#lang racket/base
(require irc/command
         racket/sequence racket/function racket/format)
(provide (all-defined-out))

(define (short-arg? v)
  (or (string? v) (symbol? v) (number? v)))

(define (ensure-all-short v)
  (unless (andmap short-arg? v)
    (error-user "You may only supply short (string, symbol, number) arguments")))

(define (stringify v)
  (cond [(string? v) (clean-control v)]
        [(symbol? v) (clean-control (symbol->string v))]
        [(number? v) (~a v)]
        [else "<invalid>"]))

(define (clean-control s)
  (list->string
    (sequence->list
      (sequence-filter (negate char-iso-control?)
                       (in-string s)))))

; insert zero-width space to prevent clients from notifying a user
(define (break-highlight s)
  (if (zero? (string-length s))
    s
    (string-append
      (substring s 0 1)
      "\u200B"
      (substring s 1))))