(use-modules (gnu packages commencement)
             (gnu packages fontutils)
             (gnu packages xorg)
             (guix gexp))

(define set-up-gcc-gexp
  (with-imported-modules '((guix build utils))
    #~(begin
        (use-modules (guix build utils))

        (set-path-environment-variable "PATH"
                                       '("bin")
                                       (list #$gcc-toolchain))
        (set-path-environment-variable "C_INCLUDE_PATH"
                                       '("include")
                                       (list #$gcc-toolchain))
        (set-path-environment-variable "LIBRARY_PATH"
                                       '("lib")
                                       (list #$gcc-toolchain)))))

(define* (compile source-filename #:key (flags '()))
  (computed-file (string-append (basename source-filename ".c")
                                ".o")
                 #~(begin
                     #$set-up-gcc-gexp
                     (invoke "gcc" "-c" #$(local-file source-filename)
                             "-o" #$output
                             #$@flags))))

(define* (link output-filename object-files #:key (flags '()))
  (computed-file output-filename
                 #~(begin
                     #$set-up-gcc-gexp
                     (invoke "gcc" "-o" #$output
                             #$@object-files
                             #$@flags))))

(let ((include-dependencies
       (directory-union "include"
                        (list (file-append fontconfig "/include")
                              (file-append freetype "/include/freetype2")
                              (file-append libx11 "/include")
                              (file-append libxft "/include")
                              (file-append libxrender "/include")
                              (file-append xorgproto "/include")))))
  (link "sent"
        (list (let ((headers `(("arg.h" ,(local-file "sent/arg.h"))
                               ("config.h" ,(local-file "sent/config.def.h"))
                               ("drw.h" ,(local-file "sent/drw.h"))
                               ("util.h" ,(local-file "sent/util.h")))))
                (compile "sent/sent.c"
                         #:flags (list "-DVERSION=\"1\""
                                       "-I" include-dependencies
                                       "-I" (file-union "include" headers))))
              (let ((headers `(("drw.h" ,(local-file "sent/drw.h"))
                               ("util.h" ,(local-file "sent/util.h")))))
                (compile "sent/drw.c"
                         #:flags (list "-I" include-dependencies
                                       "-I" (file-union "include" headers))))
              (let ((headers `(("util.h" ,(local-file "sent/util.h")))))
                (compile "sent/util.c"
                         #:flags (list "-I" (file-union "include" headers)))))
        #:flags (list "-L" (file-append fontconfig "/lib")
                      "-L" (file-append libx11 "/lib")
                      "-L" (file-append libxft "/lib")
                      "-lfontconfig" "-lm" "-lX11" "-lXft")))