totally redo the line interface, go and pagination commands

gem300.rkt

@@ -3,22 +3,51 @@
 (require (prefix-in net: "net.rkt")
          (prefix-in gmi: "gmi.rkt"))
 
-(define commands
-  (list
-   (cons "default" (lambda (line) (void)))))
+;; global state variable which will be an input port containing the
+;; rendered out gemtext document as it shall be shown to the user
+(define document-buffer null)
 
-(define (dispatch-command line)
-  (let ([split (string-split line " ")])
+(define (go-cmd url)
+  (if (non-empty-string? url)
+      (let-values ([(status meta c-in) (net:get url)])
+        (let-values ([(document) (gmi:parse (port->lines c-in))]
+                     [(db-in db-out) (make-pipe #f)])
 
-    (let ([cmd (assoc (cond [(null? split) "default"]
-                            [else (first split)])
-                      commands)])
-      (if cmd
-          ((cdr cmd) (string-join (cdr split)))
-          (displayln "no such command")))))
+          (set! document-buffer db-in)
+          (parameterize ([current-output-port db-out])
+            (gmi:render document))
 
+          (let ([remaining (pipe-content-length db-in)])
+            (printf "document retrieved. ~a bytes\n" remaining))
+
+          (next-cmd)))
+
+      (displayln "go where?")))
+
+(define (next-cmd)
+  (define (iter depth)
+    (when (> depth 0)
+      (let ()
+        (displayln (read-line document-buffer))
+        (iter (sub1 depth)))))
+
+  (iter 10)
+  (newline)
+  (let ([remaining (pipe-content-length document-buffer)])
+     (printf "~a bytes remaining\n" remaining)))
 
 (define (repl)
-  (display "G300> ")
-  (dispatch-command (read-line))
+  (display "G-300 > ")
+
+  (let ([matches (regexp-match #px"(\\w+)\\s*(.*)" (read-line))])
+    (cond
+      ;; nothing was given. default command
+      [(not matches)
+       (next-cmd)]
+
+      ;; go command
+      [(string=? (cadr matches) "go")
+       (go-cmd (caddr matches))]))
+
+
   (repl))