import { API_BASE } from '@/config'
import type { LoginResult } from '@/api/auth'
import { trackApiError } from './tracker'

interface RequestOptions {
  url: string
  method?: 'GET' | 'POST' | 'PUT' | 'DELETE'
  data?: any
}

let isRedirectingToLogin = false
/** 重登录期间挂起的请求，登录成功后统一重试 */
let pendingRetries: Array<{ resolve: (v: any) => void; reject: (e: any) => void; options: RequestOptions }> = []

/** 保存登录结果到本地存储 */
export function saveLoginResult(data: LoginResult) {
  uni.setStorageSync('xc:token', data.token)
  uni.setStorageSync('xc:userId', data.userId)
  uni.setStorageSync('xc:nickname', data.nickname)
  uni.setStorageSync('xc:avatar_url', data.avatar_url)
  if (data.role) uni.setStorageSync('xc:role', data.role)
}

/** 执行重登录 */
async function reLogin(): Promise<void> {
  // H5 环境：demo 登录
  if (typeof window !== 'undefined') {
    const data = await request<LoginResult>({ url: '/auth/demo-login', method: 'POST' })
    saveLoginResult(data)
    return
  }

  // 小程序环境：wx.login
  const loginRes = await new Promise<UniApp.LoginRes>((resolve, reject) => {
    uni.login({ provider: 'weixin', success: resolve, fail: reject })
  })
  if (!loginRes.code) throw new Error('wx.login failed')

  const data = await request<LoginResult>({ url: '/auth/login', method: 'POST', data: { code: loginRes.code } })
  saveLoginResult(data)
}

export function request<T = any>(options: RequestOptions): Promise<T> {
  return new Promise((resolve, reject) => {
    const token = uni.getStorageSync('xc:token')
    uni.request({
      url: API_BASE + options.url,
      method: options.method || 'GET',
      data: options.data,
      timeout: 15000, // 15秒超时
      header: {
        'Content-Type': 'application/json',
        ...(token ? { Authorization: `Bearer ${token}` } : {})
      },
      success: (res: any) => {
        const { statusCode, data } = res

        if (statusCode === 401) {
          uni.removeStorageSync('xc:token')
          uni.removeStorageSync('xc:userId')
          uni.removeStorageSync('xc:nickname')
          uni.removeStorageSync('xc:avatar_url')
          uni.removeStorageSync('xc:role')
          uni.removeStorageSync('xc:currentGroupId')

          // 加入重试队列
          pendingRetries.push({ resolve, reject, options })

          if (!isRedirectingToLogin) {
            isRedirectingToLogin = true

            reLogin()
              .then(() => {
                // 处理快照时已入队的 + reLogin 期间新入队的请求
                const retries = [...pendingRetries]
                pendingRetries = []
                retries.forEach(r => request(r.options).then(r.resolve).catch(r.reject))
              })
              .catch(() => {
                uni.showToast({ title: '登录失败，请刷新页面', icon: 'none' })
                const retries = [...pendingRetries]
                pendingRetries = []
                retries.forEach(r => r.reject({ code: 40100, message: '未登录' }))
              })
              .finally(() => { isRedirectingToLogin = false })
          }
          return
        }

        if (data.code === 0) {
          resolve(data.data)
        } else {
          // 埋点：API 业务错误
          trackApiError(options.url, statusCode, data.message || '请求失败')
          // "用户不存在" 不弹 toast（首次登录竞态）
          if (data.code !== 40400 || data.message !== '用户不存在') {
            uni.showToast({ title: data.message || '请求失败', icon: 'none' })
          }
          reject(data)
        }
      },
      fail: (err: any) => {
        // 埋点：网络错误
        trackApiError(options.url, 0, '网络错误')
        uni.showToast({ title: '网络错误', icon: 'none' })
        reject(err)
      }
    })
  })
}