#lang racket/base

(require racket/match)
(require racket/tcp)
(require racket/port)
(require minimart)
(require minimart/drivers/timer)
(require logbook)

(define L (default-logbook))
(define E (standard-logbook-entry L "minimart" "echo-server"))
(define Tmem (logbook-table E "memory-use" #:column-spec '(time-ms memory-use)))
(define Tconn (logbook-table E "connections" #:column-spec '(time-ms connection-count)))

(define connection-count 0)

(define (statistician)
  (list (spawn (lambda (e s)
		 (match e
		   [(message (timer-expired 'statistician now) _ _)
		    (collect-garbage)
		    (collect-garbage)
		    (collect-garbage)
		    (write-logbook-datum! Tmem (list (/ now 1000.0) (current-memory-use)))
		    (write-logbook-datum! Tconn (list (/ now 1000.0) connection-count))
		    (transition s (send (set-timer 'statistician 10000 'relative)))]
		   [_ #f]))
	       #f
	       (list (sub (timer-expired 'statistician ?))))
	(send (set-timer 'statistician 10000 'relative))))

(define (listener port-number)
  (spawn (lambda (e s)
	   (match e
	     [(message (event _ (list (list in out))) _ _)
	      (transition s (connection in out))]
	     [_ #f]))
	 #f
	 (list (sub (event (tcp-accept-evt (tcp-listen port-number 4 #t)) ?)
		    #:meta-level 1))))

(define (connection in out)
  (set! connection-count (+ connection-count 1))
  (spawn (lambda (e s)
	   (match e
	     [(message (event _ (list (? eof-object?))) _ _)
	      (close-input-port in)
	      (close-output-port out)
	      (set! connection-count (- connection-count 1))
	      (transition s (quit))]
	     [(message (event _ (list line)) _ _)
	      (fprintf out "~a\n" line)
	      (flush-output out)
	      (transition s '())]
	     [_ #f]))
	 #f
	 (list (sub (event (read-line-evt in 'any) ?)
		    #:meta-level 1))))

(run-ground (listener 5999)
	    (spawn-timer-driver)
	    (statistician))