#!/usr/bin/env -S guix shell guile guile-json -- guile --no-auto-compile -e main -s
-*- scheme -*-
!#

(use-modules (srfi srfi-1)
	     (ice-9 iconv)
	     (ice-9 receive)
	     (web client)
	     (json))

(define whois-at-hsp-endpoint "https://whois.at.hsp.sh/api/now")

(define (http-get-serialize-json url)
  (receive (response data) (http-request url)
    (values (json-string->scm (bytevector->string data "UTF-8"))
	    response)))

(define (whois-data->users whois-data)
  (assoc-ref whois-data "users"))

(define (whois-data->unknown-devices whois-data)
  (assoc-ref whois-data "unknown_devices"))

(define (whois-data->head-count whois-data)
  (assoc-ref whois-data "headcount"))

(define (whois-data->formated-users whois-data)
  (let ((users (vector->list (whois-data->users whois-data))))
    (if (> (length users) 0)
	(fold-right
	 (lambda (a b) (string-append a " " b))
	 ""
	 users)
	"No visible users!")))

(define (whois-data->summary whois-data)
  (string-append
   "Unknown devices: "
   (number->string (whois-data->unknown-devices whois-data))
   "\nUsers: [" (number->string (whois-data->head-count whois-data)) "] "
   (whois-data->formated-users whois-data)))

(define (notify data)
  (system* "notify-send"
	   "WHOIS AT HSP"
	   (whois-data->summary data)))

(define (command-line-option? option args)
  (> (length (or (member option args)
		 '()))
     0))

(define-syntax-rule (command-line-args-handle args default ((option ...) body ...) ...)
  (let ((option? (lambda (o) (command-line-option? o args))))
    (cond ((or (option? option) ...) body ...) ...
	  (#t default))))

;; (command-line-args-handle '("a" "--help")
;; 			  0
;; 			  (("-h" "--help") "dupa"))

(define (main args)
  (let ((whois-data (http-get-serialize-json whois-at-hsp-endpoint)))
    (command-line-args-handle args
      (begin (display (whois-data->summary whois-data))
	     (newline))
      (("-h" "--help")
       (display (string-append "-h, --help     Help message\n"
			       "-n, --notify   Notification massage with whois information.\n"
			       "-u             Get users\n"
			       "-H             Get head count\n"
			       "-U             Get unknown devices\n")))
      (("-n" "--notify")
       (notify whois-data))
      (("-u")
       (display (whois-data->formated-users whois-data))
       (newline))
      (("-H")
       (display (whois-data->head-count whois-data))
       (newline))
      (("-U")
       (display (whois-data->unknown-devices whois-data))
       (newline)))))