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

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

  if (action === 'status') {
    const subs = await db.collection('subscriptions').where({ openid, status: 'active' }).get()
    if (subs.data.length === 0) {
      return { code: 0, data: { plan_type: 'none', status: 'inactive', remaining_days: 0 } }
    }
    const sub = subs.data[0]
    const now = new Date()
    const end = new Date(sub.end_time)
    const remain = Math.max(0, Math.ceil((end - now) / (24 * 3600 * 1000)))
    return {
      code: 0,
      data: {
        plan_type: sub.plan_type,
        status: remain > 0 ? 'active' : 'expired',
        remaining_days: remain,
        start_time: sub.start_time,
        end_time: sub.end_time
      }
    }
  }

  if (action === 'purchase') {
    const { plan_type } = event.data
    const price = plan_type === 'monthly' ? 99 : 899
    const days = plan_type === 'monthly' ? 30 : 365

    await db.collection('subscriptions').where({ openid, status: 'active' }).update({ data: { status: 'expired' } })

    await db.collection('subscriptions').add({
      data: {
        openid,
        plan_type,
        status: 'active',
        start_time: db.serverDate(),
        end_time: new Date(Date.now() + days * 24 * 3600 * 1000),
        remaining_days: days,
        price
      }
    })

    return { code: 0, data: { order_id: 'ORD' + Date.now(), plan_type, status: 'paid' } }
  }

  if (action === 'verify') {
    return { code: 0, data: { valid: true } }
  }

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