;;======================================================================
;; 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/>.

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

;;======================================================================
;; Megatestmod:
;;
;;   Put things here don't fit anywhere else
;;======================================================================

(declare (unit fsmod))

(declare (uses debugprint))
(declare (uses mtargs))
(declare (uses configfmod))
(declare (uses commonmod))
(declare (uses processmod))

(use srfi-69)

(module fsmod
	(
	 get-df
	 get-uname
	 common:get-disk-with-most-free-space
	 common:get-disk-space-used
	 common:check-db-dir-and-exit-if-insufficient

	 )

(import scheme)
(cond-expand
 (chicken-4
  
  (import chicken
	  ports
	  (prefix base64 base64:)

	  (prefix sqlite3 sqlite3:)
	  data-structures
	  extras
	  files
	  matchable
	  md5
	  message-digest
	  pathname-expand
	  posix
	  posix-extras
	  regex
	  regex-case
	  sparse-vectors
	  srfi-1
	  srfi-18
	  srfi-69
	  typed-records
	  z3
	  
	  (prefix mtargs args:)
	  )
  (use srfi-69))
 (chicken-5
  (import (prefix sqlite3 sqlite3:)
	  ;; data-structures
	  ;; extras
	  ;; files
	  ;; posix
	  ;; posix-extras
	  chicken.base
	  chicken.condition
	  chicken.file
	  chicken.file.posix
	  chicken.io
	  chicken.pathname
	  chicken.port
	  chicken.process
	  chicken.process-context
	  chicken.process-context.posix
	  chicken.sort
	  chicken.string
	  chicken.time
	  chicken.time.posix
	  
	  matchable
	  md5
	  message-digest
	  pathname-expand
	  regex
	  regex-case
	  srfi-1
	  srfi-18
	  srfi-69
	  typed-records
	  system-information

	  )))

(import configfmod
	commonmod
	debugprint
	processmod
	)

;;======================================================================
;; given path get free space, allows override in [setup]
;; with free-space-script /path/to/some/script.sh
;;
(define (get-df path)
  (if (configf:lookup *configdat* "setup" "free-space-script")
      (with-input-from-pipe 
       (conc (configf:lookup *configdat* "setup" "free-space-script") " " path)
       (lambda ()
	 (let ((res (read-line)))
	   (if (string? res)
	       (string->number res)))))
      (get-unix-df path)))

(define (get-free-inodes path)
  (if (configf:lookup *configdat* "setup" "free-inodes-script")
      (with-input-from-pipe 
	  (conc (configf:lookup *configdat* "setup" "free-inodes-script") " " path)
	(lambda ()
	  (let ((res (read-line)))
	    (if (string? res)
		(string->number res)))))
      (get-unix-inodes path)))

;;======================================================================
;; D I S K   S P A C E 
;;======================================================================

(define (common:get-disk-space-used fpath)
  (with-input-from-pipe (conc "/usr/bin/du -s " fpath) read))

(define (get-unix-df path)
  (let* ((df-results (process:cmd-run->list (conc "df " path)))
	 (space-rx   (regexp "([0-9]+)\\s+([0-9]+)%"))
	 (freespc    #f))
    ;; (write df-results)
    (for-each (lambda (l)
		(let ((match (string-search space-rx l)))
		  (if match 
		      (let ((newval (string->number (cadr match))))
			(if (number? newval)
			    (set! freespc newval))))))
	      (car df-results))
    freespc))

(define (get-unix-inodes path)
  (let* ((df-results (process:cmd-run->list (conc "df -i " path)))
	 (space-rx   (regexp "([0-9]+)\\s+([0-9]+)%"))
	 (freenodes    0)) ;; 0 is a better failsafe than #f here.
    ;; (write df-results)
    (for-each (lambda (l)
		(let ((match (string-search space-rx l)))
		  (if match 
		      (let ((newval (string->number (cadr match))))
			(if (number? newval)
			    (set! freenodes newval))))))
	      (car df-results))
    freenodes))

(define (common:check-space-in-dir dirpath required)
  (let* ((dbspace  (if (directory? dirpath)
		       (get-df dirpath)
		       0)))
    (list (> dbspace required)
	  dbspace
	  required
	  dirpath)))

(define (get-uname . params)
  (let* ((uname-res (process:cmd-run->list (conc "uname " (if (null? params) "-a" (car params)))))
	 (uname #f))
    (if (null? (car uname-res))
	"unknown"
	(caar uname-res))))

;;======================================================================
;; check space in dbdir and in megatest dir
;; returns: ok/not dbspace required-space
;;
(define (common:check-db-dir-space)
  (let* ((required (string->number 
                    ;; default is 1GB (or actually a billion bytes) This is the number of 1 kB blocks.
		    (or (configf:lookup *configdat* "setup" "dbdir-space-required")
			"1000000")))
	 (dbdir    (common:make-tmpdir-name *toppath* "")) ;; (db:get-dbdir))
	 (tdbspace (common:check-space-in-dir dbdir required))
	 (mdbspace (common:check-space-in-dir *toppath* required)))
    (sort (list tdbspace mdbspace) (lambda (a b)
				     (< (cadr a)(cadr b))))))

;;======================================================================
;; check available space in dbdir, exit if insufficient
;;
(define (common:check-db-dir-and-exit-if-insufficient)
  (let* ((spacedat (car (common:check-db-dir-space))) ;; look only at worst for now
	 (is-ok    (car spacedat))
	 (dbspace  (cadr spacedat))
	 (required (caddr spacedat))
	 (dbdir    (cadddr spacedat)))
    (if (not is-ok)
	(begin
	  (debug:print-error 0 *default-log-port* "Insufficient space in " dbdir ", require " required ", have " dbspace  ", exiting now.")
	  (exit 1)))))

;;======================================================================
;; paths is list of lists ((name path) ... )
;;
(define (common:get-disk-with-most-free-space disks minsize)
  (let* ((best     #f)
	(bestsize 0)
        (default-min-inodes-string "1000000")
        (default-min-inodes (string->number default-min-inodes-string))
        (min-inodes (or (string->number (if (configf:lookup *configdat* "setup" "min_inodes") (configf:lookup *configdat* "setup" "min_inodes") default-min-inodes-string)) default-min-inodes)))

    (for-each 
     (lambda (disk-num)
       (let* ((dirpath    (cadr (assoc disk-num disks)))
	      (freespc    (cond
			   ((not (directory? dirpath))
			    (if (common:low-noise-print 300 "disks not a dir " disk-num)
				(debug:print 0 *default-log-port* "WARNING: disk " disk-num " at path \"" dirpath "\" is not a directory - ignoring it."))
			    -1)
			   ((not (file-write-access? dirpath))
			    (if (common:low-noise-print 300 "disks not writeable " disk-num)
				(debug:print 0 *default-log-port* "WARNING: disk " disk-num " at path \"" dirpath "\" is not writeable - ignoring it."))
			    -1)
			   ((not (eq? (string-ref dirpath 0) #\/))
			    (if (common:low-noise-print 300 "disks not a proper path " disk-num)
				(debug:print 0 *default-log-port* "WARNING: disk " disk-num " at path \"" dirpath "\" is not a fully qualified path - ignoring it."))
			    -1)
			   (else
			    (get-df dirpath))))
	      (free-inodes (cond
			   ((not (directory? dirpath))
			    (if (common:low-noise-print 300 "disks not a dir " disk-num)
				(debug:print 0 *default-log-port* "WARNING: disk " disk-num " at path \"" dirpath "\" is not a directory - ignoring it."))
			    -1)
			   ((not (file-write-access? dirpath))
			    (if (common:low-noise-print 300 "disks not writeable " disk-num)
				(debug:print 0 *default-log-port* "WARNING: disk " disk-num " at path \"" dirpath "\" is not writeable - ignoring it."))
			    -1)
			   ((not (eq? (string-ref dirpath 0) #\/))
			    (if (common:low-noise-print 300 "disks not a proper path " disk-num)
				(debug:print 0 *default-log-port* "WARNING: disk " disk-num " at path \"" dirpath "\" is not a fully qualified path - ignoring it."))
			    -1)
			   (else
			    (get-free-inodes dirpath))))
             ;;(free-inodes (get-free-inodes dirpath))
             )
             (debug:print 2 *default-log-port* "INFO: disk " disk-num " path " dirpath " free space " freespc " free inodes " free-inodes)
	 (if (and (> freespc bestsize)(> free-inodes min-inodes ))
	     (begin
	       (set! best     (cons disk-num dirpath))
	       (set! bestsize freespc)))
        ;;(print "Processing: " disk-num " bestsize: " bestsize " best: " best " freespc: " freespc " min-inodes: " min-inodes " free-inodes: " free-inodes)
      ))
     (map car disks))
    (if (and best (> bestsize minsize))
	best
	#f))) ;; #f means no disk candidate found

	
)
