Only offer to verify if a cross-signed device is available (#5433)

* Only offer to verify if a cross-signed device is available

* Fix tests

* use the right exception mapper

* adjust flag name and logic in ChooseSelfVerificationState

* add comment

* switch order of states to match previous logic

libraries/matrix/impl/src/main/kotlin/io/element/android/libraries/matrix/impl/encryption/RustEncryptionService.kt

@@ -21,6 +21,7 @@ import io.element.android.libraries.matrix.api.encryption.IdentityResetHandle
 import io.element.android.libraries.matrix.api.encryption.RecoveryState
 import io.element.android.libraries.matrix.api.encryption.identity.IdentityState
 import io.element.android.libraries.matrix.api.sync.SyncState
+import io.element.android.libraries.matrix.impl.exception.mapClientException
 import io.element.android.libraries.matrix.impl.sync.RustSyncService
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.channels.awaitClose
@@ -96,6 +97,20 @@ internal class RustEncryptionService(
     }
         .stateIn(sessionCoroutineScope, SharingStarted.Eagerly, false)
 
+    /**
+     * Check if the user has any devices available to verify against every 5 seconds.
+     * TODO This is a temporary workaround, when we will have a way to observe
+     * the sessions, this code will have to be updated.
+     */
+    override val hasDevicesToVerifyAgainst: StateFlow<Boolean> = flow {
+        while (currentCoroutineContext().isActive) {
+            val result = hasDevicesToVerifyAgainst().getOrDefault(false)
+            emit(result)
+            delay(5_000)
+        }
+    }
+        .stateIn(sessionCoroutineScope, SharingStarted.Eagerly, false)
+
     override suspend fun enableBackups(): Result<Unit> = withContext(dispatchers.io) {
         runCatchingExceptions {
             service.enableBackups()
@@ -171,6 +186,14 @@ internal class RustEncryptionService(
         }
     }
 
+    private suspend fun hasDevicesToVerifyAgainst(): Result<Boolean> = withContext(dispatchers.io) {
+        runCatchingExceptions {
+            service.hasDevicesToVerifyAgainst()
+        }.mapFailure {
+            it.mapClientException()
+        }
+    }
+
     override suspend fun resetRecoveryKey(): Result<String> = withContext(dispatchers.io) {
         runCatchingExceptions {
             service.resetRecoveryKey()

libraries/matrix/impl/src/test/kotlin/io/element/android/libraries/matrix/impl/fixtures/fakes/FakeFfiEncryption.kt

@@ -32,6 +32,10 @@ class FakeFfiEncryption : Encryption(NoPointer) {
         return false
     }
 
+    override suspend fun hasDevicesToVerifyAgainst(): Boolean {
+        return true
+    }
+
     override fun backupState(): BackupState {
         return BackupState.ENABLED
     }