fix(activity): Use long as id for activity

app/src/main/java/com/owncloud/android/ui/activities/data/activities/ActivitiesServiceApiImpl.kt

@@ -9,6 +9,7 @@
  */
 package com.owncloud.android.ui.activities.data.activities
 
+import androidx.annotation.VisibleForTesting
 import com.nextcloud.client.account.UserAccountManager
 import com.nextcloud.common.NextcloudClient
 import com.owncloud.android.MainApp
@@ -59,13 +60,7 @@ class ActivitiesServiceApiImpl(private val accountManager: UserAccountManager) :
         val client = OwnCloudClientManagerFactory.getDefaultSingleton()
             .getNextcloudClientFor(ocAccount, context)
 
-        val operation = if (lastGiven > 0) {
-            GetActivitiesRemoteOperation(lastGiven)
-        } else {
-            GetActivitiesRemoteOperation()
-        }
-
-        val result = operation.execute(client)
+        val result = createOperation(lastGiven).execute(client)
 
         if (result.isSuccess && result.getData() != null) {
             val data = result.getData()
@@ -87,5 +82,15 @@ class ActivitiesServiceApiImpl(private val accountManager: UserAccountManager) :
 
     companion object {
         private val TAG: String = ActivitiesServiceApiImpl::class.java.simpleName
+
+        // Without a file ID the operation does not filter the activities by file
+        private const val NO_FILE_ID = -1L
+
+        @VisibleForTesting
+        internal fun createOperation(lastGiven: Long): GetActivitiesRemoteOperation = if (lastGiven > 0) {
+            GetActivitiesRemoteOperation(NO_FILE_ID, lastGiven)
+        } else {
+            GetActivitiesRemoteOperation()
+        }
     }
 }

app/src/test/java/com/owncloud/android/ui/activities/data/activities/ActivitiesServiceApiImplTest.kt

@@ -0,0 +1,42 @@
+/*
+ * Nextcloud - Android Client
+ *
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+package com.owncloud.android.ui.activities.data.activities
+
+import com.owncloud.android.lib.resources.activities.GetActivitiesRemoteOperation
+import org.junit.Assert.assertEquals
+import org.junit.Test
+
+class ActivitiesServiceApiImplTest {
+
+    private fun GetActivitiesRemoteOperation.longField(name: String): Long =
+        GetActivitiesRemoteOperation::class.java.getDeclaredField(name).let {
+            it.isAccessible = true
+            it.getLong(this)
+        }
+
+    @Test
+    fun firstPageHasNoFilter() {
+        val operation = ActivitiesServiceApiImpl.createOperation(0)
+
+        assertEquals(-1L, operation.longField("fileId"))
+        assertEquals(-1L, operation.longField("lastGiven"))
+    }
+
+    @Test
+    fun nextPageKeepsTheFullActivityIdWithoutFilteringByFile() {
+        val operation = ActivitiesServiceApiImpl.createOperation(SNOWFLAKE_ACTIVITY_ID)
+
+        assertEquals(-1L, operation.longField("fileId"))
+        assertEquals(SNOWFLAKE_ACTIVITY_ID, operation.longField("lastGiven"))
+    }
+
+    companion object {
+        // Snowflake IDs need more than 32 bits
+        private const val SNOWFLAKE_ACTIVITY_ID = 130_000_000_000_000_123L
+    }
+}