#! /bin/sh
# -*- scheme -*-
exec ${GUILE-guile} --no-auto-compile -L $HOME/src/mes/build-aux -L build-aux -e '(@@ (mes-snarf) main)' -s "$0" ${1+"$@"}
!#

;;; Mes --- Maxwell Equations of Software
;;; Copyright © 2016,2017 Jan Nieuwenhuizen <janneke@gnu.org>
;;;
;;; mes-snarf.scm: This file is part of Mes.
;;;
;;; Mes 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.
;;;
;;; Mes 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 Mes.  If not, see <http://www.gnu.org/licenses/>.

(define-module (mes-snarf)
  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-26)
  #:use-module (ice-9 curried-definitions)
  #:use-module (ice-9 rdelim)
  #:use-module (ice-9 regex)
  #:use-module (oop goops))

(define ((regexp-replace regexp replace) string)
  (or (and=> (string-match regexp string)
             (cut regexp-substitute #f <> 'pre replace 'post))
      string))

(define %gcc? #t)
;; (define-record-type function (make-function name formals annotation)
;;   function?
;;   (name .name)
;;   (formals .formals)
;;   (annotation .annotation))

(define-class <file> ()
  (name #:accessor .name #:init-keyword #:name)
  (content #:accessor .content #:init-keyword #:content))

(define-class <function> ()
  (name #:accessor .name #:init-keyword #:name)
  (formals #:accessor .formals #:init-keyword #:formals)
  (annotation #:accessor .annotation #:init-keyword #:annotation))

(define (function-scm-name f)
  (or (assoc-ref (.annotation f) 'name)
      (let ((name ((compose
                    (regexp-replace "_" "-")
                    (regexp-replace "_" "-")
                    (regexp-replace "_" "-")
                    (regexp-replace "_" "-")
                    (regexp-replace "_to_" "->")
                    (regexp-replace "_x$" "!")
                    (regexp-replace "_p$" "?")
                    (regexp-replace "___" "***")
                    (regexp-replace "___" "***"))
                   (.name f))))
        (if (not (string-suffix? "-" name)) name
            (string-append "core:" (string-drop-right name 1))))))

(define %builtin-prefix% "scm_")
(define (function-builtin-name f)
  (string-append %builtin-prefix% (.name f)))

(define %cell-prefix% "cell_")
(define (function-cell-name f)
  (string-append %cell-prefix% (.name f)))

(define %start 1)
(define (symbol->header s i)
  (format #f "#define cell_~a ~a\n" s i))

(define (symbol->source s i)
  (string-append
   (format #f "g_free++;\n")
   (format #f "g_cells[cell_~a] = scm_~a;\n\n" s s)))

(define (symbol->names s i)
  (if %gcc?
      (format #f "g_cells[cell_~a].car = cstring_to_list (scm_~a.name);\n" s s)
      (format #f "g_cells[cell_~a].car = cstring_to_list (scm_~a.car);\n" s s)))

(define (function->header f i)
  (let* ((arity (or (assoc-ref (.annotation f) 'arity)
                    (if (string-null? (.formals f)) 0
                        (length (string-split (.formals f) #\,)))))
         (n (if (eq? arity 'n) -1 arity)))
    (string-append
     (format #f "SCM ~a (~a);\n" (.name f) (.formals f))
     (if %gcc?
         (format #f "struct function fun_~a = {.function~a=&~a, .arity=~a, .name=~s};\n" (.name f) arity (.name f) n (function-scm-name f))
         (format #f "struct function fun_~a = {&~a, ~a, ~s};\n" (.name f) (.name f) n (function-scm-name f)))
     (if %gcc?
         (format #f "struct scm ~a = {TFUNCTION, .name=0, .function=0};\n" (function-builtin-name f))
         (format #f "struct scm ~a = {TFUNCTION, 0, 0};\n" (function-builtin-name f)))
     (format #f "SCM cell_~a;\n\n" (.name f)))))

(define (function->source f i)
  (string-append
   (if %gcc?
       (format #f "~a.function = g_function;\n" (function-builtin-name f))
       (format #f "~a.cdr = g_function;\n" (function-builtin-name f)))
   (format #f "g_functions[g_function++] = fun_~a;\n" (.name f))
   (format #f "cell_~a = g_free++;\n" (.name f))
   (format #f "g_cells[cell_~a] = ~a;\n\n" (.name f) (function-builtin-name f))))

(define (function->environment f i)
  (string-append
   (if %gcc?
       (format #f "scm_~a.string = cstring_to_list (fun_~a.name);\n" (.name f) (.name f))
       (format #f "scm_~a.car = cstring_to_list (fun_~a.name);\n" (.name f) (.name f)))
   (if %gcc?
       (format #f "g_cells[cell_~a].string = MAKE_STRING (scm_~a.string);\n" (.name f) (.name f))
       (format #f "g_cells[cell_~a].car = MAKE_STRING (scm_~a.car);\n" (.name f) (.name f)))
   (if %gcc?
       (format #f "a = acons (lookup_symbol_ (scm_~a.string), ~a, a);\n\n" (.name f) (function-cell-name f))
       (format #f "a = acons (lookup_symbol_ (scm_~a.car), ~a, a);\n\n" (.name f) (function-cell-name f)))))

(define (snarf-symbols string)
  (let* ((matches (list-matches "\nstruct scm scm_([a-z_0-9]+) = [{](TSPECIAL|TSYMBOL)," string)))
    (map (cut match:substring <> 1) matches)))

(define (snarf-functions string)
  (let* ((matches (list-matches
                   "\nSCM[ \n]?([a-z0-9_]+) [(]((SCM ?[^,)]+|, )*)[)][^\n(]*([^\n]*)"
                   string)))
    (map (lambda (m)
           (make <function>
             #:name (match:substring m 1)
             #:formals (match:substring m 2)
             #:annotation (with-input-from-string (match:substring m 4) read)))
         matches)))

(define (content? f)
  ((compose not string-null? .content) f))

(define (internal? f)
  ((compose (cut assoc-ref <> 'internal) .annotation) f))

(define (no-environment? f)
  ((compose (cut assoc-ref <> 'no-environment) .annotation) f))

(define (generate-includes file-name)
  (let* ((string (with-input-from-file file-name read-string))
         (functions (snarf-functions string))
         (functions (delete-duplicates functions (lambda (a b) (equal? (.name a) (.name b)))))
         (functions (filter (negate internal?) functions))
         (symbols (snarf-symbols string))
         (base-name (basename file-name ".c"))
         (dir (or (getenv "OUT") "out"))
         (base-name (string-append dir "/" base-name))
         (base-name (if %gcc? base-name
                        (string-append base-name ".mes")))
         (header (make <file>
                   #:name (string-append base-name ".h")
                   #:content (string-join (map function->header functions (iota (length functions) (+ %start (length symbols)))) "")))
         (source (make <file>
                        #:name (string-append base-name ".i")
                        #:content (string-join (map function->source (filter (negate no-environment?) functions) (iota (length functions) (+ (length symbols) %start))) ""))) 
         (environment (make <file>
                        #:name (string-append base-name ".environment.i")
                        #:content (string-join (map function->environment (filter (negate no-environment?) functions) (iota (length functions) (+ (length symbols) %start))) "")))
         (symbols.h (make <file>
                      #:name (string-append base-name ".symbols.h")
                      #:content (string-join (map symbol->header symbols (iota (length symbols) %start)) "")))
         (symbols.i (make <file>
                      #:name (string-append base-name ".symbols.i")
                      #:content (string-join (map symbol->source symbols (iota (length symbols))) "")))
         (symbol-names.i (make <file>
                          #:name (string-append base-name ".symbol-names.i")
                          #:content (string-join (map symbol->names symbols (iota (length symbols))) ""))))
    (list header source environment symbols.h symbols.i symbol-names.i)))

(define (file-write file)
  (with-output-to-file (.name file) (lambda () (display (.content file)))))

(define (main args)
  (let* ((files (if (not (and (pair? (cdr args)) (equal? (cadr args) "--mes"))) (cdr args)
                    (begin (set! %gcc? #f)
                           (cddr args)))))
    (map file-write (filter content? (append-map generate-includes files)))))

;;(define string (with-input-from-file "../mes.c" read-string))