;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2013, 2014, 2015, 2019, 2020, 2021 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2013 Cyril Roelandt <tipecaml@gmail.com>
;;; Copyright © 2014 Federico Beffa <beffa@fbengineering.ch>
;;; 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 glib-or-gtk)
  #:use-module (guix store)
  #:use-module (guix utils)
  #:use-module (guix gexp)
  #:use-module (guix monads)
  #:use-module (guix derivations)
  #:use-module (guix search-paths)
  #:use-module (guix build-system)
  #:use-module (guix build-system gnu)
  #:use-module (guix packages)
  #:use-module (ice-9 match)
  #:export (%glib-or-gtk-build-system-modules
            glib-or-gtk-build
            glib-or-gtk-cross-build
            glib-or-gtk-build-system))

;; Commentary:
;;
;; This build system is an extension of the 'gnu-build-system'.  It
;; accomodates the needs of applications making use of glib or gtk+ (with "or"
;; to be interpreted in the mathematical sense).  This is achieved by adding
;; two phases run after the 'install' phase:
;;
;; 'glib-or-gtk-wrap' phase:
;;
;; a) This phase looks for GSettings schemas, GIO modules and theming data.
;; If any of these is found in any input package, then all programs in
;; "out/bin" are wrapped in scripts defining the nedessary environment
;; variables.
;;
;; b) Looks for the existence of "libdir/gtk-3.0" directories in all input
;; packages.  If any is found, then the environment variable "GTK_PATH" is
;; suitably set and added to the wrappers.  The variable "GTK_PATH" has been
;; preferred over "GTK_EXE_PREFIX" because the latter can only point to a
;; single directory, while we may need to point to several ones.
;;
;; 'glib-or-gtk-compile-schemas' phase:
;;
;; Looks for the presence of "out/share/glib-2.0/schemas".  If that directory
;; exists and does not include a file named "gschemas.compiled", then
;; "glib-compile-schemas" is run in that directory.
;;
;; Code:

(define %default-modules
  ;; Build-side modules made available in the build environment.
  '((guix build glib-or-gtk-build-system)
    (guix build utils)))

(define %glib-or-gtk-build-system-modules
  ;; Build-side modules imported and used by default.
  `((guix build glib-or-gtk-build-system)
    ,@%gnu-build-system-modules))

(define (default-glib)
  "Return the default glib package from which we use
\"glib-compile-schemas\"."
  ;; Do not use `@' to avoid introducing circular dependencies.
  (let ((module (resolve-interface '(gnu packages glib))))
    (module-ref module 'glib)))

(define* (lower name
                #:key source inputs native-inputs outputs system target
                (glib (default-glib))
                (implicit-inputs? #t)
                (implicit-cross-inputs? #t)
                (strip-binaries? #t)
                #:allow-other-keys
                #:rest arguments)
  "Return a bag for NAME."
  (define private-keywords
    `(#:glib #:inputs #:native-inputs
      #:outputs #:implicit-inputs? #:implicit-cross-inputs?
      ,@(if target '() '(#:target))))

  (bag
    (name name)
    (system system) (target target)
    (host-inputs `(,@(if source
                         `(("source" ,source))
                         '())
                   ,@(if target
                         inputs
                         '())))
    (build-inputs `(,@native-inputs
                    ,@(if target '() inputs)
                    ("glib:bin" ,glib "bin") ; to compile schemas
                    ;; Keep standard inputs of gnu-build-system.
                    ,@(if (and target implicit-cross-inputs?)
                          (standard-cross-packages target 'host)
                          '())
                    ,@(if implicit-inputs?
                          (standard-packages)
                          '())))
    ;; Keep standard inputs of 'gnu-build-system'.
    (target-inputs (if (and target implicit-cross-inputs?)
                       (standard-cross-packages target 'target)
                       '()))
    (outputs outputs)
    (build (if target glib-or-gtk-cross-build glib-or-gtk-build))
    (arguments (strip-keyword-arguments private-keywords arguments))))

(define* (glib-or-gtk-build name inputs
                            #:key guile source
                            (outputs '("out"))
                            (search-paths '())
                            (configure-flags ''())
                            ;; Disable icon theme cache generation.
                            (make-flags ''("gtk_update_icon_cache=true"))
                            (out-of-source? #f)
                            (tests? #t)
                            (test-target "check")
                            (parallel-build? #t)
                            (parallel-tests? #t)
                            (validate-runpath? #t)
                            (patch-shebangs? #t)
                            (strip-binaries? #t)
                            (strip-flags ''("--strip-debug"))
                            (strip-directories ''("lib" "lib64" "libexec"
                                                  "bin" "sbin"))
                            (phases '(@ (guix build glib-or-gtk-build-system)
                                        %standard-phases))
                            (glib-or-gtk-wrap-excluded-outputs ''())
                            (system (%current-system))
                            (imported-modules %glib-or-gtk-build-system-modules)
                            (modules %default-modules)
                            allowed-references
                            disallowed-references)
  "Build SOURCE with INPUTS.  See GNU-BUILD for more details."
  (define build
    (with-imported-modules imported-modules
      #~(begin
          (use-modules #$@(sexp->gexp modules))

          #$(with-build-variables inputs outputs
              #~(glib-or-gtk-build #:source #+source
                                   #:system #$system
                                   #:outputs %outputs
                                   #:inputs %build-inputs
                                   #:search-paths '#$(sexp->gexp
                                                      (map search-path-specification->sexp
                                                           search-paths))
                                   #:phases #$(if (pair? phases)
                                                  (sexp->gexp phases)
                                                  phases)
                                   #:glib-or-gtk-wrap-excluded-outputs
                                   #$glib-or-gtk-wrap-excluded-outputs
                                   #:configure-flags #$configure-flags
                                   #:make-flags #$make-flags
                                   #:out-of-source? #$out-of-source?
                                   #:tests? #$tests?
                                   #:test-target #$test-target
                                   #:parallel-build? #$parallel-build?
                                   #:parallel-tests? #$parallel-tests?
                                   #:validate-runpath? #$validate-runpath?
                                   #:patch-shebangs? #$patch-shebangs?
                                   #:strip-binaries? #$strip-binaries?
                                   #:strip-flags #$(sexp->gexp strip-flags)
                                   #:strip-directories
                                   #$(sexp->gexp strip-directories))))))


  (mlet %store-monad ((guile (package->derivation (or guile (default-guile))
                                                  system #:graft? #f)))
    (gexp->derivation name build
                      #:system system
                      #:target #f
                      #:allowed-references allowed-references
                      #:disallowed-references disallowed-references
                      #:guile-for-build guile)))

(define* (glib-or-gtk-cross-build name
                                  #:key
                                  target
                                  build-inputs target-inputs host-inputs
                                  guile source
                                  (outputs '("out"))
                                  (search-paths '())
                                  (native-search-paths '())
                                  (configure-flags ''())
                                  ;; Disable icon theme cache generation.
                                  (make-flags ''("gtk_update_icon_cache=true"))
                                  (out-of-source? #f)
                                  (tests? #f)
                                  (test-target "check")
                                  (parallel-build? #t)
                                  (parallel-tests? #t)
                                  (validate-runpath? #t)
                                  (make-dynamic-linker-cache? #f)
                                  (patch-shebangs? #t)
                                  (strip-binaries? #t)
                                  (strip-flags ''("--strip-debug"))
                                  (strip-directories ''("lib" "lib64" "libexec"
                                                        "bin" "sbin"))
                                  (phases '(@ (guix build glib-or-gtk-build-system)
                                              %standard-phases))
                                  (glib-or-gtk-wrap-excluded-outputs ''())
                                  (system (%current-system))
                                  (build (nix-system->gnu-triplet system))
                                  (imported-modules %glib-or-gtk-build-system-modules)
                                  (modules %default-modules)
                                  allowed-references
                                  disallowed-references)
  "Cross-build SOURCE with INPUTS.  See GNU-BUILD for more details."
  (define builder
    #~(begin
        (use-modules #$@(sexp->gexp modules))

        (define %build-host-inputs
          #+(input-tuples->gexp build-inputs))

        (define %build-target-inputs
          (append #$(input-tuples->gexp host-inputs)
                  #+(input-tuples->gexp target-inputs)))

        (define %build-inputs
          (append %build-host-inputs %build-target-inputs))

        (define %outputs
          #$(outputs->gexp outputs))

        (glib-or-gtk-build #:source #+source
                           #:system #$system
                           #:build #$build
                           #:target #$target
                           #:outputs %outputs
                           #:inputs %build-target-inputs
                           #:native-inputs %build-host-inputs
                           #:search-paths '#$(sexp->gexp
                                              (map search-path-specification->sexp
                                                   search-paths))
                           #:native-search-paths '#$(sexp->gexp
                                                     (map search-path-specification->sexp
                                                          native-search-paths))
                           #:phases #$(if (pair? phases)
                                          (sexp->gexp phases)
                                          phases)
                           #:glib-or-gtk-wrap-excluded-outputs
                           #$glib-or-gtk-wrap-excluded-outputs
                           #:configure-flags #$configure-flags
                           #:make-flags #$make-flags
                           #:out-of-source? #$out-of-source?
                           #:tests? #$tests?
                           #:test-target #$test-target
                           #:parallel-build? #$parallel-build?
                           #:parallel-tests? #$parallel-tests?
                           #:validate-runpath? #$validate-runpath?
                           #:make-dynamic-linker-cache? #$make-dynamic-linker-cache?
                           #:patch-shebangs? #$patch-shebangs?
                           #:strip-binaries? #$strip-binaries?
                           #:strip-flags #$(sexp->gexp strip-flags)
                           #:strip-directories
                           #$(sexp->gexp strip-directories))))


  (mlet %store-monad ((guile (package->derivation (or guile (default-guile))
                                                  system #:graft? #f)))
    (gexp->derivation name builder
                      #:system system
                      #:target target
                      #:modules imported-modules
                      #:allowed-references allowed-references
                      #:disallowed-references disallowed-references
                      #:guile-for-build guile)))

(define glib-or-gtk-build-system
  (build-system
    (name 'glib-or-gtk)
    (description
     "The GNU Build System—i.e., ./configure && make && make install,
augmented with definition of suitable environment variables for glib and gtk+
in program wrappers.")
    (lower lower)))