;;; Chickadee Game Toolkit
;;; Copyright © 2016 David Thompson <davet@gnu.org>
;;;
;;; Chickadee is free software: you can redistribute it and/or modify it
;;; under the terms of the GNU Lesser General Public License as
;;; published by the Free Software Foundation, either version 3 of the
;;; License, or (at your option) any later version.
;;;
;;; Chickadee 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 Lesser General
;;; Public License for more details.
;;;
;;; You should have received a copy of the GNU Lesser General Public
;;; License along with this program.  If not, see
;;; <http://www.gnu.org/licenses/>.

;;; Commentary:
;;
;; Build time configuration.
;;
;;; Code:

(define-module (chickadee config)
  #:use-module (ice-9 match)
  #:use-module (system foreign)
  #:export (dynamic-link*
            %datadir
            %chickadee-version
            %libopenal
            %libvorbisfile
            %libmpg123
            %libfreetype
            %libreadline
            scope-datadir))

;; Try to link against multiple library possibilities, such as the
;; absolute file name discovered by ./configure or by searching the
;; library load path as a fallback method.  Useful when distributing
;; relocatable builds.
(define (dynamic-link* names)
  (let loop ((names* names))
    (match names*
      (()
       (error "could not find library" names))
      ((name . rest)
       (or (false-if-exception (dynamic-link name))
           (loop rest))))))

(define %datadir
  (or (getenv "CHICKADEE_DATADIR") "@chickadee_datadir@/chickadee"))

(define %chickadee-version "@PACKAGE_VERSION@")

;; When LD_LIBRARY_PATH is set, we *don't* want to use the absolute
;; file name of the library that pkgconfig found.  Instead, we want to
;; use the library name itself so the search path is used.
(define-syntax-rule (define-library-name name
                      (absolute ...)
                      (relative ...))
  (define name
    (cond
     ((getenv "LD_LIBRARY_PATH")
      '(relative ...))
     (else
      '(absolute ...)))))

(define-library-name %libopenal
  ("@OPENAL_LIBDIR@/libopenal")
  ("libopenal"))
(define-library-name %libvorbisfile
  ("@VORBIS_LIBDIR@/libvorbisfile")
  ("libvorbisfile"))
(define-library-name %libmpg123
  ("@MPG123_LIBDIR@/libmpg123")
  ("libmpg123"))
(define-library-name %libfreetype
  ("@FREETYPE_LIBDIR@/libfreetype")
  ("libfreetype"))
(define-library-name %libreadline
  ("@READLINE_LIBDIR@/libreadline")
  ("libreadline"))

(define (scope-datadir file)
  "Append the Chickadee data directory to FILE."
  (string-append %datadir "/" file))