// 云数据库操作工具库

const db = wx.cloud.database()
const _ = db.command

/**
 * 用户相关操作
 */
const userDB = {
  /**
   * 通过 openId 查找用户，不存在则创建
   * @param {string} openid
   * @param {object} userInfo - { avatarUrl, nickName }
   * @returns {Promise<object>} 用户记录
   */
  async loginOrCreate(openid, userInfo) {
    const res = await db.collection('users').where({ _openid: openid }).get()
    if (res.data.length > 0) {
      // 已存在，更新头像昵称
      const existing = res.data[0]
      await db.collection('users').doc(existing._id).update({
        data: {
          avatarUrl: userInfo.avatarUrl,
          nickName: userInfo.nickName,
          lastLoginTime: db.serverDate()
        }
      })
      return { ...existing, avatarUrl: userInfo.avatarUrl, nickName: userInfo.nickName }
    } else {
      // 不存在，新建
      const addRes = await db.collection('users').add({
        data: {
          _openid: openid,
          avatarUrl: userInfo.avatarUrl,
          nickName: userInfo.nickName,
          createTime: db.serverDate(),
          lastLoginTime: db.serverDate()
        }
      })
      return {
        _id: addRes._id,
        _openid: openid,
        avatarUrl: userInfo.avatarUrl,
        nickName: userInfo.nickName
      }
    }
  },

  /**
   * 根据 openId 获取用户信息
   * @param {string} openid
   * @returns {Promise<object|null>}
   */
  async getByOpenId(openid) {
    const res = await db.collection('users').where({ _openid: openid }).get()
    return res.data.length > 0 ? res.data[0] : null
  }
}

/**
 * 预约相关操作
 */
const appointmentDB = {
  /**
   * 创建预约
   * @param {object} data - 预约表单数据
   * @returns {Promise<string>} 新记录 _id
   */
  async create(data) {
    const res = await db.collection('appointments').add({
      data: {
        ...data,
        status: 'pending',
        statusText: '待审核',
        createTime: db.serverDate()
      }
    })
    return res._id
  },

  /**
   * 获取当前用户的预约列表（按创建时间倒序）
   * @param {string} openid
   * @returns {Promise<Array>}
   */
  async getList(openid) {
    const res = await db.collection('appointments')
      .where({ _openid: openid })
      .orderBy('createTime', 'desc')
      .get()
    return res.data
  },

  /**
   * 获取当前用户最新一条预约
   * @param {string} openid
   * @returns {Promise<object|null>}
   */
  async getLatest(openid) {
    const res = await db.collection('appointments')
      .where({ _openid: openid })
      .orderBy('createTime', 'desc')
      .limit(1)
      .get()
    return res.data.length > 0 ? res.data[0] : null
  },

  /**
   * 取消预约
   * @param {string} id - 预约记录 _id
   * @param {string} openid - 当前用户 openid，用于权限校验
   * @returns {Promise<boolean>} 是否成功
   */
  async cancel(id, openid) {
    // 先校验该预约属于当前用户
    const res = await db.collection('appointments').doc(id).get()
    if (res.data._openid !== openid) {
      return false
    }
    if (res.data.status !== 'pending') {
      return false
    }
    await db.collection('appointments').doc(id).update({
      data: {
        status: 'cancelled',
        statusText: '已取消'
      }
    })
    return true
  }
}

module.exports = {
  db,
  _,
  userDB,
  appointmentDB
}