// 后端 API 请求工具库
const { BASE_URL, API } = require('./config')

/**
 * 封装 wx.request 为 Promise
 * @param {object} options - wx.request 参数
 * @returns {Promise<object>} 返回 result.data
 */
function request(options) {
  return new Promise((resolve, reject) => {
    wx.request({
      timeout: 30000,
      ...options,
      success: (res) => {
        const result = res.data
        if (result && result.code === 0) {
          resolve(result.data)
        } else {
          reject(new Error(result ? result.message : '请求失败'))
        }
      },
      fail: (err) => {
        console.error('请求失败', options.url, err)
        if (err.errMsg && err.errMsg.indexOf('timeout') !== -1) {
          reject(new Error('网络请求超时，请检查网络后重试'))
        } else {
          reject(new Error('网络异常，请检查网络连接'))
        }
      }
    })
  })
}

/**
 * 格式化记录中的 createTime 字段
 * @param {object} record - 含 createTime 的记录
 * @returns {object} 格式化后的记录
 */
function formatRecord(record) {
  if (!record || !record.createTime) return record
  return {
    ...record,
    createTime: new Date(record.createTime).toLocaleString('zh-CN')
  }
}

/**
 * 将后端 API 返回的预约记录映射为前端模板字段
 * 后端: id, visitDate, visitTime → 前端: _id, date, time
 */
function mapApiRecord(record) {
  if (!record) return null
  return {
    ...record,
    _id: record.id,
    date: record.visitDate,
    time: record.visitTime
  }
}

/**
 * 预约相关 API
 */
const appointmentDB = {
  /**
   * 创建预约
   * @param {object} data - 预约表单数据（需包含 openid）
   * @returns {Promise<string>} 新记录 id
   */
  async create(data) {
    const result = await request({
      url: BASE_URL + API.APPOINTMENT_CREATE,
      method: 'POST',
      header: { 'content-type': 'application/json' },
      data: {
        name: data.name,
        phone: data.phone,
        company: data.company,
        reason: data.reason,
        visitDate: data.date,
        visitTime: data.time,
        hostName: data.hostName,
        area: data.area,
        openid: data.openid
      }
    })
    return result.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 list = await request({
      url: BASE_URL + API.APPOINTMENT_LIST,
      method: 'GET',
      data: { openid }
    })
    return (list || []).map(item => mapApiRecord(item))
  },

  /**
   * 获取当前用户最新一条预约
   * @param {string} openid
   * @returns {Promise<object|null>}
   */
  async getLatest(openid) {
    const data = await request({
      url: BASE_URL + API.APPOINTMENT_LATEST,
      method: 'GET',
      data: { openid }
    })
    return mapApiRecord(data) || null
  },

  /**
   * 取消预约
   * @param {string} id - 预约记录 id
   * @param {string} openid - 当前用户 openid
   * @returns {Promise<boolean>} 是否成功
   */
  async cancel(id, openid) {
    const result = await request({
      url: BASE_URL + API.APPOINTMENT_CANCEL + '?id=' + encodeURIComponent(id) + '&openid=' + encodeURIComponent(openid),
      method: 'PUT'
    })
    return result === true
  },

  /**
   * 获取预约详情
   * @param {string} id - 预约记录 id
   * @returns {Promise<object|null>}
   */
  async getDetail(id) {
    const data = await request({
      url: BASE_URL + API.APPOINTMENT_DETAIL,
      method: 'GET',
      data: { id }
    })
    return mapApiRecord(data) || null
  }
}

/**
 * 获取小程序码
 * @param {string} scene - 场景值
 * @param {string} page - 页面路径
 * @returns {Promise<string>} Base64图片数据
 */
async function getWxacode(scene, page = 'pages/scan/result/index') {
  const envVersion = wx.getAccountInfoSync().miniProgram.envVersion

  const base64Data = await request({
    url: BASE_URL + API.WXACODE,
    method: 'POST',
    header: { 'content-type': 'application/json' },
    data: {
      scene,
      page,
      width: 430,
      envVersion
    }
  })

  return `data:image/jpeg;base64,${base64Data}`
}

module.exports = {
  request,
  formatRecord,
  appointmentDB,
  getWxacode
}