\NeedsTeXFormat{LaTeX2e}[1994/06/01]
\ProvidesPackage{inputslide}[2021/09/03 inputslide v0.1.0]

%% Copyright (c) 2021 Vincent Kuhlmann

\RequirePackage{xkeyval}
\RequirePackage{graphicx}
\RequirePackage{pdfpages}
\RequirePackage{etoolbox}
\RequirePackage{adjustbox}
\RequirePackage{xcolor}
\RequirePackage{xstring}

\let\bracechar={
\iffalse}\fi

\def\@inputslide@slidesource{}

\def\SetSlideSource#1{%
    \def\@inputslide@slidesource{#1}%
}

\newbool{@inputslide@wasSlideFound}

\newcommand\inputslide[2][\@inputslide@slidesource]{%
    \IfFileExists{#1}{%
        \begingroup
        \expandafter\let\expandafter\inputentrance\csname fi\endcsname
        %\newbool{usingframe}%
        % \def\afterframeend{%
        %     %\csname iffalse\endcsname
        % }%
        \def\inputexit{%
            \csname iffalse\endcsname
        }%
        %
        % \AtBeginEnvironment{frame}{%
        % }%
        % \AfterEndEnvironment{frame}{%
        %     \csname afterframeend\endcsname
        % }%
        \let\documentclass\inputexit
        %
        % \expandafter\let\expandafter\@inputslide@orig@end\csname end \endcsname
        % \def\@inputslide@end####1{%
        %     \typeout{Environment name was ####1}%
        %     \@inputslide@orig@end{####1}%
        %     \def\@doafter{}%
        %     \IfStrEq{####1}{frame}{%
        %         \typeout{Hit a frame, skipping!}
        %         \def\@doafter{\csname iffalse\endcsname}%
        %     }{}%
        %     \@doafter
        % }%
        % \expandafter\let\csname end \endcsname\@inputslide@end

        % BEGIN Based on: https://tex.stackexchange.com/questions/226319/run-a-command-at-end-of-each-frame
        \patchcmd{\beamer@doseveralframes}%
            {\beamer@reseteecodes}%
            {\beamer@reseteecodes
                \inputexit
            }%
            {}{}%
        % END

        %\PackageWarning{DEBUG}{end is \expandafter\meaning\csname end\endcsname}%
        %
        \def\named####1{%
            \def\aftercom{}%
            \IfStrEq{#2}{####1}{%
                \global\booltrue{@inputslide@wasSlideFound}
            }{%
                \def\aftercom{\csname iffalse\endcsname}%
            }%
            \aftercom
        }%
        \global\boolfalse{@inputslide@wasSlideFound}
        \expandafter%\iffalse
        \input{#1}%
            % \inputentrance%\csname iffalse\endcsname
            % \begin{frame}
            %     ccc
            % \end{frame}
            % \inputexit
            %\csname iffalse\endcsname
        %
        %\fi
        \endgroup
        \ifbool{@inputslide@wasSlideFound}%
        {}%
        {%
            \PackageError{inputslide}{InputSlide could not find slide `#2'}{}%
        }%
        \let\frameselection\somethingundefined
        %\PackageWarning{DEBUG}{Documentclass is \meaning\documentclass}
    }{%
        \PackageError{inputslide}{Input file not found}{}%
    }%
}