Function useSessionBackgrounding

src/hooks/useSessionBackgrounding.ts:27–158

({
  setMessages,
  setIsLoading,
  resetLoadingState,
  setAbortController,
  onBackgroundQuery,
}: UseSessionBackgroundingProps)

}

export function useSessionBackgrounding({
  setMessages,
  setIsLoading,
  resetLoadingState,
  setAbortController,
  onBackgroundQuery,
}: UseSessionBackgroundingProps): UseSessionBackgroundingResult {
  const foregroundedTaskId = useAppState(s => s.foregroundedTaskId)
  const foregroundedTask = useAppState(s =>
    s.foregroundedTaskId ? s.tasks[s.foregroundedTaskId] : undefined,
  )
  const setAppState = useSetAppState()
  const lastSyncedMessagesLengthRef = useRef<number>(0)

  const handleBackgroundSession = useCallback(() => {
    if (foregroundedTaskId) {
      // Re-background the foregrounded task
      setAppState(prev => {
        const taskId = prev.foregroundedTaskId
        if (!taskId) return prev
        const task = prev.tasks[taskId]
        if (!task) {
          return { ...prev, foregroundedTaskId: undefined }
        }
        return {
          ...prev,
          foregroundedTaskId: undefined,
          tasks: {
            ...prev.tasks,
            [taskId]: { ...task, isBackgrounded: true },
          },
        }
      })
      setMessages([])
      resetLoadingState()
      setAbortController(null)
      return
    }

    onBackgroundQuery()
  }, [
    foregroundedTaskId,
    setAppState,
    setMessages,
    resetLoadingState,
    setAbortController,
    onBackgroundQuery,
  ])

  // Sync foregrounded task's messages and loading state to the main view
  useEffect(() => {
    if (!foregroundedTaskId) {
      // Reset when no foregrounded task
      lastSyncedMessagesLengthRef.current = 0
      return
    }

    if (!foregroundedTask || foregroundedTask.type !== 'local_agent') {