\NeedsTeXFormat{LaTeX2e}
\ProvidesFile{caesar_book.cls}[2020/03/24 v1.00a Caesar book]
% Load the amsmath and the mhchem package before loading microtype
\RequirePackage{amsmath}% better math handling
\RequirePackage[version=3]{mhchem}% chemical formulas
\LoadClassWithOptions{book}% this is derived from the book class
\RequirePackage{sidenotes}% put annotations, tables and figures in the margin
\captionsetup{font=footnotesize, skip=4pt}
\RequirePackage[maxfloats=45]{morefloats}% a lot of marginals need more float 'memory'
\RequirePackage{marginfix}% automatically adjust the side-floats nicely 
\newcommand{\caesar@letterspace}[1]{#1}% allow LuaLaTeX, LaTeX letterspacing
\RequirePackage{microtype}% microtypography
\@ifpackagelater{microtype}{2011/08/18}% xxx allow LaTeX and earlier microtype
{\renewcommand{\caesar@letterspace}[1]{\textls{#1}}}%
{\AtEndDocument{\ClassWarningNoLine{caesar_book}{Need newest microtype for letterspacing.}}}
%
% Set page layout geometry -- default is science-book format
% this means a (portrait) paper size of 170mm x 240mm
%
\RequirePackage{geometry}
\geometry{paperwidth=170mm, paperheight=240mm, left=42pt, top=40pt, textwidth=280pt, marginparsep=20pt, marginparwidth=100pt, textheight=560pt, footskip=40pt}
%
% fontsize is 10pt with a leading (line spacing) of 13pt for book 
%
\renewcommand{\normalsize}{\fontsize{10pt}{13pt}\selectfont}%
\renewcommand{\footnotesize}{\fontsize{8pt}{10pt}\selectfont}%
% fullwidth environment, text across textwidth+marginparsep+marginparwidth
\newlength{\overhang}
\setlength{\overhang}{\marginparwidth}
\addtolength{\overhang}{\marginparsep}
%
\newenvironment{fullwidth}
  {\ifthenelse{\boolean{@twoside}}%
     {\begin{adjustwidth*}{}{-\overhang}}%
     {\begin{adjustwidth}{}{-\overhang}}%
  }%
  {\ifthenelse{\boolean{@twoside}}%
    {\end{adjustwidth*}}%
    {\end{adjustwidth}}%
  }
% set up the fonts
\RequirePackage{ifluatex}
\ifluatex% in LuaLateX we use fontspec
	\RequirePackage{fontspec}%
	\RequirePackage{unicode-math}% 
	\setmathfont{TeX Gyre Pagella Math}% use corresponding math font
	\setmainfont[Ligatures=TeX, Numbers=OldStyle]{Tex Gyre Pagella}% free Palatino clone
	\setmonofont{Tex Gyre Cursor}% works okay with palatino
	\setsansfont{Tex Gyre Heros}% work okay with palatino
	\mhchemoptions{textfontcommand=\addfontfeature{Numbers=Lining}} % use lining numbers for chemical formulas
\else% in LaTeX we load fonts differently
	\IfFileExists{mathpazo.sty}{\RequirePackage[osf,sc]{mathpazo}}{}% palatino clone for math
  	\IfFileExists{helvet.sty}{\RequirePackage[scaled=0.90]{helvet}}{}% helvetica is sans serif font
  	\IfFileExists{beramono.sty}{\RequirePackage[scaled=0.85]{beramono}}{}% beramono is tt font
  	\RequirePackage[T1]{fontenc}% finally load fontenc
\fi
% nice headings and TOC
\RequirePackage{titlesec,titletoc}% load the helper package
\setcounter{secnumdepth}{-1}% no numbering at all
\titleformat{\chapter}[display]{\relax\itshape\huge}{}{0pt}{\huge\rmfamily\itshape}[]% chapter format
\titleformat{\section}[hang]{\normalfont\Large\itshape}{}{1em}{}[]% section format
\titleformat{\subsection}[hang]{\normalfont\large\itshape}{}{1em}{}[]% subsection format
\titleformat{\paragraph}[runin]{\normalfont\itshape}{}{1em}{}[]% paragraph format
\renewcommand*\descriptionlabel[1]{\hspace\labelsep\normalfont\em #1}% italic description instead of bold)
\setcounter{tocdepth}{0}% The Table of Contents, only chapters 
\titlecontents{chapter}%
   [0em] % distance from left margin
   {\vspace{1.5\baselineskip}\begin{fullwidth}\LARGE\rmfamily\itshape} % above (global formatting of entry)
   {\hspace*{0em}\contentslabel{2em}} % before w/label (label = ``2'')
   {\hspace*{0em}} % before w/o label
   {\rmfamily\upshape\qquad\thecontentspage} % filler + page (leaders and page num)
   [\end{fullwidth}] % after
%set up header, footer and page numbering
\RequirePackage{fancyhdr}% helper package
\renewcommand{\headrulewidth}{0pt}% The running heads and feet do not have rules
\renewcommand{\footrulewidth}{0pt}
\fancyhf{}% set up the page numbering 
{\fancyfoot[LE,RO]{\thepage}}
\fancypagestyle{plain}{%
	\fancyhf{}
}
\renewcommand{\frontmatter}{\pagestyle{empty}}% the frontmatter is empty
\renewcommand{\mainmatter}{\cleardoublepage\pagestyle{fancy}}% mainmatter with page numbering
\RequirePackage{ragged2e} % \RaggedRight works better than \raggedright
\newcommand{\marginparstyle}{\footnotesize\RaggedRight} % initialize style with start value
\long\def\@ympar#1{% redefine margin par to avoid too many macros in the document
  \@savemarbox\@marbox{\marginparstyle#1}% marginparstyle is a prefix to the marginpar text now
  \global\setbox\@currbox\copy\@marbox % the rest of the definition is taken from original LaTeX
  \@xympar}
\renewcommand*{\marginfont}{\marginparstyle}
% setup itemize and enumerate  
\RequirePackage{enumitem}
\setlist[itemize]{leftmargin=*}
%\renewcommand{\labelitemi}{}
% compatibility with T-L
%
% titlepage
\RequirePackage{ifthen}
\newcommand{\publisher}[1]{\gdef\caesar@publisher{#1}}
\gdef\caesar@thesis{}
\newcommand{\thesis}[1]{\gdef\caesar@thesis{#1}}
\RequirePackage{textcase} % provides \MakeTextUppercase and \MakeTextLowercase
\RequirePackage{color} % the title is too black, define gray
\definecolor{darkgray}{rgb}{0.25,0.25,0.25}
\newcommand{\maketitlepage}{% the title page is generated here
  % first count the number of lines in the title
  \begin{fullwidth}
  \raggedright%
  \setbox0\vbox{\noindent\fontsize{30}{38}\selectfont\caesar@letterspace{\MakeTextUppercase{\@title}}\par
  \count@\z@
  \loop
  \unskip\unpenalty\unskip\unpenalty\unskip
  \setbox0\lastbox
  \ifvoid0
  \xdef\caesar@numlines{\the\count@}%
  \else
  \advance\count@\@ne
  \repeat}
  % now adjust the vertical spaces accordingly
  \edef\caesar@titlespace{\the\dimexpr 210pt - 15pt * \caesar@numlines \relax}% calculate the necessary space
  \cleardoublepage%
  \begingroup%
  {%
  \sffamily%
  %\begin{fullwidth}%
  \vspace*{0em}% one line extra space
  \noindent\LARGE\caesar@letterspace{\MakeTextUppercase{\@author}}\par
  \vfill%
  \noindent\fontsize{30}{38}\selectfont\textcolor{darkgray}{\caesar@letterspace{\MakeTextUppercase{\@title}}}\par
  \vfill%
  \vspace{\caesar@titlespace}%
  \noindent\Large\caesar@letterspace{\MakeTextUppercase{\caesar@publisher}}\par
  %\end{fullwidth}%
  }%
  \thispagestyle{empty}%
  \endgroup
  \cleardoublepage%
  \begin{center}%
  \vspace*{0em}% one line extra space
  \textit{\@title}%
  \end{center}%
  \end{fullwidth}%
  \cleardoublepage%
  \chapter*{\@title}
  \vspace{-3em}%
  \section*{\caesar@thesis\@author}
  % 
}
\newcommand\newthought[1]{%
   \addvspace{1.0\baselineskip plus 0.5ex minus 0.2ex}%
   \noindent\textsc{#1}%
}%
\ExplSyntaxOn
\NewDocumentCommand \sidecite { o o m }
{ 
  \IfNoValueOrEmptyTF{#1}
  {
    \IfNoValueOrEmptyTF{#2}
    {
      \sidenote{\fullcite{#3}}
    }
    {
      \sidenote{\fullcite[#2]{#3}}
    }
  }
  {
    \IfNoValueOrEmptyTF{#2}
    {
      \sidenote{\fullcite[#1]{#3}}
    }
    {
      \sidenote{\fullcite[#1][#2]{#3}}
    }
  }
}
\ExplSyntaxOff