;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2022 Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.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 packages zim-files)
  #:use-module (gnu packages)
  #:use-module (guix build-system copy)
  #:use-module (guix download)
  #:use-module (guix gexp)
  #:use-module (guix utils)
  #:use-module ((guix licenses) #:prefix license:)
  #:use-module (guix packages))

;;; Commentary:
;;;
;;; Many Guix contributors have a tendency to update packages in this
;;; way: they only update the package revision and then launch a build
;;; that fails just to make Guix tell them the right base32 hash. They
;;; then update the base32 hash and launch the build again.
;;;
;;; However some ZIM files are quite big. At the time of writing,
;;; wikipedia_en_all_maxi_2022-05.zim is about 89 GiB.
;;;
;;; So this approach will be time consuming as the second time Guix
;;; will restart downloading the same file from scratch.
;;;
;;; The solution to this issue is to download the sha256sums (for that
;;; simply append .sha256 to the URL of the ZIM file). It will give a
;;; file like that:
;;; f12163513307893c87fd75009b1d61677bae675627eaadf4cb0fa63953eea021  wikipedia_en_all_maxi_2022-05.zim
;;;
;;; You can then use this hash to compute the base32 with nix-hash:
;;; $ nix-hash --type sha256 --to-base32 \
;;; f12163513307893c87fd75009b1d61677bae675627eaadf4cb0fa63953eea021
;;; 08d0xr9kk9hgrgsavsi7arkswyv7c4frn03mzn3kr2876d8n68gi

(define-public wikipedia-en-all-maxi
  (package
    (name "wikipedia-en-all-maxi")
    (version "2022-05")
    (source (origin
              (method url-fetch)
              (uri (string-append
                    "https://mirror.download.kiwix.org/zim/wikipedia/"
                    (string-replace-substring name "-" "_")
                    "_" version ".zim"))
              (sha256
               (base32
                "08d0xr9kk9hgrgsavsi7arkswyv7c4frn03mzn3kr2876d8n68gi"))))
    (build-system copy-build-system)
    (arguments
     (list
      ;; We are not (yet) generating the zim file, so it doesn't make sense to
      ;; build substitutes.
      #:substitutable? #f
      ;; If we use kiwix-serve, the path of the ZIM file needs to be passed to
      ;; it. And if the filename has a version in it, we'd need to update the
      ;; path manually each time the package is updated. We also need to
      ;; change the filename to match the package name.
      #:install-plan #~'((#$(string-append
                             (string-replace-substring name "-" "_")
                             "_" version ".zim")
                          #$(string-append "share/" name ".zim")))))
    (synopsis
     "Complete English Wikipedia packed in a ZIM file, for offline usage with
Kiwix")
    (description
     "Wikipedia is a free Encyclopedia.  This is the English version.  It
contains all the articles, and all the medias (images, etc) present in
the articles in a scaled down resolution.")
    (home-page "https://en.wikipedia.org/wiki/Main_Page")
    (license license:cc-by-sa3.0)))