// app.js
const { BASE_URL, API } = require('./utils/config')
const { request } = require('./utils/api')

App({
  onLaunch() {
    // 优先从本地缓存恢复登录态，避免阻塞页面
    const cached = wx.getStorageSync('userInfo')
    if (cached && cached.openid) {
      this.globalData.userInfo = cached
      this.globalData.isLoggedIn = true
    }
    // 静默登录获取最新 session，不阻塞页面
    this.silentLogin()
  },

  silentLogin() {
    this._loginPromise = new Promise((resolve) => {
      this._loginResolve = resolve
      wx.login({
        success: (loginRes) => {
          if (loginRes.code) {
            this.loginWithCode(loginRes.code)
          } else {
            console.error('wx.login 失败', loginRes.errMsg)
            this.handleLoginFail()
          }
        },
        fail: (err) => {
          console.error('wx.login 调用失败', err)
          this.handleLoginFail()
        }
      })
    })
  },

  /**
   * 返回登录完成的 Promise，供页面 await 使用
   * @param {boolean} useCache - 是否在已有缓存时立即 resolve
   * @returns {Promise<object|null>}
   */
  waitLogin(useCache = false) {
    if (useCache && this.globalData.isLoggedIn) {
      return Promise.resolve(this.globalData.userInfo)
    }
    return this._loginPromise || Promise.resolve(this.globalData.userInfo || null)
  },

  async loginWithCode(code) {
    try {
      const data = await request({
        url: BASE_URL + API.LOGIN,
        method: 'GET',
        data: { code }
      })
      const userInfo = {
        openid: data.openid,
        sessionKey: data.session_key,
        unionid: data.unionid || ''
      }
      this.globalData.userInfo = userInfo
      this.globalData.isLoggedIn = true
      this.globalData.loginFailed = false
      wx.setStorageSync('userInfo', userInfo)
      if (this._loginResolve) this._loginResolve(userInfo)
    } catch (err) {
      console.error('后端登录失败', err)
      // 如果有缓存登录态，登录失败不立即清除，让页面继续使用缓存
      if (!this.globalData.isLoggedIn) {
        this.handleLoginFail()
      } else {
        this.globalData.loginFailed = true
        if (this._loginResolve) this._loginResolve(this.globalData.userInfo)
      }
    }
  },

  handleLoginFail() {
    this.globalData.isLoggedIn = false
    this.globalData.loginFailed = true
    if (this._loginResolve) this._loginResolve(null)
  },

  globalData: {
    userInfo: null,
    isLoggedIn: false,
    loginFailed: false
  }
})