;;;; This file is part of LilyPond, the GNU music typesetter.
;;;;
;;;; Copyright (C) 2005--2022 Jan Nieuwenhuizen <janneke@gnu.org>
;;;; Han-Wen Nienhuys <hanwen@xs4all.nl>
;;;;
;;;; LilyPond 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.
;;;;
;;;; LilyPond 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 LilyPond.  If not, see <http://www.gnu.org/licenses/>.

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; backend helpers.

(use-modules (lily ps-to-png)
             (lily paper-system)
             (ice-9 optargs)
             (srfi srfi-1))

(define-public (ly:system command)
  (ly:debug (G_ "Invoking `~a'...") (string-join command))
  (let ((status (apply ly:spawn command)))
    (if (not (= status 0))
        (begin
          (ly:warning (G_ "`~a' failed (~a)\n") command status)
          ;; hmmm.  what's the best failure option?
          (throw 'ly-file-failed)))))

(define-public (search-executable names)
  (define (helper path lst)
    (if (null? (cdr lst))
        (car lst)
        (if (search-path path (car lst)) (car lst)
            (helper path (cdr lst)))))

  (let ((path (parse-path (getenv "PATH"))))
    (helper path names)))

(define-public (ly:gs-cli args run-str)
  (let*
      ((tmp (make-tmpfile #f))
       (tmp-name (port-filename tmp)))
    (set-port-encoding! tmp "UTF-8")

    (ly:debug (G_ "Preparing Ghostscript command to `~a': ~a")
              tmp-name run-str)
    (display run-str tmp)
    (close-port tmp)
    (set! args (append args (list tmp-name)))
    (ly:system args)
    (delete-file tmp-name)
    ))

(define-public (gs-cmd-args is-eps fit-page)
  (filter string?
          (list
           (search-executable '("gs"))
           (if (not (ly:get-option 'verbose)) "-q")
           "-dNODISPLAY"
           ;; see function gs-safe-run below where we use .setsafe instead
           "-dNOSAFER"
           "-dNOPAUSE"
           "-dBATCH"
           (if (and is-eps (not fit-page)) "-dEPSCrop")
           (if fit-page "-dEPSFitPage")
           "-dAutoRotatePages=/None"
           "-dPrinted=false"
           ;; Load `nocache.ps` to define `uncachedevice`, which we need to
           ;; reset the page counter for some devices; see `ps-to-png.scm`.
           (if (ly:get-option 'gs-api)
               (format #f "~a/ps/nocache.ps" (ly:get-option 'datadir)))
          )))

(define-public (gs-safe-run input)
  ;; The PostScript Language Reference Manual says "run is a convenience
  ;; operator that combines the functions of file and exec". (This does
  ;; not seem to hold for Ghostscript, the second operator must be 'run'
  ;; for PNG output).
  ;; To enable access control (as usually done with -dSAFER), we need to
  ;; insert the operator .setsafe between file and run, _after_ we have
  ;; opened the input file. We cannot use .addcontrolpath because it was
  ;; introduced in version 9.50, but .setsafe should also work with older
  ;; releases.
  (string-join
   (list
    (format #f "(~a)" input)
    "(r) file"
    (if (or (ly:get-option 'gs-api)
            (ly:get-option 'gs-load-fonts)
            (ly:get-option 'gs-load-lily-fonts)
            (eq? PLATFORM 'windows))
        ""
        ".setsafe")
    "run")
   " "))

(define-public (postscript->pdf paper-width paper-height
                                base-name tmp-name is-eps)
  (let* ((pdf-name (format #f "~a/~a.pdf"
                           ;; Create the file in the same directory as the
                           ;; destination, or renaming won't work across
                           ;; filesystems, but ...
                           (dirname base-name)
                           ;; make sure there are no special characters in
                           ;; the filename to avoid problems with Ghostscript
                           ;; on Windows.
                           (basename tmp-name)))
         ;; The temporary file for flushing can go next to the temporary ps file
         ;; in /tmp.
         (flush-name (string-append tmp-name ".flush"))
         (dest (string-append base-name ".pdf"))
         (output-file (string-join (string-split pdf-name #\%) "%%"))
         (run-strings
          (filter string?
                  (list
                   "<<"
                   (format #f "/OutputFile (~a)" output-file)
                   ;; Ghostscript's default level may change with future
                   ;; releases, the current being 1.7 since 9.24. This
                   ;; results in a warning when embedding the produced PDF
                   ;; with XeTeX, which currently defaults to PDF 1.5.
                   ;; Set a fixed version of 1.4, which is also the basis
                   ;; of the standard PDF/A and has all features we need.
                   "/CompatibilityLevel 1.4"
                   (if (not is-eps)
                       (ly:format "/PageSize [~$ ~$]" paper-width paper-height))
                   "/OutputDevice /pdfwrite >> setpagedevice"
                   ;; `setpagedevice` does not set some defaults, causing larger
                   ;; output files than necessary, among other things.  To fix
                   ;; this we call a gs-specific procedure.
                   "/.setdefaultscreen where {"
                   "pop .setdefaultscreen"
                   "} {"
                   "(Warning: .setdefaultscreen not available) print"
                   "} ifelse"
                   ;; from Resource/Init/gs_pdfwr.ps; needed here because we
                   ;; do not have the pdfwrite device initially (-dNODISPLAY).
                   "newpath fill"
                   (gs-safe-run tmp-name)))
          ))

    (ly:message (G_ "Converting to `~a'...\n") dest)
    ((if (ly:get-option 'gs-api) ly:gs-api ly:gs-cli)
     (gs-cmd-args is-eps #f) (string-join run-strings " "))

    ;; for pdfwrite, the output is only finalized once a new output
    ;; file is opened.
    (if (ly:get-option 'gs-api)
        (begin
          (ly:gs-api (gs-cmd-args is-eps #f)
                     (string-join
                      (list
                       "<<"
                       (format #f "/OutputFile (~a)" flush-name)
                       "/OutputDevice /pdfwrite >> setpagedevice"
                       ;; see above
                       "/.setdefaultscreen where {"
                       "pop .setdefaultscreen"
                       "} {"
                       "(Warning: .setdefaultscreen not available) print"
                       "} ifelse"
                       ;; see above
                       "newpath fill")
                      " "))
          (delete-file flush-name)))

    (ly:rename-file pdf-name dest)
    ))

(define-public (postscript->png resolution paper-width paper-height bbox
                                base-name tmp-name is-eps)
  ;; Do not try to guess the name of the png file,
  ;; GS produces PNG files like BASE-page%d.png.
  (ly:message (G_ "Converting to ~a...") "PNG")
  ;; If option `png-width` and/or `png-height` is set, `resolution`
  ;; is ignored.
  (make-ps-images base-name tmp-name is-eps
                  #:resolution resolution
                  #:page-width paper-width
                  #:page-height paper-height
                  #:bbox bbox
                  #:anti-alias-factor (ly:get-option 'anti-alias-factor)
                  #:pixmap-format (ly:get-option 'pixmap-format)
                  #:png-width (ly:get-option 'png-width)
                  #:png-height (ly:get-option 'png-height))
  (ly:progress "\n"))

(define-public (postscript->ps base-name tmp-name is-eps)
  (let* ((ps-name (string-append base-name
                                 (if is-eps ".eps" ".ps"))))
    (if (not (equal? ps-name tmp-name))
        (begin
          (ly:message (G_ "Copying to `~a'...\n") ps-name)
          (copy-binary-file tmp-name ps-name)))))

(define-public (mkdir-if-not-exist path . mode)
  (catch
   'system-error
   (lambda ()
     ;; mkdir:
     ;; If the directory already exists, it raises system-error.
     (if (null? mode)
         (mkdir path)
         (mkdir path (car mode)))
     #t)
   (lambda stuff
     ;; Catch the system-error
     (if (= EEXIST (system-error-errno stuff))
         ;; If the directory already exists, avoid error and return #f.
         (begin #f)
         ;; If the cause is something else, re-throw the error.
         (throw 'system-error (cdr stuff))))))

(define-public (symlink-if-not-exist oldpath newpath)
  (catch
   'system-error
   (lambda ()
     ;; symlink:
     ;; If the file already exists, it raises system-error.
     (symlink oldpath newpath)
     #t)
   (lambda stuff
     ;; Catch the system-error
     (if (= EEXIST (system-error-errno stuff))
         ;; If the file already exists, avoid error and return #f.
         (begin #f)
         ;; If the cause is something else, re-throw the error.
         (throw 'system-error (cdr stuff))))))

(define-public (close-port-rename port name)
  (let* ((tmp (port-filename port)))
    (close-port port)
    (ly:rename-file tmp name)))

(define-public (symlink-or-copy-if-not-exist oldpath newpath)
  (if (eq? PLATFORM 'windows)
      (let ((port (create-file-exclusive newpath)))
        (if port
            (begin
              (close port)
              (copy-binary-file oldpath newpath)
              #t)
            (begin #f)))
      (symlink-if-not-exist oldpath newpath)))

(define-public (create-file-exclusive path . mode)
  (catch
   'system-error
   (lambda ()
     ;; Exclusive file create:
     ;; If the file already exists, it raises system-error.
     (if (null? mode)
         (open path (logior O_WRONLY O_CREAT O_EXCL))
         (open path (logior O_WRONLY O_CREAT O_EXCL) (car mode))))
   (lambda stuff
     ;; Catch the system-error
     (if (= EEXIST (system-error-errno stuff))
         ;; If the file already exists, avoid error and return #f.
         (begin #f)
         ;; If the cause is something else, re-throw the error.
         (throw 'system-error (cdr stuff))))))

(define-public (copy-binary-file from-name to-name)
  (if (eq? PLATFORM 'windows)
      ;; MINGW hack: MinGW Guile's copy-file is broken.
      ;; It opens files by the text mode instead of the binary mode.
      ;; (It is fixed from Guile 2.0.9.)
      ;; By the text mode, copied binary files are broken.
      ;; So, we open files by the binary mode and copy by ourselves.
      (let ((port-from (open-file from-name "rb"))
            (port-to (open-file to-name "wb")))
        (let loop((c (read-char port-from)))
          (if (eof-object? c)
              (begin (close port-from)
                     (close port-to))
              (begin (write-char c port-to)
                     (loop (read-char port-from))))))
      ;; Cygwin and other platforms:
      ;; Pass through to copy-file
      ;; TODO: this should write destination atomically.
      (copy-file from-name to-name)))

(define-public (make-tmpfile dir)
  "Return a temporary file (as a Scheme port).  If @var{dir} is @code{#f},
a file in the directory given by the environment variable @code{$TMPDIR} is
created."
  (define max-try 10)
  (define (inner dir tries)
    (if (> tries 0)
        (let*
            ;; An all-ASCII name saves us the trouble of dealing with special
            ;; characters in the names of temporary files.
            ((name (format #f "~a/lilypond-tmp-~a" dir (random 10000000)))
             (port (create-file-exclusive name #o666))
             (bport #f))

          (if port
              (begin
                (set! bport (open-file name "wb"))
                (close-port port)
                bport)

              (inner dir (1- tries))))

        (ly:error (G_ "can't create temp file in ~a after ~a times") dir max-try)
        ))

  (if (not dir)
      (set! dir (cond
                 ;; MINGW hack: TMP / TEMP may include
                 ;; unusable characters (Unicode etc.).
                 ((eq? PLATFORM 'windows) ".")
                 ;; Cygwin can handle any characters
                 ;; including Unicode.
                 ((eq? PLATFORM 'cygwin) (or (getenv "TMP")
                                             (getenv "TEMP")))
                 ;; Other platforms (POSIX platforms)
                 ;; use TMPDIR or /tmp.
                 (else (or (getenv "TMPDIR")
                           "/tmp")))))

  (inner dir max-try))


(define-public (postprocess-output paper module formats
                                   base-name tmp-name is-eps)
  (let* ((completed (completize-formats formats is-eps)))
    (for-each (lambda (f)
                ((eval (string->symbol (format #f "convert-to-~a" f)) module)
                 paper base-name tmp-name is-eps)) completed)
    (if (and (ly:get-option 'delete-intermediate-files)
             (or (not is-eps)
                 (not (member "ps" completed)))
             (file-exists? tmp-name))
        (delete-file tmp-name))))

(define (write-lilypond-book-aux-files basename count)
  (let* ((write-file (lambda (str-port ext)
                       (let* ((name (format #f "~a-systems.~a" basename ext))
                              (port (make-tmpfile (dirname basename))))
                         (ly:message (G_ "Writing ~a...") name)
                         (display (get-output-string str-port) port)
                         (close-port-rename port name))))
         (tex-system-port (open-output-string))
         (texi-system-port (open-output-string))
         (count-system-port (open-output-string)))
    (for-each (lambda (c)
                (if (< 0 c)
                    (format tex-system-port
                            "\\ifx\\betweenLilyPondSystem \\undefined
  \\linebreak
\\else
  \\expandafter\\betweenLilyPondSystem{~a}%
\\fi
" c))
                (format tex-system-port "\\includegraphics{~a-~a}%\n"
                        basename (1+ c))
                (format texi-system-port "@image{~a-~a}\n"
                        basename (1+ c)))
              (iota count))
    (display "@c eof\n" texi-system-port)
    (display "% eof\n" tex-system-port)
    (format count-system-port "~a" count)
    (write-file texi-system-port "texi")
    (write-file tex-system-port "tex")
    ;; do this as the last action so we know the rest is complete if
    ;; this file is present.
    (write-file count-system-port "count")))

(define-public (completize-formats formats is-eps)
  (define new-fmts '())
  (if (and is-eps (member "eps" formats))
      (set! formats (cons "ps" formats)))
  (if (not (or (member "pdf" formats)
               (member "png" formats)))
      (set! formats (cons "ps" formats)))
  (for-each (lambda (x)
              (if (member x formats) (set! new-fmts (cons x new-fmts))))
            '("ps" "pdf" "png"))
  (uniq-list (reverse new-fmts)))

(define (header-to-file file-name key value)
  (set! key (symbol->string key))
  (if (not (equal? "-" file-name))
      (set! file-name (string-append file-name "." key)))
  (ly:message (G_ "Writing header field `~a' to `~a'...")
              key
              (if (equal? "-" file-name) "<stdout>" file-name))
  (if (equal? file-name "-")
      (display value)
      (let ((port (open-file file-name "w")))
        (set-port-encoding! port "UTF-8")
        (display value port)
        (close-port port)))
  "")

(define-public (output-scopes scopes fields basename)
  (for-each
   (lambda (field)
     (let*
         ((val (ly:modules-lookup scopes field #f)))
       (if val
           (header-to-file basename field val))
       ))
   fields))

(define (relevant-book-systems book)
  (let ((systems (ly:paper-book-systems book)))
    ;; skip booktitles.
    (if (and (not (ly:get-option 'include-book-title-preview))
             (pair? systems)
             (ly:prob-property (car systems) 'is-book-title #f))
        (cdr systems)
        systems)))

(define (relevant-dump-systems systems)
  (let ((to-dump-systems '()))
    (for-each
     (lambda (sys)
       (if (or (paper-system-title? sys)
               (not (pair? to-dump-systems))
               (paper-system-title? (car to-dump-systems)))
           (set! to-dump-systems (cons sys to-dump-systems))))
     systems)
    to-dump-systems))

(define-public (generate-preview-stencil paper-book)
  "Returns a stencil for a preview of given Paper_book"
  (let* ((systems (relevant-book-systems paper-book))
         (to-dump-systems (relevant-dump-systems systems)))

    (stack-stencils Y DOWN 0.0
                    (map paper-system-stencil
                         (reverse to-dump-systems)))
    ))

(define-public (generate-crop-stencil paper-book)
  "Returns a stencil for the cropped output of the given Paper_book"
  (let* ((systems (relevant-book-systems paper-book)))
    (stack-stencils Y DOWN 0.0
                    (map paper-system-stencil
                         (reverse (reverse systems))))))

(define (clip-systems-to-region-stencils basename systems region)
  "Returns NAME . STENCIL alist"
  (let* ((extents-system-pairs
          (filter-map (lambda (paper-system)
                        (let* ((x-ext (system-clipped-x-extent
                                       (paper-system-system-grob paper-system)
                                       region)))
                          (if x-ext
                              (cons x-ext paper-system)
                              #f)))
                      systems))
         (count 0))
    (map
     (lambda (ext-system-pair)
       (let* ((xext (car ext-system-pair))
              (paper-system (cdr ext-system-pair))
              (yext (paper-system-extent paper-system Y))
              (bbox (list (car xext) (car yext)
                          (cdr xext) (cdr yext)))
              (filename (if (< 0 count)
                            (format #f "~a-~a" basename count)
                            basename)))
         (set! count (1+ count))
         (cons filename
               (ly:make-stencil (ly:stencil-expr (paper-system-stencil paper-system))
                                xext yext))))

     extents-system-pairs)))

(define (clipped-systems-stencils basename systems)
  (define (clip-score-systems-stencils basename systems)
    (let*
        ((layout (ly:grob-layout (paper-system-system-grob (car systems))))
         (regions (ly:output-def-lookup layout 'clip-regions)))
      (apply append (map
                     (lambda (region)
                       (clip-systems-to-region-stencils
                        (format #f "~a-from-~a-to-~a-clip"
                                basename
                                (rhythmic-location->file-string (car region))
                                (rhythmic-location->file-string (cdr region)))
                        systems region))
                     regions))))

  ;; partition in system lists sharing their layout blocks
  (let* ((count 0)
         (score-system-list '()))
    (fold
     (lambda (system last-system)
       (if (not (and last-system
                     (equal? (paper-system-layout last-system)
                             (paper-system-layout system))))
           (set! score-system-list (cons '() score-system-list)))
       (if (paper-system-layout system)
           (set-car! score-system-list (cons system (car score-system-list))))
       ;; pass value.
       system)
     #f
     systems)

    (apply append (map (lambda (system-list)
                         ;; filter out headers and top-level markup
                         (if (pair? system-list)
                             (clip-score-systems-stencils
                              (if (> count 0)
                                  (format #f "~a-~a" basename count)
                                  basename)
                              system-list)))
                       score-system-list))))

(define (generate-system-stencils paper-book)
  "Generate list of stencils for lilypond-book output"
  (let*
      ((stencils (map paper-system-stencil
                      (ly:paper-book-systems paper-book)))

       ;; Change STENCILS to use the union for the left extents in every
       ;; stencil so that LaTeX's \\includegraphics command doesn't modify the
       ;; alignment.
       (left (if (pair? stencils)
                 (apply min
                        (map (lambda (stc)
                               (interval-start (ly:stencil-extent stc X)))
                             stencils))
                 0.0)))

    (map (lambda (stil)
           (ly:make-stencil
            (ly:stencil-expr stil)
            (cons left
                  (cdr (ly:stencil-extent stil X)))
            (ly:stencil-extent stil Y)))
         stencils)))

(define-public (font-name-split font-name)
  "Return @code{(@var{font-name} . @var{design-size})} from @var{font-name}
string or @code{#f}."
  (let ((match (regexp-exec (make-regexp "(.*)-([0-9]*)") font-name)))
    (if (regexp-match? match)
        (cons (match:substring match 1) (match:substring match 2))
        (cons font-name-designsize #f))))

;; Example of a pango-physical-font
;; ("Emmentaler-11" "/home/janneke/vc/lilypond/out/share/lilypond/current/fonts/otf/emmentaler-11.otf" 0)
(define-public (pango-pf-font-name pango-pf)
  "Return the font name of the Pango physical font @var{pango-pf}."
  (list-ref pango-pf 0))
(define-public (pango-pf-file-name pango-pf)
  "Return the file name of the Pango physical font @var{pango-pf}."
  (list-ref pango-pf 1))
(define-public (pango-pf-fontindex pango-pf)
  "Return the font index of the Pango physical font @var{pango-pf}."
  (list-ref pango-pf 2))

(define (pango-font-name pango-font)
  (let ((pf-fonts (ly:pango-font-physical-fonts pango-font)))
    (if (pair? pf-fonts)
        (pango-pf-font-name (car pf-fonts))
        "")))

(define-public (define-fonts paper define-font define-pango-pf)
  "Return a string of all fonts used in @var{paper}, invoking the functions
@var{define-font} and @var{define-pango-pf} for producing the actual font
definition."

  (let* ((font-list (ly:paper-fonts paper))
         (pango-fonts (filter ly:pango-font? font-list))
         (other-fonts (remove ly:pango-font? font-list))
         (other-font-names (map ly:font-name other-fonts))
         (pango-only-fonts
          (remove (lambda (x)
                    (member (pango-font-name x) other-font-names))
                  pango-fonts)))

    (define (font-load-command font)
      (let* ((font-name (ly:font-name font))
             (designsize (ly:font-design-size font))
             (magnification (* (ly:font-magnification font)))
             (ops (ly:output-def-lookup paper 'output-scale))
             (scaling (* ops magnification designsize)))
        (if (equal? font-name "unknown")
            (display (list font font-name)))
        (define-font font font-name scaling)))

    (define (pango-font-load-command pango-font)
      (let* ((pf-fonts (ly:pango-font-physical-fonts pango-font))
             (pango-pf (if (pair? pf-fonts) (car pf-fonts) '("" "" 0)))
             (font-name (pango-pf-font-name pango-pf))
             (scaling (ly:output-def-lookup paper 'output-scale)))
        (if (equal? font-name "unknown")
            (display (list pango-font font-name)))
        (define-pango-pf pango-pf font-name scaling)))

    ;; sort entries (which come from a hash) for reproducibility
    (string-append
     (string-concatenate
      (sort (map font-load-command other-fonts) string<?))
     (string-concatenate
      (sort (map pango-font-load-command pango-only-fonts) string<?)))))
