#! /usr/bin/env python

##############################################
# Convert each utfsym picture to a PDF file. #
#                                            #
# Author: Scott Pakin <scott.clsl@pakin.org> #
##############################################

import concurrent.futures
import glob
import os
import re
import subprocess
import sys


def kpsewhich(fname):
    'Find a filename in the TeX tree.'
    proc = subprocess.run(['kpsewhich', fname], capture_output=True,
                          check=True, encoding='utf-8')
    return proc.stdout.strip()


# Extract the package description from utfsym.sty.
desc_re = re.compile(r'\\ProvidesExplPackage\{utfsym\}(\{.*\})$')
sty = kpsewhich('utfsym.sty')
with open(sty) as r:
    for ln in r:
        match = desc_re.search(ln)
        if match is not None:
            desc = match[1]
            break

# Acquire a list of all defined symbols.
udir = os.path.dirname(kpsewhich('usym1F600.tikz'))
tikz_files = glob.glob(os.path.join(udir, '*.tikz'))
symbols = [os.path.splitext(os.path.basename(fn))[0] for fn in tikz_files]
symbols.sort(key=lambda s: int(s[4:], 16))

# Create a fakeutfsym.sty file.
with open('fakeutfsym.sty', 'w') as w:
    w.write('''\
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% This is a generated file.  DO NOT EDIT. %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

''')
    w.write('''\
\\NeedsTeXFormat{LaTeX2e}
\\ProvidesExplPackage{fakeutfsym}%s
\\RequirePackage{graphicx}

\\NewDocumentCommand{\\usym}{m}{\\includegraphics{utfsym/usym#1}}
\\NewDocumentCommand{\\usymW}{m m}{\\includegraphics[width=#2]{utfsym/usym#1}}
\\NewDocumentCommand{\\usymH}{m m}{\\includegraphics[height=#2]{utfsym/usym#1}}

\\endinput
''' % desc)

# Create and switch to a utfsym subdirectory.
try:
    os.mkdir('utfsym')
except FileExistsError:
    pass
os.chdir('utfsym')


def run_and_return_output(cmd_line):
    'Run a command line and return its combined stdout + stderr.'
    stdout = 'RUN: ' + ' '.join(cmd_line) + '\n'
    proc = subprocess.run(cmd_line, check=True,
                          stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
    stdout += proc.stdout.decode('utf-8')
    return stdout


# For speed, dump a LaTeX format file with utfsym preloaded.
with open('preloaded.tex', 'w') as w:
    w.write(r'''
\documentclass{minimal}
\usepackage{utfsym}
\begin{document}
\end{document}
'''[1:])
subprocess.run([
    'pdflatex',
    '--ini',
    '&pdflatex',
    'mylatex.ltx',
    'preloaded.tex'
],
    check=True)


def generate_graphic(sym):
    'Generate a PDF file for a given utfsym symbol.'
    stdout = f'*** PROCESSING {sym} ***\n\n'

    # Create a LaTeX file.
    stdout += f'CREATE: {sym}.tex\n'
    with open(sym + '.tex', 'w') as w:
        w.write(r'''
\documentclass{minimal}
\usepackage{utfsym}
\begin{document}
\usym{%s}
\end{document}
''' % sym[4:])

    # Compile the LaTeX file to PDF.
    stdout += run_and_return_output(['pdflatex', '&mylatex', sym + '.tex'])

    # Crop the PDF file.
    stdout += run_and_return_output(['pdfcrop', sym + '.pdf'])

    # Overwrite the original PDF file with the cropped version.
    stdout += f'RUN: mv {sym}-crop.pdf {sym}.pdf\n'
    os.rename(f'{sym}-crop.pdf', f'{sym}.pdf')

    # Output the buffered output.
    stdout += '\n'
    print(stdout)


# Concurrently process all symbols.
with concurrent.futures.ProcessPoolExecutor() as executor:
    executor.map(generate_graphic, symbols)