;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;
;;; git.setup - git egg installation script
;;;
;;; Verifies the CHICKEN and libgit2 library version before installation.
;;;
;;; Copyright (c) 2013-2016, Evan Hanson
;;; See LICENSE for details.
;;;

(define *required-chicken* "4.8.0")
(define *required-libgit2* "0.23.0")

;;
;; Verify the CHICKEN version.
;;

(unless (version>=? (chicken-version) *required-chicken*)
  (error "git: This extension requires CHICKEN version" *required-chicken*))

;;
;; Verify the libgit2 version.
;;
;; Due to API instability, the library's major and minor versions must
;; match the required version precisely, while its patch version may be
;; equal to or greater than required.
;;

(define (libgit2-version-ok? version-string)
  (version>=? version-string *required-libgit2*))

;; If pkg-config is available, consult it first.
(define pkg-config-version
  (string-trim-both (with-input-from-pipe "pkg-config --modversion libgit2" read-string)))

;; Assign a libgit2 version feature identifier.
(define libgit2-version
  (cond
    ((string-null? pkg-config-version)
     (warning "git: Unable to detect libgit2 version, guessing" *required-libgit2*)
     (fprintf (current-error-port) "\n")
     (string-append "libgit2-" *required-libgit2*))
    ((libgit2-version-ok? pkg-config-version)
     (string-append "libgit2-" pkg-config-version))
    (else
     (error "git: This extension requires libgit2 version" *required-libgit2*))))

;; Shared libraries.
(compile -sJ -O3 -d0 -specialize libgit2.scm -lgit2 -D ,libgit2-version)
(compile -sJ -O3 -d0 -specialize git.scm -D ,libgit2-version)

;; Static libraries.
(compile -no-module-registration -cJ -O3 -d0 -specialize -unit libgit2 libgit2.scm -o libgit2.o -D ,libgit2-version)
(compile -no-module-registration -cJ -O3 -d0 -specialize -uses libgit2 -unit git git.scm -o git.o -emit-type-file git.types -D ,libgit2-version)

;; Import libraries.
(compile -s -O3 -d0 libgit2.import.scm)
(compile -s -O3 -d0 git.import.scm)

;; If we couldn't detect libgit2's version via pkg-config, check it
;; directly now.
(when (string-null? pkg-config-version)
  (load "./libgit2.so")
  (load "./libgit2.import.so")
  (import (only libgit2 libgit2-version))
  ;; `libgit2-version` returns a vector `#(<major> <minor> <patch>)`;
  ;; format it as an "X.X.X" version string against which to compare.
  (unless (libgit2-version-ok? (apply format "~a.~a.~a" (vector->list (libgit2-version))))
    (error "git: This extension requires libgit2" *required-libgit2*)))

(install-extension 'git
 '("libgit2.so" "libgit2.import.so"
   "git.so" "git.import.so" "git.types"
   "git.o" "libgit2.o")
 '((version "0.0.36")))