try to fix login by formatting the form correctly

smol-http/http-msg.rkt

@@ -14,6 +14,7 @@
 
          http-body?
          empty-http-body
+         form-alist->http-body
          write-http-body
          force-http-body
          in-http-body-chunks)
@@ -21,6 +22,8 @@
 (require racket/match
          racket/port
          racket/stream
+         net/uri-codec
+
          "./util.rkt")
 
 (module+ test
@@ -154,6 +157,11 @@
 
 (define empty-http-body #f)
 
+;; (form-alist->http-body al) -> http-body?
+;; al : (listof (cons/c symbol? string?))
+(define (form-alist->http-body al)
+  (string->bytes/utf-8 (alist->form-urlencoded al)))
+
 ;; (write-http-body bdy [port]) -> void?
 ;; bdy : http-body?
 ;; port : output-port?

webcrawler

@@ -86,12 +86,16 @@
 
 ;; Logs in with the given username and password
 (define (crawler-login username password)
+  (void (crawler-fetch 'POST LOGIN-PATH
+                       (form-alist->http-body
+                        `([username . ,username]
+                          [password . ,password]
+                          [csrfmiddlewaretoken . ,(crawler-get-csrf-token!)])))))
+
+;; -> string?
+(define (crawler-get-csrf-token!)
   (crawler-fetch 'GET LOGIN-PATH)
-  (define form-body
-    (format "username=~a&password=~a&csrfmiddlewaretoken=~a&next="
-            username password (cookie-jar-ref (current-cookie-jar) "csrftoken")))
-  (crawler-fetch 'POST LOGIN-PATH (string->bytes/utf-8 form-body))
-  (void))
+  (cookie-jar-ref (current-cookie-jar) "csrftoken"))
 
 ;; Checks if this is a URL we should crawl
 (define (crawler-valid-url? page-url)