Fix chained conditional task logic

app/src/main/java/org/groundplatform/android/ui/datacollection/TaskSequenceHandler.kt

@@ -47,7 +47,16 @@ class TaskSequenceHandler(
   /** Generates the task sequence based on task's conditions. */
   fun generateValidTasksList(): List<Task> {
     val selections = taskDataHandler.getTaskSelections()
-    return allTasks.filter { it.isConditionFulfilled(selections) }
+    val validTasks = ArrayList<Task>()
+    val validTaskIds = HashSet<String>()
+    for (task in allTasks) {
+      val validSelections = selections.filterKeys { taskId -> validTaskIds.contains(taskId) }
+      if (task.isConditionFulfilled(validSelections)) {
+        validTasks.add(task)
+        validTaskIds.add(task.id)
+      }
+    }
+    return validTasks
   }
 
   /** Returns true if the specified task would be last in the sequence with the given value. */

app/src/test/java/org/groundplatform/android/ui/datacollection/TaskSequenceHandlerTest.kt

@@ -288,4 +288,41 @@ class TaskSequenceHandlerTest {
       taskSequenceHandler.getTaskPosition(conditionalTask.id)
     }
   }
+
+  @Test
+  fun `generateValidTasksList handles large chain of conditional tasks`() {
+    // Create a chain of 100 tasks, each depending on the previous one.
+    val tasks = ArrayList<Task>()
+    tasks.add(createTask("task0", 0))
+    for (i in 1 until 100) {
+      tasks.add(createTask("task$i", i, condition = createCondition("task${i - 1}", option1.id)))
+    }
+
+    val handler = TaskSequenceHandler(tasks, taskDataHandler)
+
+    // Set task0 to option2 (condition fail for task1)
+    taskDataHandler.setData(
+      tasks[0],
+      MultipleChoiceTaskData(multipleChoice, listOf(conditionalOption.id)),
+    )
+
+    handler.invalidateCache()
+    val sequence = handler.getValidTasks()
+
+    // Expected: Only task0 visible.
+    assertThat(sequence.map { it.id }).containsExactly("task0")
+
+    // Set task0 to option1 (condition met for task1)
+    taskDataHandler.setData(tasks[0], MultipleChoiceTaskData(multipleChoice, listOf(option1.id)))
+    // Set all other tasks to satisfy next condition
+    for (i in 1 until 99) {
+      taskDataHandler.setData(tasks[i], MultipleChoiceTaskData(multipleChoice, listOf(option1.id)))
+    }
+
+    handler.invalidateCache()
+    val fullSequence = handler.getValidTasks()
+
+    // Expected: All tasks visible
+    assertThat(fullSequence).hasSize(100)
+  }
 }