\input ptb-utils

\_checkloaded{key-value}

\def\novalue{\novalue}

\def\_update_lastkeys#1#2#3{%
    \_xp\_xp\_xp\def\_xp\_xp\_xp#1\_xp\_xp\_xp{\_xp#1\_xp{\_xp{\_id#2}{#3}}}%
}

% #1: lastkeys, #2: key name, #3: key value
\def\_vanilla_mapkey#1#2#3{%
    \_xp\def\csname key@\_id#2\endcsname{#3}%
    \_update_lastkeys{#1}{#2}{#3}%
}

\def\__mapkeys#1#2#3=#4=#5,{%
    \def\_temp{#3}%
    \ifx\_nul\_temp%
    \else%
        \_xp#1\_xp{\_xp#2\_xp}\_xp{\_id#3}{#4}%
        \_afterfi{\_mapkeys{#1}{#2}}%
    \fi%
}

\def\_mapkeys#1#2#3,{%
    \__mapkeys{#1}{#2}#3==,%
}

% #1: setter, #2: lastkeys, #3: map
\def\_mapkeys_with_setter#1#2#3{%
    \def#2{}%
    \def\_temp{#3}%
    \ifx\_temp\empty%
    \else%
        \_afterfi{\_mapkeys{#1}{#2}#3,\_nul=,}%
    \fi%
}

\def\getvalue#1{%
    \csname key@#1\endcsname%
}

\def\__keyexists#1#2#3#4{%
    \bgroup%
    \def\_regA{#1}\def\_regB{#3}%
    \ifx\_regA\_regB%
        \egroup\def#2{#4}%
    \else%
        \egroup%
    \fi%
}

\def\_keyexists#1#2#3{%
    \ifx\_nul#3%
    \else%
        \__keyexists{#1}{#2}#3%
        \_afterfi{\_keyexists{#1}{#2}}%
    \fi%
}

\def\keyexists#1#2#3{%
    \let#2=\_nul%
    \def\_temp{\_keyexists{#1}{#2}}%
    \_xp\_temp#3\_nul%
}

\def\ifkeyexists#1{%
    \unless\ifx\_nul#1%
}

\def\_letnamedmacro#1#2{%
    \_xp\let\csname #1\endcsname=#2%
}

\def\___setdefault#1#2{%
    \def\_temp{#2}%
    \unless\ifx\_temp\empty%
        \_mapkeys_with_setter\_vanilla_mapkey\_settings{#2}%
        \keyexists{default}\_keydefault\_settings%
        \unless\ifx\_nul\_keydefault%
            \def\_temp{\_xp\def\csname key@#1\endcsname}%
            \_xp\_temp\_xp{\_keydefault}%
            \keyexists{name}\_keyname\_settings%
            \unless\ifx\_nul\_keyname%
                \_xp\_xp\_xp\_letnamedmacro\_xp\_xp\_xp{\_xp\_keyname\_xp}\_xp{\csname key@#1\endcsname}%
                %\_xp\_xp\_xp\let\_xp\_keyname\csname key@#1\endcsname%
            \fi%
        \else%
            \keyexists{required}\_keyrequired\_settings%
            \unless\ifx\_nul\_keyrequired%
                \_xp\def\_xp\_requiredkeys\_xp{\_requiredkeys{#1}}%
                \_xp\let\csname required@#1\endcsname=\_nul%
            \fi%
        \fi%
    \fi%
}

\def\__setdefault#1{%
    \ifx\_nul#1%
    \else%
        \___setdefault#1%
        \_xp\__setdefault%
    \fi%
}

\def\_setdefaults#1{%
    \def\_requiredkeys{}%
    \__setdefault#1\_nul%
}

\def\_vardef_mapkey#1#2#3{%
    \def\_tempdef{\_xp\_vardef\csname key@\_id#2\endcsname}%
    \_xp\_tempdef\_xp{\_varmap{#3}}%
    \_update_lastkeys{#1}{#2}{#3}%
}

\def\_protected_mapkey#1#2#3{%
    \keyexists{#2}\_keysettings\_keymappings%
    \unless\ifx\_nul\_keysettings%
        \let\_varmap=\_id%
        \def\_vardef{\def}%
        \let\_keyname=\_nul%
        \unless\ifx\_keysettings\empty%
            \_xp\_mapkeys_with_setter\_xp\_vanilla_mapkey\_xp\_settings\_xp{\_keysettings}%
            \keyexists{mapping}\_varmap\_settings%
            \ifx\_nul\_varmap%
                \let\_varmap=\_id%
            \fi%
            \keyexists{definition}\_vardef\_settings%
            \ifx\_nul\_vardef%
                \def\_vardef{\def}%
            \fi%
            \keyexists{name}\_keyname\_settings%
        \fi%
        \_vardef_mapkey{#1}{#2}{#3}%
        \_xp\let\csname required@#2\endcsname=\undefined%
        \unless\ifx\_nul\_keyname%
            %\_xp\_xp\_xp\let\_xp\_keyname\_xp=\csname key@#2\endcsname%
            \_xp\_xp\_xp\_letnamedmacro\_xp\_xp\_xp{\_xp\_keyname\_xp}\_xp{\csname key@#2\endcsname}%
        \fi%
    \else%
        \errhelp={Key `#2' supplied, but not present in key list}%
        \errmessage{Invalid key supplied}%
    \fi%
}

\def\_check_required#1{%
    \def\_temp{#1}%
    \unless\ifx\_nul\_temp%
        \ifcsname required@#1\endcsname%
            \errhelp={Key `#1' was required by the key list, but not supplied}%
            \errmessage{Required key not defined}%
        \fi%
        \_xp\_check_required%
    \fi%
}


\def\_check_required_supplied{%
    \_xp\_check_required\_requiredkeys\_nul%
}

\def\mapkeys#1#2{%
    \_mapkeys_with_setter\_vanilla_mapkey\_keymappings{#1}%
    \_xp\_setdefaults\_xp{\_keymappings}%
    \_mapkeys_with_setter\_protected_mapkey\lastkeys{#2}%
    \_check_required_supplied%
}