#lang racket

(provide request)

(require openssl)
(require net/url-string)

;; sends a request to a gemini server, and returns the status, header,
;; and the input port for the rest of the body.
;; this procedure will fail if the response is malformed, however, it
;; is not up to it to validate the contents of the response.
(define (request url-str)
  (define url (string->url url-str))
  (define-values (c-in c-out)
    (ssl-connect (url-host url)
                 (or (url-port url) 1965)))

  (write-string url-str c-out)
  (write-string "\r\n" c-out)

  (define-values (status header)
    (read-response c-in))

  (values status header c-in))

(define (read-response (c-in (current-input-port)))
  (define maxlen 1027)

  (let ([header (peek-string maxlen 0 c-in)])

    (if (not (string-contains? header "\r\n"))
        (error "header exceeds maximum length")

        (let ([header (read-line c-in 'return-linefeed)])
          (define-values (status meta)
            (let ([status-meta (string-split header " ")])
              (values (car status-meta)
                      (string-join (cdr status-meta)))))

          (cond
            [(> (string-length status) 2)
             (error "status code exceeds maximum length")]

            [(andmap (compose not char-numeric?) (string->list status))
             (error "status code is not numeric")]

            [else
             (values (string->number status) meta)])))))