;;
;; brmsaptool.scm
;;
;; ISC License
;;
;; Copyright 2023 Brmlab, z.s.
;; Dominik Pantůček <dominik.pantucek@trustica.cz>
;;
;; Permission to use, copy, modify, and/or distribute this software
;; for any purpose with or without fee is hereby granted, provided
;; that the above copyright notice and this permission notice appear
;; in all copies.
;; 
;; THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
;; WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
;; WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
;; AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
;; CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
;; OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
;; NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
;; CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
;;
(import (chicken condition)
	(chicken file)
	(chicken pathname)
	(chicken file posix)
	(chicken io)
	(chicken string)
	(chicken format)
	(chicken sort)
	(chicken time)
	(chicken time posix)
	(chicken process-context)
	dictionary
	month
	period
	member-file)

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Static default configuration

(define *members-directory* (make-parameter "members"))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Members database

;; Loads all symlinks from (*members-directory*) returning a list of
;; pairs (name . destination)
(define (load-members-raw-index)
  (let loop ((fns (directory (*members-directory*)))
	     (rs '()))
    (if (null? fns)
	(let ()
	  (display "-")
	  rs)
	(let* ((fn (car fns))
	       (ffn (make-pathname (*members-directory*) fn))
	       (sl (if (symbolic-link? ffn) (read-symbolic-link ffn) #f)))
	  (loop (cdr fns)
		(if sl
		    (cons (cons fn sl) rs)
		    rs))))))

;; Converts the raw members index to a list of dictionaries with keys
;; 'id, 'name and 'file. File names are without directory element.
(define (expand-members-raw-index ri)
  (let loop ((ri ri)
	     (ds '()))
    (if (null? ri)
	(let ()
	  (display "*")
	  ds)
	(let* ((mp (car ri))
	       (lnk (car mp))
	       (dfn (cdr mp))
	       (lnkn (string->number lnk))
	       (dfnn (string->number dfn))
	       (id (or dfnn lnkn))
	       (name (if lnkn dfn lnk)))
	  (loop (cdr ri)
		(cons (list (cons 'id id)
			    (cons 'name name)
			    (cons 'file dfn))
		      ds))))))

;; Adds the 'info key to all expanded index entries by loading
;; appropriate 'file key file from the members directory.
(define (load-members-from-expanded-index ei)
  (let loop ((ei ei)
	     (mdb '()))
    (if (null? ei)
	mdb
	(let ((mi (car ei)))
	  (let ((mid (load-member-file
		      (make-pathname
		       (*members-directory*)
		       (dict-ref mi 'file)))))
	    (loop (cdr ei)
		  (cons (dict-set mi
				  'info
				  mid)
			mdb)))))))

;; Loads all member information from given members database.
(define (load-members)
  (load-members-from-expanded-index
   (expand-members-raw-index
    (load-members-raw-index))))

;; Gets member based by generic predicate
(define (find-member-by-predicate mdb pred)
  (let loop ((mdb mdb))
    (if (null? mdb)
	#f
	(let ((mr (car mdb)))
	  (if (pred mr)
	      mr
	      (loop (cdr mdb)))))))

;; Gets member record by member key
(define (find-member-by-key mdb key val)
  (find-member-by-predicate
   mdb
   (lambda (mr)
     (equal? (dict-ref mr key) val))))

;; Gets member record by member id (from file/symlink)
(define (find-member-by-id mdb id)
  (find-member-by-key mdb 'id id))

;; Gets member record by member name (from file/symlink)
(define (find-member-by-name mdb name)
  (find-member-by-key mdb 'name name))

;; Gets member record by member nick in member file the key 'nick
(define (find-member-by-nick mdb nick)
  (find-member-by-predicate
   mdb
   (lambda (mr)
     (equal? (dict-ref (dict-ref mr 'info) 'nick) nick))))

;; Returns the list of all members ids
(define (list-members-ids mdb)
  (map (lambda (mr) (dict-ref mr 'id)) mdb))

;; Returns the list of all file names in members database
(define (list-members-names mdb)
  (map (lambda (mr) (dict-ref mr 'name)) mdb))

;; Returns the list of all members nicks
(define (list-members-nicks mdb)
  (map (lambda (mr) (dict-ref (dict-ref mr 'info) 'nick)) mdb))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Member predicates

(define (member-suspended? mr)
  #f)

(define (member-student? mr)
  #f)

(define (member-destroyed? mr)
  #f)

;; Returns true if the member is neither suspended nor destroyed
(define (member-active? mr)
  (not (or (member-suspended? mr)
	   (member-destroyed? mr))))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Command-line parsing

;; Prints simple help
(define (print-help)
  (print "Command-line arguments:

  -h        prints this help
  -M dir    specifies the members database directory
  -mi id    member id
  -mn nick  member nick
")
  (exit 0))

;; Consumes given number of arguments from the list and returns the
;; remainder of the list and a list of arguments consumed.
(define (consume-args args num)
  (let loop ((args args)
	     (res '())
	     (num num))
    (if (= num 0)
	(list args (reverse res))
	(if (null? args)
	    (error 'consume-args "Not enough arguments" num)
	    (loop (cdr args)
		  (cons (car args) res)
		  (- num 1))))))

;; Gets command-line arguments after the "--" of csi (not useful when
;; compiled)
(define (get-command-line-arguments . explicit-argv)
  (let* ((args (if (null? explicit-argv) (argv) explicit-argv))
	 (rargs (member "--" args)))
    (if rargs
	(cdr rargs)
	(cdr args))))

;; Performs the actual parsing based on specification.
(define (do-parse-command-line specs)
  (let loop ((args (get-command-line-arguments)))
    (when (not (null? args))
      (let* ((arg (car args))
	     (specp (assoc arg specs)))
	(when (not specp)
	  (error 'parse-command-line "Unknown argument" arg))
	(let* ((proc (cadr specp))
	       (info (procedure-information proc))
	       (nargs (- (length info) 1))
	       (aargsl (consume-args (cdr args) nargs))
	       (args (car aargsl))
	       (aargs (cadr aargsl)))
	  (apply proc aargs)
	  (loop args))))))

;; Simple syntax wrapper for command-line arguments specification
(define-syntax parse-command-line
  (syntax-rules ()
    ((_ ((arg proc) ...))
     (do-parse-command-line
      `((arg ,proc) ...)))))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Run everything

(define action (make-parameter #f))
(define member-parm (make-parameter #f))

;; Print banner
(print "brmsaptool 0.1 (c) 2023 Brmlab, z.s.")
(newline)

;; Handle options
(parse-command-line
 (("-h" print-help)
  ("-M" (lambda (dn) (*members-directory* dn)))
  ("-mi" (lambda (id)
	   (action 'member-by-id)
	   (member-parm (string->number id))))
  ("-mn" (lambda (nick)
	   (action 'member-by-nick)
	   (member-parm nick)))
  ))

;; Run tests
(print "Running self-tests:")
(dictionary-tests!)
(month-tests!)
(period-tests!)
(print "All self-tests ok!")
(newline)

;; Load the members database
(display "Loading members ")
(define MDB (load-members))
(print " ok.")
(print "Members in database: " (length MDB))
(newline)

;; Perform requested action
(case (action)
  ((member-by-id member-by-nick)
   (let ((mr (if (eq? (action) 'member-by-id)
		 (find-member-by-id MDB (member-parm))
		 (find-member-by-nick MDB (member-parm)))))
     (if mr
	 (let* ((id (dict-ref mr 'id))
		(name (dict-ref mr 'name))
		(info (dict-ref mr 'info))
		(sinfo (sort info
			     (lambda (a b)
			       (string<?
				(symbol->string (car a))
				(symbol->string (car b)))))))
	   (print "User " id " alias " name)
	   (let loop ((sinfo sinfo))
	     (when (not (null? sinfo))
	       (let* ((kv (car sinfo))
		      (k (car kv))
		      (v (cdr kv)))
		 (print "  " k ":\t"
			(if (member k '(student suspend))
			    (periods->string v)
			    v))
		 (loop (cdr sinfo))))))
	 (let ()
	   (print "No such member " (member-parm) ".")))))
  ((#f) (print "No action specified.")))