;;; -*-scheme-*-
;;;

;;; Lepton EDA netlister
;;; Copyright (C) 1998-2010 Ales Hvezda
;;; Copyright (C) 2007-2016 gEDA Contributors
;;; Copyright (C) 2018-2021 Lepton EDA Contributors
;;;
;;; This program 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 2 of the License, or
;;; (at your option) any later version.
;;;
;;; This program 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 this program; if not, write to the Free Software
;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

;;  gsch2pcb format  (based on PCBboard format by JM Routoure & Stefan Petersen)
;;  Bill Wilson    billw@wt.net
;;  6/17/2003

(use-modules (ice-9 popen)
             (ice-9 rdelim)
             (netlist schematic)
             (netlist schematic toplevel))


;;
;;
(define gsch2pcb:write-top-header
  (lambda ()
    (display "# release: pcb 1.99x\n")
    (display "# To read pcb files, the pcb version (or the")
    (display " cvs source date) must be >= the file version\n")
    (display "FileVersion[20070407]\n")
    (display "PCB[\"\" 600000 500000]\n")
    (display "Grid[10000.000000 0 0 0]\n")
    (display "Cursor[0 0 0.000000]\n")
    (display "PolyArea[200000000.000000]\n")
    (display "Thermal[0.500000]\n")
    (display "DRC[1000 1000 1000 1000 1500 1000]\n")
    (display "Flags(\"nameonpcb,uniquename,clearnew,snappin\")\n")
    (display "Groups(\"1,c:2:3:4:5:6,s:7:8\")\n")
    (display "Styles[\"Signal,1000,3600,2000,1000:")
    (display "Power,2500,6000,3500,1000:")
    (display "Fat,4000,6000,3500,1000:")
    (display "Skinny,600,2402,1181,600\"]\n")
))

;;
;;
(define gsch2pcb:write-bottom-footer
  (lambda ()
    (display "Layer(1 \"top\")\n(\n)\n")
    (display "Layer(2 \"ground\")\n(\n)\n")
    (display "Layer(3 \"signal2\")\n(\n)\n")
    (display "Layer(4 \"signal3\")\n(\n)\n")
    (display "Layer(5 \"power\")\n(\n)\n")
    (display "Layer(6 \"bottom\")\n(\n)\n")
    (display "Layer(7 \"outline\")\n(\n)\n")
    (display "Layer(8 \"spare\")\n(\n)\n")
    (display "Layer(9 \"silk\")\n(\n)\n")
    (display "Layer(10 \"silk\")\n(\n)")
    (newline)))

;;
;;

;; Splits a string with space separated words and returns a list
;; of the words (still as strings).
(define (gsch2pcb:split-to-list the-string)
  (filter!
   (lambda (x) (not (string=? "" x)))
   (string-split the-string #\space)))

;; Check if `str' contains only characters valid in an M4 function
;; name.  Note that this *doesn't* check that str is a valid M4
;; function name.
(define gsch2pcb:m4-valid?
  (let ((rx (make-regexp "^[A-Za-z0-9_]*$")))
    (lambda (str)
      (regexp-exec rx str))))

;; Quote a string to protect from M4 macro expansion
(define (gsch2pcb:m4-quote str)
  (string-append "`" str "'"))

;; Write the footprint for the package `refdes' to `port'.  If M4
;; footprints are enabled, writes in a format suitable for
;; macro-expansion by M4.  Any footprint names that obviously can't be
;; M4 footprints are protected from macro-expansion.
(define (gsch2pcb:write-value-footprint refdes port)

  (let* ((value (gnetlist:get-package-attribute refdes "value"))
         (footprint (gsch2pcb:split-to-list
                     (gnetlist:get-package-attribute refdes "footprint")))
         (fp (car footprint))
         (fp-args (cdr footprint))

         (nq (lambda (x) x)) ; A non-quoting operator
         (q (if gsch2pcb:use-m4 gsch2pcb:m4-quote nq))) ; A quoting operator

    (format port "~A(~A,~A,~A~A)\n"
            ;; If the footprint is obviously not an M4 footprint,
            ;; protect it from macro-expansion.
            ((if (gsch2pcb:m4-valid? fp) nq q) (string-append "PKG_" fp))
            (q (string-join footprint "-"))
            (q refdes)
            (q value)
            (string-join (map q fp-args) "," 'prefix))))

;; Write the footprints for all the refdes' in `lst'.
(define (gsch2pcb:write-value-footprints port lst)
  (for-each (lambda (x) (gsch2pcb:write-value-footprint x port)) lst))

;;
;;

(define gsch2pcb:use-m4 #f)

;; Macro that defines and sets a variable only if it's not already defined.
(define-syntax define-undefined
  (syntax-rules ()
    ((_ name expr)
     (define name
       (if (defined? (quote name))
           name
           expr)))))

;; Let the user override the m4 command, the directory
;; where pcb stores its m4 files and the pcb config directory.
(define-undefined gsch2pcb:pcb-m4-command "/usr/bin/m4")
(define-undefined gsch2pcb:pcb-m4-dir "/usr/share/pcb/m4")
(define-undefined gsch2pcb:m4-files "")

;; Let the user override the m4 search path
(define-undefined gsch2pcb:pcb-m4-path '("$HOME/.pcb" "."))

;; List of the m4 command line entries
(define (gsch2pcb:build-m4-command-line-list)
  (delv ""
        (append
          (list
            gsch2pcb:pcb-m4-command
            "-d")
          (map-in-order
            (lambda (x) (string-append "-I" x))
            (cons
              gsch2pcb:pcb-m4-dir
              gsch2pcb:pcb-m4-path))
          (list
            (string-append gsch2pcb:pcb-m4-dir "/common.m4")
            gsch2pcb:m4-files
            "-"))))

;; Build up the m4 command line
(define (gsch2pcb:build-m4-command-line)
  (string-join
    (gsch2pcb:build-m4-command-line-list)
    " "
    'infix))

;; run a child process and return a pair of input and output ports.
;; Executes the program 'command' with optional arguments 'args'
;; (all strings) in a subprocess.
;; Two ports to the process (based on pipes) are created and
;; returned.
;; The procedure is a modified version of the popen open-pipe*
;; procedure. Its functionality is close to that of
;; open-input-output-pipe. Changes are made to make it return two
;; ports instead of one in order to have a possibility to close
;; each one separately. This allows closing of the input pipe by
;; using (close-port port) when needed and emit EOF to the running
;; child process.
(define (gsch2pcb:open-io-pipe command . args)
  (let* ((c2p (pipe))  ; child to parent
         (p2c (pipe))) ; parent to child

    ; setvbuf( port, mode ) function:
    ; [mode] is a  symbol  (either 'none,  'line  or 'block)
    ;
    (setvbuf (cdr c2p) 'none)
    (setvbuf (cdr p2c) 'none)

    (let ((pid (primitive-fork)))
      (if (= pid 0)
        (begin
         ;; child process
         (ensure-batch-mode!)

         ;; select the three file descriptors to be used as
         ;; standard descriptors 0, 1, 2 for the new
         ;; process. They are pipes to/from the parent or taken
         ;; from the current Scheme input/output/error ports if
         ;; possible.

         (let ((input-fdes (fileno (car p2c)))
           (output-fdes (fileno (cdr c2p)))
           (error-fdes
             (or (false-if-exception (fileno (current-error-port)))
                 (open-fdes *null-device* O_WRONLY))))

           ;; close all file descriptors in ports inherited from
           ;; the parent except for the three selected above.
           ;; this is to avoid causing problems for other pipes in
           ;; the parent.

           ;; use low-level system calls, not close-port or the
           ;; scsh routines, to avoid side-effects such as
           ;; flushing port buffers or evicting ports.

           (port-for-each (lambda (pt-entry)
                (false-if-exception
                 (let ((pt-fileno (fileno pt-entry)))
                   (if (not (or (= pt-fileno input-fdes)
                        (= pt-fileno output-fdes)
                        (= pt-fileno error-fdes)))
                       (close-fdes pt-fileno))))))

           ;; Copy the three selected descriptors to the standard
           ;; descriptors 0, 1, 2, if not already there

           (if (not (= input-fdes 0))
             (begin
               (if (= output-fdes 0) (set! output-fdes (dup->fdes 0)))
               (if (= error-fdes  0) (set! error-fdes  (dup->fdes 0)))
               (dup2 input-fdes 0)
               ;; it's possible input-fdes is error-fdes
               (if (not (= input-fdes error-fdes))
                 (close-fdes input-fdes))))

           (if (not (= output-fdes 1))
             (begin
               (if (= error-fdes 1) (set! error-fdes (dup->fdes 1)))
               (dup2 output-fdes 1)
               ;; it's possible output-fdes is error-fdes
               (if (not (= output-fdes error-fdes))
                 (close-fdes output-fdes))))

           (if (not (= error-fdes 2))
             (begin
               (dup2 error-fdes 2)
               (close-fdes error-fdes)))

           (apply execlp command command args)))
        (begin
          ;; parent process
          ;; the forked child process should use these ports so
          ;; the parent process doesn't need them any more
          (close-port (cdr c2p))
          (close-port (car p2c))
          ;; return input and output ports
          (cons (car c2p) (cdr p2c))
          )))))

(define (gsch2pcb output-filename)
  (gsch2pcb:write-top-header)

  (format (current-error-port)
          "=====================================================
gsch2pcb backend configuration:

   ----------------------------------------
   Variables which may be changed in gafrc:
   ----------------------------------------
   gsch2pcb:pcb-m4-command:    ~S
   gsch2pcb:pcb-m4-dir:        ~S
   gsch2pcb:pcb-m4-path:       ~S
   gsch2pcb:m4-files:          ~S

   ---------------------------------------------------
   Variables which may be changed in the project file:
   ---------------------------------------------------
   gsch2pcb:use-m4:            ~A

   ----------------
   M4 command line:
   ----------------
   ~A

=====================================================
"
          gsch2pcb:pcb-m4-command
          gsch2pcb:pcb-m4-dir
          gsch2pcb:pcb-m4-path
          gsch2pcb:m4-files
          (if gsch2pcb:use-m4 "yes" "no")
          (gsch2pcb:build-m4-command-line))

  (let ((packages (schematic-package-names (toplevel-schematic))))
    ;; If we have defined gsch2pcb:use-m4 then run the footprints
    ;; through the pcb m4 setup.  Otherwise skip m4 entirely
    (if gsch2pcb:use-m4
        ;; pipe with the macro define in pcb program
        (let* ((pipe-ports
                (apply gsch2pcb:open-io-pipe
                       (gsch2pcb:build-m4-command-line-list)))
               (ip (car pipe-ports))
               (op (cdr pipe-ports)))

          (message "Using the m4 processor for pcb footprints\n")
          ;; packages is a list with the different refdes value
          (gsch2pcb:write-value-footprints op packages)
          (close-port op)
          (do ((line (read-line ip) (read-line ip)))
              ((eof-object? line))
            (display line)
            (newline)))

        ;; don't use m4
        (begin
          (message "Skipping the m4 processor for pcb footprints\n")
          (gsch2pcb:write-value-footprints (current-output-port) packages))))

  (gsch2pcb:write-bottom-footer))
