const RECOVERY_STORAGE_KEY = 'cc-admin-route-asset-recovery:v1'
const RECOVERY_WINDOW_MS = 30_000

const staleAssetErrorPatterns = [
  /failed to fetch dynamically imported module/i,
  /error loading dynamically imported module/i,
  /importing a module script failed/i,
  /chunkloaderror/i,
  /loading (css )?chunk [\w-]+ failed/i,
]

export interface NavigationRecoveryDependencies {
  storage: Pick<Storage, 'getItem' | 'setItem' | 'removeItem'>
  now: () => number
  hasUnsavedWork: () => boolean
  confirmDiscard: () => Promise<boolean>
  discardUnsavedWork: () => void
  navigate: (target: string) => void
  showError: (message: string) => void
}

interface RecoveryAttempt {
  target: string
  attemptedAt: number
}

function errorMessage(error: unknown) {
  if (error instanceof Error) return error.message
  return typeof error === 'string' ? error : ''
}

export function isStaleRouteAssetError(error: unknown) {
  const message = errorMessage(error)
  return staleAssetErrorPatterns.some((pattern) => pattern.test(message))
}

function recentAttempt(dependencies: NavigationRecoveryDependencies, target: string) {
  try {
    const parsed = JSON.parse(dependencies.storage.getItem(RECOVERY_STORAGE_KEY) || 'null') as RecoveryAttempt | null
    return Boolean(parsed
      && parsed.target === target
      && dependencies.now() - parsed.attemptedAt < RECOVERY_WINDOW_MS)
  } catch {
    return false
  }
}

export async function recoverNavigationError(
  error: unknown,
  target: string,
  dependencies: NavigationRecoveryDependencies,
) {
  if (!isStaleRouteAssetError(error)) {
    dependencies.showError('页面切换失败，请重试')
    return false
  }
  if (recentAttempt(dependencies, target)) {
    dependencies.showError('页面资源加载失败，请稍后重试或手动刷新')
    return false
  }
  if (dependencies.hasUnsavedWork() && !await dependencies.confirmDiscard()) return true

  dependencies.storage.setItem(RECOVERY_STORAGE_KEY, JSON.stringify({
    target,
    attemptedAt: dependencies.now(),
  } satisfies RecoveryAttempt))
  dependencies.discardUnsavedWork()
  dependencies.navigate(target)
  return true
}

export function clearNavigationRecoveryAttempt(storage: Pick<Storage, 'removeItem'>) {
  storage.removeItem(RECOVERY_STORAGE_KEY)
}