discord bot that evals april

aplbot.lisp

#|
BSD 2-Clause License

Copyright (c) 2022, LdBeth
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this
   list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above copyright notice,
   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|#
;;; sbcl --dynamic-space-size 512 --load aplbot.lisp

(ql:quickload :lispcord)
(ql:quickload :april)
(ql:quickload :cl-ppcre)

(defpackage :apl.bot
  (:use :cl :lispcord))

(in-package :apl.bot)

(defvar *apl-bot*)

(defun get-apl (msg)
  (multiple-value-bind (has-code codes)
      (cl-ppcre:scan-to-strings "^```\\w*\\n\\s*⋄([\\s\\S]+?)```|`(⋄.+?)`" msg)
    (when has-code
      (or (aref codes 0)
          (aref codes 1)))))

(defun post-apl (apl)
  (multiple-value-bind
   (res err)
   (ignore-errors
     (sb-ext:with-timeout 3
       (april:april (with (:state :output-printed :only))
                    apl)))
   (if err
       (format nil "APL ERROR: ~A" err)
     (let ((output (string-trim '(#\Space #\Newline)
                                res)))
       (if (= 0 (length output))
           "Response looks like a 0-by-0 matrix."
         (format nil "```~%~A~%```~%"
                 output))))))

;;specify the behaviour of the bot for "on-message-create" events:
(defun message-create (msg)
  (when (not (botp (lc:author msg)))
    ;; If the command was invoked via an @mention, we want to get rid of
    ;; that as well as any surrounding whitespace
    ;; #'ME simply returns the user-instance of the current bot
    (if (commandp msg)
        (let ((cmd (string-trim " " (remove-mention (me) (lc:content msg)))))
          (cond ((string= cmd "bye!")
                 (if (string= "LdBeth" (lc:name (lc:author msg)))
                     (disconnect *apl-bot*)
                   (reply msg "You are not admin.")))
                ((string= cmd "clear!")
                 (reply msg (april:april-clear-workspace april::common)))))
        (let ((apl (get-apl (lc:content msg))))
          (when apl
            (reply msg (post-apl apl)))))))

(defun run (token)
  (setf *apl-bot* (make-bot token))
  ;; set up a handler waiting for message_create events
  (add-event-handler :on-message-create 'message-create)
  (add-event-handler :on-ready
       (lambda (ready)
         (format t "User: ~a~%Session: ~a~%Connected!"
           (lc:name (lc:user ready))
           (lc:session-id ready))))
  (connect *apl-bot*))

(defun exit ()
  (disconnect *apl-bot*)
  (sb-ext:exit))

(defconstant +token+ "TOKEN")

(run +token+)