export function createSearch<T>(
  search: (q: string, signal: AbortSignal) => Promise<T>,
  onResult: (value: T) => void,
  onError: (error: unknown) => void,
) {
  let timer: ReturnType<typeof setTimeout> | undefined
  let controller: AbortController | undefined
  let version = 0

  function cancel() {
    version++ // 输入一变就让旧结果失效，不等新请求发出
    if (timer !== undefined) clearTimeout(timer)
    timer = undefined
    controller?.abort()
    controller = undefined
  }

  function run(query: string) {
    cancel()
    const q = query.trim()
    if (!q) return // 调用方同步清空搜索结果
    const currentVersion = version
    const currentController = new AbortController()
    controller = currentController

    timer = setTimeout(async () => {
      timer = undefined
      try {
        const value = await search(q, currentController.signal)
        if (currentVersion === version && !currentController.signal.aborted) {
          onResult(value)
        }
      } catch (error) {
        if (currentVersion === version && !currentController.signal.aborted) {
          onError(error)
        }
      } finally {
        if (controller === currentController) controller = undefined
      }
    }, 300)
  }

  return { run, cancel } // 输入时 run，组件卸载时 cancel
}