;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2016 Ricardo Wurmus <rekado@elephly.net>
;;;
;;; 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 ant-build-system)
  #:use-module ((guix build gnu-build-system) #:prefix gnu:)
  #:use-module (guix build utils)
  #:use-module (sxml simple)
  #:use-module (ice-9 match)
  #:use-module (ice-9 ftw)
  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-26)
  #:export (%standard-phases
            ant-build))

;; Commentary:
;;
;; Builder-side code of the standard build procedure for Java packages using
;; Ant.
;;
;; Code:

(define (default-build.xml jar-name prefix)
  "Create a simple build.xml with standard targets for Ant."
  (let ((file (open-output-file "build.xml")))
    (sxml->xml
     `(project (@ (basedir "."))
               (property (@ (name "classes.dir")
                            (value "${basedir}/build/classes")))
               (property (@ (name "jar.dir")
                            (value "${basedir}/build/jar")))
               (property (@ (name "dist.dir")
                            (value ,prefix)))

               ;; respect the CLASSPATH environment variable
               (property (@ (name "build.sysclasspath")
                            (value "first")))
               (property (@ (environment "env")))
               (path (@ (id "classpath"))
                     (pathelement (@ (location "${env.CLASSPATH}"))))

               (target (@ (name "compile"))
                       (mkdir (@ (dir "${classes.dir}")))
                       (javac (@ (includeantruntime "false")
                                 (srcdir "src")
                                 (destdir "${classes.dir}")
                                 (classpath (@ (refid "classpath"))))))

               ;; Reset the ctime/mtime on all files to ensure that the
               ;; jar archive for the same class files is bit-identical.
               (target (@ (name "touch"))
                       (exec (@ (executable "find"))
                             (arg (@ (line "${classes.dir} -exec touch -d @0 {} ;")))))

               (target (@ (name "jar")
                          (depends "compile,touch"))
                       (mkdir (@ (dir "${jar.dir}")))
                       ;; We cannot use the simpler "jar" task here, because
                       ;; there is no way to disable generation of a
                       ;; manifest.  We do not include a generated manifest
                       ;; to ensure determinism, because we cannot easily
                       ;; reset the ctime/mtime before creating the archive.
                       (exec (@ (executable "jar"))
                             (arg (@ (line ,(string-append "-Mcf ${jar.dir}/" jar-name
                                                           " -C ${classes.dir} ."))))))

               (target (@ (name "install"))
                       (copy (@ (todir "${dist.dir}"))
                             (fileset (@ (dir "${jar.dir}"))
                                      (include (@ (name "**/*.jar")))))))
     file)
    (close-output-port file)
    (utime "build.xml" 0 0)
    #t))

(define (generate-classpath inputs)
  "Return a colon-separated string of full paths to jar files found among the
INPUTS."
  (string-join
   (apply append (map (match-lambda
                        ((_ . dir)
                         (find-files dir "\\.*jar$")))
                      inputs)) ":"))

(define* (configure #:key inputs outputs (jar-name #f)
                    #:allow-other-keys)
  (when jar-name
    (default-build.xml jar-name
      (string-append (assoc-ref outputs "out")
                     "/share/java")))
  (setenv "JAVA_HOME" (assoc-ref inputs "jdk"))
  (setenv "CLASSPATH" (generate-classpath inputs)))

(define* (build #:key (make-flags '()) (build-target "jar")
                #:allow-other-keys)
  (zero? (apply system* `("ant" ,build-target ,@make-flags))))

(define* (check #:key target (make-flags '()) (tests? (not target))
                (test-target "check")
                #:allow-other-keys)
  (if tests?
      (zero? (apply system* `("ant" ,test-target ,@make-flags)))
      (begin
        (format #t "test suite not run~%")
        #t)))

(define* (install #:key (make-flags '()) #:allow-other-keys)
  (zero? (apply system* `("ant" "install" ,@make-flags))))

(define %standard-phases
  (modify-phases gnu:%standard-phases
    (replace 'configure configure)
    (replace 'build build)
    (replace 'check check)
    (replace 'install install)))

(define* (ant-build #:key inputs (phases %standard-phases)
                    #:allow-other-keys #:rest args)
  "Build the given Java package, applying all of PHASES in order."
  (apply gnu:gnu-build #:inputs inputs #:phases phases args))

;;; ant-build-system.scm ends here