import { useEffect } from 'react'

export function useTitle(title) {
  useEffect(() => { document.title = title }, [title])
}

// 401 之外的业务错误（404/409/503…）直接展示后端 message；401 在 dataProvider 里转跳登录页。
export function displayError(error) {
  return error?.message || '操作失败'
}

export function conflictError(error, fallback) {
  if (error?.status === 409) return `冲突（409）：${error.body?.reason || fallback}`
  if (error?.status === 503) return `资源未就绪（503）：${error.message}`
  return displayError(error)
}

export function useUnsavedChanges(dirty) {
  useEffect(() => {
    if (!dirty) return undefined
    const click = (event) => {
      const anchor = event.target.closest?.("a[href]")
      if (!anchor || !anchor.getAttribute("href")?.startsWith("#/")) return
      if (window.confirm("当前内容尚未保存，确定离开吗？")) return
      event.preventDefault()
      event.stopPropagation()
    }
    document.addEventListener("click", click, true)
    return () => {
      document.removeEventListener("click", click, true)
    }
  }, [dirty])
}