;; Bitbasel

    ;; (impl-trait .nft-trait.nft-trait)
    (impl-trait 'ST1PQHQKV0RJXZFY1DGX8MNSNYVE3VGZJSRTPGZGM.nft-trait.nft-trait)

    ;; Non Fungible Token, using sip-009
    (define-non-fungible-token Bitbasel uint)

    ;; Constants
    (define-constant err-no-more-nfts u300)
    (define-constant err-invalid-user u500)

    ;; Internal variables
    



(define-data-var mint-limit uint u5000)
(define-data-var last-id uint u0)
(define-map nft-meta-data uint (string-ascii 80))
    ;; private functions
    ;; Internal - Mint new NFT

(define-private (mint-private (new-owner principal))   
  (let ((next-id (+ u1 (var-get last-id)))
        (count (var-get last-id)))   
      (asserts! (< count (var-get mint-limit)) (err err-no-more-nfts))
    (begin
      (mint-helper new-owner next-id))))

(define-private (mint-helper (new-owner principal) (next-id uint))   
    (match (nft-mint? Bitbasel next-id new-owner) success
              (begin
                (var-set last-id next-id)
                (ok next-id))
            error (err error)))

    ;; public functions
(define-public (mint (data (string-ascii 80)))   
  (match (mint-private tx-sender) success
    (begin 
      (map-set nft-meta-data success data)
      (ok data))
    error (err error)))

(define-public (transfer (token-id uint) (sender principal) (recipient principal))   
  (if (and
        (is-eq tx-sender sender))
      (match (nft-transfer? Bitbasel token-id sender recipient)
        success (ok success)
        error (err error))
      (err err-invalid-user)))

    ;; read-only functions
    ;; SIP009: Get the owner of the specified token ID
(define-read-only (get-owner (token-id uint))   
  (ok (nft-get-owner? Bitbasel token-id)))

    ;; SIP009: Get the last token ID
(define-read-only (get-last-token-id)   
  (ok (var-get last-id)))

(define-read-only (get-token-uri (token-id uint))   
  (begin (match (map-get? nft-meta-data token-id) entry 
          (ok (some entry))
          (ok none))))