Send back the total price to the client

scontrini.rkt

@@ -7,16 +7,19 @@
 (define port 4444)
 (define hostname "127.0.0.1")
 
+; Send a json-expr on the output, prepending it with 4 bytes that contain the JSON length
+(define (send-json json-expr-to-send output)
+	(write-bytes (integer->integer-bytes (bytes-length (jsexpr->bytes json-expr-to-send)) 4 #f) output)
+	(write-json json-expr-to-send output))
+
 ; Return a list of all the pizzas from the local JSON file
 (define (get-all-pizzas)
 	(let ((file (open-input-file "pizzas_list.json")))
 		(read-json file)))
 
-; Send the list of all pizzas as a JSON, prepending it with 4 bytes that contain the list length
+; Send the list of all pizzas as a JSON
 (define (send-pizzas-list output)
-	(let ((all-pizzas-list (get-all-pizzas)))
+  	(send-json (get-all-pizzas) output))
-		(write-bytes (integer->integer-bytes (bytes-length (jsexpr->bytes all-pizzas-list)) 4 #f) output)
-		(write-json all-pizzas-list output)))
 
 ; Print the to-print string on the printer
 ; TODO add synchronization to avoid race conditions
@@ -37,23 +40,36 @@
 		(* found-price (hash-ref pizza 'quantity))))
 
 ; Format the pizzas list coming from the client in a human-readable way
-(define (format-pizza pizzas-list)
+(define (format-pizza pizzas-list price)
-	(let ((str "")
+	(let ((str ""))
-		  (price 0)
+		(for-each (lambda (pizza-hashmap)
+			(set! str (string-append str (format "~a : ~s\n" (hash-ref pizza-hashmap 'quantity) (hash-ref pizza-hashmap 'name)))))
+			pizzas-list)
+		(set! str (string-append str (format "Total price: ~a\n" price)))
+		str))
+
+; Get the price of each type of pizza and calculate the total price
+(define (get-total-price pizzas-list)
+	(let ((price 0)
 		  (all-pizzas-list (hash-ref (get-all-pizzas) 'pizzas)))
 		(for-each (lambda (pizza-hashmap)
-			(set! str (string-append str (format "~a : ~s\n" (hash-ref pizza-hashmap 'quantity) (hash-ref pizza-hashmap 'name))))
 			(set! price (+ price (get-price-from-pizza pizza-hashmap all-pizzas-list))))
 			pizzas-list)
-		(set! str (string-append str (format "Total price ~a" price)))
+		price))
-		str))
+
+; Create a format string with the received pizza list, calculate the
+; price of the whole order, print them and send it back to the client
+(define (print-pizzas-and-send-price pizzas-list output)
+  	(let* ((total-price (get-total-price pizzas-list)))
+		(printer-print (format-pizza pizzas-list total-price))
+		(send-json (hash 'total_price total-price) output)))
 
 ; Parse the commands given in the JSON
 (define (parse-json message output)
   	(let ((parsed-json (with-input-from-string message (lambda () (read-json))))) ; parse the JSON
 		(case (hash-ref parsed-json 'command)
 			(("print") (printer-print (hash-ref parsed-json 'text)))
-			(("pizza") (printer-print (format-pizza (hash-ref parsed-json 'pizzas))))
+			(("pizza") (print-pizzas-and-send-price (hash-ref parsed-json 'pizzas) output))
 			(("get-pizzas") (send-pizzas-list output))
 			(else (displayln "Unknown command")))))