\version "2.19.17"

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%% SETUP LANGUAGE COMMAND %%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% PREREQUISITES %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% modified from define-note-names.scm:970
#(define-public (note-names-language parser lang)
   (_ "Select note names language.")
   (let ((alist (assoc-get lang
                  language-pitch-names
                  '())))
     (if (pair? alist)
         (begin
          (ly:debug (_ "Using `~a' note names...") lang)
          (set! pitchnames alist)
          (ly:parser-set-note-names parser alist))
         (ly:warning (_ "Could not find language `~a'.  Ignoring.") lang))))

#(define output-language 'english)

% FUNCTION DEFINITION %%%%%%%%%%%%%%%%%%%%%%%%%%%%

% extended from music-functions-init.ly:603
language =
#(define-void-function
  (parser location arg)
  ;; Usage:
  ;; \language input.LANG or
  ;; \language output.LANG or
  ;; \language LANG—which is equivalent to
  ;; \language general.LANG or to the first two combined
  (symbol-list-or-symbol?)
  (_i "Define languages for input (i.e. set note names for @var{language}), output (i.e. display tagline and table of contents in @var{language}), or both.")


  (let* ((correct-input (if (> (length arg) 2) #f #t))
         (channel (if (= 2 (length arg)) ;if a channel is given,
                      (car arg)          ;use it
                      'general))         ;else apply to both
         (language (cond ((= 1 (length arg)) (list-ref arg 0))
                     ((= 2 (length arg)) (list-ref arg 1))))
         (input-lang (if language ;if input isn’t wrong
                         language
                         'nederlands)) ;default
         (output-lang (if language
                          language
                          'english)))

    (if (not correct-input) (ly:warning "\\language must be given a list of one or two symbols. Using default languages."))

    (if (not (eq? channel 'output))
        (note-names-language parser input-lang))

    (if (not (eq? channel 'input))
        (set! output-language output-lang))))

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%\language input.deutsch
%\language output.deutsch
\language deutsch

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% SETUP TAGLINES %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% should probably go into titling-init.ly
englishTaglineText =
#(format #f
   "Music typeset using LilyPond ~a~awww.lilypond.org"
   (lilypond-version)
   (ly:wide-char->utf-8 #x2014) ;; 2014 = em dash.
   )
germanTaglineText =
#(format #f
   "Noten gesetzt mit LilyPond ~a ~a www.lilypond.org"
   (lilypond-version)
   (ly:wide-char->utf-8 #x2013) ;;2013 = en dash.
   )

tagline-texts = #`((deutsch . ,germanTaglineText)
                   (english . ,englishTaglineText)
                   )

% should this go into define-markup-commands.scm? if yes, where?
#(define-markup-command
  (format-tagline layout props text)
  (markup?)
  (interpret-markup layout props
    #{
      \markup {
        \pad-to-box #'(0 . 0) #'(0 . 3)
        {
          \with-url #"http://lilypond.org/"
          $text
        }
      }
    #}))

% adapted from titling-init.ly:13
tagline =
\markup \format-tagline
#(let
  ((tagl (assoc-get output-language tagline-texts)))
  (if tagl
      tagl
      (begin
       (ly:warning (format #f
                     "Tagline for ~a not defined, using the english one."
                     (symbol->string output-language)))
       (assoc-get 'english tagline-texts))))

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% SETUP TOC  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% should go into toc-init.ly

% Using capitals is not due to German brutishness,
% but adopted from some reference scores I consulted :-)
germanTocTitleText = "INHALT"
% This is current Lilypond default.
englishTocTitleText = "Table of Contents"

toc-title-texts = #`((deutsch . ,germanTocTitleText)
                     (english . ,englishTocTitleText)
                     )

% should this go into define-markup-commands.scm? if yes, where?
#(define-markup-command
  (format-toc-title layout props text)
  (markup?)
  (interpret-markup layout props
    #{
      \markup \huge \column {
        \fill-line { \null $text \null }
        \null
      }
    #}))

\paper {
  % adapted from toc-init.ly:26
  tocTitleMarkup =
  \markup \format-toc-title
  #(let ((text (assoc-get output-language toc-title-texts)))
     (if text
         text
         (begin (ly:warning (format #f
                              "Title of Table of Contents is not defined for ~a, using the english one."
                              (symbol->string output-language)))
           (assoc-get 'english toc-title-texts))))
}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% TEST MUSIC %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% necessary to update tagline in this test case only
\header { }

\markup \fill-line {
  \override #'(line-width . 25)
  \box
  \pad-markup #2
  \column
  \table-of-contents
}

\tocItem "H"
{ h }

\tocItem "C"
{ c' }

\tocItem "D"
{ d' }

%%%