#!/bin/sh
# -*- scheme -*-
exec ${GUILE:-@GUILE@} --no-auto-compile -e main -s "$0" "$@"
!#
;;;; cuirass - continuous integration system
;;;
;;; Copyright © 2016 Mathieu Lirzin <mthl@gnu.org>
;;;
;;; This file is part of Cuirass.
;;;
;;; Cuirass 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.
;;;
;;; Cuirass 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 Cuirass.  If not, see <http://www.gnu.org/licenses/>.

(use-modules (cuirass base)
             (ice-9 match))

(define %guix-repository
  (make-parameter "git://git.savannah.gnu.org/guix.git"))

(define* (pull-changes dir)
  "Get the latest version of Guix repository.  Clone repository in directory
DIR if required."
  (or (file-exists? dir) (mkdir dir))
  (with-directory-excursion dir
    (let ((guixdir "guix"))
      (or (file-exists? guixdir)
          (system* "git" "clone" (%guix-repository) guixdir))
      (with-directory-excursion guixdir
        (and (zero? (system* "git" "fetch")) ;no 'git pull' to avoid merges
             (zero? (system* "git" "reset" "--hard" "origin/master")))))))

(define (compile dir)
  "Compile files in Guix cloned repository in directory DIR."
  (with-directory-excursion (string-append dir "/guix")
    (or (file-exists? "configure") (system* "./bootstrap"))
    (or (file-exists? "Makefile")
        (system* "./configure" "--localstatedir=/var"))
    (zero? (system* "make" "-j" (number->string (current-processor-count))))))

(define %user-module
  ;; Cuirass user module.
  (let ((m (make-module)))
    (beautify-user-module! m)
    m))

(define (build-packages store jobs)
  "Build JOBS which is a list of job.  ((job-symbol pair ...) ...)"
  (map (lambda (thing)
         (let ((name (symbol->string (car thing)))
               (drv  (cdadr thing)))
           (format #t "building ~A => ~A~%" name drv)
           ((guix-variable 'derivations 'build-derivations) store (list drv))))
       jobs))

(define (evaluate dir)
  "Evaluate and build package derivations in directory DIR."
  (save-module-excursion
   (lambda ()
     (set-current-module %user-module)
     (primitive-load (string-append dir "/guix/build-aux/hydra/gnu-system.scm"))))
  (let ((store ((guix-variable 'store 'open-connection))))
    (dynamic-wind
      (const #t)
      (lambda ()
        ((guix-variable 'store 'set-build-options) store
         #:use-substitutes? #f)
        (build-packages
         store
         (match ((module-ref %user-module 'hydra-jobs) store '())
           (((names . thunks) ...)
            (map (lambda (job thunk)
                   (format (current-error-port) "evaluating '~a'... " job)
                   (force-output (current-error-port))
                   (cons job (call-with-time-display thunk)))
                 names thunks)))))
      (lambda ()
        ((guix-variable 'store 'close-connection) store)))))


;;;
;;; Entry point.
;;;

(define* (main #:optional (args (command-line)))
  (match args
    ((program interval)
     (let ((cachedir (getenv "CUIRASS_CACHEDIR")))
       (while #t
         (pull-changes cachedir)
         (compile cachedir)
         (evaluate cachedir)
         (sleep (string->number interval)))))
    (_ (main (list (car args) "60")))))