(define-module (guile-nrepl bencode)
  #:use-module (ice-9 format)
  #:export (string->bencode
            integer->bencode
            list->bencode
            pair->bencode))

(define (string->bencode input-str)
  (when (string? input-str)
    (format #f "~d:~a" (string-length input-str) input-str)))

(define (integer->bencode input-int)
  (when (integer? input-int)
    (format #f "i~de" input-int)))

(define (list->bencode input-list)
  (when (list? input-list)
    (format #f "l~ae" (apply string-append (map bencode-encode-dispatch input-list)))))

(define (pair->bencode input-pair)
  (when (pair? input-pair)
    (format #f  "d~a~ae"
            (bencode-encode-dispatch (car input-pair))
            (bencode-encode-dispatch (cdr input-pair)))))

(define (bencode-encode-dispatch input-value)
  (cond
   ((string? input-value) (string->bencode input-value))
   ((integer? input-value) (integer->bencode input-value))
   ((list? input-value) (list->bencode input-value))
   ((pair? input-value) (pair->bencode input-value))))