Megatest

  (server-url        (if *toppath* (server:check-if-running *toppath*))) ;; (server:check-if-running *toppath*) #f))
  (last-server-check 0)  ;; last time we checked to see if the server was alive
  (conndat           #f)
  (transport         *transport-type*)
  (server-timeout    (server:expiration-timeout))
  (force-server      #f)
  (ro-mode           #f)  
  (ro-mode-checked   #f) ;; flag that indicates we have checked for ro-mode
  (ulex:conn         #f) ;; ulex db conn is not exactly a db connector, more like a network connector 
  )

;; launching and hosts
(defstruct host
  (reachable    #f)
  (last-update  0)
  (last-used    0)
  (last-cpuload 1))

	       ;(mtdbmodtime  (if mtdbexists (common:lazy-sqlite-db-modification-time mtdbpath)   #f)) ; moving this before db:open-megatest-db is called. if wal mode is on -WAL and -shm file get created with causing the  tmpdbmodtime timestamp always greater than mtdbmodtime
	       ;(tmpdbmodtime (if dbfexists  (common:lazy-sqlite-db-modification-time tmpdbfname) #f)) 
					;if wal mode is on -WAL and -shm file get created when db:open-megatest-db is called. modtimedelta will always be < 10 so db in tmp not get synced
          ;(tmpdbmodtime (if dbfexists (db:get-last-update-time (car tmpdb)) #f))    
          ;(fmt (file-modification-time tmpdbfname))
	       (modtimedelta (and mtdbmodtime tmpdbmodtime (- mtdbmodtime tmpdbmodtime))))

	  (handle-exceptions
	   exn
	   (let ((call-chain (get-call-chain))
		 (msg        ((condition-property-accessor 'exn 'message) exn)))
	     (debug:print 0 *default-log-port* "ERROR: attempted to drop triggers on MTRA/megatest.db but failed. Error is " msg)
	     (set! write-access #f)) ;; if we failed to drop the triggers then we probably don't have write access
	   (when write-access
		 (sqlite3:execute (car mtdb) "drop trigger if exists update_tests_trigger")
		 (sqlite3:execute (car mtdb) "drop trigger if exists update_runs_trigger")))
          
         ;(print "mtdbmodtime " mtdbmodtime " tmpdbmodtime " tmpdbmodtime " mtdbpath " mtdbpath " " (conc *toppath* "/megatest.db"))
	        ;;(debug:print-info 13 *default-log-port* "db:open-db>> mtdbpath="mtdbpath" mtdbexists="mtdbexists" and write-access="write-access)
          (if (and dbexists (not write-access))
              (begin
                (set! *db-write-access* #f)
                (dbr:dbstruct-read-only-set! dbstruct #t)))

(declare (unit rmt))
(declare (uses api))
(declare (uses http-transport))
(include "common_records.scm")
(declare (uses rmtmod))

(import rmtmod)


;;
;; THESE ARE ALL CALLED ON THE CLIENT SIDE!!!
;;

;; generate entries for ~/.megatestrc with the following
;;

	      cinfo
	      (if (server:check-if-running areapath)
		  (client:setup areapath)
		  #f))))

(define *send-receive-mutex* (make-mutex)) ;; should have separate mutex per run-id



;; this entry point can decide based on cmd whether to dispatch to old api calls via remote or via ulex
;;
(define (rmt:send-receive cmd rid params #!key (attemptnum 1)(area-dat #f))
  (if (member cmd '(blah))
      (begin
	(mutex-lock! *send-receive-mutex*)
	(if (not *runremote*)(set! *runremote* (make-remote)))
	(let ((ulex:conn (remote-ulex:conn *runremote*)))
	  (if (not ulex:conn)(remote-ulex:conn-set! *runremote* (rmtmod:setup-ulex *toppath*)))
	  (rmtmod:send-receive-ulex ulex:conn cmd rid params attemptnum area-dat)))
      (rmt:send-receive-orig cmd rid params attemptnum: attemptnum area-dat: area-dat)))

;; RA => e.g. usage (rmt:send-receive 'get-var #f (list varname))
;;
(define (rmt:send-receive-orig cmd rid params #!key (attemptnum 1)(area-dat #f)) ;; start attemptnum at 1 so the modulo below works as expected

  #;(common:telemetry-log (conc "rmt:"(->string cmd))
                        payload: `((rid . ,rid)
                                   (params . ,params)))
                          
  
  ;;DOT digraph megatest_state_status {
  ;;DOT   ranksep=0;
  ;;DOT   // rankdir=LR;

	   (> (current-seconds) ;; if it has been more than server-timeout seconds since last contact, close this connection and start a new on
	      (+ (http-transport:server-dat-get-last-access (remote-conndat runremote))
		 (remote-server-timeout runremote))))
      (debug:print-info 0 *default-log-port* "Connection to " (remote-server-url runremote) " expired due to no accesses, forcing new connection.")
      (http-transport:close-connections area-dat: runremote)
      (remote-conndat-set! runremote #f) ;; invalidate the connection, thus forcing a new connection.
      (mutex-unlock! *rmt-mutex*)
      (rmt:send-receive-orig cmd rid params attemptnum: attemptnum))
     
     ;;DOT CASE5 [label="local\nread"];
     ;;DOT MUTEXLOCK -> CASE5 [label="server not required,\non homehost,\nread-only query"]; {rank=same "case 5" CASE5};
     ;;DOT CASE5 -> "rmt:open-qry-close-locally";

     ;; on homehost and this is a read
     ((and (not (remote-force-server runremote)) ;; honor forced use of server, i.e. server NOT required

           (not (member cmd api:read-only-queries))  ;; this is a write
           (remote-server-url runremote)             ;; have a server
           (not (server:ping (remote-server-url runremote))))  ;; server has died. NOTE: this is not a cheap call! Need better approach.
      (set! *runremote* (make-remote))
      (remote-force-server-set! runremote (common:force-server?))
      (mutex-unlock! *rmt-mutex*)
      (debug:print-info 12 *default-log-port* "rmt:send-receive, case  6")
      (rmt:send-receive-orig cmd rid params attemptnum: attemptnum))

     ;;DOT CASE7 [label="homehost\nwrite"];
     ;;DOT MUTEXLOCK -> CASE7 [label="server not required,\non homehost,\na write,\nhave a server"]; {rank=same "case 7" CASE7};
     ;;DOT CASE7 -> "rmt:open-qry-close-locally";
     ;; on homehost and this is a write, we already have a server
     ((and (not (remote-force-server runremote))     ;; honor forced use of server, i.e. server NOT required
	   (cdr (remote-hh-dat runremote))           ;; on homehost

	  (and (not (cdr (remote-hh-dat runremote)))        ;; not on a homehost 
	       (not (remote-conndat runremote))))           ;; and no connection
      (debug:print-info 12 *default-log-port* "rmt:send-receive, case 9, hh-dat: " (remote-hh-dat runremote) " conndat: " (remote-conndat runremote))
      (mutex-unlock! *rmt-mutex*)
      (if (not (server:check-if-running *toppath*)) ;; who knows, maybe one has started up?
	  (server:start-and-wait *toppath*))
      (remote-conndat-set! runremote (rmt:get-connection-info *toppath*)) ;; calls client:setup which calls client:setup-http
      (rmt:send-receive-orig cmd rid params attemptnum: attemptnum)) ;; TODO: add back-off timeout as

     ;;DOT CASE10 [label="on homehost"];
     ;;DOT MUTEXLOCK -> CASE10 [label="server not required,\non homehost"]; {rank=same "case 10" CASE10};
     ;;DOT CASE10 -> "rmt:open-qry-close-locally";
     ;; all set up if get this far, dispatch the query
     ((and (not (remote-force-server runremote))
	   (cdr (remote-hh-dat runremote))) ;; we are on homehost

;;======================================================================
;; Copyright 2019, Matthew Welland.
;; 
;; This file is part of Megatest.
;; 
;;     Megatest is free software: you can redistribute it and/or modify
;;     it under the terms of the GNU General Public License as published by
;;     the Free Software Foundation, either version 3 of the License, or
;;     (at your option) any later version.

(module rmtmod
	*
	
(import scheme chicken data-structures extras)
(import (prefix sqlite3 sqlite3:) posix typed-records srfi-18)
(import commonmod)
(use (prefix ulex ulex:))

;; Hack to make these functions visible to the refactored code, goal is to eliminate these over time.
(define (rmt:send-receive . params) #f)
(define (http-transport:close-connections . params) #f)
;; from remote defstruct in common.scm
(define (remote-conndat-set! . params) #f)
(define (remote-server-url-set! . params) #f)
(define (remote-ro-mode . params) #f)
(define (remote-ro-mode-set! . params) #f)
(define (remote-ro-mode-checked-set! . params) #f)
(define (remote-ro-mode-checked . params) #f)
(define (debug:print . params) #f)
(define (debug:print-info . params) #f)

(define (set-functions send-receive        rsus
		       close-connections   rcs
		       dbgp                dbgpinfo
		       ro-mode             ro-mode-set
		       ro-mode-checked-set ro-mode-checked
		       ) 
  (set! rmt:send-receive            send-receive)
  (set! remote-server-url-set!           rsus)
  (set! http-transport:close-connections close-connections)
  (set! remote-conndat-set!              rcs)
  (set! debug:print                      dbgp)
  (set! debug:print-info                 dbgpinfo)
  (set! remote-ro-mode                   ro-mode)
  (set! remote-ro-mode-set!              ro-mode-set)

	(mutex-lock! *rmt-mutex*)
	(http-transport:close-connections area-dat: runremote)
	(set! *runremote* #f) ;; force starting over
	(mutex-unlock! *rmt-mutex*)
	(thread-sleep! wait-delay)
	(rmt:send-receive cmd rid params attemptnum: (+ attemptnum 1)))
      res)) ;; All good, return res

;;======================================================================
;; ulex and steps stuff
;;======================================================================

(define (rmtmod:setup-ulex toppath)
  (ulex:make-area
   dbdir:   (conc toppath "/ulexdb")
   pktsdir: (conc toppath "/pkts") 
   ))



(define (rmtmod:send-receive-ulex ulex:conn cmd rid params attemptnum area-dat)
  #f)

)