#!/bin/sh
# -*- scheme -*-
GUILE_LOAD_PATH="$1"
export GUILE_LOAD_PATH
exec ${GUILE:-@GUILE@} --no-auto-compile -e main -s "$0" "$@"
!#
;;;; evaluate - convert a specification to a job list
;;; Copyright © 2016 Ludovic Courtès <ludo@gnu.org>
;;; 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 (ice-9 format)
             (ice-9 match)
             (ice-9 pretty-print)
             (guix store)
             (srfi srfi-19))

(define-syntax-rule (with-directory-excursion dir body ...)
  "Run BODY with DIR as the process's current directory."
  (let ((init (getcwd)))
    (dynamic-wind
      (λ () (chdir dir))
      (λ () body ...)
      (λ () (chdir init)))))

(define (call-with-time thunk kont)
  "Call THUNK and pass KONT the elapsed time followed by THUNK's return
value."
  (let* ((start  (current-time time-monotonic))
         (result (thunk))
         (end    (current-time time-monotonic)))
    (kont (time-difference end start) result)))

(define (call-with-time-display thunk)
  "Call THUNK and write to the current output port its duration."
  (call-with-time thunk
    (λ (time result)
      (let ((duration (+ (time-second time)
                         (/ (time-nanosecond time) 1e9))))
        (format (current-error-port) "evaluate '~A': ~,3f seconds~%"
                (assq-ref result #:job-name)
                duration)
        (acons #:duration duration result)))))

(define* (main #:optional (args (command-line)))
  (match args
    ((command load-path cachedir specstr)
     ;; Load FILE, a Scheme file that defines Hydra jobs.
     (let* ((%user-module (make-fresh-user-module))
            (spec (eval-string specstr %user-module))
            (stdout (current-output-port))
            (stderr (current-error-port)))
       (save-module-excursion
        (λ ()
          (set-current-module %user-module)
          (with-directory-excursion
              (string-append cachedir "/" (assq-ref spec #:name))
            (primitive-load (assq-ref spec #:file)))))
       (with-store store
         ;; Make sure we don't resort to substitutes.
         (set-build-options store #:use-substitutes? #f #:substitute-urls '())
         ;; Grafts can trigger early builds.  We do not want that to happen
         ;; during evaluation, so use a sledgehammer to catch such problems.
         (set! build-things
               (λ (store . args)
                 (display "error: trying to build things during evaluation!~%"
                          stderr)
                 (format stderr "'build-things' arguments: ~S~%" args)
                 (exit 1)))
         ;; Call the entry point of FILE and print the resulting job sexp.
         (pretty-print
          (let* ((proc   (module-ref %user-module 'hydra-jobs) )
                 (thunks (proc store (assq-ref spec #:arguments))))
            (map (λ (thunk)
                   (call-with-time-display thunk))
                 thunks))
          stdout))))
    ((command _ ...)
     (format (current-error-port) "Usage: ~A FILE
Evaluate the Hydra jobs defined in FILE.~%"
             command)
     (exit 1))))