eval-bot: rewrite with telebot

eval-bot/main.rkt

@@ -1,9 +1,12 @@
 #lang racket/base
-(require web-server/servlet
+(require (only-in web-server/servlet
+                  response/empty request-post-data/raw dispatch-case)
          web-server/servlet-env
          json
          telebot
-         "commands.rkt")
+         racket/match
+         racket/string
+         "eval.rkt")
 
 (define token (getenv "BOT_TOKEN"))
 (define port (string->number (getenv "PORT")))
@@ -13,29 +16,93 @@
   (error "does not setup BOT_TOKEN env-var"))
 (define bot (make-bot token))
 
-(define app
-  (dispatch-case
-   [("webhook") #:method "post" handle-webhook]))
+(define (handle-update update)
+  (define message (ref (update : update) .message #f))
+  (define resp (handle-message message))
+  (when resp
+    (bot-send-message bot resp)))
 
-(define (handle-webhook req)
-  (thread
-   (lambda ()
-     (handle-update
-      (bytes->jsexpr (request-post-data/raw req)))))
+;; TODO: i need a robuster way to parse commands
+(define (handle-message message)
+  (define text (ref (message : message) .text #f))
+  (match text
+    ;; currently only handle "message" updates with `text` field
+    ;; `#f` represents not to respond
+    [#f #f]
+    [(regexp #rx"^/start")
+     (start message)]
+    [(regexp #rx"^/help")
+     (help message)]
+    [(regexp #px"^/eval\\b(@[a-z_]+)?(.+)$" (list _ _ code))
+     (eval message (string-trim code))]
+    [(regexp #px"^/eval_chez\\b(@[a-z_]+)?(.+)$" (list _ _ code))
+     (eval-chez message (string-trim code))]
+    [_
+     (cond
+       [(equal? (ref (message : message) .chat .type)
+                "private")
+        (match text
+          [(regexp #rx"^/")
+           (bad-request message)]
+          [_ (eval message text)])]
+       [else #f])]))
 
-  (response/empty #:code 200))
+(define (start message)
+  (make-response #:chat-id (ref (message : message) .chat .id)
+                 #:parse-mode "MarkdownV2"
+                 #:text #<<END
+Welcome to *racket\-eval\-bot*\!
+Type your code, and wait for the result\.
+END
+                 ))
 
-(define (handle-update update)
-  (define message (hash-ref update 'message #f))
-  ;; currently only handle "message" updates with `text` field
-  (when (and message (hash-ref message 'text #f))
-    (define res (handle-message message))
-    (when res
-      (bot-send-message bot res))))
+(define (help message)
+  (make-response #:chat-id (ref (message : message) .chat .id)
+                 #:parse-mode "MarkdownV2"
+                 #:text #<<END
+/start\: start to use this bot
+/eval \<code\>\: eval code
+/eval\_chez \<code\>\: eval code with Chez Scheme \(inside Racket\)
+/help\: show this message
+END
+                 ))
+
+(define (bad-request message)
+  (make-response #:chat-id (ref (message : message) .chat .id)
+                 #:parse-mode "MarkdownV2"
+                 #:text "Not supported command"))
+
+(define (eval message code)
+  (define result (eval-code code))
+  (make-response #:chat-id (ref (message : message) .chat .id)
+                 #:reply (make-reply-params
+                          #:message-id (ref (message : message) .id))
+                 #:parse-mode "HTML"
+                 #:text result))
+
+(define (eval-chez message code)
+  (define result (eval-code/chez code))
+  (make-response #:chat-id (ref (message : message) .chat .id)
+                 #:reply (make-reply-params
+                          #:message-id (ref (message : message) .id))
+                 #:parse-mode "HTML"
+                 #:text result))
 
 (module+ main
   (bot-set-webhook bot webhook-url)
 
+  (define (handle-webhook req)
+    (thread
+     (lambda ()
+       (handle-update
+        (jsexpr->update (bytes->jsexpr (request-post-data/raw req))))))
+
+    (response/empty #:code 200))
+
+  (define app
+    (dispatch-case
+     [("webhook") #:method "post" handle-webhook]))
+
   (serve/servlet app
                  #:port port
                  #:listen-ip #f