const cloud = require('wx-server-sdk')
cloud.init({ env: cloud.DYNAMIC_CURRENT_ENV })
const db = cloud.database()
const _ = db.command

exports.main = async (event, context) => {
  const wxContext = cloud.getWXContext()
  const openid = wxContext.OPENID
  const { action } = event

  if (action === 'bind') {
    const { device_id } = event.data
    if (!device_id) return { code: -1, message: '缺少设备ID' }

    const existBind = await db.collection('bindings').where({ openid, status: 'active' }).count()
    if (existBind.total > 0) {
      const exist = await db.collection('bindings').where({ openid, status: 'active' }).get()
      return { code: 2001, message: '已绑定设备', data: { device_id: exist.data[0].device_id } }
    }

    await db.collection('bindings').add({
      data: {
        openid,
        device_id,
        status: 'active',
        bind_time: db.serverDate()
      }
    })

    const subExist = await db.collection('subscriptions').where({ openid, status: 'active' }).count()
    if (subExist.total === 0) {
      await db.collection('subscriptions').add({
        data: {
          openid,
          plan_type: 'trial',
          status: 'active',
          start_time: db.serverDate(),
          end_time: new Date(Date.now() + 7 * 24 * 3600 * 1000),
          remaining_days: 7
        }
      })
    }

    return {
      code: 0,
      data: {
        device_id,
        bind_token: 'bt_' + Date.now(),
        subscription: { plan_type: 'trial', remaining_days: 7 }
      }
    }
  }

  if (action === 'unbind') {
    await db.collection('bindings').where({ openid, status: 'active' }).update({ data: { status: 'inactive' } })
    return { code: 0, data: {} }
  }

  if (action === 'list') {
    const bindings = await db.collection('bindings').where({ openid, status: 'active' }).get()
    const devices = bindings.data.map(b => ({
      device_id: b.device_id,
      name: '我的光面膜',
      status: 'online',
      bind_time: b.bind_time
    }))
    return { code: 0, data: { devices, total: devices.length } }
  }

  if (action === 'detail') {
    const { device_id } = event.data
    const bindings = await db.collection('bindings').where({ openid, device_id, status: 'active' }).get()
    if (bindings.data.length === 0) return { code: -1, message: '设备未绑定' }
    const b = bindings.data[0]
    return {
      code: 0,
      data: {
        device_id: b.device_id,
        name: '我的光面膜',
        firmware_version: '1.0.0',
        battery_level: 85,
        status: 'online',
        bind_time: b.bind_time
      }
    }
  }

  return { code: -1, message: '未知操作' }
}