Handling non-interactive use with faces

[carlmarcos--- via Users list for the GNU Emacs text editor <help-gnu-emacs@gnu.org>]

How can this function be made to handle the case of non-interactive use to pass a face for displaying its properties?


(defun laxy-descface (facenm)
  "Describe the typeface properties of face name FACENM."

  (interactive
   (list
    (let* ( (cseq '("default" "mode-line" "mode-line-inactive"
    "list" "text-property")) )
      (completing-read "Face_property: " cseq nil t "text-property"))))

  (pcase facenm
    ("text-property"
        (describe-face (get-text-property (point) 'face)))
    ("default"
        (describe-face (intern facenm)))
    ("mode-line"
        (describe-face (intern facenm)))
    ("mode-line-inactive"
        (describe-face (intern facenm)))
    ("list"
        (list-faces-display))) )