Megatest

;;   See README in the distribution at https://www.kiatoa.com/fossils/ulex
;; NOTES:
;;   Why sql-de-lite and not say, dbi?  - performance mostly, then simplicity.
;;
;;======================================================================

;; (use rpc pkts mailbox sqlite3)

(module ulex
    *

(import scheme posix chicken data-structures ports extras files mailbox)
(import srfi-18 pkts matchable regex
	typed-records srfi-69 srfi-1
	srfi-4 regex-case
	(prefix sqlite3 sqlite3:)
	foreign
	tcp6
	;; ulex-netutil
	hostinfo)

;;======================================================================
;; network utilities
;;======================================================================

(define (rate-ip ipaddr)
  (regex-case ipaddr
    ( "^127\\..*" _ 0 )
    ( "^(10\\.0|192\\.168)\\..*" _ 1 )
    ( else 2 ) ))

;; Change this to bias for addresses with a reasonable broadcast value?
;;
(define (ip-pref-less? a b)
  (> (rate-ip a) (rate-ip b)))
  

(define (get-my-best-address)
  (let ((all-my-addresses (get-all-ips))
        ;;(all-my-addresses-old (vector->list (hostinfo-addresses (hostname->hostinfo (get-host-name)))))
        )
    (cond
     ((null? all-my-addresses)
      (get-host-name))                                          ;; no interfaces?
     ((eq? (length all-my-addresses) 1)
      (car all-my-addresses))                      ;; only one to choose from, just go with it
     
     (else
      (car (sort all-my-addresses ip-pref-less?)))
     ;; (else 
     ;;  (ip->string (car (filter (lambda (x)                      ;; take any but 127.
     ;;    			 (not (eq? (u8vector-ref x 0) 127)))
     ;;    		       all-my-addresses))))

     )))

(define (get-all-ips-sorted)
  (sort (get-all-ips) ip-pref-less?))

(define (get-all-ips)
  (map ip->string (vector->list 
		   (hostinfo-addresses
		    (host-information (current-hostname))))))

;; make it a global? Well, it is local to area module

(define *captain-pktspec*
  `((captain (host     . h)
	     (port     . p)
	     (pid      . i)

(defstruct udat
  (captain-address #f)
  (captain-host    #f)
  (captain-port    #f)
  (captain-pid     #f)
  (cpkts-dir       (conc (get-environment-variable "HOME") "/.ulex/pkts"))
  (cpkt-spec       *captain-pktspec*)
  (my-cpkt-key     #f)   ;; put Z card here when I create a pkt for myself as captain
  (my-address      #f)
  (my-hostname     #f)
  (my-port         #f)
  (my-pid          (current-process-id))
  (serv-listener   #f)
  )

;;======================================================================
;; Captain pkt functions
;;======================================================================

;; given a pkts dir read 
;;
(define (get-all-captain-pkts udata)
  (let* ((pktsdir       (let ((d (udat-cpkts-dir udata)))
			  (if (file-exists? d)
			      d
			      (begin
				(create-directory d #t)
				d))))
	 (all-pkt-files (glob (conc pktsdir "/*.pkt")))
	 (pkt-spec      (udat-cpkt-spec udata)))
    (map (lambda (pkt-file)
	   (read-pkt->alist pkt-file pktspec: pkt-spec))
	 all-pkt-files)))

;; sort by D then Z, return one, choose the oldest then
;; differentiate if needed using the Z key
;;
(define (get-winning-pkt pkts)
  (if (null? pkts)
      #f
      (car (sort pkts (lambda (a b)
			(let ((ad (string->number (alist-ref 'D a)))
			      (bd (string->number (alist-ref 'D b))))
			  (if (eq? a b)
			      (let ((az (alist-ref 'Z a))
				    (bz (alist-ref 'Z b)))
				(string>=? az bz))
			      (> ad bd))))))))

;; create a tcp listener and return a populated udat struct with
;; my port, address, hostname, pid etc.
;; return #f if fail to find a port to allocate.
;;
(define (start-server-find-port udata #!optional (port 9999)) 
  (handle-exceptions
      exn
      (if (< port 65535)(start-server-find-port (+ port 1)) #f)
    (start-server udata port)))

(define (start-server udata port)
  ;; (tcp-listener-socket LISTENER)(socket-name so)
  ;; sockaddr-address, sockaddr-port, sockaddr->string
  (let* ((tlsn (tcp-listen port 1000 #f)) ;; (tcp-listen TCPPORT [BACKLOG [HOST]])
	 (addr (get-my-best-address))) ;; (hostinfo-addresses (host-information (current-hostname)))
    (udat-my-address-set!    udata addr)
    (udat-my-port-set!       udata port)
    (udat-my-hostname-set!   udata (get-host-name))
    (udat-serv-listener-set! udata tlsn)
    udata))

;; put the host, ip, port and pid into a pkt in
;; the captain pkts dir
;;  - assumes user has already fired up a server
;;    which will be in the udata struct
;;
(define (create-captain-pkt udata)
  (if (not (udat-serv-listener udata))
      (begin
	(print "ERROR: create-captain-pkt called with out a listener")
	#f)
      (let* ((pktdat `((port   . ,(udat-my-port udata))
		       (host   . ,(udat-my-hostname udata))
		       (ipaddr . ,(udat-my-address udata))
		       (pid    . ,(udat-my-pid     udata))))
	     (pktdir  (udat-cpkts-dir udata))
	     (pktspec (udat-cpkt-spec udata))
	     )
	(udat-my-cpkt-key-set!
	 udata
	 (write-alist->pkt
	  pktdir
	  pktdat
	  pktspec: pktspec
	  ptype:   'captain))
	(udat-my-cpkt-key udata))))
    
;;======================================================================
;; connection setup and management functions
;;======================================================================

;; find or become the captain, return a ulex object
;;
(define (setup)
  (let* ((udata (make-udat))
	 (cpkts (get-all-captain-pkts udata)) ;; read captain pkts
	 (captn (get-winning-pkt cpkts)))
    (if captn

	;;  then run setup again
	;;
	udata
	)))
    
(define (connect udata dbfname)
  udata)

) ;; END OF ULEX


;;; ;;======================================================================
;;; ;; D E B U G   H E L P E R S
;;; ;;======================================================================
;;;     
;;; (define (dbg> . args)
;;;   (with-output-to-port (current-error-port)

;;     http://www.cs.toronto.edu/~gfb/scheme/simple-macros.html
;;
;; Syntax for defining macros in a simple style similar to function definiton,
;;  when there is a single pattern for the argument list and there are no keywords.
;;
;; (define-simple-syntax (name arg ...) body ...)
;;
;; 
;; (define-syntax define-simple-syntax
;;   (syntax-rules ()
;;     ((_ (name arg ...) body ...)
;;      (define-syntax name (syntax-rules () ((name arg ...) (begin body ...)))))))
;; 
;; (define-simple-syntax (catch-and-dump proc procname)
;;   (handle-exceptions
;;    exn
;;    (begin
;;      (print-call-chain (current-error-port))
;;      (with-output-to-port (current-error-port)
;;        (lambda ()
;;          (print ((condition-property-accessor 'exn 'message) exn))
;;          (print "Callback error in " procname)
;;          (print "Full condition info:\n" (condition->list exn)))))
;;    (proc)))
;; 
;; 
;;======================================================================
;;  R E C O R D S
;;======================================================================

;;; ;; information about me as a server
;;; ;;
;;; (defstruct area

;;; 
;;;      )))
;;; 
;;; (define (get-all-ips-sorted)
;;;   (sort (get-all-ips) ip-pref-less?))
;;; 
;;;