/**
 * Shared state for tile cache invalidation after admin "Rebuild zooms".
 * Admin sets the timestamp on success; MapView on mount clears tile caches
 * when a rebuild was done recently, so the map shows fresh tiles even if
 * SSE was missed (e.g. admin in another tab).
 */
const REBUILD_DONE_TTL_MS = 5 * 60 * 1000 // 5 minutes

export function useRebuildZoomsInvalidation() {
  const rebuildZoomsDoneAt = useState('rebuildZoomsDoneAt', () => 0)

  function markRebuildDone() {
    rebuildZoomsDoneAt.value = Date.now()
  }

  function shouldInvalidateTileCache(): boolean {
    if (rebuildZoomsDoneAt.value <= 0) return false
    return Date.now() - rebuildZoomsDoneAt.value < REBUILD_DONE_TTL_MS
  }

  function clearRebuildDoneFlag() {
    rebuildZoomsDoneAt.value = 0
  }

  return {
    markRebuildDone,
    shouldInvalidateTileCache,
    clearRebuildDoneFlag,
  }
}