num/cloudfunctions/checkSession/index.js

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

exports.main = async (event) => {
  const { OPENID } = cloud.getWXContext();

  try {
    const userRes = await db.collection('users').where({
      _openid: OPENID,
    }).get();

    if (userRes.data.length === 0) {
      return { isValid: false };
    }

    const user = userRes.data[0];
    const now = Date.now();
    const isPractitioner = user.practitionerExpireAt
      && new Date(user.practitionerExpireAt).getTime() > now;

    return {
      isValid: true,
      role: isPractitioner ? 'practitioner' : 'regular',
      expireAt: user.practitionerExpireAt || null,
      referralCode: user.referralCode || null,
      referralStats: user.referralStats || {
        directCount: 0,
        indirectCount: 0,
        convertedCount: 0,
      },
      userInfo: {
        name: user.nickName || '',
        createdAt: user.createdAt,
      },
    };
  } catch (err) {
    return { isValid: false, error: err.message };
  }
};