Function acceptReferralCode

server/src/db/referral-codes-db.ts:172–263

(
  code: string,
  referredOrgId: string,
  referredUserId: string
)

 * Atomically increments used_count to prevent over-use.
 */
export async function acceptReferralCode(
  code: string,
  referredOrgId: string,
  referredUserId: string
): Promise<Referral | null> {
  const referralCode = await getReferralCode(code);

  if (!referralCode) {
    logger.warn({ code }, 'Referral code not found');
    return null;
  }

  if (referralCode.status !== 'active') {
    logger.warn({ code, status: referralCode.status }, 'Referral code is not active');
    return null;
  }

  if (referralCode.expires_at && referralCode.expires_at < new Date()) {
    await query(
      `UPDATE referral_codes SET status = 'expired', updated_at = NOW() WHERE id = $1`,
      [referralCode.id]
    );
    logger.warn({ code }, 'Referral code expired');
    return null;
  }

  if (referralCode.max_uses !== null && referralCode.used_count >= referralCode.max_uses) {
    logger.warn({ code }, 'Referral code has reached max uses');
    return null;
  }

  // Atomically increment used_count and create the referral in 'accepted' state
  const referralResult = await query<Referral>(
    `WITH updated_code AS (
       UPDATE referral_codes
       SET used_count = used_count + 1, updated_at = NOW()
       WHERE id = $1
         AND status = 'active'
         AND (max_uses IS NULL OR used_count < max_uses)
       RETURNING id, referrer_org_id, referrer_user_id, target_company_name
     )
     INSERT INTO referrals
       (referral_code_id, referral_code, referrer_org_id, referrer_user_id,
        target_company_name, referred_org_id, referred_user_id,
        status, accepted_at, expires_at)
     SELECT
       uc.id, $2, uc.referrer_org_id, uc.referrer_user_id,
       uc.target_company_name, $3, $4,
       'accepted', NOW(), NOW() + INTERVAL '30 days'
     FROM updated_code uc
     RETURNING *`,
    [referralCode.id, code.toUpperCase(), referredOrgId, referredUserId]
  );

  if (referralResult.rows.length === 0) {
    logger.warn({ code }, 'Referral code could not be accepted (race condition or already maxed)');
    return null;
  }