#! /bin/sh
# aside from this initial boilerplate, this is actually -*- scheme -*- code
main='(module-ref (resolve-module '\''(scheme guimb)) '\'main')'
exec ${GUILE-guile} -l $0 -c "(apply $main (list (command-line)))" "$@"
!#
;;;; GNU Mailutils -- a suite of utilities for electronic mail
;;;; Copyright (C) 1999-2021 Free Software Foundation, Inc.
;;;;
;;;; GNU Mailutils 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, or (at your option)
;;;; any later version.
;;;; 
;;;; GNU Mailutils 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 GNU Mailutils.  If not, see <http://www.gnu.org/licenses/>.
;;;;
(if (not (member "/usr/share/guile/site/2.2" %load-path))
    (set! %load-path (cons "/usr/share/guile/site/2.2" %load-path)))
(define-module (scheme guimb)
  :export (guimb))

(use-modules (ice-9 getopt-long)
	     (ice-9 rdelim)
	     (ice-9 eval-string)
	     (srfi srfi-1)
	     (mailutils mailutils))

(define program-name "guimb")
(define output-mailbox-name #f)
(define output-mailbox-mode #f)
(define source-file-name #f)
(define source-expression #f)
(define user-name #f)
(define input-mailbox-names '())
(define script-arguments '())

(define output-mailbox #f)

(define (guimb-version)
  (format #t "guimb (~A) ~A~%" mu-package mu-version)
  (exit 0))

(define (guimb-help)
  (format #t "Usage: guimb [OPTIONS] [MAILBOX [MAILBOX...]]
guimb -- apply a scheme function to each message in mailboxes

The following options stop argument processing, and pass the remaining
arguments to the guimb-getopt function, if it is defined in the module:

  -c, --code=EXPR            execute given Scheme expression
  -s, --source=MODNAME       load Scheme module MODNAME

The following options have the same effect, but do not affect further
options parsing:

  -e, --expression=EXPR      execute given Scheme expression
  -f, --file=MODNAME         load Scheme module MODNAME

The module to be loaded is normally defined in a file named MODNAME.scm
somewhere in your %load-path.

Other options:

  -M, --mailbox=NAME         set output mailbox name
  -u, --user[=NAME]          direct output to the system mailbox of the
                             user NAME (default - current user)
  -r, --read-only            open mailbox in read-only mode

Script arguments:

  -g, --guile-arg=ARG        append ARG to the command line passed to script
  -{ args... -}              append args to the command line passed to script
  --lparen args... --rparen  likewise

  -L, --load-path=PATH       append PATH to the beginning of the %load-path

  -?, --help                 give this help list
      --usage                give a short usage message
  -V, --version              print program version

Mandatory or optional arguments to long options are also mandatory or optional
for any corresponding short options.

")
  (format #t "Report bugs to <~A>.~%" mu-bugreport)
  (exit 0))

(define (guimb-usage)
  ; FIXME
  (guimb-help))

(define (error fmt . rest)
  (with-output-to-port
      (current-error-port)
    (lambda ()
      (format #t "~A: " program-name)
      (apply format #t fmt rest)
      (newline))))

(define (extract-args arglist)
  (let ((level 0))
    (let ((result (filter
		   (lambda (x)
		     (cond
		      ((or (string=? x "--lparen")
			   (string=? x "-{"))
		       (set! level (+ level 1))
		       #f)
		      ((or (string=? x "--rparen")
			   (string=? x "-}"))
		       (if (> level 0)
			   (set! level (- level 1))
			   (set! script-arguments (append script-arguments
							  (list x))))
		       #f)
		      ((> level 0)
		       (set! script-arguments (append script-arguments
						      (list x)))
		       #f)
		      (else
		       #t)))
		   arglist)))
      (if (> level 0)
	  (error "missing closing -}"))
      result)))
		
(define (parse-cmdline cmdline)
  (let ((grammar `((source      (single-char #\s)
				(value #t))
		   (code        (single-char #\c)
				(value #t))
		   (file        (single-char #\f)
				(value #t))
		   (expression  (single-char #\e)
				(value #t))
		   (mailbox     (single-char #\M)
				(value #t))
		   (user        (single-char #\u)
				(value optional))
		   (read-only   (single-char #\r))
		   (guile-arg   (single-char #\g)
				(value #t))
		   (load-path   (single-char #\L)
				(value #t))
		   (help        (single-char #\?))
		   (usage)
		   (version     (single-char #\V)))))
    (do ((arglist (getopt-long (extract-args (command-line)) grammar)
		  (cdr arglist)))
	((null? arglist))
      (let ((x (car arglist)))
	(case (car x)
	  ((mailbox)
	   (set! output-mailbox-name (cdr x)))
	  ((source file)
	   (set! source-file-name (cdr x)))
	  ((code expression)
	   (set! source-expression (cdr x)))
	  ((load-path)
	   (set! %load-path (append
			     (string-split (cdr x) #\:)
			     %load-path)))
	  ((user)
	   (set! user-name (cdr x)))
	  ((guile-arg)
	   (set! script-arguments (append script-arguments (list (cdr x)))))
	  ((version)
	   (guimb-version))
	  ((help)
	   (guimb-help))
	  ((usage)
	   (guimb-usage))
	  ((read-only)
	   (set! output-mailbox-mode "r"))
	  ('()
	   (if (not (null? (cdr x)))
	       (set! input-mailbox-names (append input-mailbox-names
						 (cdr x))))))))))

(define guimb-module #f)

(define (get-module)
    (if (not guimb-module)
	(set! guimb-module (resolve-module '(scheme guimb))))
    guimb-module)

(define-macro (bound? name)
  `(and (module-defined? (get-module) ',name)
	(procedure? ,name)))

(define (guimb-parse-command-line cmdline)
  (let ((script-args '())
	(argtail (find-tail
		  (lambda (x)
		    (or (string=? x "-c")
			(string=? x "--code")
			(string=? x "-s")
			(string=? x "--source")
			(string-prefix? "--code=" x)
			(string-prefix? "--source=" x)))
		  cmdline)))
    (cond
     (argtail
      (if (let ((x (car argtail)))
	    (not (or (string-prefix? "--code=" x)
		     (string-prefix? "--source=" x))))
	  (set! argtail (cdr argtail)))
      (cond ((not (null? argtail))
	     (set! script-args (cdr argtail))
	     (set-cdr! argtail '())))))
    (parse-cmdline cmdline)
    (set! script-arguments (append script-arguments script-args))

    (if (not output-mailbox-mode)
	(set! output-mailbox-mode (if (null? input-mailbox-names) "wr" "a")))
    
    (if (and (not output-mailbox-name) user-name)
	(set! output-mailbox-name (if (string? user-name)
			 (string-append "%" user-name)
			 #f)))
    (set! output-mailbox (mu-mailbox-open output-mailbox-name
						    output-mailbox-mode))
;    (write output-mailbox)(newline)

    (if source-file-name
	(module-use!
	 (get-module)
	 (resolve-interface (list (string->symbol source-file-name)))))
    (if source-expression
	(eval-string source-expression))

    (if (bound? guimb-getopt)
	(guimb-getopt script-arguments)) ))

(define (guimb-single-mailbox mbox)
  (let msg-loop ((msg (mu-mailbox-first-message mbox)))
    (if (not (eof-object? msg))
	(begin
	  (guimb-message msg)
	  (msg-loop (mu-mailbox-next-message mbox))))))
  
(define (guimb-process-mailbox mbox)
  (if (not output-mailbox)
      (guimb-single-mailbox mbox)
      (let msg-loop ((msg (mu-mailbox-first-message mbox)))
	(if (not (eof-object? msg))
	    (let ((x (guimb-message msg)))
	      (if (mu-message? x)
		  (mu-mailbox-append-message output-mailbox x))
	      (msg-loop (mu-mailbox-next-message mbox)))))))

(define (guimb cmdline)
  (mu-register-format)
  (guimb-parse-command-line cmdline)
  (if (null? input-mailbox-names)
    (guimb-single-mailbox output-mailbox)
    (for-each
     (lambda (mbox-name)
       (let ((current-mailbox (mu-mailbox-open mbox-name "r")))
	 (guimb-process-mailbox current-mailbox)))
     input-mailbox-names))
  (if (bound? guimb-end)
      (guimb-end)))

(debug-options '(show-file-name #t
		 stack 20000
		 backtrace
		 depth 20
		 width 79))

(define main guimb)

;;;; End of guimb