[bug#49828] [PATCH 04/20] build-system: Add 'minetest-mod-build-system'.

[Maxime Devos <maximedevos@telenet.be>]

* guix/build-system/minetest.scm: New module.
* Makefile.am (MODULES): Add it.
* doc/guix.texi (Build Systems): Document 'minetest-mod-build-system'.
---
 Makefile.am                    |  1 +
 doc/guix.texi                  |  7 +++++
 guix/build-system/minetest.scm | 53 ++++++++++++++++++++++++++++++++++
 3 files changed, 61 insertions(+)
 create mode 100644 guix/build-system/minetest.scm

diff --git a/Makefile.am b/Makefile.am
index d5ec909213..f6fae09579 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -141,6 +141,7 @@ MODULES =					\
   guix/build-system/go.scm			\
   guix/build-system/meson.scm			\
   guix/build-system/minify.scm			\
+  guix/build-system/minetest.scm		\
   guix/build-system/asdf.scm			\
   guix/build-system/copy.scm			\
   guix/build-system/glib-or-gtk.scm		\
diff --git a/doc/guix.texi b/doc/guix.texi
index b3c16e6507..43c248234d 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -7895,6 +7895,13 @@ declaration.  Its default value is @code{(default-maven-plugins)} which is
 also exported.
 @end defvr
 
+@defvr {Scheme Variable} minetest-mod-build-system
+This variable is exported by @code{(guix build-system minetest)}.  It
+implements a build procedure for @uref{https://www.minetest.net, Minetest}
+mods, which consists of copying lua code, images and other resources to
+the location Minetest searches for mods.
+@end defvr
+
 @defvr {Scheme Variable} minify-build-system
 This variable is exported by @code{(guix build-system minify)}.  It
 implements a minification procedure for simple JavaScript packages.
diff --git a/guix/build-system/minetest.scm b/guix/build-system/minetest.scm
new file mode 100644
index 0000000000..29866ced6d
--- /dev/null
+++ b/guix/build-system/minetest.scm
@@ -0,0 +1,53 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2021 Maxime Devos <maximedevos@telenet.be>
+;;;
+;;; 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 (guix build-system minetest)
+  #:use-module (guix build-system copy)
+  #:use-module (guix build-system)
+  #:export (minetest-mod-build-system))
+
+;;
+;; Build procedure for minetest mods.  This is implemented as an extension
+;; of ‘copy-build-system’.
+;;
+;; Code:
+
+(define (guix-name->mod-name package-name)
+  ;; The "minetest-" prefix is useless.  Don't make it appear in the
+  ;; ‘select mods’ menu when "modpack.conf" or "mod.conf" do not have
+  ;; the "name" field set.
+  (if (string-prefix? "minetest-" package-name)
+      (substring package-name 9)
+      package-name))
+
+(define (lower-mod name . arguments)
+  (define lower (build-system-lower copy-build-system))
+  (apply lower
+    name
+    #:install-plan
+    `'(("." ,(string-append "share/minetest/mods/"
+                            (guix-name->mod-name name))))
+    arguments))
+
+(define minetest-mod-build-system
+  (build-system
+    (name 'minetest-mod)
+    (description "The build system for minetest mods")
+    (lower lower-mod)))
+
+;;; minetest.scm ends here
-- 
2.32.0