;;; 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 locale)
  #:use-module (gnu installer utils)
  #:use-module ((gnu build locale) #:select (normalize-codeset))
  #:use-module (guix records)
  #:use-module (json)
  #:use-module (srfi srfi-1)
  #:use-module (ice-9 match)
  #:use-module (ice-9 regex)
  #:export (locale-language
            locale-territory
            locale-codeset
            locale-modifier

            locale->locale-string
            supported-locales->locales

            iso639->iso639-languages
            language-code->language-name

            iso3166->iso3166-territories
            territory-code->territory-name

            locale->configuration))


;;;
;;; Locale.
;;;

;; A glibc locale string has the following format:
;; language[_territory[.codeset][@modifier]].
(define locale-regexp "^([^_@]+)(_([^\\.@]+))?(\\.([^@]+))?(@([^$]+))?$")

;; LOCALE will be better expressed in a (guix record) that in an association
;; list. However, loading large files containing records does not scale
;; well. The same thing goes for ISO639 and ISO3166 association lists used
;; later in this module.
(define (locale-language assoc)
  (assoc-ref assoc 'language))
(define (locale-territory assoc)
  (assoc-ref assoc 'territory))
(define (locale-codeset assoc)
  (assoc-ref assoc 'codeset))
(define (locale-modifier assoc)
  (assoc-ref assoc 'modifier))

(define* (locale-string->locale string #:optional codeset)
  "Return the locale association list built from the parsing of STRING and,
optionally, CODESET."
  (let ((matches (string-match locale-regexp string)))
    `((language  . ,(match:substring matches 1))
      (territory . ,(match:substring matches 3))
      (codeset   . ,(or codeset (match:substring matches 5)))
      (modifier  . ,(match:substring matches 7)))))

(define (locale->locale-string locale)
  "Reverse operation of locale-string->locale."
  (let ((language (locale-language locale))
        (territory (locale-territory locale))