Added automatic push distributor selection

app/src/main/kotlin/at/bitfire/davdroid/push/PushRegistrationManager.kt

@@ -26,6 +26,8 @@ import at.bitfire.davdroid.push.PushRegistrationManager.Companion.mutex
 import at.bitfire.davdroid.repository.AccountRepository
 import at.bitfire.davdroid.repository.DavCollectionRepository
 import at.bitfire.davdroid.repository.DavServiceRepository
+import at.bitfire.davdroid.settings.Settings.EXPLICIT_PUSH_DISABLE
+import at.bitfire.davdroid.settings.SettingsManager
 import at.bitfire.davdroid.sync.account.InvalidAccountException
 import dagger.Lazy
 import dagger.hilt.android.qualifiers.ApplicationContext
@@ -64,7 +66,9 @@ class PushRegistrationManager @Inject constructor(
     private val httpClientBuilder: Provider<HttpClientBuilder>,
     @IoDispatcher private val ioDispatcher: CoroutineDispatcher,
     private val logger: Logger,
-    private val serviceRepository: DavServiceRepository
+    private val serviceRepository: DavServiceRepository,
+    private val settings: SettingsManager,
+    private val distributorPreferences: DistributorPreferences,
 ) {
 
     /**
@@ -87,8 +91,16 @@ class PushRegistrationManager @Inject constructor(
         }
     }
 
+    /**
+     * Get the distributor registered by the user.
+     * @return The distributor package name if any, else `null`.
+     */
     fun getCurrentDistributor() = UnifiedPush.getSavedDistributor(context)
 
+    /**
+     * Get a list of available distributors installed on the system.
+     * @return The list of distributor's package name.
+     */
     fun getDistributors() = UnifiedPush.getDistributors(context)
 
 
@@ -102,6 +114,27 @@ class PushRegistrationManager @Inject constructor(
      * with [update(serviceId)].
      */
     suspend fun update() = mutex.withLock {
+        val currentDistributor = getCurrentDistributor()
+        val isPushDisabled = settings.getBooleanOrNull(EXPLICIT_PUSH_DISABLE)
+        if (currentDistributor == null) {
+            if (isPushDisabled == true) {
+                logger.info("Push is explicitly disabled, no distributor will be selected.")
+            } else {
+                val availableDistributors = getDistributors()
+                if (availableDistributors.isNotEmpty()) {
+                    logger.fine("No Push distributor selected, but ${availableDistributors.size} distributors are available.")
+                    // select preferred distributor if available, otherwise first available
+                    val distributor = distributorPreferences.packageNames.firstNotNullOfOrNull { preferredPackageName ->
+                        availableDistributors.find { it == preferredPackageName }
+                    } ?: availableDistributors.first()
+                    logger.fine("Automatically selecting Push distributor: $distributor")
+                    UnifiedPush.saveDistributor(context, distributor)
+                } else {
+                    logger.fine("No Push distributor selected and no distributors are available.")
+                }
+            }
+        }
+
         for (service in serviceRepository.getAll())
             updateService(service.id)
 
@@ -352,6 +385,19 @@ class PushRegistrationManager @Inject constructor(
     }
 
 
+    /**
+     * Allows preferring certain distributors over others.
+     */
+    interface DistributorPreferences {
+        /**
+         * A list of package names ordered by preference.
+         * If any of those is available, it will be automatically selected.
+         * Otherwise, another available distributor will be chosen automatically.
+         */
+        val packageNames: List<String>
+    }
+
+
     companion object {
 
         private const val WORKER_UNIQUE_NAME = "push-registration"

app/src/main/kotlin/at/bitfire/davdroid/settings/Settings.kt

@@ -65,5 +65,12 @@ object Settings {
 
     /** max. number of accounts */
     const val MAX_ACCOUNTS = "max_accounts"
+
+
+    /**
+     * By default, a push distributor is automatically selected when needed. However, the user can choose to disable push completely.
+     * This setting reflects that choice.
+     */
+    const val EXPLICIT_PUSH_DISABLE = "push_disable"
 
 }

app/src/main/kotlin/at/bitfire/davdroid/ui/AppSettingsModel.kt

@@ -164,6 +164,13 @@ class AppSettingsModel @Inject constructor(
         viewModelScope.launch(ioDispatcher) {
             pushRegistrationManager.setPushDistributor(pushDistributor)
 
+            if (pushDistributor == null) {
+                // Disable push explicitly, this will disable the automatic distributor selector
+                settings.putBoolean(Settings.EXPLICIT_PUSH_DISABLE, true)
+            } else {
+                settings.remove(Settings.EXPLICIT_PUSH_DISABLE)
+            }
+
             _pushDistributor.value = pushDistributor
         }
     }

app/src/ose/kotlin/at/bitfire/davdroid/di/OseFlavorModule.kt

@@ -4,6 +4,8 @@
 
 package at.bitfire.davdroid.di
 
+import at.bitfire.davdroid.push.DistributorPreferencesProvider
+import at.bitfire.davdroid.push.PushRegistrationManager
 import at.bitfire.davdroid.ui.intro.OseIntroPageFactory
 
 import at.bitfire.davdroid.ui.AboutActivity
@@ -47,6 +49,9 @@ interface OseModules {
     interface Global {
         @Binds
         fun introPageFactory(impl: OseIntroPageFactory): IntroPageFactory
+
+        @Binds
+        fun pushDistributorPreferences(impl: DistributorPreferencesProvider): PushRegistrationManager.DistributorPreferences
     }
 
 }

app/src/ose/kotlin/at/bitfire/davdroid/push/DistributorPreferencesProvider.kt

@@ -0,0 +1,12 @@
+/*
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ */
+
+package at.bitfire.davdroid.push
+
+import javax.inject.Inject
+
+class DistributorPreferencesProvider @Inject constructor() : PushRegistrationManager.DistributorPreferences {
+    // No special preferences for OSE flavor, select the first distributor available
+    override val packageNames: List<String> = emptyList()
+}