;; Under construction

(define-module (services tailscale)
	       #:use-module (gnu services)
	       #:use-module (gnu services shepherd)
	       #:use-module (gnu services configuration)
	       #:use-module (guix records)
	       #:use-module (guix gexp)
	       #:use-module (ice-9 match)
	       #:use-module (packages tailscale)
	       #:use-module (gnu packages linux)
	       #:export (tailscaled-service-type tailscaled-configuration))

;; TODO: https://tailscale.com/kb/1188/linux-dns/#dhcp-dhclient-overwriting-etcresolvconf

(define-record-type* <tailscaled-configuration>
		     tailscaled-configuration make-tailscaled-configuration
		     tailscaled-configuration?
		     (tailscale tailscaled-configuration-tailscale
				(default tailscale))
		     (listen-port tailscaled-configuration-listen-port
			   (default "41641"))
		     (state-file tailscaled-configuration-state-file
				 (default "tailscaled.state")))

(define (tailscaled-activation config)
  "Run tailscaled --cleanup"
  #~(begin
      (system* #$(file-append tailscale "/usr/bin/tailscaled") "--cleanup")))

(define (tailscaled-shepherd-service config)
  "Return a <shepherd-service> for Tailscaled with CONFIG"
  (let ((tailscale
	   (tailscaled-configuration-tailscale config))
	(listen-port
	   (tailscaled-configuration-listen-port config))
	(state-file
	   (tailscaled-configuration-state-file config))
	(environment #~(list (string-append
			       "PATH=" ; iptables is required for tailscale to work
			       (string-append #$iptables "/sbin")
			       ":"
			       (string-append #$iptables "/bin")))))
      (list
	(shepherd-service
         (provision '(tailscaled))
	 (requirement '(networking)) ;; services this depends on
         (start #~(make-forkexec-constructor
		    (list #$(file-append tailscale "/usr/bin/tailscaled")
 		     "-state" #$state-file
		     ;"-port" #$listen-port
		     "-verbose" "10")
		    #:environment-variables #$environment
		    #:log-file "/var/log/tailscaled.log"))
         (stop #~(make-kill-destructor))))))

(define tailscaled-service-type
  (service-type
    (name 'tailscaled)
    (extensions
      (list (service-extension shepherd-root-service-type
			       tailscaled-shepherd-service)
            (service-extension activation-service-type
			       tailscaled-activation)))
    (default-value (tailscaled-configuration))
    (description "Launch tailscaled.")))