% Copyright (c) ???
%
% Permission is granted to copy, distribute and/or modify this
% software under the terms of the LaTeX Project Public License
% (LPPL), version 1.3c or any later version.
%
% This software is provided 'as is', without warranty of any kind,
% either expressed or implied, including, but not limited to, the
% implied warranties of merchantability and fitness for a
% particular purpose.

\NeedsTeXFormat{LaTeX2e}
\ProvidesPackage{luacas}
    [2022/11/15 v1.0.1 CAS written in Lua for LaTeX]

\RequirePackage{iftex}
\ifluatex
  \RequirePackage{luacode}
\else
  {\PackageError{luacas}
  {Not running under LuaLaTeX}
  {This package requires LuaLaTeX. Try compiling this document with\MessageBreak 'lualatex' instead of 'latex'. This is a fatal error; I'm aborting now.}%
  }\stop
\fi

%Required Packages
\RequirePackage{xparse}
\RequirePackage{pgfkeys}
\RequirePackage{verbatim}
\RequirePackage{tikz}
\RequirePackage{xcolor}
\RequirePackage{mathtools}

%These files contain Lua code for parsing luacas output; they also initialize the CAS itself
\directlua{require('test.parser')
           require('test.helper')
} 

\NewDocumentEnvironment{CAS}%
  {+b}%
  {\luaexec{CASparse([[#1]])}}%
  {}

\newcommand{\get}%
  [2][true]%
  {\directlua{disp(#2, #1)}}  
    
\newcommand{\fetch}[1]{
  \directlua{tex.print(tostring(#1))}
}

\NewDocumentCommand{\store}{m O{#1}}{
  \expandafter\def\csname #2\endcsname{%
    \directlua{
      input = #1
      if not input[1] then
        tex.sprint{tostring(input)}
      else
        tex.sprint("{")
        for _,entry in ipairs(input) do 
            tex.sprint(tostring(entry),",")
        end
        tex.sprint("}")
      end
    }%
  }%
}%

%%%%%%%%%%
%% Core %%
%%%%%%%%%%

%pretty print

\NewDocumentCommand{\print}{s m}{%
  \IfBooleanTF{#1}{%
    \directlua{
      local sym = #2
      if sym then 
        tex.print(sym:autosimplify():tolatex())
      else
        tex.print('nil')
      end
    }%
  }{%
    \directlua{
      local sym = #2
      if sym then 
        tex.print(sym:tolatex())
      else
        tex.print('nil')
      end
    }%
  }%
}

\NewDocumentCommand{\vprint}{s m}{%
  \IfBooleanTF{#1}{%
    \directlua{
      local sym = #2
      tex.sprint([[\unexpanded{\begin{verbatim}]] .. tostring(sym) .. [[\end{verbatim}}]])
    }%
  }{%
    \directlua{
      local sym = #2
      tex.sprint([[\unexpanded{\begin{verbatim}]] .. tostring(sym:autosimplify()) .. [[\end{verbatim}}]])
    }%
  }%
}

\NewDocumentCommand{\lprint}{m O{nil,nil}}{%
  \luaexec{
    local tbl = #1
    local low,upp = #2
    local tmp =0
    if tbl[0] == nil then 
      tmp = 1
    end
    upp = upp or \#tbl 
    low = low or tmp
    for i=low,upp do 
      tex.print(tbl[i]:tolatex())
      if tbl[i+1] then 
          tex.print(",")
      end 
    end
  }
}

%prints the first level of an expression tree; for use within a tikzpicture environment

\NewDocumentCommand{\printshrub}{s m}{%
  \IfBooleanTF{#1}{%
    \directlua{
      local sym = #2
      sym = sym:autosimplify()
      tex.print("\\node [label=90:", whatis(sym), "] {", nameof(sym), "}")
      tex.print(sym:gettheshrub())
      tex.print(";")
    }%
  }{%
    \directlua{
      local sym = #2
      tex.print("\\node [label=90:", whatis(sym), "] {", nameof(sym), "}")
      tex.print(sym:gettheshrub())
      tex.print(";")
    }%
    }
}

%prints the full expression tree; for use within a tikzpicture environment
    
\NewDocumentCommand{\printtree}{s m}{%
  \IfBooleanTF{#1}{%
    \luaexec{
      local sym = #2
      sym = sym:autosimplify()
      tex.print("\\node {",nameof(sym),"}")
      tex.print(sym:getthetree())
      tex.print(";")
    }%
  }{%
    \luaexec{
      local sym = #2
      tex.print("\\node {",nameof(sym),"}")
      tex.print(sym:getthetree())
      tex.print(";")
    }%
  }
}

%parses an expression tree for use within the forest environment; result is stored in \forestresult

\NewDocumentCommand{\parseforest}{s m}{%
  \IfBooleanTF{#1}{%
    \luaexec{
      local sym = #2
      sym = sym:autosimplify()
      tex.print("\\def\\forestresult{")
      tex.print("[")
      tex.print(nameof(sym))
      tex.print(sym:gettheforest())
      tex.print("]")
      tex.print("}")
    }%
  }{%
    \luaexec  {
      local sym = #2
      tex.print("\\def\\forestresult{")
      tex.print("[")
      tex.print(nameof(sym))
      tex.print(sym:gettheforest())
      tex.print("]")
      tex.print("}")
    }%
  }
}

\NewDocumentCommand{\parseshrub}{s m}{%
  \IfBooleanTF{#1}{%
    \luaexec{
      local sym = #2
      sym = sym:autosimplify()
      tex.print("\\def\\shrubresult{")
      tex.print("[")
      tex.print(nameof(sym))
      tex.print(", tikz+={\\node[anchor=south] at (.north) {test};}")
      tex.print(sym:getthefancyshrub())
      tex.print("]")
      tex.print("}")
    }%
  }{%
    \luaexec{
      local sym = #2
      tex.print("\\def\\shrubresult{")
      tex.print("[")
      tex.print(nameof(sym))
      tex.print(", tikz+={\\node[anchor=south  font=\\ttfamily\\footnotesize,gray] at (.north) {",longwhati  (sym),"};}")
      tex.print(sym:getthefancyshrub())
      tex.print("]")
      tex.print("}")
    }%
  }
}

\NewDocumentCommand{\whatis}{m}{%
  \luaexec{
    tex.sprint("{\\ttfamily",longwhatis(#1),"}")
  }%
}