;; Copyright (C) 2023 Camden Dixie O'Brien
;; SPDX-License-Identifier: AGPL-3.0-only

(define (tsv-fields line)
  (reverse
   (let iter ((len (string-length line))
              (rem (string-copy line))
              (idx 0)
              (res '()))
     (cond ((>= idx len) (cons rem res))
           ((char=? #\tab (string-ref rem idx))
            (iter (- len idx 1)
                  (substring rem (+ idx 1) len)
                  0
                  (cons (substring rem 0 idx) res)))
           (else (iter len rem (+ idx 1) res))))))

(define (vcard name number)
  (format "BEGIN:VCARD~%N:;~a;;;~%TEL;TYPE=cell:~a~%END:VCARD~%" name number))

(define (tsv-contact->vcard line)
  (let* ((fields (tsv-fields line))
         (number (list-ref fields 0))
         (name (list-ref fields 1)))
    (vcard name number)))

(define (foreach-line thunk)
  (let loop ()
    (let ((line (get-line (current-input-port))))
      (unless (eof-object? line)
        (display (thunk line))
        (loop)))))

(foreach-line tsv-contact->vcard)