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

// 用户注册（首次微信登录时调用）
// 处理：创建用户记录 + 上下级关系绑定
exports.main = async (event) => {
  const { referrerCode } = event;
  const { OPENID } = cloud.getWXContext();

  try {
    // 检查用户是否已存在
    const userRes = await db.collection('users').where({
      _openid: OPENID,
    }).get();

    if (userRes.data.length > 0) {
      return {
        code: 0,
        isNew: false,
        role: userRes.data[0].role || 'regular',
        message: '用户已存在',
      };
    }

    // 解析上级
    let invitedBy = null;
    if (referrerCode) {
      const refRes = await db.collection('users').where({
        referralCode,
      }).get();

      if (refRes.data.length > 0) {
        const refUser = refRes.data[0];
        // 不能自己邀请自己
        if (refUser._openid !== OPENID) {
          invitedBy = refUser._openid;

          // 更新上级的推广统计
          const stats = refUser.referralStats || {};
          await db.collection('users').doc(refUser._id).update({
            data: {
              'referralStats.directCount': (stats.directCount || 0) + 1,
            },
          });
        }
      }
    }

    // 创建新用户
    const userData = {
      _openid: OPENID,
      role: 'regular',
      practitionerExpireAt: null,
      invitedBy,
      referralStats: {
        directCount: 0,
        indirectCount: 0,
        convertedCount: 0,
      },
      createdAt: db.serverDate(),
      updatedAt: db.serverDate(),
    };

    await db.collection('users').add({ data: userData });

    return {
      code: 0,
      isNew: true,
      role: 'regular',
      hasReferrer: !!invitedBy,
    };
  } catch (err) {
    return { code: 500, error: err.message };
  }
};