% Copyright (c) 2020 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 (2020-07-13): first public release

\NeedsTeXFormat{LaTeX2e}
\ProvidesPackage{tikzPackets}

\RequirePackage{tikz}

\RequirePackage{xparse}

% need by \packetsPrintRangeOnRight:
\ifdefined\tcbsetmacrotoheightofnode\else\RequirePackage[skins]{tcolorbox}\fi
\RequirePackage{pbox}

%
% init counters, etc
%

\newdimen\packetsBitWidth\packetsBitWidth=5mm
\newcounter{packets@FieldCounter}

\newcommand{\packetsInit}{
	\let\packetsFirstNodeInLastLine\undefined
	\let\packets@ContinueLine\undefined
	\setcounter{packets@FieldCounter}{0}
	\newcommand{\packetsBitFont}{\tiny}
	\packetsBitWidth=5mm
	\tikzstyle{protocolsFieldBase}=[
		anchor = north west, outer sep = 0pt % node position <=> position of left upper node corner
	]
	\tikzstyle{protocolsField}=[
		protocolsFieldBase,
		draw, minimum height = 1cm,
	]
	\tikzstyle{bitScaleInfo}=[
		protocolsFieldBase, inner sep = 0pt,
		minimum width = \packetsBitWidth, minimum height = 8pt,
		node font=\packetsBitFont
	]
}

%
% print bits numbering
%


\newcommand{\packetsPrintBitNumber}[1]{
	\parbox[b][5pt]{\packetsBitWidth}{\hspace{1pt}#1}
}

\newcommand{\packetsPrintBitScale}[1]{
	\node [bitScaleInfo] (bitScaleInfo_0)  {\packetsPrintBitNumber{0}};
	\foreach \n[remember=\n as \lastn (initially 0)] in {1,...,#1} {
		\node [bitScaleInfo] (bitScaleInfo_\n) [] at (bitScaleInfo_\lastn.north east) {\packetsPrintBitNumber{\n}};
		\draw[thin] (bitScaleInfo_\n.south west) |- (bitScaleInfo_\n.north west);
	}
	\draw (bitScaleInfo_0.south west)  |- (bitScaleInfo_0.north west);
	\draw (bitScaleInfo_#1.south east) |- (bitScaleInfo_#1.north east);
	
	\def\packetsFirstNodeInLastLine{bitScaleInfo_0}
	\def\packetsLastNode{bitScaleInfo_#1}
}

\newcommand{\packetsPrintRangeOnRight}[3][\packetsLastNode]{
	\tcbsetmacrotoheightofnode{\packets@NodeHeight}{#1}
	\node [anchor = south, outer sep = 2pt, inner sep = 0pt, rotate = -90, align=center, node font=\packetsBitFont] [] at (#1.east) {\pbox{\packets@NodeHeight}{#2-#3}};
}

\newcommand{\packetsPrintRangeOnLeft}[3][\packetsFirstNodeInLastLine]{
	\node [anchor = east, outer sep = 2pt, inner sep = 0pt, align=center, node font=\packetsBitFont] [] at (#1.west) {#2};
}

%
% add protocol fields
%
%\newcommand{\packetsPutField}[3][protocolsField]{
\NewDocumentCommand{\packetsPutField}{ O{protocolsField} m o m } {
	% if provide custom node name, use it
	\IfValueTF {#3} {
		\edef\packets@NewNodeName{#3}
	}{
		% otherwise get new node name and step counter
		\edef\packets@NewNodeName{packetsFieldNode_\arabic{packets@FieldCounter}}
		\stepcounter{packets@FieldCounter}
	}
	
	% if continue line
	\ifdefined\packets@ContinueLine
		\node[#1, minimum width=#2\packetsBitWidth] (\packets@NewNodeName) [] at (\packetsLastNode.north east) {#4};
	% if start new line
	\else
		% if not first line
		\ifdefined\packetsFirstNodeInLastLine
			\node[#1, minimum width=#2\packetsBitWidth] (\packets@NewNodeName) [] at (\packetsFirstNodeInLastLine.south west) {#4};
		\else
			\node[#1, minimum width=#2\packetsBitWidth] (\packets@NewNodeName) {#4};
		\fi
		\let\packetsFirstNodeInLastLine\packets@NewNodeName
		\def\packets@ContinueLine{true}
	\fi
	
	% remember new node name as \packetsLastNode
	\let\packetsLastNode\packets@NewNodeName
}

%
% finish line of fields
%

\newcommand{\packetsNextLine}{
	\let\packets@ContinueLine\undefined
}

\newcommand{\packetsEndLine}[2]{
	\packetsPrintRangeOnLeft{#1}{#2}
	\packetsNextLine
}