[Push] Update registration worker to actively select distributor

[ArnyminerZ]

Purpose

Implements the automatic push distributor selection logic detailed in #2153

Short description

• Add automatic push distributor resolution

• Add notification for instances where a distributor cannot be resolved automatically (no distributor, or more than one available)

  Screenshots

  

Checklist

• The PR has a proper title, description and label.
• I have self-reviewed the PR.
• I have added documentation to complex functions and functions that can be used by other modules.
• I have added reasonable tests or consciously decided to not add tests.

[Copilot]

Pull request overview

Implements the push distributor auto-selection flow described in #2153 by adding distributor resolution, a user-facing notification when selection is required, and a dialog activity to guide the user through distributor setup.

Changes:

• Added automatic UnifiedPush distributor resolution (getAckDistributor + resolveDefaultDistributor) when push is enabled.
• Added a high-importance “user interaction” notification channel and a notification prompting distributor selection.
• Introduced PushDistributorSelectionActivity to launch the UP selection flow or guide installation/disable push.

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 7 comments.

Show a summary per file

File	Description
core/src/main/res/values/strings.xml	Adds notification/channel strings related to distributor selection and missing distributors.
core/src/main/kotlin/at/bitfire/davdroid/ui/NotificationRegistry.kt	Adds a new notification ID and a high-importance channel for user-interaction notifications.
core/src/main/kotlin/at/bitfire/davdroid/push/PushRegistrationManager.kt	Triggers unregister/unsubscribe + posts “select distributor” notification when no distributor is available.
core/src/main/kotlin/at/bitfire/davdroid/push/PushNotificationManager.kt	Generalizes notification posting API used by both push-pending and selection-required notifications.
core/src/main/kotlin/at/bitfire/davdroid/push/PushDistributorSelectionActivity.kt	New dialog activity to drive distributor selection / show “no distributor” guidance.
core/src/main/kotlin/at/bitfire/davdroid/push/PushDistributorManager.kt	Implements distributor resolution logic (saved/ack distributor, otherwise resolve default).
core/src/main/AndroidManifest.xml	Registers the new selection activity.
core/src/androidTest/kotlin/at/bitfire/davdroid/push/PushDistributorManagerTest.kt	Updates tests to use getAckDistributor (but needs additional stubbing for the new resolution path).

[sunkup]

When I add an account with push-capable collections, like our nextcloud testaccount, currently no distributor is actively being chosen (by the registration worker). Not FCM and not any other.

I get 10:50:21.883 D Push is disabled. Unregistering all instance, and unsubscribing from all services

Line 100 in PushDistributorManager has me think though it should be enabled by default now?

/**
 * Checks whether push notifications are enabled in settings.
 *
 * @return `true` if push notifications are enabled (default), `false` if disabled.
 */
fun isPushEnabled(): Boolean =
    settingsManager.getBooleanOrNull(Settings.PUSH_ENABLED) ?: true

[Copilot]

Pull request overview

Copilot reviewed 8 out of 8 changed files in this pull request and generated 2 comments.

Comments suppressed due to low confidence (1)

core/src/androidTest/kotlin/at/bitfire/davdroid/push/PushDistributorManagerTest.kt:92

• issue (blocking): testGetDistributor_PushEnabled_NoDistributorToUse doesn't stub UnifiedPush.resolveDefaultDistributor()

getDistributorToUse() calls resolveDefaultDistributor() when getAckDistributor() returns null, so this test will hit an un-stubbed static UnifiedPush method and typically fails under MockK. Stub resolveDefaultDistributor() to a deterministic value (and consider adding dedicated tests for Found/ToSelect/NoneAvailable).

    fun testGetDistributor_PushEnabled_NoDistributorToUse() {
        // Given push is enabled but no distributor is set
        settingsManager.putBoolean(Settings.PUSH_ENABLED, true)
        every { UnifiedPush.getAckDistributor(any()) } returns null

        // When getting current distributor
        val result = pushDistributorManager.getDistributorToUse()
        

[sunkup]

The earlier issue is unfortunately still present. I think it would be good to address it in this PR, otherwise we should create an issue for it - which is also fine.

issue: sunup (+other distributors?) installed after DAVx5 will become default, but won't register.

• install davx5 on device with play services (chosen as default)
• install sunup (sunup is automatically chosen as default)
• setup account with push capable collections
• -> registration with sunup does not happen. Not even when enabling/disabling or refreshing collections.

--

I found another problem with the curent version. See this video:

Details

Screencast.From.2026-05-04.09-50-24.mp4

The notification reappears when selecting a non-default distributor and the choice is not persisted / reset?.

[ArnyminerZ]

The notification reappears when selecting a non-default distributor and the choice is not persisted / reset?.

I think this was caused only for FCM, because the choice was not being persisted. Fixed

[ArnyminerZ]

The earlier issue is unfortunately still present. I think it would be good to address it in this PR, otherwise we should create an issue for it - which is also fine.

I've skipped this on this PR (installing a distributor after automatically having selected FCM) to keep this one shorter, and to further discuss behavior if needed

[sunkup]

Works well now. Only minor things.

[sunkup]

The earlier issue is unfortunately still present. I think it would be good to address it in this PR, otherwise we should create an issue for it - which is also fine.

I've skipped this on this PR (installing a distributor after automatically having selected FCM) to keep this one shorter, and to further discuss behavior if needed

Very well. I have created #2199