.

System notifications use `R.drawable.ic_bell` and a content intent that re-launches the app via `getLaunchIntentForPackage(packageName)`.

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## In-App Sheet — `NotificationsSheetFragment`

Opened from the bell icon in the toolbar (`HomeActivity.openNotificationsSheet()` at line 687). A `BottomSheetDialogFragment` containing:

- A `TabLayout` + `ViewPager2` with one page per active bank login
- Each page is a `RecyclerView` of `AppNotification` grouped by date headers
- An "Mark all read" action

Notifications are loaded from `NotificationsCache` first for instant display, then refreshed from the network. Read state is tracked in `NotificationsCache` (`getMibReadIds()` etc.) so the bell toolbar icon (`HomeActivity.kt:640-684`) can switch between `ic_bell` and `ic_bell_read`.

`onUnreadCountChanged` callback is wired from `HomeActivity` so the bell icon updates whenever the sheet's contents change.

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## Cache — `util/NotificationsCache`

Encrypted JSON files in `filesDir` (via `CacheEncryption`), one per bank+loginId. Stores the full notifications payload plus a separate "read IDs" set. Cleared along with the rest of the per-account history when the user invokes [Settings → Storage → Clear All Caches](17-settings-storage.md) (read state is excluded from that clear — verified in `17-settings-storage.md`).

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## Opt-In

The polling service is not started automatically. The user must:

1. Tap Settings → Notifications
2. Toggle the switch on
3. Grant `POST_NOTIFICATIONS` (API 33+)
4. Optionally allow battery-optimisation exemption

See [Settings → Notifications](27-settings-notifications.md) for the full flow.

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