;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2018 Mathieu Othacehe <m.othacehe@gmail.com>
;;; Copyright © 2019 Ludovic Courtès <ludo@gnu.org>
;;;
;;; 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/>.

(define-module (gnu installer utils)
  #:use-module (guix utils)
  #:use-module (guix build utils)
  #:use-module (guix i18n)
  #:use-module (srfi srfi-34)
  #:use-module (ice-9 rdelim)
  #:use-module (ice-9 regex)
  #:use-module (ice-9 textual-ports)
  #:export (read-lines
            read-all
            nearest-exact-integer
            read-percentage
            run-shell-command))

(define* (read-lines #:optional (port (current-input-port)))
  "Read lines from PORT and return them as a list."
  (let loop ((line (read-line port))
             (lines '()))
    (if (eof-object? line)
        (reverse lines)
        (loop (read-line port)
              (cons line lines)))))

(define (read-all file)
  "Return the content of the given FILE as a string."
  (call-with-input-file file
    get-string-all))

(define (nearest-exact-integer x)
  "Given a real number X, return the nearest exact integer, with ties going to
the nearest exact even integer."
  (inexact->exact (round x)))

(define (read-percentage percentage)
  "Read PERCENTAGE string and return the corresponding percentage as a
number. If no percentage is found, return #f"
  (let ((result (string-match "^([0-9]+)%$" percentage)))
    (and result
         (string->number (match:substring result 1)))))

(define* (run-shell-command command #:key locale)
  "Run COMMAND, a string, with Bash, and in the given LOCALE.  Return true if
COMMAND exited successfully, #f otherwise."
  (define (pause)
    (format #t (G_ "Press Enter to continue.~%"))
    (read-line (current-input-port)))

  (call-with-temporary-output-file
   (lambda (file port)
     (when locale
       (let ((supported? (false-if-exception
                          (setlocale LC_ALL locale))))
         ;; If LOCALE is not supported, then set LANGUAGE, which might at
         ;; least give us translated messages.
         (if supported?
             (format port "export LC_ALL=\"~a\"~%" locale)
             (format port "export LANGUAGE=\"~a\"~%"
                     (string-take locale
                                  (string-index locale #\_))))))

     (format port "exec ~a~%" command)
     (close port)

     (guard (c ((invoke-error? c)
                (newline)
                (format (current-error-port)
                        (G_ "Command failed with exit code ~a.~%")
                        (invoke-error-exit-status c))
                (pause)
                #f))
       (invoke "bash" "--init-file" file)
       (newline)
       (pause)
       #t))))
cally authorize the coordinator's signing key.</a><span class='msg-avail'>...</span></td><td>Jakob L. Kreuze</td></tr>
<tr><td><span title='2019-08-15 07:43:09 -0400'>2019-08-15</span></td><td><a href='/guix/commit/gnu/machine/ssh.scm?id=9c70c460a05b2bc60f3f3602f0a2dba0f79ce86c'>machine: Implement 'roll-back-machine'.</a><span class='msg-avail'>...</span></td><td>Jakob L. Kreuze</td></tr>
<tr><td><span title='2019-08-15 07:43:03 -0400'>2019-08-15</span></td><td><a href='/guix/commit/gnu/machine/ssh.scm?id=5ea7537b9a650cfa525401c19879080a9cf42e13'>machine: Allow non-root users to deploy.</a><span class='msg-avail'>...</span></td><td>Jakob L. Kreuze</td></tr>
<tr><td><span title='2019-08-14 15:38:09 -0400'>2019-08-14</span></td><td><a href='/guix/commit/gnu/machine/ssh.scm?id=2c8e04f13670c8c7ad8c7195c305960dd1905363'>remote: Build derivations appropriate for the remote's</a><span class='msg-avail'>...</span></td><td>Jakob L. Kreuze</td></tr>
<tr><td><span title='2019-08-07 18:29:07 -0400'>2019-08-07</span></td><td><a href='/guix/commit/gnu/machine/ssh.scm?id=d84e9b75b2aba98583531f2876d9298871389585'>machine: Add 'build-locally?' field for managed hosts.</a><span class='msg-avail'>...</span></td><td>Jakob L. Kreuze</td></tr>
<tr><td><span title='2019-08-06 16:40:25 -0400'>2019-08-06</span></td><td><a href='/guix/commit/gnu/machine/ssh.scm?id=fd3119db4fed02a1f3491460be776a3b5d2b2cd3'>machine: Implement safety checks.</a><span class='msg-avail'>...</span></td><td>Jakob L. Kreuze</td></tr>
<tr><td><span title='2019-08-06 15:48:51 -0400'>2019-08-06</span></td><td><a href='/guix/commit/gnu/machine/ssh.scm?id=d97ce20400b5d2967bfbc0e9fbfb99bbb2daed4f'>machine: Rename 'system' field.</a><span class='msg-avail'>...</span></td><td>Jakob L. Kreuze</td></tr>
<tr><td><span title='2019-07-26 19:19:49 +0200'>2019-07-26</span></td><td><a href='/guix/commit/gnu/machine/ssh.scm?id=5c793753b31b1dcd9a554bce953124f7ae88ca9a'>guix system: Add 'reconfigure' module.</a><span class='msg-avail'>...</span></td><td>Jakob L. Kreuze</td></tr>
<tr><td><span title='2019-07-18 12:57:00 +0200'>2019-07-18</span></td><td><a href='/guix/commit/gnu/machine/ssh.scm?id=53f21b3fe9ed57f0feef003185b561efc9b3e30c'>machine: Fix typo.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2019-07-06 02:10:04 -0400'>2019-07-06</span></td><td><a href='/guix/commit/gnu/machine/ssh.scm?id=fa9edf09e992db7510c7471486dffc93e1e707e5'>gnu: Add machine type for deployment specifications.</a><span class='msg-avail'>...</span></td><td>Jakob L. Kreuze</td></tr>