css-in-js to css elisp command

cssjs-to-css.el

(defun un-camelcase-string (s)
  (let ((case-fold-search nil))
    (while (string-match "[A-Z]" s 1)
      (setq s (replace-match (concat "-"
                                     (downcase (match-string 0 s)))
                             t nil s)))
    (downcase s)))

(defun cssjs-to-css ()
  (interactive)
  (insert (let ((lines (split-string (delete-and-extract-region (region-beginning) (region-end)) "\n")))
    (mapconcat (lambda (line)
                 (if (= (length line) 0) ""

                   (let ((parts (split-string line ":")))
                     (if (/= (length parts) 2)
                         (error "Invalid line %s" line)
                       (concat
                        (un-camelcase-string (car parts))
                        ": "
                        (string-trim
                         (replace-regexp-in-string "'" ""(replace-regexp-in-string "," ";" (car (cdr parts))))))))))
                 lines
                 "\n"))))