;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2015 Alex Kost <alezost@gmail.com>
;;;
;;; This file is part of GNU Guix.
;;;
;;; GNU Guix 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.
;;;
;;; GNU Guix 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 Guix.  If not, see <http://www.gnu.org/licenses/>.

;;;
;;; Generate AUTHORS file for directory with the Guix git repository.
;;;

(use-modules
 (ice-9 popen)
 (ice-9 rdelim)
 (ice-9 match)
 (srfi srfi-1)
 (guix config)
 (guix utils)
 (guix build utils))

(define %guix-dir
  (make-parameter #f))

(define-syntax-rule (append-maybe init-lst (test add-lst) ...)
  (let* ((lst init-lst)
         (lst (if test
                  (append lst add-lst)
                  lst))
         ...)
    lst))

(define (command-output cmd . args)
  "Execute CMD with ARGS and return its output without trailing newspace."
  (let* ((port (apply open-pipe* OPEN_READ cmd args))
         (output (read-string port)))
    (close-port port)
    (string-trim-right output #\newline)))

(define (git-output . args)
  "Execute git command with ARGS and return its output without trailing
newspace."
  (with-directory-excursion (%guix-dir)
    (apply command-output "git" args)))

(define* (contributors-string #:optional (range "HEAD"))
  "Return a string with names of people contributed to commit RANGE."
  (git-output "shortlog" "--numbered" "--summary" "--email" range))

(define* (tags #:key pattern sort)
  "Return a list of the git repository tags.
PATTERN is passed to '--list' and SORT is passed to '--sort' options of
'git tag' command."
  (let* ((args (append-maybe
                '("tag")
                (pattern (list "--list" pattern))
                (sort    (list "--sort" sort))))
         (output (apply git-output args)))
    (string-split output #\newline)))

(define (version-tags)
  "Return only version tags (v0.8, etc.) sorted from the biggest version
to the smallest one."
  (tags #:pattern "v*"
        #:sort "-version:refname"))

(define (generate-authors-file file)
  "Generate authors FILE."
  (define previous-release-tag
    (find (lambda (tag<tr><td><span title='2019-10-16 22:53:40 +0200'>2019-10-16</span></td><td><a href='/guix/commit/build-aux/test-env.in?id=a1aaca314ca94700ebe3449d6bd73522f2d243bc'>build: Remove references to 'NIX_LOCALSTATE_DIR'.</a><span class='msg-avail'>...<span class='msg-tooltip'>* build-aux/test-env.in: Remove references to 'NIX_LOCALSTATE_DIR'.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2019-10-16 22:53:40 +0200'>2019-10-16</span></td><td><a href='/guix/commit/build-aux/test-env.in?id=47e99e626b46b2fc433506a822d251de68ad6241'>daemon: Remove traces of 'NIX_ROOT_FINDER'.</a><span class='msg-avail'>...<span class='msg-tooltip'>This is a followup to 2e3e5d21988fc2cafb2a9eaf4b00976ea425629d.

* build-aux/test-env.in: Remove mentions of 'NIX_ROOT_FINDER'.
* nix/libstore/gc.cc (LocalStore::collectGarbage): Adjust comment
accordingly.
</span></span></td><td>Ludovic Courtès</td></tr>

    ((me _ ...)
     (format #t "Usage: guile ~a DIRECTORY AUTHORS
Generate AUTHORS file for DIRECTORY with the Guix git repository.\n"
             me))))

(match (command-line)
  ((_ guix-dir authors-file)
   (parameterize ((%guix-dir guix-dir))
     (generate-authors-file authors-file)))
  (_
   (show-help)
   (exit 1)))

;;; generate-authors.scm ends here