#lang racket/base

(require "../main.rkt")

(provide exercise01
         exercise02
         exercise03
         exercise04
         exercise05
         all-dom-exercises
         show-dom-exercises)

;; JavaScript DOM Exercises 01 Tutorial: https://youtu.be/EHF7xBUAmrQ

;; Exercise 01
;; Highlight all words over 8 characters long in the paragraph text.
(define exercise01
  (js
   (let* ([p (send document querySelector "p")])
     (set! p.innerHTML
           (regexp-replace* #px"\\b\\w{9,}\\b"
                            p.innerHTML
                            (λ (word)
                              (string-append "<span style=\"background: yellow\">"
                                             word
                                             "</span>")))))))

;; Exercise 02
;; Add a link back to the source of the text after the paragraph tag.
(define exercise02
  (js
   (let* ([p (send document querySelector "p")])
     (send p insertAdjacentHTML
           "afterend"
           "<a href=\"https://forcemipsum.com/\">Source: ForceM Ipsum</a>"))))

;; Exercise 03
;; Split each new sentence on to a separate line in the paragraph text.
;; A sentence is assumed to be terminated with a period.
(define exercise03
  (js
   (let* ([p (send document querySelector "p")])
     (set! p.innerHTML
           (regexp-replace* #rx"\\.\\s*" p.textContent ".<br>")))))

;; Exercise 04
;; Count the number of words in the paragraph tag and display the count
;; after the heading. Words are separated by one singular whitespace.
(define exercise04
  (js
   (let* ([heading (send document querySelector "h1")]
          [p       (send document querySelector "p")]
          [words   (regexp-split #rx" " p.textContent)]
          [count   (length words)])
     (send heading insertAdjacentHTML
           "afterend"
           (string-append "<p>" (number->string count) " words</p>")))))

;; Exercise 05
;; Replace question marks with thinking faces and exclamation marks with
;; astonished faces.
(define exercise05
  (js
   (let* ([p    (send document querySelector "p")]
          [step (regexp-replace* #rx"\\?" p.innerHTML "🤔")]
          [out  (regexp-replace* #rx"!" step "😲")])
     (set! p.innerHTML out))))

(define all-dom-exercises
  `((exercise01 . ,exercise01)
    (exercise02 . ,exercise02)
    (exercise03 . ,exercise03)
    (exercise04 . ,exercise04)
    (exercise05 . ,exercise05)))

(define (show-dom-exercises)
  (for ([entry (in-list all-dom-exercises)])
    (displayln (format "// ~a" (car entry)))
    (displayln (cdr entry))
    (newline)))

(module+ main
  (show-dom-exercises))