Parsing unloaded .el files for defun interactive forms

I've struggled to list interactive functions from .el files using obarray 
symbols, as it requires prior loading.  I need to parse unloaded .el files 
directly to extract defun forms with (interactive ...).

Current broken code:

(defun ramazones-smbptn (smb pattern file)
  "Filter symbol SMB defined in a specific file that are currently loaded."
  (when (and (commandp smb)
             (string-match-p pattern (symbol-name smb)))
    smb))

(defun ramazonas-agfun (file pattern)
  "List all interactive functions defined in FILE."
  
  (interactive
    (list 
      (read-file-name "File: ")
      (read-regexp "Symbol Pattern (RET for all): ")))

  (let ( (smbs   nil)
         (count  0) )
    (when (find-file-noselect file)
      (mapatoms (lambda (smb)
                  (when (ramazonas-smbptn smb pattern file)
                    (setq count (1+ count))
                    (push smb smbs))))

      (if (> count 0)
          (progn (message "Interactive functions: %s"
                   (seq-filter #'commandp smbs))
                 (seq-filter #'commandp smbs))
        (message "No interactive functions found")))))