#!/usr/bin/env python3
# This is ugly, so I (Cley Faye) release it as Public Domain.
from subprocess import call
import re


def splitIntoPages(source, template):
    args = ['pdftk', source, 'burst', 'output', template, 'compress']
    call(args);


def pdfToText(source):
    args = ['pdftotext', source]
    call(args)


def grabAllTitles(sources):
    titles = []

    REGEXES = [
            (1, re.compile('^Livre [0-9]+(er)? : (?P<TITLE>.*)')),
            (2, re.compile('^Titre [0-9]+(er)? : (?P<TITLE>.*)')),
            (3, re.compile('^(?P<TITLE>Article L.*)'))
            ]

    page = 0
    for filename in sources:
        page += 1
        with open(filename, 'r') as infile:
            lines = infile.read().split('\n')
        for line in lines:
            line = line.strip()
            for level, regex in REGEXES:
                match = regex.match(line)
                if match:
                    titles.append((page, level, match.group('TITLE')))
                    break
    return titles


def extractMeta(pdf):
    args = ['pdftk', pdf, 'dump_data', 'output', 'temp.txt']
    call(args)
    meta = []
    with open('temp.txt', 'r') as infile:
        meta += infile.read().split('\n')
    return meta


def addTitleToMeta(meta, titles):
    for page, level, title in titles:
        meta += [
                'BookmarkBegin',
                'BookmarkTitle: %s' % title,
                'BookmarkLevel: %s' % level,
                'BookmarkPageNumber: %s' % page
                ]


def putMetaIn(pdf, meta, out):
    with open('temp.txt', 'w') as outfile:
        for metaline in meta:
            outfile.write('%s\n' % metaline)
    args = ['pdftk', pdf, 'update_info_utf8', 'temp.txt', 'output', out]
    call(args)


def main():
    SOURCE="in.pdf"
    OUT="out.pdf"
    TEMPLATE="out_%03d.pdf"
    TEXTTEMPLATE="out_%03d.txt"
    PAGECOUNT=444
    splitIntoPages(SOURCE, TEMPLATE)
    sourceTextFiles = []
    for x in range(PAGECOUNT):
        sourceTextFiles.append(TEXTTEMPLATE % (x + 1))
        pdfToText(TEMPLATE % (x + 1))
    titles = grabAllTitles(sourceTextFiles)
    meta = extractMeta(SOURCE)
    addTitleToMeta(meta, titles)
    putMetaIn(SOURCE, meta, OUT)


main()