% 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}
    [2023/05/26 v1.0.2 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.luacas-parser')
           require('test.luacas-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
        }%
    }%
}%

\NewDocumentCommand{\yoink}{m O{#1}}{%
\expandafter\def\csname #2\endcsname{%
    \directlua{
        tex.print(tostring(#1))
        }%
    }%
}

%\newcommand{\eval}[1]{\luaexec{tex.print(parse('#1'):tolatex())}}

%%%%%%%%%%
%% 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
        }%
    }%
}

%verbatim print

\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) {",longwhatis(sym),"};}")
            tex.print(sym:getthefancyshrub())
            tex.print("]")
            tex.print("}")
        }%
    }
}

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

\NewDocumentCommand{\freeof}{s m m}{%
    \IfBooleanTF{#1}{%
        \luaexec{
            local sym1 = #2
            local sym2 = #3
            if sym1:freeof(sym2) then
                tex.print(1)
            else
                tex.print(0)
            end
        }
    }{%
        \luaexec{
            local sym1 = #2
            local sym2 = #3
            sym1 = sym1:autosimplify()
            sym2 = sym2:autosimplify()
            if sym1:freeof(sym2) then
                tex.print(1)
            else
                tex.print(0)
            end
        }%
    }%
}

\NewDocumentCommand{\isatomic}{s m}{%
    \IfBooleanTF{#1}{
        \luaexec{
            local sym = #2
            if sym:isatomic() then
                tex.print(1)
            else
                tex.print(0)
            end
        }
    }{%
        \luaexec{
            local sym = #2
            sym = sym:autosimplify()
            if sym:isatomic() then
                tex.print(1)
            else
                tex.print(0)
            end
        }%
    }%
}

\NewDocumentCommand{\isconstant}{s m}{%
    \IfBooleanTF{#1}{%
        \luaexec{
            local sym = #2
            if sym:isconstant() then
                tex.print(1)
            else
                tex.print(0)
            end
        }%
    }{%
        \luaexec{%
            local sym = #2
            sym = sym:autosimplify()
            if sym:isconstant() then
                tex.print(1)
            else
                tex.print(0)
            end
        }%
    }%
}