(define-constant E1 (err u830))
(define-map referrals principal principal)
(define-map ref-count principal uint)
(define-public (set-referrer (referrer principal))
(begin
(asserts! (not (is-eq tx-sender referrer)) E1)
(asserts! (is-none (map-get? referrals tx-sender)) E1)
(map-set referrals tx-sender referrer)
(map-set ref-count referrer
(+ (default-to u0 (map-get? ref-count referrer)) u1))
(ok true)))
(define-read-only (get-referrer (u principal))
(map-get? referrals u))
(define-read-only (get-referral-count (u principal))
(default-to u0 (map-get? ref-count u)))
(define-read-only (was-referred (u principal))
(is-some (map-get? referrals u)))