// 云函数入口文件
const cloud = require('wx-server-sdk')

cloud.init({ env: cloud.DYNAMIC_CURRENT_ENV })

const db = cloud.database()

// 云函数入口函数
exports.main = async (event, context) => {
  const wxContext = cloud.getWXContext()
  const openid = wxContext.OPENID

  // 查找是否已存在用户
  const userRes = await db.collection('users').where({ _openid: openid }).get()

  let user
  if (userRes.data.length > 0) {
    // 已存在，更新登录时间（如果传了头像昵称也一并更新）
    user = userRes.data[0]
    const updateData = {
      lastLoginTime: db.serverDate()
    }
    if (event.avatarUrl) updateData.avatarUrl = event.avatarUrl
    if (event.nickName) updateData.nickName = event.nickName
    await db.collection('users').doc(user._id).update({ data: updateData })
    // 合并最新数据返回
    if (event.avatarUrl) user.avatarUrl = event.avatarUrl
    if (event.nickName) user.nickName = event.nickName
  } else {
    // 新用户，创建记录
    const addRes = await db.collection('users').add({
      data: {
        _openid: openid,
        avatarUrl: event.avatarUrl || '',
        nickName: event.nickName || '',
        createTime: db.serverDate(),
        lastLoginTime: db.serverDate()
      }
    })
    user = {
      _id: addRes._id,
      _openid: openid,
      avatarUrl: event.avatarUrl || '',
      nickName: event.nickName || ''
    }
  }

  return {
    openid: openid,
    appid: wxContext.APPID,
    unionid: wxContext.UNIONID,
    userInfo: user
  }
}