%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% media4svg.sty
%
% multimedia inclusion package for the `dvisvgm' backend
%
% Supported workflows:
%
%   [dvilua | p | up]latex + dvisvgm
%   xelatex --no-pdf + dvisvgm
%
% Copyright 2020--\today, Alexander Grahn
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% This work may be distributed and/or modified under the
% conditions of the LaTeX Project Public License.
%
% The latest version of this license is in
%   http://mirrors.ctan.org/macros/latex/base/lppl.txt
%
% This work has the LPPL maintenance status `maintained'.
%
% The Current Maintainer of this work is A. Grahn.

\RequirePackage{iftex}
\ifpdf
  \PackageError{media4svg}{%
    Wrong output format (PDF).\MessageBreak
    This package only works with the `dvisvgm' backend.\MessageBreak
    A TeX engine must be used that produces\MessageBreak
    DVI or XDV output%
  }{}%
\fi

\RequirePackage{expl3}
\RequirePackage{l3keys2e}
\RequirePackage{xparse}
\RequirePackage{atbegshi}

\def\g@msvg@date@tl{2020/04/16}
\def\g@msvg@version@tl{0.4}

\ProvidesExplPackage{media4svg}{\g@msvg@date@tl}{\g@msvg@version@tl}
{acrobat-9/X compatible media}

\tl_gset_eq:NN\g_msvg_date_tl\g@msvg@date@tl
\tl_gset_eq:NN\g_msvg_version_tl\g@msvg@version@tl

\msg_set:nnnn{media4svg}{support~outdated}{
  Support~package~`#1'~too~old.
}{
  Update~your~installation~of~`#1'.~Aborting.
}
\@ifpackagelater{expl3}{2020/04/06}{}{
  \msg_fatal:nnn{media4svg}{support~outdated}{l3kernel}
  \tex_endinput:D
}
\@ifpackagelater{l3keys2e}{2020/03/06}{}{
  \msg_fatal:nnn{media4svg}{support~outdated}{l3packages}
  \tex_endinput:D
}

%package options
\msg_set:nnnn{media4svg}{unknown~package~option}{Unknown~package~option~`#1'.}{
  Package option~`#1'~is~unknown;\\
  perhaps~it~is~spelled~incorrectly.
}

\bool_new:N\g_msvg_dvisvgm_bool
\bool_new:N\g_msvg_pkgdraft_bool
\bool_new:N\g_msvg_pkgembed_bool
\bool_gset_true:N\g_msvg_pkgembed_bool
\int_new:N\g_msvg_pkgresizeflag_int% resizing flag according to options given
\tl_gset:Nn\g_msvg_pkgwdarg_tl{\width}
\tl_gset:Nn\g_msvg_pkghtarg_tl{\height}
\tl_gset:Nn\g_msvg_pkgttarg_tl{\totalheight}
\bool_new:N\g_msvg_pkgiso_bool
\tl_gset:Nn\g_msvg_pkgscalearg_tl{1.0}
\tl_new:N\g_msvg_pkgcontrols_tl
\tl_new:N\g_msvg_pkgautoplay_tl
\tl_new:N\g_msvg_pkgloop_tl
\tl_new:N\g_msvg_pkgtime_tl
\tl_new:N\g_msvg_pkgmuted_tl
\tl_gset:Nn\g_msvg_pkgmtype_tl{audio/mpeg}

\keys_define:nn{media4svg}{
  dvisvgm .choice:,
  dvisvgm / true .code:n = {
    \bool_gset_true:N\g_msvg_dvisvgm_bool
%    \PassOptionsToPackage{dvisvgm}{pdfbase}
  },
  dvisvgm / false .code:n = {\bool_gset_false:N\g_msvg_dvisvgm_bool},
  dvisvgm .default:n = {true},

  draft .bool_gset:N = \g_msvg_pkgdraft_bool,

  final .bool_gset_inverse:N = \g_msvg_pkgdraft_bool,

  autoplay .choice:,
  autoplay / true .code:n = {\tl_gset:Nn\g_msvg_pkgautoplay_tl{autoplay=''~}},
  autoplay / false .code:n = {\tl_gclear:N\g_msvg_pkgautoplay_tl},
  autoplay .default:n = {true},

  loop .choice:,
  loop / true .code:n = {\tl_gset:Nn\g_msvg_pkgloop_tl{loop=''~}},
  loop / false .code:n = {\tl_gclear:N\g_msvg_pkgloop_tl},
  loop .default:n = {true},

  controls .choice:,
  controls / true .code:n = {\tl_gset:Nn\g_msvg_pkgcontrols_tl{controls=''~}},
  controls / false .code:n = {\tl_gclear:N\g_msvg_pkgcontrols_tl},
  controls .default:n = {true},

  muted .choice:,
  muted / true .code:n = {\tl_gset:Nn\g_msvg_pkgmuted_tl{muted=''~}},
  muted / false .code:n = {\tl_gclear:N\g_msvg_pkgmuted_tl},
  muted .default:n = {true},

  time .code:n = {\tl_gset:Nn\g_msvg_pkgtime_tl{currentTime='#1'~}},
  time .value_required:n = {true},

  mimetype .tl_gset:N = \g_msvg_pkgmtype_tl,

  url .bool_gset_inverse:N = \g_msvg_pkgembed_bool,

  embed .bool_gset:N = \g_msvg_pkgembed_bool,

  width .code:n = {
    \tl_gset:Nn\g_msvg_pkgwdarg_tl{#1}
    \tl_if_exist:NF\l_msvg_pkgwd_tl{
      \int_gadd:Nn\g_msvg_pkgresizeflag_int{4}
      \tl_set:Nn\l_msvg_pkgwd_tl{}
    }
  },
  width .value_required:n = {true},

  height .code:n = {
    \tl_gset:Nn\g_msvg_pkghtarg_tl{#1}
    \tl_if_exist:NF\l_msvg_pkght_tl{
      \int_gadd:Nn\g_msvg_pkgresizeflag_int{2}
      \tl_set:Nn\l_msvg_pkght_tl{}
    }
  },
  height .value_required:n = {true},

  totalheight .code:n = {
    \tl_gset:Nn\g_msvg_pkgttarg_tl{#1}
    \tl_if_exist:NF\l_msvg_pkgtt_tl{
      \int_gadd:Nn\g_msvg_pkgresizeflag_int{\c_one_int}
      \tl_set:Nn\l_msvg_pkgtt_tl{}
    }
  },
  totalheight .value_required:n = {true},

  keepaspectratio .bool_gset:N = \g_msvg_pkgiso_bool,

  scale .code:n = {\tl_gset:Nx\g_msvg_pkgscalearg_tl{#1}},
  scale .value_required:n = {true},

  unknown .code:n = {
    \msg_error:nnx{media4svg}{unknown~package~option}{\l_keys_key_tl}
  }
}
\ProcessKeysOptions{media4svg}

\msg_set:nnnn{media4svg}{missing~driver~option}{Global~option~`dvisvgm'~no~set.}{
  This~package~only~works~with~the~`dvisvgm'~backend.\\
  Set~`dvisvgm'~as~documentclass~option.
}
\bool_if:NF\g_msvg_dvisvgm_bool{
  \msg_error:nn{media4svg}{missing~driver~option}
}

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

\group_begin:
\char_set_catcode_other:N\%
\cs_new_nopar:Nn\msvg_percent:{%}
\group_end:

\NewDocumentCommand\includemedia{O{}mm}{% #1 options, #2 text/image,
  \tl_gset:Nx\g_msvg_media_arg_tl{#3}   % #3 media file or url
  \msvg_uriend:
  \group_begin:
  \msvg_beginLTR:
  \leavevmode
  \msvg_reset:
  \keys_set:nn{media4svg/user}{#1}
  \sbox\l_msvg_poster_box{#2}
  \msvg_scale:n{\l_msvg_poster_box}
  \special{dvisvgm:bbox~\g_msvg_wd_tl~\g_msvg_ht_tl~\g_msvg_dp_tl~transform}
  \bool_if:NTF\g_msvg_draft_bool{
    \tl_if_blank:oTF{#2}{
      \msvg_draftbox:n{\g_msvg_media_arg_tl}
    }{
      \hbox_to_wd:nn{\g_msvg_wd_tl}{
        \vrule~width~\c_zero_dim~height~\g_msvg_ht_tl~depth~\g_msvg_dp_tl
        \box_use:N\l_msvg_poster_box\hss
      }
    }
  }{
    \hbox_overlap_right:n{\box_use:N\l_msvg_poster_box}
    \tl_gclear_new:N\g_msvg_media_blob_tl
    \bool_if:NT\g_msvg_embed_bool{
      \file_get_full_name:VNTF\g_msvg_media_arg_tl\l_msvg_full_name_tl{
        \sys_if_engine_luatex:T{\message{<\l_msvg_full_name_tl}}
      }{
        \msg_error:nnx{media4svg}{file~not~found}{\g_msvg_media_arg_tl}
      }
      % base64-encode (non-Lua way) the media file
      \sys_if_engine_luatex:F{
        \msvg_convert_file_to_blob:nN{
          \l_msvg_full_name_tl}\g_msvg_media_blob_tl
      }
    }
    \special{dvisvgm:raw {?nl}
      \tl_if_blank:VT\g_msvg_controls_tl{
        <svg~
          id='msvg@kbdCtrl@\g_msvg_id_tl'~
          width='0'~
          height='0'~
          onfocus=''~
          onkeydown='
            event.preventDefault();event.stopPropagation();
            switch(event.key){
              case "~":
                if($("\g_msvg_id_tl").paused){
                  $("\g_msvg_id_tl").play();
                }else{
                  $("\g_msvg_id_tl").pause();
                }
                break;
              case "ArrowUp":
                if(event.ctrlKey){$("\g_msvg_id_tl").muted=false;}else{
                  try{$("\g_msvg_id_tl").volume+=0.02;}catch(e){}}
                break;
              case "ArrowDown":
                if(event.ctrlKey){$("\g_msvg_id_tl").muted=true;}else{
                  try{$("\g_msvg_id_tl").volume-=0.02;}catch(e){}}
                break;
              case "ArrowLeft":
                if(event.ctrlKey){
                  $("\g_msvg_id_tl").currentTime-=$("\g_msvg_id_tl").duration/10;
                }else{
                  $("\g_msvg_id_tl").currentTime-=$("\g_msvg_id_tl").duration/100;
                }
                break;
              case "ArrowRight":
                if(event.ctrlKey){
                  $("\g_msvg_id_tl").currentTime+=$("\g_msvg_id_tl").duration/10;
                }else{
                  $("\g_msvg_id_tl").currentTime+=$("\g_msvg_id_tl").duration/100;
                }
                break;
              case "Home":
                $("\g_msvg_id_tl").currentTime=0;
                break;
              case "End":
                $("\g_msvg_id_tl").currentTime=$("\g_msvg_id_tl").duration;
                break;
              case "F11":
                if ($("\g_msvg_id_tl").requestFullscreen){
                  $("\g_msvg_id_tl").requestFullscreen();
                }
                break;
            }
          '
        ></svg>{?nl}
      }
      <foreignObject~
        transform='translate({?x},{?(y-(\dim_to_decimal_in_bp:n{\g_msvg_ht_tl}))})'
        width='\dim_to_decimal_in_bp:n{\g_msvg_wd_tl}'~
        height='\dim_to_decimal_in_bp:n{\g_msvg_tt_tl}'~
        \tl_if_blank:VT\g_msvg_controls_tl{
          ontouchstart='
            event.preventDefault();event.stopPropagation();
            if($("\g_msvg_id_tl").paused){
              $("\g_msvg_id_tl").play();
            }else{
              $("\g_msvg_id_tl").pause();
            }
            return;% <-- this prevents download-video-? dialogue in Chrome
          '~
          cursor='pointer'
        }
      >{?nl}
        <video~
          x="0"~y="0"~
          id='msvg@\g_msvg_id_tl'~
          width='100\msvg_percent:'~height='100\msvg_percent:'~
          \g_msvg_controls_tl\g_msvg_autoplay_tl\g_msvg_loop_tl\g_msvg_muted_tl
          \tl_if_blank:VT\g_msvg_controls_tl{
            onplaying='                          % in Chrome, keyboard control
              $("kbdCtrl@\g_msvg_id_tl").focus();% via separate <svg> element
              event.target.focus(); % Firefox
            '~
            onkeydown='
              event.preventDefault();event.stopPropagation();
              switch(event.key){
                case "~":
                  if(event.target.paused){
                    event.target.play();
                  }else{
                    event.target.pause();
                  }
                  break;
                case "ArrowUp":
                  if(event.ctrlKey){event.target.muted=false;}else{
                    try{event.target.volume+=0.02;}catch(e){}}
                  break;
                case "ArrowDown":
                  if(event.ctrlKey){event.target.muted=true;}else{
                    try{event.target.volume-=0.02;}catch(e){}}
                  break;
                case "ArrowLeft":
                  if(event.ctrlKey){
                    event.target.currentTime-=event.target.duration/10;
                  }else{
                    event.target.currentTime-=event.target.duration/100;
                  }
                  break;
                case "ArrowRight":
                  if(event.ctrlKey){
                    event.target.currentTime+=event.target.duration/10;
                  }else{
                    event.target.currentTime+=event.target.duration/100;
                  }
                  break;
                case "Home":
                  event.target.currentTime=0;
                  break;
                case "End":
                  event.target.currentTime=event.target.duration;
                  break;
                case "F11":
                  if (event.target.requestFullscreen){
                    event.target.requestFullscreen();
                  }
                  break;
                }
            '~
            onmouseup='event.preventDefault();event.stopPropagation();
              event.target.play();'~
            onmousedown='event.preventDefault();event.stopPropagation();
              event.target.pause();'~
          }
          \tl_if_blank:VF\g_msvg_time_tl{
            onloadstart='event.target.currentTime=\g_msvg_time_tl;'~
          }
          xmlns='http://www.w3.org/1999/xhtml'
        >{?nl}
        \bool_if:NTF\g_msvg_embed_bool{
          \sys_if_engine_luatex:TF{
            <source~src='data:\g_msvg_mtype_tl;base64,{?nl}
              \directlua{media4svg.base64("\l_msvg_full_name_tl",72,"{?nl}")}'~
              type='\g_msvg_mtype_tl'/>{?nl}
          }{
            <source~src='data:\g_msvg_mtype_tl;base64,{?nl}
              \g_msvg_media_blob_tl'~type='\g_msvg_mtype_tl'/>{?nl}
          }
        }{
          <source~src='\g_msvg_media_arg_tl'~type='\g_msvg_mtype_tl'/>{?nl}
        }
        </video>{?nl}
      </foreignObject>
    }
    \bool_if:NT\g_msvg_embed_bool{
      \sys_if_engine_luatex:T{\message{>}}}
    \hbox_to_wd:nn{\g_msvg_wd_tl}{
      \vrule~width~\c_zero_dim~height~\g_msvg_ht_tl~depth~\g_msvg_dp_tl\hss
    }
    \int_gincr:N\g_msvg_mmcnt_int
  }
  \msvg_endLTR:
  \group_end:
}
\tl_set_eq:NN\l_msvg_includemedia_tl\includemedia
\tl_set:Nn\includemedia{\msvg_uribegin:\l_msvg_includemedia_tl}

%environment \msvg_uribegin: ... \msvg_uriend: to sanitize possibly
%active chars in URLs (RFC 2396), path specifications and JavaScript
\group_begin:
\char_set_catcode_other:n{`\~}
\cs_new_protected_nopar:Npn\msvg_uribegin:{
  \group_begin:
  %code contributed by J. Wright
  \tl_map_inline:nn{.:;?!/''*+,->=<$@([])^_`|~}{
    \cs_set_nopar:Npx\__msvg_tmp:w{\token_to_str:N##1}
    \char_set_active_eq:NN##1\__msvg_tmp:w
  }
  \tl_map_inline:nn{\#\&\%\\\{\}}{
    \cs_set_nopar:Npx##1{\token_to_str:N##1}
  }
}
\group_end:
\cs_set_eq:NN\msvg_uriend:\group_end:

%calculates widget dimensions from natural ones, taking resizing options
%into account
\int_new:N\g_msvg_resizeflag_int% resizing flags according to options given
\cs_new:Nn\msvg_scale:n{% #1 box number
  %totalheight overrides height if both height & totalheight options were given
  \bool_if:nT{
    \int_compare_p:n{\g_msvg_resizeflag_int=3} ||
    \int_compare_p:n{\g_msvg_resizeflag_int=7}
  }{\int_gsub:Nn\g_msvg_resizeflag_int{2}}
  \group_begin:
    %natural dimensions \width, \height, \depth, \totalheight
    \tl_set:Nn\width {\box_wd:N#1}
    \tl_set:Nn\height{\box_ht:N#1}
    \tl_set:Nn\depth {\box_dp:N#1}
    \tl_set:Nn\totalheight{\dimexpr\height+\depth\relax}
    \tl_gset:Nx\g_tmpa_tl{\dim_eval:n{\width}}
    \tl_gset:Nx\g_tmpb_tl{\dim_eval:n{\totalheight}}
    %evaluate width/height/totalheight options
    \tl_gset:Nx\g_msvg_wd_tl{\dim_abs:n{\g_msvg_wdarg_tl}}
    \tl_gset:Nx\g_msvg_ht_tl{\dim_abs:n{\g_msvg_htarg_tl}}
    \tl_gset:Nx\g_msvg_tt_tl{\dim_abs:n{\g_msvg_ttarg_tl}}
    \dim_compare:nT{\width=\c_zero_dim}{\box_gset_wd:Nn#1{\g_msvg_wd_tl}}
    \dim_compare:nT{\totalheight=\c_zero_dim}{
      \bool_if:nT{ %height option given
        \int_compare_p:n{\g_msvg_resizeflag_int=6}||
        \int_compare_p:n{\g_msvg_resizeflag_int=2}
      }{\box_gset_ht:Nn#1{\g_msvg_ht_tl}}
      \bool_if:nT{ %totalheight option given
        \int_compare_p:n{\g_msvg_resizeflag_int=5}||
        \int_compare_p:n{\g_msvg_resizeflag_int=\c_one_int}
      }{\box_gset_ht:Nn#1{\g_msvg_tt_tl}}
    }
  \group_end:
  \tl_gset:Nn\g_msvg_dp_tl{\c_zero_dim} %to be initialised here
  %now resize (originally non-zero size) poster box according to the
  %options given
  \bool_if:nF{
    \dim_compare_p:n{\g_tmpa_tl=\c_zero_dim}||
    \dim_compare_p:n{\g_tmpb_tl=\c_zero_dim}
  }{
    %bit 2^2=width, 2^1=height, 2^0=totalhight given
    \int_case:nn{\g_msvg_resizeflag_int}{
      {\c_one_int}{
        \box_resize_to_ht_plus_dp:Nn#1{\g_msvg_tt_tl}
      }
      {2}{
        \box_resize_to_ht:Nn#1{\g_msvg_ht_tl}
      }
      {4}{
        \box_resize_to_wd:Nn#1{\g_msvg_wd_tl}
      }
      {5}{
        \bool_if:NTF\g_msvg_iso_bool{
          \dim_set:Nn\l_tmpa_dim{
            (\box_ht:N#1+\box_dp:N#1)*\dim_ratio:nn{\g_msvg_wd_tl}{\box_wd:N#1}
          }
          \dim_set:Nn\l_tmpa_dim{\dim_abs:n{\l_tmpa_dim}}
          \dim_set:Nn\l_tmpb_dim{\dim_abs:n{\g_msvg_tt_tl}}
          \dim_compare:nTF{\l_tmpa_dim<\l_tmpb_dim}{
            \box_resize_to_wd:Nn#1{\g_msvg_wd_tl}
          }{
            \box_resize_to_ht_plus_dp:Nn#1{\g_msvg_tt_tl}
          }
        }{
          \box_resize_to_wd_and_ht_plus_dp:Nnn#1{\g_msvg_wd_tl}{\g_msvg_tt_tl}
        }
      }
      {6}{
        \bool_if:NTF\g_msvg_iso_bool{
          \dim_set:Nn\l_tmpa_dim{
            \box_ht:N#1*\dim_ratio:nn{\g_msvg_wd_tl}{\box_wd:N#1}
          }
          \dim_set:Nn\l_tmpa_dim{\dim_abs:n{\l_tmpa_dim}}
          \dim_set:Nn\l_tmpb_dim{\dim_abs:n{\g_msvg_ht_tl}}
          \dim_compare:nTF{\l_tmpa_dim<\l_tmpb_dim}{
            \box_resize_to_wd:Nn#1{\g_msvg_wd_tl}
          }{
            \box_resize_to_ht:Nn#1{\g_msvg_ht_tl}
          }
        }{
          \box_resize_to_wd_and_ht:Nnn#1{\g_msvg_wd_tl}{\g_msvg_ht_tl}
        }
      }
    }
  }
  %apply scaling factor
  \box_scale:Nnn#1{\g_msvg_scalearg_tl}{\g_msvg_scalearg_tl}
  %dimensions after resizing
  \tl_gset:Nx\g_msvg_wd_tl{\dim_use:N\box_wd:N#1}
  \tl_gset:Nx\g_msvg_ht_tl{\dim_use:N\box_ht:N#1}
  \tl_gset:Nx\g_msvg_dp_tl{\dim_use:N\box_dp:N#1}
  \tl_gset:Nx\g_msvg_tt_tl{\dim_eval:n{\box_ht:N#1+\box_dp:N#1}}
  \dim_compare:nT{\g_msvg_wd_tl=\c_zero_dim}{\msg_warning:nn{media4svg}{zero~width}}
  \dim_compare:nT{\g_msvg_tt_tl=\c_zero_dim}{
      \msg_warning:nn{media4svg}{zero~height}}
}

%environment for setting LTR typesetting direction with e-TeX based engines
\cs_new:Nn\msvg_beginLTR:{
  \cs_if_exist:NT\TeXXeTstate{
    \int_compare:nT{\TeXXeTstate>\c_zero_int}{\beginL}
  }
}
\cs_new:Nn\msvg_endLTR:{
  \cs_if_exist:NT\TeXXeTstate{
    \int_compare:nT{\TeXXeTstate>\c_zero_int}{\endL}
  }
}

\cs_new:Nn\msvg_draftbox:n{ %#1 text string to be shown
  \hbox_overlap_right:n{
    \hbox_to_wd:nn{\g_msvg_wd_tl}{
      \vrule~height~\g_msvg_ht_tl~depth~\g_msvg_dp_tl\hss
      \vrule
    }
  }
  \box_move_down:nn{\g_msvg_dp_tl}{
    \hbox_to_wd:nn{\g_msvg_wd_tl}{
      \vbox_to_ht:nn{\g_msvg_tt_tl}{
        \hrule~width~\g_msvg_wd_tl\vss
        \hbox_to_wd:nn{\g_msvg_wd_tl}{\hss\ttfamily{\tiny#1}\hss}\vss
        \hrule
      }
    }
  }
}

\box_new:N\l_msvg_poster_box
\dim_new:N\g_msvg_wd_dim
\dim_new:N\g_msvg_ht_dim
\dim_new:N\g_msvg_dp_dim

\int_new:N\g_msvg_mmcnt_int

\msg_set:nnn{media4svg}{zero~width}{
  Media~widget~\msg_line_context:\ has~zero~width.
}

\msg_set:nnn{media4svg}{zero~height}{
  Media~widget~\msg_line_context:\ has~zero~height.
}

%missing package error message
\msg_set:nnn{media4svg}{missing~package}{
  Package~`#1'~has~not~been~loaded~yet.\\
  Put~the~line\\
  ~~\string\usepackage#2{#1}\\
  to~the~preamble~of~your~document.
}

\msg_set:nnn{media4svg}{incompatible~package}{
  Packages~`media4svg'~and~`#1'~are~incompatible.\\
  Remove~`#1'~from~the~document~preamble.
}

%creating global definitions
\cs_new:Npn\msvg@newkey#1#2{\tl_gset:cx{#1}{#2}}

\AtBeginDocument{
  \iow_now:Nx\@mainaux{
    \token_to_str:N\providecommand\token_to_str:N\msvg@newkey[2]{}}
  \@ifpackageloaded{media9}{
    \msg_error:nnn{media4svg}{incompatible~package}{media9}}{}%
}

%macros for writing global defs to \jobname.aux
\msg_set:nnn{media4svg}{rerun}{Rerun~to~get~internal~references~right!}
\msg_set:nnn{media4svg}{undefined~reference}{
  Line~\msg_line_number: :~Media~reference~`#1'~not~defined.
}
\msg_set:nnn{media4svg}{undefined~references}{
  There~were~undefined~media~references!}
\msg_set:nnn{media4svg}{same~id}{
  Line~\msg_line_number: :~Label~`#1'~multiply~defined.
}
\msg_set:nnn{media4svg}{multiple~ids}{There~were~multiply-defined~ids!}

\cs_new_nopar:Nn\msvg_keytoaux_now:nn{
  \iow_now:Nx\@mainaux{\token_to_str:N\msvg@newkey{#1}{#2}}
  \bool_if:nT{
    !\cs_if_exist:cTF{#1}{
      \str_if_eq_p:ee{\tl_use:c{#1}}{#2}
    }{
      \c_false_bool
    }
  }{
    \cs_if_exist:NF\g_msvg_rerunwarned_tl{
      \tl_new:N\g_msvg_rerunwarned_tl
      \AtEndDocument{\msg_warning:nn{media4svg}{rerun}}
    }
  }
}
\cs_new_nopar:Nn\msvg_keytoaux_shipout:nn{
  \iow_shipout_x:Nx\@mainaux{\token_to_str:N\msvg@newkey{#1}{#2}}
  \cs_if_exist:cF{#1}{
    \cs_if_exist:NF\g_msvg_rerunwarned_tl{
      \tl_new:N\g_msvg_rerunwarned_tl
      \AtEndDocument{\msg_warning:nn{media4svg}{rerun}}
    }
  }
}

%reset various variables for every new media inclusion
\cs_new:Nn\msvg_reset:{
  \tl_gset:Nx\g_msvg_id_tl{\int_use:N\g_msvg_mmcnt_int}
  \bool_gset_eq:NN\g_msvg_draft_bool\g_msvg_pkgdraft_bool
  \tl_gset_eq:NN\g_msvg_autoplay_tl\g_msvg_pkgautoplay_tl
  \tl_gset_eq:NN\g_msvg_loop_tl\g_msvg_pkgloop_tl
  \tl_gset_eq:NN\g_msvg_controls_tl\g_msvg_pkgcontrols_tl
  \tl_gset_eq:NN\g_msvg_mtype_tl\g_msvg_pkgmtype_tl
  \bool_gset_eq:NN\g_msvg_embed_bool\g_msvg_pkgembed_bool
  \tl_gset_eq:NN\g_msvg_time_tl\g_msvg_pkgtime_tl
  \tl_gset_eq:NN\g_msvg_muted_tl\g_msvg_pkgmuted_tl
  \tl_set_eq:NN\l_msvg_wd_tl\l_msvg_pkgwd_tl
  \tl_set_eq:NN\l_msvg_ht_tl\l_msvg_pkght_tl
  \tl_set_eq:NN\l_msvg_tt_tl\l_msvg_pkgtt_tl
  \tl_gset_eq:NN\g_msvg_wdarg_tl\g_msvg_pkgwdarg_tl
  \tl_gset_eq:NN\g_msvg_htarg_tl\g_msvg_pkghtarg_tl
  \tl_gset_eq:NN\g_msvg_ttarg_tl\g_msvg_pkgttarg_tl
  \bool_gset_eq:NN\g_msvg_iso_bool\g_msvg_pkgiso_bool
  \tl_gset_eq:NN\g_msvg_scalearg_tl\g_msvg_pkgscalearg_tl
  \int_gset_eq:NN\g_msvg_resizeflag_int\g_msvg_pkgresizeflag_int
  \box_clear:N\l_msvg_poster_box
}

%document command options

\msg_set:nnnn{media4svg}{unknown~option}{
  Line~\msg_line_number: :~Unknown~option~`#1'.
}{
  Option~`#1'~is~not~known~by~media4svg:\\
  perhaps~it~is~spelled~incorrectly.
}

\bool_new:N\g_msvg_draft_bool
\bool_new:N\g_msvg_iso_bool
\bool_new:N\g_msvg_embed_bool

\keys_define:nn{media4svg/user}{
  %user override automatic id
  id .code:n = {
    \tl_gset:Nx\g_msvg_id_tl{#1}
    \tl_gtrim_spaces:N\g_msvg_id_tl
    \cs_if_exist:cTF{msvg@\g_msvg_id_tl}{
      \msg_warning:nnx{media4svg}{same~id}{#1}
      \cs_if_exist:NF\g_msvg_sameid_tl{
        \tl_new:N\g_msvg_sameid_tl
        \AtEndDocument{\msg_warning:nn{media4svg}{multiple~ids}}
      }
    }{
      \tl_new:c{msvg@\g_msvg_id_tl}
    }
  },
  id .value_required:n = {true},

  draft .bool_gset:N = \g_msvg_draft_bool,

  final .bool_gset_inverse:N = \g_msvg_draft_bool,

  autoplay .choice:,
  autoplay / true .code:n = {\tl_gset:Nn\g_msvg_autoplay_tl{autoplay=''~}},
  autoplay / false .code:n = {\tl_gclear:N\g_msvg_autoplay_tl},
  autoplay .default:n = {true},

  loop .choice:,
  loop / true .code:n = {\tl_gset:Nn\g_msvg_loop_tl{loop=''~}},
  loop / false .code:n = {\tl_gclear:N\g_msvg_loop_tl},
  loop .default:n = {true},

  controls .choice:,
  controls / true .code:n = {\tl_gset:Nn\g_msvg_controls_tl{controls=''~}},
  controls / false .code:n = {\tl_gclear:N\g_msvg_controls_tl},
  controls .default:n = {true},

  muted .choice:,
  muted / true .code:n = {\tl_gset:Nn\g_msvg_muted_tl{muted=''~}},
  muted / false .code:n = {\tl_gclear:N\g_msvg_muted_tl},
  muted .default:n = {true},

  time .code:n = {\tl_gset:Nn\g_msvg_time_tl{#1}},
  time .value_required:n = {true},

  mimetype .tl_gset:N = \g_msvg_mtype_tl,

  url .bool_gset_inverse:N = \g_msvg_embed_bool,

  embed .bool_gset:N = \g_msvg_embed_bool,

  width .code:n = {
    \tl_gset:Nn\g_msvg_wdarg_tl{#1}
    \tl_if_exist:NF\l_msvg_wd_tl{
      \int_gadd:Nn\g_msvg_resizeflag_int{4}
      \tl_set:Nn\l_msvg_wd_tl{}
    }
  },
  width .value_required:n = {true},

  height .code:n = {
    \tl_gset:Nn\g_msvg_htarg_tl{#1}
    \tl_if_exist:NF\l_msvg_ht_tl{
      \int_gadd:Nn\g_msvg_resizeflag_int{2}
      \tl_set:Nn\l_msvg_ht_tl{}
    }
  },
  height .value_required:n = {true},

  totalheight .code:n = {
    \tl_gset:Nn\g_msvg_ttarg_tl{#1}
    \tl_if_exist:NF\l_msvg_tt_tl{
      \int_gadd:Nn\g_msvg_resizeflag_int{\c_one_int}
      \tl_set:Nn\l_msvg_tt_tl{}
    }
  },
  totalheight .value_required:n = {true},

  keepaspectratio .bool_gset:N = \g_msvg_iso_bool,

  scale .code:n = {\tl_gset:Nx\g_msvg_scalearg_tl{#1}},
  scale .value_required:n = {true},

  unknown .code:n = {
    \msg_error:nnx{media4svg}{unknown~option}{\l_keys_key_tl}
  }
}

\NewDocumentCommand\addmediapath{m}{
  \str_set:Nn\l_tmpa_str{#1}
  \seq_put_right:NV\l_file_search_path_seq\l_tmpa_str
}

% external Lua script `media4svg.lua' defines
% media4svg.base64("<file name>", <chunk size>, "<end-of-line string>")
\sys_if_engine_luatex:T{\directlua{require('media4svg')}}

% base64-encodes external binary file into tl variable;
% non-LuaTeX version, running media4svg.lua via shell-escape
% (very slow!)
\cs_set_eq:NN\ior_msvg_shell_open:Nn\ior_shell_open:Nn
\cs_generate_variant:Nn\ior_msvg_shell_open:Nn{Nx}
\cs_new_protected_nopar:Nn\msvg_convert_file_to_blob:nN{% #1 filename, #2 tlvar
  \sys_if_shell_unrestricted:F{
    \msg_error:nnx{media4svg}{unrestricted~shell~required}{#1}
  }
  % get path to media4svg.lua
  \ior_shell_open:Nn\g_tmpa_ior{kpsewhich~media4svg.lua}
  \ior_str_get:NN\g_tmpa_ior\l_tmpa_tl
  \tl_if_blank:VT\l_tmpa_tl{
    \msg_error:nnxx{media4svg}{missing~script}{media4svg.lua}{#1}
  }
  \ior_close:N\g_tmpa_ior
  % encode
  \ior_msvg_shell_open:Nx\g_tmpa_ior{texlua~\l_tmpa_tl\space #1}
  \message{<#1}
  \tl_gclear_new:N#2
  \ior_str_map_inline:Nn\g_tmpa_ior{
    \tl_gput_right:Nn#2{##1{?nl}}\message{.}}\message{>}
  \ior_close:N\g_tmpa_ior
}

\msg_set:nnnn{media4svg}{file~not~found}{
  Line~\msg_line_number:\\
  File\\
  `#1'\\
  not~found.
}{
  Make~sure~file\\
  `#1'\\
  exists~and~is~readable,~or~set~command~option~`url'~if~it~is~a~remote~file!
}

\msg_set:nnnn{media4svg}{unrestricted~shell~required}{
  Line~\msg_line_number: :~In~order~to~embed~file~`#1',\\
  LaTeX~must~be~invoked~with~the~--shell-escape~option.
}{
  Alternatively,~use~one~of~the~package/command~options\\
  `url'~or~`embed=false'~to~prevent~embedding.
}

\msg_set:nnnn{media4svg}{missing~script}{
  Line~\msg_line_number: :~Script~`#1'~couldn't~be~found.\\
  In~order~to~embed~file~`#2',~it~must~be~present~on~the~system.
}{
  File~`#2'~is~part~of~the~`media4svg'~package.\\
  Make~sure~the~package~was~correctly~installed.
}

\int_new:N\g@msvg@page@int %abs. page counter (zero based)
\int_gset:Nn\g@msvg@page@int{-1}

\AtBeginShipout{
  \int_gincr:N\g@msvg@page@int
  \AtBeginShipoutUpperLeft{
    \special{dvisvgm:rawdef {?nl}
      <script~type="text/javascript">{?nl}
        <![CDATA[{?nl}
          function~$(id)~{
            return~document.getElementById("msvg@"+id.toString().trim());
          };{?nl}
        ]]>{?nl}
      </script>
    }
  }
}