/** 管理端 API client：token 注入 + 统一信封解包 + 401 跳登录 */

const TOKEN_KEY = 'sundynix-admin-token'

export function getToken(): string | null {
  return localStorage.getItem(TOKEN_KEY)
}

export function setToken(token: string) {
  localStorage.setItem(TOKEN_KEY, token)
}

export function clearToken() {
  localStorage.removeItem(TOKEN_KEY)
}

interface Envelope<T> {
  code: number
  message: string
  data: T
}

export class ApiError extends Error {
  status: number
  code: number

  constructor(status: number, code: number, message: string) {
    super(message)
    this.status = status
    this.code = code
  }
}

export async function request<T>(
  path: string,
  init: RequestInit = {},
): Promise<T> {
  const headers = new Headers(init.headers)
  headers.set('Content-Type', 'application/json')
  const token = getToken()
  if (token) headers.set('Authorization', `Bearer ${token}`)

  const res = await fetch(path, { ...init, headers })

  if (res.status === 401) {
    clearToken()
    // basename=/admin，登录路由实际是 /admin/login
    if (!window.location.pathname.endsWith('/login')) {
      window.location.href = '/admin/login'
    }
    throw new ApiError(401, 40100, '登录已过期')
  }

  let body: Envelope<T> | null = null
  try {
    body = (await res.json()) as Envelope<T>
  } catch {
    // 非 JSON 响应
  }
  if (!res.ok || !body || body.code !== 0) {
    throw new ApiError(
      res.status,
      body?.code ?? -1,
      body?.message ?? `请求失败（${res.status}）`,
    )
  }
  return body.data
}