%% This program is free software; you can redistribute it and/or
%% modify it under the terms of the GNU General Public License
%% as published by the Free Software Foundation; either version 2
%% of the License, or (at your option) any later version.
%%
%% This program is distributed in the hope that it will be useful,
%% but WITHOUT ANY WARRANTY; without even the implied warranty of
%% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
%% GNU General Public License for more details.
%%
%% You should have received a copy of the GNU General Public License
%% along with this program; if not, write to the Free Software
%% Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
%%

%% 0.4 Version by Hernán Grecco <hgrecco@gmail.com>
%% 0.3 Version by James Brotchie <brotchie@gmail.com>
%%
%% Author: Martin R. Ehmsen, ehmsen@imada.sdu.dk.
%% Department of Mathematics and Computer Science,
%% University of Southern Denmark, DK
%%

%% You can find an online copy of the GPL at
%% http://www.gnu.org/copyleft/gpl.html .
%% 
%% Note: shell-escape needs to be activated for this to work.
%% This can either be done by passing -shell-escape as an option to
%% latex or by adding/changing "shell_escape = t" in your texmf.cnf .


% Python-sty Changelog
% ====================
%
%
% 0.4 (2013-11-28)
% ----------------
% - Python code is only executed if it has changed.
% - Option to save auxiliary files in a subfolder.
% - Option to choose the python binary.
% - Code refactoring.
% - UTF-8 support.
%
%
% 0.3 (2011-12-22)
% ----------------
%
% - Intermediate files are now stored with different filenames.
% - The return code of each Python shell execution is stored 
%   in an .rc file.
% - Any stderr output of a failed Python shell execution is 
%   inserted as a red verbatim in the resulting document.
%                     -- James Brotchie <brotchie@gmail.com>
%
% 0.21
% ----
%
% - Moved \newwrite\@module from \@writemodule and out, since 
%   no more than 15 \newwrites are allowed (and the previous 
%   version created a new every time \@writemodule was called.
% 
%

\NeedsTeXFormat{LaTeX2e}[1994/12/01]
\ProvidesPackage{python}[2013/11/17 v0.4 Python in LaTeX]
\RequirePackage{etoolbox}
\RequirePackage{verbatim}
\RequirePackage{color}
\RequirePackage{ifplatform}
\RequirePackage{fancyvrb}
\RequirePackage{inputenc}
\RequirePackage{kvoptions}

% Put the resulting Python code in separate files.
\newcommand{\@PYT@outname}{\jobname\arabic{@PythonEnvironmentCounter}}
\newcounter{@PythonEnvironmentCounter}
\setcounter{@PythonEnvironmentCounter}{1}

% Package Options
\SetupKeyvalOptions{
	family=PYT,
	prefix=PYT@
}

\DeclareVoidOption{subfolder}{ 
  \renewcommand{\@PYT@outname}{py/\jobname\arabic{@PythonEnvironmentCounter}}
}

\DeclareStringOption[python]{bin}[python]

\ProcessKeyvalOptions*

\newcommand{\@pythonbin}{\PYT@bin \space runpy.py \space}

\typeout{PYTHON: Binary \@pythonbin}

\newread\@PYT@retcode
\newread\@PYT@diff

\newcommand{\@PYT@copytocache}{
    \ifwindows
    		\immediate\write18{copy \@PYT@outname.py \@PYT@outname.py.cache}
    \else
    		\immediate\write18{cp \@PYT@outname.py \@PYT@outname.py.cache}
    \fi
}

\newcommand{\@PYT@deletescript}{
	\ifwindows
		\immediate\write18{del \@PYT@outname.py}
	\else
		\immediate\write18{rm \@PYT@outname.py}
	\fi
}

\newcommand{\@PYT@comparefiles}{
	\ifwindows
		\immediate\write18{fc \@PYT@outname.py \@PYT@outname.py.cache & call echo ^\@percentchar ERRORLEVEL ^\@percentchar > \@PYT@outname.cmp.rc}
	\else
		\immediate\write18{cmp \@PYT@outname.py \@PYT@outname.py.cache; echo $? > \@PYT@outname.cmp.rc}
	\fi
}

\newcommand{\@PYT@executescript}{
    \typeout{PYTHON: Running file \@PYT@outname.py}
	\immediate\write18{\@pythonbin \space\@PYT@outname.py}
	
	% Copy to the current script to keep a cache.
	\@PYT@copytocache
	\@PYT@deletescript
	
}

\newcommand{\@PYT@returncode}{
	\inputencoding{utf8}
	\input{\@PYT@outname}
	
	% Read the return code of the executed Python script.
	\immediate\openin\@PYT@retcode=\@PYT@outname.py.rc
	\immediate\read\@PYT@retcode to \rc
	\immediate\closein\@PYT@retcode
	
	% If the return code isn't zero then include
	% the traceback.
	\ifnumequal{\rc}{0}{
	    \typeout{PYTHON: Run was successful}
	}{%
	    \typeout{PYTHON: Run failed}
	    \begingroup
	        \color{red}
	        \verbatiminput{\@PYT@outname.py.err}
	    \endgroup
	}
}

\newenvironment{python}
{
	\typeout{PYTHON: Writing file \@PYT@outname.py}
	\@PYT@deactivateeightbit\VerbatimOut{\@PYT@outname.py}}
{
	\endVerbatimOut

	\@PYT@comparefiles
	\immediate\openin\@PYT@diff=\@PYT@outname.cmp.rc
	\immediate\read\@PYT@diff to \rc
	\immediate\closein\@PYT@diff

	\ifnumequal{\rc}{0}{
		% Old file and new file are identical
		\typeout{PYTHON: No need to run the script again}
	}{
		% Old file and new file are different or old is not present
		\@PYT@executescript
	}
	\@PYT@returncode

	\immediate\stepcounter{@PythonEnvironmentCounter}
}

\newcommand{\@PYT@deactivateeightbit}{%
  \count@=127
  \loop
    \catcode\count@=12
    \ifnum\count@<255
    \advance\count@\@ne
  \repeat
}