(define-module (tests test-graphemes-stream)
  #:use-module (uniseg graphemes)
  #:use-module (uniseg graphemes stream)
  #:use-module (uniseg internal)
  #:use-module (srfi srfi-41)
  #:use-module (srfi srfi-64))

(test-begin "tests-graphemes-stream")

;; silly double-em dash
(define stream (string->grapheme-stream "Trans 🏳️‍⚧️ rights are human rights⸺and that's a promise!"))

(define* (advance-stream! #:optional (times 1))
  (for-each
   (λ (_) (set! stream (stream-cdr stream)))
   (make-list times)))

(advance-stream! 10)

(define trans-flag-grapheme (stream-car stream))

(test-equal "Trans flag stream is correct"
  "🏳️‍⚧️" (grapheme-string trans-flag-grapheme))

(test-equal "Trans flag is width 2"
  2 (grapheme-width trans-flag-grapheme))

(advance-stream! 2)

(define r-grapheme (stream-car stream))

(test-equal "r in rights is in correct place"
  "r" (grapheme-string r-grapheme))

(test-equal "r is width 1"
  1 (grapheme-width r-grapheme))

(advance-stream! 23)

(define double-em-dash-grapheme (stream-car stream))

(test-equal "double-em-dash is in right place"
  "⸺" (grapheme-string double-em-dash-grapheme))

(test-equal "double-em-dash is triple-width"
  3 (grapheme-width double-em-dash-grapheme))

(advance-stream!)

(define a-grapheme (stream-car stream))

(test-equal "advancing one goes to the a"
  "a" (grapheme-string a-grapheme))

(define empty-stream (string->grapheme-stream ""))

(test-equal "a stream of nothing resolves to an empty stream"
  #t (stream-null? empty-stream))

(define singleton-stream (string->grapheme-stream "a"))

(set! a-grapheme (stream-car stream))

(test-equal "a stream with a single character resolves to a grapheme"
  "a" (grapheme-string a-grapheme))

(test-end "tests-graphemes-stream")