% Copyright (c) 2015-2019 Robert Ryszard Paciorek <rrp@opcode.eu.org>
% 
% MIT License
% 
% Permission is hereby granted, free of charge, to any person obtaining a copy
% of this software and associated documentation files (the "Software"), to deal
% in the Software without restriction, including without limitation the rights
% to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
% copies of the Software, and to permit persons to whom the Software is
% furnished to do so, subject to the following conditions:
% 
% The above copyright notice and this permission notice shall be included in all
% copies or substantial portions of the Software.
% 
% THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
% IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
% FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
% AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
% LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
% OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
% SOFTWARE.

% Version 1.0 (2019-05-13): first public release


\NeedsTeXFormat{LaTeX2e}
\ProvidesPackage{labels4easylist}

\RequirePackage{xparse}
\RequirePackageWithOptions{easylist}

%
% configurable refernece labels for easylist items
%

% add label to item entry, usage:
%  \itemLabel{LabelName}[skipA][skibB]
% skipA - number of level to skip at front
% skipB - number of level to skip at end
\DeclareDocumentCommand{\itemLabel}{ m O{0} o } {%
	% prepare ref-label text in \elLabel@currRefLabel
	\xdef\elLabel@currRefLabel{}{%
		\elLabel@currLevel=1%
		\elLabel@minLevel=#2%
		\elLabel@maxLevel=\el@PreviousItem%
		\IfValueTF{#3}{\advance\elLabel@maxLevel by -#3}{\elLabel@GetLastLevel}%
		\elLabel@RecurencyGetEnumLevel%
	}%
	% create ref-label with id from #1 and text from \elLabel@currRefLabel
	\let\@currentlabel\elLabel@currentlabel%
	\def\@currentlabel{\elLabel@currRefLabel}%
	\label{#1}%
	\let\elLabel@currentlabel\@currentlabel%
}

% counters
\newcount\elLabel@currLevel
\newcount\elLabel@minLevel
\newcount\elLabel@maxLevel

% recursive skip final unused levels and not enumerate levels
\newcommand{\elLabel@GetLastLevel} {
	\ifnum\elLabel@maxLevel>\elLabel@minLevel%
		\ifnum\elLabel@maxLevel=\csname Hide\the\elLabel@maxLevel\endcsname
			\advance\elLabel@maxLevel by -1
			\elLabel@GetLastLevel
		\else%
			\ifnum\value{List\the\elLabel@maxLevel}=0
				\advance\elLabel@maxLevel by -1
				\elLabel@GetLastLevel
			\fi%
		\fi%
	\fi%
}

% recursive build label text for reference
\newcommand{\elLabel@RecurencyGetEnumLevel} {%
	% if (minLev < currLev AND currLev <= maxLev AND value !=0)
	\ifnum\elLabel@currLevel>\elLabel@minLevel \ifnum\elLabel@currLevel>\elLabel@maxLevel\else \ifnum\value{List\the\elLabel@currLevel}=0\else%
		\xdef\elLabel@currRefLabel{\elLabel@currRefLabel%
			\csname el@NumberDenotation:\csname Numbers\the\elLabel@currLevel\endcsname\endcsname{List\the\elLabel@currLevel}%
			\ifnum\elLabel@currLevel<\elLabel@maxLevel \csname Mark\the\elLabel@currLevel\endcsname \fi%
		}%
	\fi\fi\fi%
	% recursion:
	\ifnum\elLabel@currLevel<\elLabel@maxLevel
		\advance\elLabel@currLevel by 1
		\elLabel@RecurencyGetEnumLevel
	\fi%
}