%LaTeX package for writing fancy mathematics fast, specifically tailored to writing assignments and course notes.
%Requires and integrates with the fancycom package, which defines many mathematical command shortcuts.
%Not carefully checked for integration with other packages.
%Written by Adam Walsh
%Version 1.0

%----------Identification------------
\NeedsTeXFormat{LaTeX2e}
\ProvidesPackage{fancymath}[2016/06/17 v1.0 Fancy Maths Package]

%----------Initial code--------------

\RequirePackage{ifthen}

%Layout colour
%% 0=Full (default)
%% 1=Black (no colour)
%% 2=Grey (Greyscale colours)
\newcounter{colour}
\newboolean{fullcolour}
\setboolean{fullcolour}{true}
\newcommand{\colour}{}

%Default Layouts
%% 0=plain (default)
%% 1=Assignment
%% 2=General Submission
%% 3=Course Notes
%% 4=
\newcounter{layout}


%Separate questions on different pages (for question and answer environment)
%%0= multiple questions per page (default)
%%1= One question and answer per page
\newboolean{sepquest}

\newboolean{qthm}

%----------Option Declaration------------

%Colour selection
\DeclareOption{grey}{%
	\setcounter{colour}{2}%
	\setboolean{fullcolour}{false}%
	\renewcommand{\colour}{\color{Gray}}}

\DeclareOption{black}{%
	\setcounter{colour}{1}%
	\setboolean{fullcolour}{false}%
	\renewcommand{\colour}{\color{Black}}}

%Default Layout selection
\DeclareOption{ass}{\setcounter{layout}{1}}
\DeclareOption{general}{\setcounter{layout}{2}}
\DeclareOption{notes}{\setcounter{layout}{3}}

%Seperate questions option
\DeclareOption{qsep}{\setboolean{sepquest}{true}}

\DeclareOption{qthm}{\setboolean{qthm}{true}}

%---------Process Options----------------
\ProcessOptions

%------------Package Loading---------------

\RequirePackage[table,dvipsnames]{xcolor} %To use coloured layout
\RequirePackage{fancyhdr} %To make the headers and footers fancy
\RequirePackage{geometry} %To manipulate the geometry of the pages

\RequirePackage{calc} %For manipulating values


%------------Main Code---------------


%Some formatting lengths not usually useful in mathematical submissions.
\setlength{\parindent}{0mm}
\setlength{\parskip}{0mm}



%General values used in titles and styling
\newcommand{\authorname}{}
\newcommand{\authornumber}{}
\newcommand{\coursename}{}
\newcommand{\coursenumber}{}
\newcommand{\submissiontitle}{}
\newcommand{\assignmentnumber}{}
\newcommand{\thetitle}{\submissiontitle}
\newcommand{\theauthor}{\authorname}
\newcommand{\therightfoot}{}
\newcommand{\theleftfoot}{}
\newcommand{\thelefthead}{}
\newcommand{\therighthead}{}



%Control sequences for basic style values
\newcommand{\aname}[1]{%
	\renewcommand{\authorname}{#1}}
\newcommand{\anum}[1]{%
	\renewcommand{\authornumber}{#1}}
\newcommand{\cname}[1]{%
	\renewcommand{\coursename}{#1}}
\newcommand{\cnum}[1]{%
	\renewcommand{\coursenumber}{#1}}
\newcommand{\stitle}[1]{%
	\renewcommand{\submissiontitle}{#1}}
\newcommand{\assnum}[1]{%
	\renewcommand{\assignmentnumber}{#1}}

%Advanced control sequences for controlling styling
\newcommand{\rawtitle}[1]{%
	\renewcommand{\thetitle}{#1}}
\newcommand{\rawauthor}[1]{%
	\renewcommand{\theauthor}{#1}}
\newcommand{\rawrfoot}[1]{%
	\renewcommand{\therightfoot}{#1}}
\newcommand{\rawlfoot}[1]{%
	\renewcommand{\theleftfoot}{#1}}
\newcommand{\rawlhead}[1]{%
	\renewcommand{\thelefthead}{#1}}
\newcommand{\rawrhead}[1]{%
	\renewcommand{\therighthead}{#1}}


%Styling common to all layouts, including plain

%The page geometry
\geometry{%
	a4paper,%
	left=20mm,%
	right=20mm,%
	top=20mm,%
	bottom=20mm,%
	heightrounded}



%Styling common to general non-plain layouts
\ifthenelse{\not \value{layout}=0}{%
	%Base colours, determined from colour option
	\newcommand{\titlecolour}{%
		\ifthenelse{\boolean{fullcolour}}{\color{Brown}}{\colour}}
	\newcommand{\headcolour}{%
		\ifthenelse{\boolean{fullcolour}}{\color{Blue}}{\colour}}
	\newcommand{\headrulecolour}{%
		\ifthenelse{\boolean{fullcolour}}{\color{Brown}}{\colour}}
	\newcommand{\enumcolour}{%
		\ifthenelse{\boolean{fullcolour}}{\color{Brown}}{\colour}}

	%Some default values for the footers
	\rawlfoot{\authorname}
	\rawrfoot{\today}
	\rawlhead{\submissiontitle}
	\rawrhead{\thepage}

	%Page style
	\pagestyle{fancy}
	
	%Set the headers and footers
	\fancyhead{}
	\fancyfoot{}
	\fancyfoot[L]{\headcolour\theleftfoot}
	\fancyfoot[C]{\headcolour\thepage}
	\fancyfoot[R]{\headcolour{}\therightfoot}
	\fancyhead[L]{\headcolour\thelefthead}
	\fancyhead[R]{\headcolour\therighthead}

	%Make the headrule
	\renewcommand{\headrule}{\headrulecolour\vbox to 0pt{\hbox to\headwidth{\hrulefill}\vss}}
	\headheight=21pt

	%Slightly modify line spacing
	\renewcommand{\baselinestretch}{1.1}
	
	%Set the style and colour of the enumerate labels
	\renewcommand{\theenumi}{\alph{enumi}}	
	\renewcommand{\theenumii}{\roman{enumii}}	
	\renewcommand{\theenumiii}{\alph{enumiii}}	
	\renewcommand{\labelenumi}{\enumcolour(\theenumi)}
	\renewcommand{\labelenumii}{\enumcolour(\theenumii)}
	\renewcommand{\labelenumiii}{\enumcolour(\theenumiii)}

	%Make title info for maketitle
	\author{\titlecolour\theauthor}
	\title{\titlecolour\thetitle}
	\date{\titlecolour\today}

}{}

%---Notes specific layout and styling---
\ifthenelse{\value{layout}=3}{%
	%Set the Notes specific headers and footers
	\rawlfoot{\authorname, \today}
	\rawrfoot{Notes}
	\rawlhead{\coursenumber -- \coursename}
	
	%Assignment specific title and Author
	\rawauthor{\authorname}
	\rawtitle{\coursename -- Notes}
}{}

%---Assignment specific layout and styling---
\ifthenelse{\value{layout}=1}{%
	%Set the Assignment specific headers and footers
	\rawlfoot{\authorname}
	\rawrfoot{\today}
	\rawrhead{Assignment \assignmentnumber}
	\rawlhead{\coursenumber -- \coursename}
	
	%Assignment specific title and Author
	\rawauthor{\authorname, Student \authornumber}
	\rawtitle{\coursenumber -- Assignment \assignmentnumber}
}{}


%Defining the Question-and-Answer environment for use in assignments.
%%Formats Questions and Answers with incrementing counters
%Base lengths
%%Amount questions and answers are indented
\newlength{\qmargin}
\setlength{\qmargin}{5mm}

%%Amount of vertical space between question/answer title and question/answer.
\newlength{\qgap}
\setlength{\qgap}{5mm}

%%Amount of vertical space between end of question and answer.
\newlength{\qagap}
\setlength{\qagap}{0.5em}


%Base colours, determined from colour option
%%Default colour is gray anyway
\newcommand{\qcolour}{%
    \ifthenelse{\boolean{fullcolour}}{\color{Gray}}{\colour}}


\ifthenelse{\boolean{qthm}}{
  %Values
  \newcounter{question}
  \newcounter{nextanswer}

  \newboolean{firstquest}
  \newboolean{questopen}
  \newboolean{answeropen}

  \RequirePackage{amsthm}
  \theoremstyle{plain}
  \newtheorem{Question}[question]{Question}


  \makeatletter

  \newcommand{\theanswer}{Answer \arabic{nextanswer}}

  \newcommand{\qnum}[1]{%
      \setcounter{question}{#1}%
      \addtocounter{question}{-1}%
      \setcounter{nextanswer}{#1}%
  }

  \newcommand{\startqanda}{%
    \setcounter{question}{0}%
    \setcounter{nextanswer}{0}%
    \setboolean{firstquest}{true}%
    \setboolean{questopen}{false}%
    \setboolean{answeropen}{false}%
  }

  \newcommand{\closeqanda}{%
    \ifthenelse{\boolean{questopen}}{\closequestion}{}%
    \ifthenelse{\boolean{answeropen}}{\closeanswer}{}%
  }

  \newcommand{\question}[1][0]{%
    \closeqanda%
    \ifthenelse{\boolean{sepquest} \and \not \boolean{firstquest} }{\newpage}{}%
    \setboolean{firstquest}{false}%
    \ifthenelse{#1=0}{}{\qnum{#1}}%
    \begin{Question}
      \@minipagetrue%
      \setboolean{questopen}{true}%
      \setcounter{nextanswer}{\value{question}}%
  }
  \newcommand{\closequestion}{%
    \end{Question}%
    \setboolean{questopen}{false}%
  }

  \newcommand{\answer}[1][0]{%
    \closeqanda%
    \ifthenelse{#1=0}{}{\qnum{#1}\stepcounter{question}\stepcounter{question}}%
    \begin{proof}[\theanswer]
      \@minipagetrue%
      \setboolean{answeropen}{true}%
      \setcounter{question}{\value{nextanswer}}%
      \stepcounter{nextanswer}%
      \phantom{}%
  }
  \newcommand{\closeanswer}{%
    \ifvmode\vspace*{-\baselineskip}\fi%
    %\unskip%
    \end{proof}%
    \setboolean{answeropen}{false}%
  }

  \newenvironment{qanda}{%
    \startqanda%
  }{%
    \closeqanda%
  }
  \makeatother
}{

  %Values
  \newcounter{question}
  \newcounter{lastquestion}
  \newboolean{firstquest}


  %Control Sequences
  \newcommand{\qnum}[1]{%
      \setcounter{question}{#1}%
      \addtocounter{question}{-1}%
      \setcounter{lastquestion}{\value{question}}}

  %The environment
  \newenvironment{qanda}{%
      \setcounter{question}{0}%
      \setcounter{lastquestion}{0}%
      \setboolean{firstquest}{true}%
      \begin{list}{}{%
          \renewcommand{\makelabel}[1]{\qcolour\textbf{##1}\\}%
          \setlength{\leftmargin}{\qmargin}%
      }%
  }{%
      \end{list}%
  }

  %The question and answer commands
  \makeatletter
  \newcommand{\question}[1][0]{%
      \ifthenelse{\boolean{sepquest} \and \not \boolean{firstquest} }{\newpage}{}%
      \setboolean{firstquest}{false}%
      \ifthenelse{#1=0}{%
          \stepcounter{question}%
          \setcounter{lastquestion}{\value{question}}%
          \item[Question \arabic{question}]%
      }{%
          \setcounter{lastquestion}{#1}%
          \item[Question #1]%
      }%
    \hfill\break\@minipagetrue%
  }

  \newcommand{\answer}[1][0]{%
      \vspace{\the\qagap}%
      \ifthenelse{#1=0}{%
          \item[Answer \arabic{lastquestion}]%
      }{%
          \item[Answer #1]%
      }%
    \hfill\break%
    \@minipagetrue%
  }
  \makeatother
}