;;======================================================================
;; Copyright 2017, 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.
;; 
;;     Megatest is distributed in the hope that it will be useful,
;;     but WITHOUT ANY WARRANTY; without even the implied warranty of
;;     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;;     GNU General Public License for more details.
;; 
;;     You should have received a copy of the GNU General Public License
;;     along with Megatest.  If not, see <http://www.gnu.org/licenses/>.

;;======================================================================

(declare (unit dbfile))
;; (declare (uses debugprint))
(declare (uses commonmod))

(module dbfile
	*
	
  (import scheme
	  chicken
	  data-structures
	  extras
	  matchable)
  
(import (prefix sqlite3 sqlite3:)
	posix typed-records srfi-18 srfi-1
	srfi-69
	stack
	files
	ports

	commonmod
	)

;; (import debugprint)

;;======================================================================
;;  R E C O R D S
;;======================================================================

;; a single Megatest area with it's multiple dbs is
;; managed in a dbstruct
;;
(defstruct dbr:dbstruct
  (areapath  #f)
  (homehost  #f)
  (tmppath   #f)
  (read-only #f)
  (subdbs (make-hash-table))
  )

;; NOTE: Need one dbr:subdb per main.db, 1.db ...
;;
(defstruct dbr:subdb
  (dbname      #f) ;; .db/1.db
  (mtdbfile    #f) ;; mtrah/.db/1.db
  (mtdbdat     #f) ;; only need one of these for syncing
  ;; (dbdats      (make-hash-table))  ;; id => dbdat 
  (tmpdbfile   #f) ;; /tmp/.../.db/1.db
  ;; (refndbfile  #f) ;; /tmp/.../.db/1.db_ref
  (dbstack     (make-stack)) ;; stack for tmp dbr:dbdat,
  (homehost    #f) ;; not used yet
  (on-homehost #f) ;; not used yet
  (read-only   #f)
  (last-sync   0)
  (last-write  (current-seconds))
  )                ;; goal is to converge on one struct for an area but for now it is too confusing

;; need to keep dbhandles and cached statements together
(defstruct dbr:dbdat
  (dbfile      #f)
  (dbh         #f)    
  (stmt-cache  (make-hash-table))
  (read-only   #f)
  (birth-sec   (current-seconds)))

(define *dbstruct-dbs* #f)
(define *db-access-mutex* (make-mutex))
(define *no-sync-db*   #f)
(define *db-sync-in-progress* #f)
(define *db-with-db-mutex*    (make-mutex))
(define *max-api-process-requests* 0)
(define *api-process-request-count* 0)
(define *db-write-access*     #t)
(define *db-last-sync*        0)                 ;; last time the sync to megatest.db happened
(define *db-multi-sync-mutex* (make-mutex))      ;; protect access to *db-sync-in-progress*, *db-last-sync*

(define (db:generic-error-printout exn . message)
  (print-call-chain (current-error-port))
  (apply dbfile:print-err message)
  (dbfile:print-err
    ", error: "     ((condition-property-accessor 'exn 'message)   exn)
    ", arguments: " ((condition-property-accessor 'exn 'arguments) exn)
    ", location: "  ((condition-property-accessor 'exn 'location)  exn)
    ))

(define (dbfile:run-id->key run-id)
  (or run-id 'main))

(define (db:safely-close-sqlite3-db db stmt-cache #!key (try-num 3))
  (if (<= try-num 0)
      #f
      (handle-exceptions
	  exn
	(begin
	  (print "Attempt to safely close sqlite3 db failed. Trying again. exn=" exn)
	  (thread-sleep! 3)
	  (sqlite3:interrupt! db)
	  (db:safely-close-sqlite3-db db stmt-cache try-num: (- try-num 1)))
	(if (sqlite3:database? db)
	    (let* ((stmts (and stmt-cache (hash-table-ref/default stmt-cache db #f))))
	      (if stmts (map sqlite3:finalize! (hash-table-values stmts)))
	      (sqlite3:finalize! db)
	      #t)
            (begin
             (dbfile:print-err "db:safely-close-sqlite3-db: " db " is not an sqlite3 db")
	     #f
            )
        ))))

;; close all opened run-id dbs
(define (db:close-all dbstruct)
  (if (dbr:dbstruct? dbstruct)
;; (handle-exceptions
;; 	  exn
;; 	  (begin
;; 	    (debug:print 0 *default-log-port* "WARNING: Finalizing failed, "  ((condition-property-accessor 'exn 'message) exn) ", note - exn=" exn)
;; 	    (print-call-chain *default-log-port*))
	;; (db:sync-touched dbstruct 0 force-sync: #t) ;; NO. Do not do this here. Instead we rely on a server to be started when there are writes, even if the server itself is not going to be used as a server.
        (let* ((subdbs     (hash-table-values (dbr:dbstruct-subdbs dbstruct))))
	  (for-each
	   (lambda (subdb)
	     (let* ((tdbs       (stack->list (dbr:subdb-dbstack subdb)))
		    (mtdbdat    (dbr:dbdat-dbh (dbr:subdb-mtdbdat subdb)))
		    #;(rdb        (dbr:dbdat-dbh (dbr:subdb-refndb subdb))))
		    
	       (map (lambda (dbdat)
		      (let* ((stmt-cache (dbr:dbdat-stmt-cache dbdat))
			     (dbh        (dbr:dbdat-dbh        dbdat)))
			(db:safely-close-sqlite3-db dbh stmt-cache)))
		    tdbs)
	       (db:safely-close-sqlite3-db mtdbdat (dbr:dbdat-stmt-cache  (dbr:subdb-mtdbdat subdb))) 
               ;; (if (sqlite3:database? mdb) (sqlite3:finalize! mdb))
	       #;(db:safely-close-sqlite3-db rdb #f))) ;; stmt-cache))))) ;; (if (sqlite3:database? rdb) (sqlite3:finalize! rdb))))))
	   subdbs)
           #t
          )
          #f
  )
)

;; ;; set up a single db (e.g. main.db, 1.db ... etc.)
;; ;;
;; (define (db:setup-db dbstruct areapath run-id)
;;   (let* ((dbname   (db:run-id->dbname run-id))
;; 	 (dbstruct (hash-table-ref/default dbstructs dbname #f)))
;;     (if dbstruct
;; 	dbstruct
;; 	(let* ((dbstruct-new (make-dbr:dbstruct)))
;; 	  (db:open-db dbstruct-new run-id areapath: areapath do-sync: #t)
;; 	  (hash-table-set! dbstructs dbname dbstruct-new)
;; 	  dbstruct-new))))
    
;; ; Returns the dbdat for a particular dbfile inside the area
;; ;;
;; (define (dbr:dbstruct-get-dbdat dbstruct dbfile)
;;   (hash-table-ref/default (dbr:dbstruct-dbdats dbstruct) dbfile #f))
;; 
;; (define (dbr:dbstruct-dbdat-put! dbstruct dbfile db)
;;   (hash-table-set! (dbr:dbstruct-dbdats dbstruct) dbfile db))
;; 
;; (define (db:run-id->first-num run-id)
;;   (let* ((s (number->string run-id))
;; 	 (l (string-length s)))
;;     (substring s (- l 1) l)))

;; 1234 => 4/1234.db
;;   #f => 0/main.db
;;   (abandoned the idea of num/db)
;; 
(define (dbfile:run-id->path apath run-id)
  (conc apath"/"(dbfile:run-id->dbname run-id)))

(define (db:dbname->path apath dbname)
  (conc apath"/"dbname))

(define (dbfile:run-id->dbname run-id)
  (cond
   ((number? run-id) (conc ".db/" (modulo run-id 100) ".db"))
   ((not run-id)     (conc ".db/main.db"))
   (else             run-id)))

;; Make the dbstruct, setup up auxillary db's and call for main db at least once
;;
;; called in http-transport and replicated in rmt.scm for *local* access. 
;;
(define (dbfile:setup do-sync areapath tmppath)
  (cond
   (*dbstruct-dbs*
    (dbfile:print-err "WARNING: dbfile:setup called when *dbstruct-dbs* is already initialized")
    *dbstruct-dbs*) ;; TODO: when multiple areas are supported, this optimization will be a hazard
   (else
    (let* ((dbstruct (make-dbr:dbstruct)))
      (set! *dbstruct-dbs* dbstruct)
      (dbr:dbstruct-areapath-set! dbstruct areapath)
      (dbr:dbstruct-tmppath-set!  dbstruct tmppath)
      dbstruct))))

(define (dbfile:get-subdb dbstruct run-id)
  (let* ((dbfname (dbfile:run-id->dbname run-id)))
    (hash-table-ref/default (dbr:dbstruct-subdbs dbstruct) dbfname #f)))

(define (dbfile:set-subdb dbstruct run-id subdb)
  (hash-table-set! (dbr:dbstruct-subdbs dbstruct) (dbfile:run-id->dbname run-id) subdb))

(define *dbfile:num-handles-in-use* 0)

;; Get/open a database
;;    if run-id => get run specific db
;;    if #f     => get main db
;;    if run-id is a string treat it as a filename
;;    if db already open - return inmem
;;    if db not open, open inmem, rundb and sync then return inmem
;;    inuse gets set automatically for rundb's
;;
(define (dbfile:get-dbdat dbstruct run-id)
  (let* ((subdb (dbfile:get-subdb dbstruct run-id)))
    (if (stack-empty? (dbr:subdb-dbstack subdb))
	#f
	(begin
	  (set! *dbfile:num-handles-in-use* (+ *dbfile:num-handles-in-use* 1))
	  (stack-pop! (dbr:subdb-dbstack subdb))))))

;; return a previously opened db handle to the stack of available handles
(define (dbfile:add-dbdat dbstruct run-id dbdat)
  (let* ((subdb (dbfile:get-subdb dbstruct run-id))
	 (age   (- (current-seconds)(dbr:dbdat-birth-sec dbdat))))
    (if (> age 300) ;; just testing - discard and close after 30 sec
	(begin
	  ;; (map sqlite3:finalize! (hash-table-values (dbr:dbdat-stmt-cache dbdat)))
	  ;; (sqlite3:finalize! (dbr:dbdat-dbh dbdat))
	  (dbfile:print-err "INFO: Discarded dbdat over 30 sec old ("age"s)"))
	(begin
	  (set! *dbfile:num-handles-in-use* (- *dbfile:num-handles-in-use* 1))
	  (stack-push! (dbr:subdb-dbstack subdb) dbdat)))))

;; set up a subdb
;;
(define (dbfile:init-subdb dbstruct run-id init-proc)
  (let* ((dbname    (dbfile:run-id->dbname run-id))
	 (areapath  (dbr:dbstruct-areapath dbstruct))
	 (tmppath   (dbr:dbstruct-tmppath  dbstruct))
	 (mtdbpath  (dbfile:run-id->path areapath run-id))
	 (tmpdbpath (dbfile:run-id->path tmppath run-id))
	 (mtdbdat   (dbfile:open-sqlite3-db mtdbpath init-proc))
	 (newsubdb  (make-dbr:subdb dbname:    dbname
				    mtdbfile:  mtdbpath
				    tmpdbfile: tmpdbpath
				    mtdbdat:   mtdbdat)))
    (dbfile:set-subdb dbstruct run-id newsubdb)
    newsubdb)) ;; return the new subdb - but shouldn't really use it

;; returns dbdat with dbh and dbfilepath
;;
;; NOTE: the handle is on /tmp db file!
;;
;;  1. if needed setup the subdb for the given run-id
;;  2. if there is no existing db handle in the stack
;;     create a new handle and return it (do NOT add
;;     it to the stack).
;;
(define (dbfile:open-db dbstruct run-id init-proc)
  (if (> *dbfile:num-handles-in-use* 10)
      (let* ((wait-delay (- *dbfile:num-handles-in-use* 9)))
	(dbfile:print-err "INFO: over ten dbfile handle threads in use ("*dbfile:num-handles-in-use*") delaying "wait-delay" second")
	(thread-sleep! wait-delay)))
  (let* ((subdb (dbfile:get-subdb dbstruct run-id)))
    (if (not subdb) ;; not yet defined
	(begin
	  (dbfile:init-subdb dbstruct run-id init-proc)
	  (dbfile:open-db dbstruct run-id init-proc))
	(let* ((dbdat (dbfile:get-dbdat dbstruct run-id)))
	  (if dbdat
	      dbdat
	      (let* ((tmppath   (dbr:dbstruct-tmppath  dbstruct))
		     (tmpdbpath (dbfile:run-id->path tmppath run-id)))
		(dbfile:open-sqlite3-db tmpdbpath init-proc)))))))

;; COMBINE dbfile:open-sqlite-db and dbfile:lock-create-open
;;

;; this stuff is for initial debugging, please remove it when
;; this code stabilizes
(define *dbopens* (make-hash-table))
(define (dbfile:inc-db-open dbfile)
  (let* ((curr-opens-count (+ (hash-table-ref/default *dbopens* dbfile 0) 1)))
    (if (> curr-opens-count 1) ;; this should NOT be happening
	(dbfile:print-err "INFO: db "dbfile" has been opened "curr-opens-count" times!"))
    (hash-table-set! *dbopens* dbfile curr-opens-count)
    curr-opens-count))

;; Open the classic megatest.db file (defaults to open in toppath)
;;
;;   NOTE: returns a dbdat not a dbstruct!
;;
(define (dbfile:open-sqlite3-db dbpath init-proc)
  (let* ((dbexists     (file-exists? dbpath))
	 (write-access (file-write-access? dbpath))
	 (db           (dbfile:cautious-open-database dbpath init-proc))) #;(sqlite3:open-database dbpath)
    (dbfile:inc-db-open dbpath)
    (sqlite3:set-busy-handler! db (sqlite3:make-busy-timeout 10000))
    (sqlite3:execute db (conc "PRAGMA synchronous = 0;"))
    ;; (init-proc db)
    (make-dbr:dbdat dbfile: dbpath dbh: db read-only: (not write-access))))

(define (dbfile:print-and-exit . params)
  (with-output-to-port
      (current-error-port)
    (lambda ()
      (apply print params)))
  (exit 1))
    
(define (dbfile:print-err . params)
  (with-output-to-port
      (current-error-port)
    (lambda ()
      (apply print params))))
    
;; open an sql database inside a file lock
;; returns: db existed-prior-to-opening
;; RA => Returns a db handler; sets the lock if opened in writable mode
;;
;; (define *db-open-mutex* (make-mutex))
;;
#;(define (dbfile:lock-create-open fname initproc)
  (let* ((parent-dir   (or (pathname-directory fname)(current-directory))) ;; no parent? go local
         (raw-fname    (pathname-file fname))
	 (dir-writable (file-write-access? parent-dir))
	 (file-exists  (file-exists? fname))
	 (file-write   (if file-exists
			   (file-write-access? fname)
			   dir-writable )))
    ;; (mutex-lock! *db-open-mutex*) ;; tried this mutex, not clear it helped.
    (if file-write ;; dir-writable
	(condition-case
         (let* ((lockfname   (conc fname ".lock"))
                (readyfname  (conc parent-dir "/.ready-" raw-fname))
                (readyexists (common:file-exists? readyfname)))
           (if (not readyexists)
               (common:simple-file-lock-and-wait lockfname))
           (let ((db      (sqlite3:open-database fname)))
             (sqlite3:set-busy-handler! db (sqlite3:make-busy-timeout 136000))
             (sqlite3:execute db "PRAGMA synchronous = 0;")
             (if (not file-exists)
                 (initproc db))
             (if (not readyexists)
                 (begin
                   (common:simple-file-release-lock lockfname)
                   (with-output-to-file
                       readyfname
                     (lambda ()
                       (print "Ready at " 
                              (seconds->year-work-week/day-time 
                               (current-seconds)))))))
             db))
         (exn (io-error)  (dbfile:print-and-exit "ERROR: i/o error with " fname ". Check permissions, disk space etc. and try again."))
         (exn (corrupt)   (dbfile:print-and-exit "ERROR: database " fname " is corrupt. Repair it to proceed."))
         (exn (busy)      (dbfile:print-and-exit "ERROR: database " fname " is locked. Try copying to another location, remove original and copy back."))
         (exn (permission)(dbfile:print-and-exit "ERROR: database " fname " has some permissions problem."))
         (exn () (dbfile:print-and-exit "ERROR: Unknown error with database " fname " message: " ((condition-property-accessor 'exn 'message) exn))))
        
	(condition-case
         (begin
           (dbfile:print-err "WARNING: opening db in non-writable dir " fname)
           (let ((db (sqlite3:open-database fname)))
             (sqlite3:set-busy-handler! db (sqlite3:make-busy-timeout 136000))
             (sqlite3:execute db "PRAGMA synchronous = 0;")
	     ;; (mutex-unlock! *db-open-mutex*)
             db))
         (exn (io-error)
	      (dbfile:print-and-exit
	       "ERROR: i/o error with " fname ". Check permissions, disk space etc. and try again."))
         (exn (corrupt)
	      (dbfile:print-and-exit
	       "ERROR: database " fname " is corrupt. Repair it to proceed."))
         (exn (busy)
	      (dbfile:print-and-exit
	       "ERROR: database " fname " is locked. Try copying to another location, remove original and copy back."))
         (exn (permission)
	      (dbfile:print-and-exit
	       "ERROR: database " fname " has some permissions problem."))
         (exn ()
	      (dbfile:print-and-exit
	       "ERROR: Unknown error with database " fname " message: " ((condition-property-accessor 'exn 'message) exn))))
	)))


;; This routine creates the db if not already present. It is only called if the db is not already opened
;;
#;(define (db:init-dbstruct dbstruct run-id init-proc #!key (do-sync #t))
  (let* ((subdb          (dbfile:get-subdb dbstruct run-id))
	 (tmpdb-stack    (dbr:subdb-dbstack subdb)) 
	 (max-stale-tmp  (dbr:dbstruct-max-stale-secs dbstruct));; (configf:lookup-number *configdat* "server" "filling-db-max-stale-seconds" default: 10))
	   (dbpath       (dbr:dbstruct-tmppath dbstruct)) ;;  (db:dbfile-path))      ;; path to tmp db area
	   (dbname       (dbfile:run-id->dbname run-id))
	   (dbexists     (file-exists? dbpath))
	   (areapath     (dbr:dbstruct-areapath dbstruct))
	   (mtdbfname    (conc areapath "/"dbname))
	   (mtdbexists   (file-exists? mtdbfname))
	   (mtdbmodtime  (if mtdbexists (dbfile:lazy-sqlite-db-modification-time mtdbfname)  #f))
	   (mtdb         (db:open-sqlite-db mtdbfname init-proc))
	   ;; the reference db for syncing
	   (refdbfname   (conc dbpath "/"dbname"_ref"))
	   (refndb       (db:open-megatest-db refdbfname))
	   ;; (mtdbpath     (dbr:dbdat-dbfile mtdb))
	   ;; the tmpdb
	   (tmpdbfname   (conc dbpath"/"dbname)) ;; /tmp/<stuff>/.db/[main|1,2...].db 
	   (tmpdb        (db:open-megatest-db tmpdbfname)) ;; lock-create-open dbpath db:initialize-main-db))
	   (dbfexists    (common:file-exists? tmpdbfname))  ;; (conc dbpath "/megatest.db")))
	   (tmpdbmodtime (if dbfexists  (common:lazy-sqlite-db-modification-time tmpdbfname) #f))
	   
	   (write-access (file-write-access? mtdbfname))
	   
	   ;; (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))))

    (when write-access
      (sqlite3:execute (dbr:dbdat-dbh mtdb) "drop trigger if exists update_tests_trigger")
      (sqlite3:execute (dbr:dbdat-dbh 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:subdb-read-only-set! subdb #t)))
    (dbr:subdb-mtdb-set!   subdb mtdb)
    (dbr:subdb-tmpdb-set!  subdb tmpdb)
    (dbr:subdb-dbstack-set! subdb (make-stack)) ;; BB: why a stack?  Why would the number of db's be indeterminate?  Is this a legacy of 1.db 2.db .. ?
    (stack-push! (dbr:subdb-dbstack subdb) tmpdb) ;; olddb is already a (cons db path)
    (dbr:subdb-refndb-set! subdb refndb)
    (if (and  (or (not dbfexists)
		  (and modtimedelta
		       (> modtimedelta max-stale-tmp))) ;; if db in tmp is over ten seconds older than the file in MTRA then do a sync back
	      do-sync)
	(begin
	  (dbfile:print-err "filling db " (dbr:dbdat-dbfile tmpdb) " with data \n    from " (dbr:dbdat-dbfile mtdb) " mod time delta: " modtimedelta)
	  (db:sync-tables (db:sync-all-tables-list subdb) #f mtdb refndb tmpdb)
	  ;; touch tmp db to avoid wal mode wierdness  
	  (set! (file-modification-time tmpdbfname) (current-seconds))  
	  (dbfile:print-err "INFO: db:sync-all-tables-list done.")
	  )
	(dbfile:print-err " db, " (dbr:dbdat-dbfile tmpdb) " already exists or fresh enough, not propogating data from\n     " (dbr:dbdat-dbfile mtdb) " mod time delta: " modtimedelta) )
    ;; (db:multi-db-sync subdb 'old2new))  ;; migrate data from megatest.db automatically
    tmpdb))
		
;;======================================================================
;; no-sync.db - small bits of data to be shared between servers
;;======================================================================

;; if we are not a server create a db handle. this is not finalized
;; so watch for problems. I'm still not clear if it is needed to manually
;; finalize sqlite3 dbs with the sqlite3 egg.
;;

(define (dbfile:cautious-open-database fname init-proc #!optional (tries-left 50))
  (let* ((busy-file  (conc fname"-journal"))
	 (delay-time (* (- 51 tries-left) 1.1))
	 (retry      (lambda ()
		       (thread-sleep! delay-time)
		       (if (> tries-left 0)
			   (dbfile:cautious-open-database fname init-proc (- tries-left 1))))))
    (assert (>= tries-left 0) (conc "FATAL: too many attempts in dbfile:cautious-open-database of "fname", giving up."))
    (if (and (file-write-access? fname)
	     (file-exists? busy-file))
	(begin
	  (dbfile:print-err "INFO: dbfile:cautious-open-database: journal file " busy-file " exists, trying again in few seconds.")
	  (thread-sleep! 1)
	  (if (eq? tries-left 2)
	      (begin
		(dbfile:print-err "INFO: forcing journal rollup "busy-file)
		(dbfile:brute-force-salvage-db fname)))
	  (dbfile:cautious-open-database fname init-proc (- tries-left 1)))
	(let* ((result (condition-case
			   (dbfile:with-simple-file-lock
			    (conc fname ".lock")
			    (lambda ()
			      (let* ((db-exists (file-exists? fname))
				     (db        (sqlite3:open-database fname)))
				(if (and init-proc (not db-exists))
				    (init-proc db))
				db)))
			 (exn (io-error)
			      (dbfile:print-err exn "ERROR: i/o error with " fname ". Check permissions, disk space etc. and try again.")
			      (retry))
			 (exn (corrupt)
			      (dbfile:print-err exn "ERROR: database " fname " is corrupt. Repair it to proceed.")
			      (retry))
			 (exn (busy)
			      (dbfile:print-err exn "ERROR: database " fname
						" is locked. Try copying to another location, remove original and copy back.")
			      (retry))
			 (exn (permission)(dbfile:print-err exn "ERROR: database " fname " has some permissions problem.")
			      (retry))
			 (exn ()
			      (dbfile:print-err exn "ERROR: Unknown error with database " fname " message: "
						((condition-property-accessor 'exn 'message) exn))
			      (retry)))))
          #;(if (file-write-access? fname)
	  (dbfile:simple-file-release-lock lock-file))
	  result))))

(define (dbfile:brute-force-salvage-db fname)
  (let* ((backupfname (conc fname"-"(current-process-id)".bak"))
	 (cmd (conc "cp "fname" "backupfname";mv "fname" "(conc fname ".delme;")
		    "cp "backupfname" "fname)))
    (dbfile:print-err "WARNING: attempting recovery of file "fname" by running commands:\n"
		      "  "cmd)
    (system cmd)))

#;(define (dbfile:cautious-open-database-orig fname init-proc #!optional (tries-left 50))
  (let* ((lock-file  (conc fname".lock"))
	 (delay-time (* (- 51 tries-left) 1.1))
	 (retry      (lambda ()
		       (thread-sleep! delay-time)
		       (if (> tries-left 0)
			   (dbfile:cautious-open-database fname init-proc (- tries-left 1))))))
    (assert (>= tries-left 0) (conc "FATAL: too many attempts in dbfile:cautious-open-database of "fname", giving up."))
    (if (and (file-write-access? fname) (not (dbfile:simple-file-lock lock-file expire-time: 3)))
	(begin
	  (dbfile:print-err "INFO: dbfile:cautious-open-database: lock file " lock-file " exists, trying again in few seconds.")
	  (thread-sleep! 1)
	  (if (eq? tries-left 2)
	      (begin
		(dbfile:print-err "INFO: stealing the lock "lock-file)
		(delete-file* lock-file)))
	  (dbfile:cautious-open-database fname init-proc (- tries-left 1)))
	(let* ((db-exists (file-exists? fname))
	       (result (condition-case
			   (let* ((db (sqlite3:open-database fname)))
			     (if (and init-proc (not db-exists))
				 (init-proc db))
			     db)
			(exn (io-error)
			     (dbfile:print-err exn "ERROR: i/o error with " fname ". Check permissions, disk space etc. and try again.")
			     (retry))
			(exn (corrupt)
			     (dbfile:print-err exn "ERROR: database " fname " is corrupt. Repair it to proceed.")
			     (retry))
			(exn (busy)
			     (dbfile:print-err exn "ERROR: database " fname
					       " is locked. Try copying to another location, remove original and copy back.")
			     (retry))
			(exn (permission)(dbfile:print-err exn "ERROR: database " fname " has some permissions problem.")
			     (retry))
			(exn ()
			     (dbfile:print-err exn "ERROR: Unknown error with database " fname " message: "
					       ((condition-property-accessor 'exn 'message) exn))
			     (retry)))))
          (if (file-write-access? fname)
	    (dbfile:simple-file-release-lock lock-file)
          )
	  result))))


(define (dbfile:open-no-sync-db dbpath)
  (if *no-sync-db*
      *no-sync-db*
      (begin
	(if (not (file-exists? dbpath))
	    (create-directory dbpath #t))
	(let* ((dbname    (conc dbpath "/no-sync.db"))
	       (db-exists (file-exists? dbname))
	       (init-proc (lambda (db)
			    (if (not db-exists)
				(begin
				  (sqlite3:execute db "PRAGMA synchronous = 0;")
				  (sqlite3:execute db "CREATE TABLE IF NOT EXISTS no_sync_metadat (var TEXT,val TEXT, CONSTRAINT no_sync_metadat_constraint UNIQUE (var));"))
				)))
	       (db        (dbfile:cautious-open-database dbname init-proc))) ;; (sqlite3:open-database dbname)))
	  (sqlite3:set-busy-handler! db (sqlite3:make-busy-timeout 136000))
	  ;;(sqlite3:execute db "PRAGMA journal_mode=WAL;")
	  (set! *no-sync-db* db)
	  db))))

(define (db:no-sync-set db var val)
  (sqlite3:execute db "INSERT OR REPLACE INTO no_sync_metadat (var,val) VALUES (?,?);" var val))

(define (db:no-sync-del! db var)
  (sqlite3:execute db "DELETE FROM no_sync_metadat WHERE var=?;" var))

(define (db:no-sync-get/default db var default)
  (let ((res default))
    (sqlite3:for-each-row
     (lambda (val)
       (set! res val))
     db
     "SELECT val FROM no_sync_metadat WHERE var=?;"
     var)
    (if res
        (let ((newres (if (string? res)
			  (string->number res)
			  #f)))
          (if newres
              newres
              res))
        res)))

;; transaction protected lock aquisition
;; either:
;;    fails    returns  (#f . lock-creation-time)
;;    succeeds (returns (#t . lock-creation-time)
;; use (db:no-sync-del! db keyname) to release the lock
;;
(define (db:no-sync-get-lock db keyname)
  (sqlite3:with-transaction
   db
   (lambda ()
     (condition-case
	 (let* ((curr-val (db:no-sync-get/default db keyname #f)))
	   (if curr-val
	       `(#f . ,curr-val)   ;; (sqlite3:first-result db "SELECT val FROM no_sync_metadat WHERE var=?;" keyname))
	       (let ((lock-time (current-seconds)))
		 (sqlite3:execute db "INSERT OR REPLACE INTO no_sync_metadat (var,val) VALUES(?,?);" keyname lock-time)
		 `(#t . ,lock-time))))
       (exn (io-error)  (dbfile:print-err "ERROR: i/o error with no-sync db. Check permissions, disk space etc. and try again."))
       (exn (corrupt)   (dbfile:print-err "ERROR: database no-sync db is corrupt. Repair it to proceed."))
       (exn (busy)      (dbfile:print-err "ERROR: database no-sync db is locked. Try copying to another location, remove original and copy back."))
       (exn (permission)(dbfile:print-err "ERROR: database no-sync db has some permissions problem."))
       (exn () ;; (status done) ;; I don't know how to detect status done but no data!
	    (dbfile:print-err "ERROR: Unknown error with database no-sync db message: exn="(condition->list exn)", \n"
			      ((condition-property-accessor 'exn 'message) exn))
	    `(#f . ,(current-seconds)))))))

(define (db:no-sync-get-lock-timeout db keyname timeout)
  (let* ((lockdat (db:no-sync-get-lock db keyname)))
    (match lockdat
      ((#f . lock-time)
       (if (> (- (current-seconds) (if (string? lock-time)(string->number lock-time)lock-time)) timeout)
	   (let ((lock-time (current-seconds)))
	     ;; (debug:print-info 2 *default-log-port* "db:no-sync-get-lock keyname=" keyname ", lock-time=" lock-time ", exn=" exn)
	     (sqlite3:execute db "INSERT OR REPLACE INTO no_sync_metadat (var,val) VALUES(?,?);" keyname lock-time)
	     `(#t . ,lock-time))
	   lockdat))
      (else lockdat))))

;; NOTE: This will steal the lock after timeout of waiting.
;;
(define (db:with-no-sync-lock db keyname timeout proc)
  (let* ((lockdat  (db:no-sync-get-lock-timeout db keyname))
	 (gotlock  (car lockdat))
	 (locktime (cdr lockdat)))
    (if gotlock
	(let ((res (proc)))
	  (db:no-sync-del! db keyname)
	  res))))
  
;;======================================================================
;; sync back functions pulled from db.scm
;;======================================================================

;; Get a lock from the no-sync-db for the from-db, then delta sync the from-db to the to-db, otherwise return #f
;;
(define (db:lock-and-delta-sync no-sync-db dbstruct from-db-file runid keys dbinit)
  (assert (not *db-sync-in-progress*) "FATAL: db:lock-and-sync called while a sync is in progress.")
  ;; (dbfile:print-err *default-log-port* "db:lock-and-delta-sync")
  (let* ((lock-file (conc from-db-file ".lock")))
    (if (common:simple-file-lock lock-file)
	(begin
	  (dbfile:print-err "INFO: db:lock-and-delta-sync copying db "runid" at "(current-seconds))
	  (set! *db-sync-in-progress* #t)
	  (db:sync-touched dbstruct runid keys dbinit)
	  (set! *db-sync-in-progress* #f)
	  (delete-file* lock-file)
	  #t)
        (begin
          (dbfile:print-err "INFO: could not get lock for " from-db-file ", sync likely in progress.")
	  #f
	  ))))

;; ;; Get a lock from the no-sync-db for the from-db, then delta sync the from-db to the to-db, otherwise return #f
;; ;;
;; (define (db:lock-and-delta-sync-orig no-sync-db dbstruct from-db-file runid keys dbinit)
;;   (assert (not *db-sync-in-progress*) "FATAL: db:lock-and-sync called while a sync is in progress.")
;;   ;; (dbfile:print-err *default-log-port* "db:lock-and-delta-sync")
;;   (let* ((lockdat  (db:no-sync-get-lock-timeout no-sync-db from-db-file 60))
;; 	 (gotlock  (car lockdat))
;; 	 (locktime (cdr lockdat)))
;;     ;; (debug:print-info 3 *default-log-port* "db:lock-and-delta-sync: got lock?")
;;     
;;     (if gotlock
;; 	(begin
;;           (dbfile:print-err "INFO: db:lock-and-delta-sync copying db "runid" at "(current-seconds))
;; 	  (set! *db-sync-in-progress* #t)
;;           (db:sync-touched dbstruct runid keys dbinit)
;; 	  (set! *db-sync-in-progress* #f)
;; 	  (db:no-sync-del! no-sync-db from-db-file)
;; 	  #t)
;;         (begin
;;           (dbfile:print-err "ERROR: could not get lock for " from-db-file " from no-sync-db")
;; 	  #f
;;         ))))

;; sync run from tmp disk to nfs disk if touched
;;
;; call with dbinit=db:initialize-main-db
;;
(define (db:sync-touched dbstruct run-id keys #!key dbinit (force-sync #f))
  (dbfile:print-err "db:sync-touched Syncing: " (conc (if run-id run-id "main") ".db"))
  (let* (;; the subdb is needed to access the mtdbdat
	 (subdb     (or (dbfile:get-subdb dbstruct run-id)
			(dbfile:init-subdb dbstruct run-id dbinit)))
         (tmpdbfile (dbr:subdb-tmpdbfile subdb))
	 (mtdb      (dbr:subdb-mtdbdat subdb))
         (tmpdb     (dbfile:open-db dbstruct run-id dbinit)) ;; sqlite3-db tmpdbfile #f))
	 (start-t   (current-seconds)))
    (mutex-lock! *db-multi-sync-mutex*)
    (let ((update_info (cons "last_update" (if force-sync 0 *db-last-sync*) )))
      (mutex-unlock! *db-multi-sync-mutex*)
      (db:sync-tables (db:sync-all-tables-list dbstruct keys) update_info tmpdb mtdb))
    (mutex-lock! *db-multi-sync-mutex*)
    (set! *db-last-sync* start-t)
    (set! *db-last-access* start-t)
    (mutex-unlock! *db-multi-sync-mutex*)
    (dbfile:add-dbdat dbstruct run-id tmpdb)
  #t))

;; just tests, test_steps and test_data tables
(define db:sync-tests-only
  (list
   ;; (list "strs"
   ;;       '("id"             #f)
   ;;       '("str"            #f))
   (list "tests" 
	 '("id"             #f)
	 '("run_id"         #f)
	 '("testname"       #f)
	 '("host"           #f)
	 '("cpuload"        #f)
	 '("diskfree"       #f)
	 '("uname"          #f)
	 '("rundir"         #f)
	 '("shortdir"       #f)
	 '("item_path"      #f)
	 '("state"          #f)
	 '("status"         #f)
	 '("attemptnum"     #f)
	 '("final_logf"     #f)
	 '("logdat"         #f)
	 '("run_duration"   #f)
	 '("comment"        #f)
	 '("event_time"     #f)
	 '("fail_count"     #f)
	 '("pass_count"     #f)
	 '("archived"       #f)
         '("last_update"    #f))
  (list "test_steps"
	 '("id"             #f)
	 '("test_id"        #f)
	 '("stepname"       #f)
	 '("state"          #f)
	 '("status"         #f)
	 '("event_time"     #f)
	 '("comment"        #f)
	 '("logfile"        #f)
         '("last_update"    #f))
   (list "test_data"
	 '("id"             #f)
	 '("test_id"        #f)
	 '("category"       #f)
	 '("variable"       #f)
	 '("value"          #f)
	 '("expected"       #f)
	 '("tol"            #f)
	 '("units"          #f)
	 '("comment"        #f)
	 '("status"         #f)
	 '("type"           #f)
         '("last_update"    #f))))

;; needs db to get keys, this is for syncing all tables
;;
(define (db:sync-main-list dbstruct keys)
  (let ((keys  keys)) ;; (db:get-keys dbstruct)))
    (list
     (list "keys"
	   '("id"        #f)
	   '("fieldname" #f)
	   '("fieldtype" #f))
     (list "metadat" '("var" #f) '("val" #f))
     (append (list "runs" 
		   '("id"  #f))
	     (map (lambda (k)(list k #f))
		  (append keys
			  (list "runname" "state" "status" "owner" "event_time" "comment" "fail_count" "pass_count" "contour" "last_update"))))
     (list "archive_disks"
           '("id" #f)
           '("archive_area_name" #f) 
           '("disk_path" #f)
           '("last_df" #f)
           '("last_df_time" #f)
           '("creation_time" #f)) 

     (list "archive_blocks"
           '("id" #f)
           '("archive_disk_id" #f) 
           '("disk_path" #f)
           '("last_du" #f)
           '("last_du_time" #f)
           '("creation_time" #f)) 

     (list "test_meta"
	   '("id"             #f)
	   '("testname"       #f)
	   '("owner"          #f)
	   '("description"    #f)
	   '("reviewed"       #f)
	   '("iterated"       #f)
	   '("avg_runtime"    #f)
	   '("avg_disk"       #f)
	   '("tags"           #f)
	   '("jobgroup"       #f)))))

(define (db:sync-all-tables-list dbstruct keys)
  (append (db:sync-main-list dbstruct keys)
	  db:sync-tests-only))

;; tbls is ( ("tablename" ( "field1" [#f|proc1] ) ( "field2" [#f|proc2] ) .... ) )
;; db's are dbdat's
;;
;; if last-update specified ("field-name" . time-in-seconds)
;;    then sync only records where field-name >= time-in-seconds
;;    IFF field-name exists
;;
(define (db:sync-tables tbls last-update fromdb todb . slave-dbs)
  (handle-exceptions
   exn
   (begin
     (dbfile:print-err  "EXCEPTION: database probably overloaded or unreadable in db:sync-tables.")
     (print-call-chain (current-error-port))
     (dbfile:print-err  " message: " ((condition-property-accessor 'exn 'message) exn))
     (dbfile:print-err  "exn=" (condition->list exn))
     (dbfile:print-err  " status:  " ((condition-property-accessor 'sqlite3 'status) exn))
     (dbfile:print-err  " src db:  " (dbr:dbdat-dbfile fromdb))
     (for-each (lambda (dbdat)
		 (let ((dbpath (dbr:dbdat-dbfile dbdat)))
		   (dbfile:print-err  " dbpath:  " dbpath)
		   (if #t ;; (not (db:repair-db dbdat))
		       (begin
			 (dbfile:print-err "Failed to rebuild (repair is turned off) " dbpath ", exiting now.")
			 (exit)))))
	       (cons todb slave-dbs))
     
     0)

   ;; this is the work to be done")
   (cond
    ((not fromdb) (dbfile:print-err  "WARNING: db:sync-tables called with fromdb missing")
     -1)
    ((not todb)   (dbfile:print-err  "WARNING: db:sync-tables called with todb missing")
     -2)
    ((not (sqlite3:database? (dbr:dbdat-dbh fromdb)))
     (dbfile:print-err "db:sync-tables called with fromdb not a database " fromdb)
   -3)
    ((not (sqlite3:database? (dbr:dbdat-dbh todb)))
     (dbfile:print-err "db:sync-tables called with todb not a database " todb)
   -4)

    ((not (file-write-access? (dbr:dbdat-dbfile todb)))
     (dbfile:print-err "db:sync-tables called with todb not a read-only database " todb)
     -5)
    ((not (null? (let ((readonly-slave-dbs
                        (filter
                         (lambda (dbdat)
                           (not (file-write-access? (dbr:dbdat-dbfile todb))))
                         slave-dbs)))
                   (for-each
                    (lambda (bad-dbdat)
                      (dbfile:print-err "db:sync-tables called with todb not a read-only database " bad-dbdat))
                    readonly-slave-dbs)
                   readonly-slave-dbs))) -6)
    (else
     ;; (dbfile:print-err "db:sync-tables: args are good")

     (let ((stmts       (make-hash-table)) ;; table-field => stmt
	   (all-stmts   '())              ;; ( ( stmt1 value1 ) ( stml2 value2 ))
	   (numrecs     (make-hash-table))
	   (start-time  (current-milliseconds))
	   (tot-count   0))
       (for-each ;; table
	(lambda (tabledat)
	  (let* ((tablename        (car tabledat))
		 (fields           (cdr tabledat))
		 (has-last-update  (member "last_update" fields))
		 (use-last-update  (cond
				    ((and has-last-update
					  (member "last_update" fields))
				     #t) ;; if given a number, just use it for all fields
				    ((number? last-update) #f) ;; if not matched first entry then ignore last-update for this table
				    ((and (pair? last-update)
					  (member (car last-update)    ;; last-update field name
						  (map car fields)))
                                        #t)
				    ((and last-update (not (pair? last-update)) (not (number? last-update)))
				     (dbfile:print-err  "ERROR: parameter last-update for db:sync-tables must be a pair or a number, received: " last-update);; found in fields
				     #f)
				    (else
				     #f)))
		 (last-update-value (if use-last-update ;; no need to check for has-last-update - it is already accounted for
					(if (number? last-update)
					    last-update
					    (cdr last-update))
					#f))
		 (last-update-field (if use-last-update
					(if (number? last-update)
					    "last_update"
					    (car last-update))
					#f))
		 (num-fields (length fields))
		 (field->num (make-hash-table))
		 (num->field (apply vector (map car fields))) ;; BBHERE
		 (full-sel   (conc "SELECT " (string-intersperse (map car fields) ",") 
				   " FROM " tablename (if use-last-update ;; apply last-update criteria
							  (conc " WHERE " last-update-field " >= " last-update-value)
							  "")
				   ";"))
		 (full-ins   (conc "INSERT OR REPLACE INTO " tablename " ( " (string-intersperse (map car fields) ",") " ) "
				   " VALUES ( " (string-intersperse (make-list num-fields "?") ",") " );"))
		 (fromdat    '())
		 (fromdats   '())
		 (totrecords 0)
		 (batch-len  100) ;; (string->number (or (configf:lookup *configdat* "sync" "batchsize") "100")))
		 (todat      (make-hash-table))
		 (count      0)
                 (field-names (map car fields))
                 (delay-handicap  0) ;; (string->number (or (configf:lookup *configdat* "sync" "delay-handicap") "0")))
                 )

	    ;; set up the field->num table
	    (for-each
	     (lambda (field)
	       (hash-table-set! field->num field count)
	       (set! count (+ count 1)))
	     fields)

	    ;; read the source table
            ;; store a list of all rows in the table in fromdat, up to batch-len.
            ;; Then add fromdat to the fromdats list, clear fromdat and repeat.
	    (sqlite3:for-each-row
	     (lambda (a . b)
	       (set! fromdat (cons (apply vector a b) fromdat))
	       (if (> (length fromdat) batch-len)
		   (begin
		     (set! fromdats (cons fromdat fromdats))
		     (set! fromdat  '())
		     (set! totrecords (+ totrecords 1)))
               )
             )
	     (dbr:dbdat-dbh fromdb)
	     full-sel)

             ;; Count less than batch-len as a record
             (if (> (length fromdat) 0)
                 (set! totrecords (+ totrecords 1)))

	    ;; tack on remaining records in fromdat
	    (if (not (null? fromdat))
		(set! fromdats (cons fromdat fromdats)))

	    (if (common:low-noise-print 120 "sync-records")
		(dbfile:print-err  "found " totrecords " records to sync"))

	    (sqlite3:for-each-row
	     (lambda (a . b)
	       (hash-table-set! todat a (apply vector a b)))
	     (dbr:dbdat-dbh todb)
	     full-sel)

            (when (and delay-handicap (> delay-handicap 0))
              (dbfile:print-err "imposing synthetic sync delay of "delay-handicap" seconds since sync/delay-handicap is configured")
              (thread-sleep! delay-handicap)
              (dbfile:print-err "synthetic sync delay of "delay-handicap" seconds completed")
              )
            
	    ;; first pass implementation, just insert all changed rows

	    (for-each 
	     (lambda (targdb)
	       (let* ((db                 (dbr:dbdat-dbh targdb))
                      (drp-trigger        (if (member "last_update" field-names)
					      (db:drop-trigger db tablename) 
					      #f))
		      (has-last-update    (member "last_update" field-names))
                      (is-trigger-dropped (if has-last-update
                                              (db:is-trigger-dropped db tablename)
					      #f)) 
		      (stmth  (sqlite3:prepare db full-ins))
                      (changed-rows 0))
		 ;; (db:delay-if-busy targdb) ;; NO WAITING
                 (if (and
		      has-last-update
		      (common:low-noise-print 120 "is-trigger-dropped"))
                     (dbfile:print-err "is-trigger-dropped: " is-trigger-dropped))
		 (for-each
		  (lambda (fromdat-lst)
		    (sqlite3:with-transaction
		     db
		     (lambda ()
		       (for-each ;; 
			(lambda (fromrow)
			  (let* ((a    (vector-ref fromrow 0))
				 (curr (hash-table-ref/default todat a #f))
				 (same #t))
			    (let loop ((i 0))
			      (if (or (not curr)
				      (not (equal? (vector-ref fromrow i)(vector-ref curr i))))
				  (set! same #f))
			      (if (and same
				       (< i (- num-fields 1)))
				  (loop (+ i 1))))
			    (if (not same)
				(begin
				  (apply sqlite3:execute stmth (vector->list fromrow))
				  (hash-table-set! numrecs tablename (+ 1 (hash-table-ref/default numrecs tablename 0)))
                                  (set! changed-rows (+ changed-rows 1))
                                )
                            )
                            ))
			fromdat-lst))))
		  fromdats)


                 (if (> changed-rows 0)
	           (dbfile:print-err  "table " tablename " changed rows: " changed-rows)
                 )


		 (sqlite3:finalize! stmth)
                 (if (member "last_update" field-names)
                    (db:create-trigger db tablename))))
	     (append (list todb) slave-dbs)
           )
          )
        )
	tbls)
       (let* ((runtime      (- (current-milliseconds) start-time))
	      (should-print (or ;; (debug:debug-mode 12)
				(common:low-noise-print 120 "db sync" (> runtime 500))))) ;; low and high sync times treated as separate.
	 (if should-print (dbfile:print-err  "INFO: db sync, total run time " runtime " ms"))
	 (for-each 
	  (lambda (dat)
	    (let ((tblname (car dat))
		  (count   (cdr dat)))
	      (set! tot-count (+ tot-count count))
	      (if (> count 0)
		  (if should-print (dbfile:print-err "FIXME: tblname: " tblname", count: "count" "))))) ;; (format #f "    ~10a ~5a" tblname count))))))
	  (sort (hash-table->alist numrecs)(lambda (a b)(> (cdr a)(cdr b))))))
       tot-count)))))

;;======================================================================
;; trigger setup/takedown
;;======================================================================

(define db:trigger-list 
     (list (list "update_runs_trigger"  "CREATE TRIGGER IF NOT EXISTS update_runs_trigger AFTER UPDATE ON runs
                             FOR EACH ROW
                               BEGIN 
                                 UPDATE runs SET last_update=(strftime('%s','now'))
                                   WHERE id=old.id;
                               END;" ) 
	   (list "update_run_stats_trigger"  "CREATE TRIGGER  IF NOT EXISTS update_run_stats_trigger AFTER UPDATE ON run_stats
                             FOR EACH ROW
                               BEGIN 
                                 UPDATE run_stats SET last_update=(strftime('%s','now'))
                                   WHERE id=old.id;
                               END;" )
	   (list "update_tests_trigger"  "CREATE TRIGGER  IF NOT EXISTS update_tests_trigger AFTER UPDATE ON tests
                             FOR EACH ROW
                               BEGIN 
                                 UPDATE tests SET last_update=(strftime('%s','now'))
                                   WHERE id=old.id;
                               END;" )
	   (list "update_teststeps_trigger"  "CREATE TRIGGER  IF NOT EXISTS update_teststeps_trigger AFTER UPDATE ON test_steps
                             FOR EACH ROW
                               BEGIN 
                                 UPDATE test_steps SET last_update=(strftime('%s','now'))
                                   WHERE id=old.id;
                               END;" )
	   (list "update_test_data_trigger"  "CREATE TRIGGER  IF NOT EXISTS update_test_data_trigger AFTER UPDATE ON test_data
                             FOR EACH ROW
                               BEGIN 
                                 UPDATE test_data SET last_update=(strftime('%s','now'))
                                   WHERE id=old.id;
                               END;" )))
;;
;; ADD run-id SUPPORT
;;
(define (db:create-all-triggers dbstruct)
  (db:with-db
   dbstruct #f #f
   (lambda (dbdat db)
     (db:create-triggers db))))

(define (db:create-triggers db)
    (for-each (lambda (key)
              (sqlite3:execute db (cadr key)))
          db:trigger-list))

(define (db:drop-all-triggers dbstruct)
  (db:with-db
   dbstruct #f #f
   (lambda (dbdat db)
     (db:drop-triggers db))))

(define (db:is-trigger-dropped db tbl-name)
  (let* ((trigger-name (if (equal? tbl-name "test_steps")
			   "update_teststeps_trigger" 
                           (conc "update_" tbl-name "_trigger")))
	 (res          #f))
    (sqlite3:for-each-row
     (lambda (name)
       (if (equal? name trigger-name)
	   (set! res #t)))
     db 
     "SELECT name FROM sqlite_master WHERE type = 'trigger' ;")
    res))

(define (db:drop-triggers db)
  (for-each
   (lambda (key) 
     (sqlite3:execute db (conc "drop trigger if exists " (car key))))
   db:trigger-list))

(define  (db:drop-trigger db tbl-name)
  (let* ((trigger-name (if (equal? tbl-name "test_steps")
			   "update_teststeps_trigger" 
                           (conc "update_" tbl-name "_trigger"))))
    (for-each
     (lambda (key) 
       (if (equal? (car key) trigger-name)
           (sqlite3:execute db (conc "drop trigger if exists " trigger-name))))
     db:trigger-list)))

(define  (db:create-trigger db tbl-name)
      (let* ((trigger-name (if (equal? tbl-name "test_steps")
                              "update_teststeps_trigger" 
                              (conc "update_" tbl-name "_trigger"))))
       (for-each (lambda (key) 
             (if (equal? (car key) trigger-name)
             (sqlite3:execute db (cadr key))))
      db:trigger-list))) 

;;======================================================================
;; db access stuff
;;======================================================================

;; call with dbinit=db:initialize-main-db
;;
(define (db:open-db dbstruct run-id dbinit)
  (let* ((dbdat (dbfile:open-db dbstruct run-id dbinit)))
    (set! *db-write-access* (not (dbr:dbdat-read-only dbdat)))
    dbdat))

(define dbfile:db-init-proc (make-parameter #f))

;; (db:with-db dbstruct run-id sqlite3:exec "select blah fgrom blaz;")
;; r/w is a flag to indicate if the db is modified by this query #t = yes, #f = no
;;
(define (db:with-db dbstruct run-id r/w proc . params)
  (let* ((have-struct (dbr:dbstruct? dbstruct))
         (dbdat     (if have-struct                ;; this stuff just allows us to call with a db handle directly
			(db:open-db dbstruct run-id (dbfile:db-init-proc)) ;; (dbfile:get-subdb dbstruct run-id)
			#f))
	 (db        (if have-struct                ;; this stuff just allows us to call with a db handle directly
			(dbr:dbdat-dbh dbdat)
			dbstruct))
	 (fname     (if dbdat
			(dbr:dbdat-dbfile dbdat)
			"nofilenameavailable"))
	 #;(subdb     (if have-struct
			(dbfile:get-subdb dbstruct run-id)
			#f))
	 (use-mutex (> *api-process-request-count* 25))) ;; was 25
    (if (and use-mutex
	     (common:low-noise-print 120 "over-50-parallel-api-requests"))
	(dbfile:print-err *api-process-request-count* " parallel api requests being processed in process " (current-process-id) ", throttling access"))
    (if (common:low-noise-print 600 (conc "parallel-api-requests" *max-api-process-requests*))
	(dbfile:print-err "Parallel api request count: " *api-process-request-count* " max parallel requests: " *max-api-process-requests*))
    (condition-case
	(begin
	  (if use-mutex (mutex-lock! *db-with-db-mutex*))
	  (let ((res (apply proc dbdat db params)))
	    (if use-mutex (mutex-unlock! *db-with-db-mutex*))
	    ;; (if (vector? dbstruct)(db:done-with dbstruct run-id r/w))
	    (if dbdat
		(dbfile:add-dbdat dbstruct run-id dbdat))
	    res))
      (exn (io-error)
	   (db:generic-error-printout exn "ERROR: i/o error with " fname ". Check permissions, disk space etc. and try again."))
      (exn (corrupt)
	   (db:generic-error-printout exn "ERROR: database " fname " is corrupt. Repair it to proceed."))
      (exn (busy)
	   (db:generic-error-printout exn "ERROR: database " fname
				      " is locked. Try copying to another location, remove original and copy back."))
      (exn (permission)(db:generic-error-printout exn "ERROR: database " fname " has some permissions problem."))
      (exn ()
	   (db:generic-error-printout exn "ERROR: Unknown error with database " fname " message: "
				      ((condition-property-accessor 'exn 'message) exn))))))
      

;;======================================================================
;; file utils
;;======================================================================

;;======================================================================
;; lazy-safe get file mod time. on any error (file not existing etc.) return 0
;;
(define (dbfile:lazy-modification-time fpath)
  (handle-exceptions
      exn
    (begin
      (dbfile:print-err "Failed to get modification time for " fpath ", treating it as zero. exn=" exn)
      0)
    (if (file-exists? fpath)
	(file-modification-time fpath)
	0)))

;;======================================================================
;; find timestamp of newest file associated with a sqlite db file
(define (dbfile:lazy-sqlite-db-modification-time fpath)
  (let* ((glob-list (handle-exceptions
			exn
		      (begin
			(dbfile:print-err "Failed to glob " fpath "*, exn=" exn)
			`(,(conc "/no/such/file, message: " ((condition-property-accessor 'exn 'message) exn))))
		      (glob (conc fpath "*"))))
         (file-list (if (eq? 0 (length glob-list))
			'("/no/such/file")
			glob-list)))
  (apply max
	 (map
	  dbfile:lazy-modification-time 
	  file-list))))

;; dot-locking egg seems not to work, using this for now
;; if lock is older than expire-time then remove it and try again
;; to get the lock
;;
(define (dbfile:simple-file-lock fname #!key (expire-time 300))
  (let ((fmod-time (handle-exceptions
		       ext
		     (current-seconds)
		     (file-modification-time fname))))
    (if (file-exists? fname)
	(if (> (- (current-seconds) fmod-time) expire-time)
	    (begin
	      (handle-exceptions exn #f (delete-file* fname))	
	      (dbfile:simple-file-lock fname expire-time: expire-time))
	    #f)
	(let ((key-string (conc (get-host-name) "-" (current-process-id)))
	      (oup        (open-output-file fname)))
	  (with-output-to-port
	      oup
	    (lambda ()
	      (print key-string)))
	  (close-output-port oup)
	  #;(with-output-to-file fname ;; bizarre. with-output-to-file does not seem to be cleaning up after itself.
	    (lambda ()
	  (print key-string)))
	  (thread-sleep! 0.25)
	  (if (file-exists? fname)
	      (handle-exceptions exn
                #f 
                (with-input-from-file fname
	  	  (lambda ()
		    (equal? key-string (read-line)))))
	      #f)
       )
    )
  )
)

(define (dbfile:simple-file-lock-and-wait fname #!key (expire-time 300))
  (let ((end-time (+ expire-time (current-seconds))))
    (let loop ((got-lock (dbfile:simple-file-lock fname expire-time: expire-time)))
      (if got-lock
	  #t
	  (if (> end-time (current-seconds))
	      (begin
		(thread-sleep! 3)
		(loop (dbfile:simple-file-lock fname expire-time: expire-time)))
	      #f)))))

(define (dbfile:simple-file-release-lock fname)
  (handle-exceptions
      exn
      #f ;; I don't really care why this failed (at least for now)
    (delete-file* fname)))

(define (dbfile:with-simple-file-lock fname proc #!key (expire-time 300))
  (let ((gotlock (dbfile:simple-file-lock-and-wait fname expire-time: expire-time)))
    (if gotlock
	(let ((res (proc)))
	  (dbfile:simple-file-release-lock fname)
	  res)
	(assert #t "FATAL: simple file lock never got a lock."))))
  
)
