Trac Wiki to Markdown converter

trac2md.py

#!/usr/bin/env python
#
# Trac Wiki to Markdown converter
#
# Copyright(c) 2019 Keisuke MORI ([email protected])
#
# 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
#

### for Python 2/3 compatible code in Python 3 style
#    https://stackoverflow.com/questions/5868506/backwards-compatible-input-calls-in-python
##   print
from __future__ import print_function
##   raw_input/input
if hasattr(__builtins__, 'raw_input'):
    input = raw_input
## urllib
#   'urllib is the hardest module to use from Python 2/3 compatible code.'
#    - from https://python-future.org/compatible_idioms.html
try:
    # Python 3
    from urllib.request import urlopen, Request
    from urllib.error import HTTPError
except ImportError:
    # Python 2.7
    from urllib2 import urlopen, Request, HTTPError

import sys
import re

import ssl
import getpass
import base64
import io

raw = False
table = False
raw_indent = '  '

list_level = -1
list_indent = [-1]

def list_adjust_indent(m):
    global list_level, list_indent
    num_spaces = len(m.group(1))

    while num_spaces < list_indent[-1]:
        list_level -= 1
        list_indent = list_indent[:-1]
    if num_spaces > list_indent[-1]:
        list_level += 1
        list_indent.append(num_spaces)

    return (' ' * (1 + list_level * 2)) + '* '

def do_raw(line):
    global raw
    line, count = re.subn(r'^}}}$', r'```', line)
    if count > 0:
        raw = False
    line = raw_indent + line
    return line

def do_tracwiki(line):
    global raw, table
    # section
    line = re.sub(r'^=\s+(.*?)(\s+=)?$', r'# \1', line)
    line = re.sub(r'^==\s+(.*?)(\s+==)?$', r'## \1', line)
    line = re.sub(r'^===\s+(.*?)(\s+===)?$', r'### \1', line)
    line = re.sub(r'^====\s+(.*?)(\s+====)?$', r'#### \1', line)

    # list
    line = re.sub(r'^(\s*)\* ', list_adjust_indent, line)
    line = re.sub(r'^(\s*)\- ', list_adjust_indent, line)

    # text
    line = re.sub(r'\'\'\'(.*?)\'\'\'', r'*\1*', line)
    line = re.sub(r'\'\'(.*?)\'\'', r'_\1_', line)

    # code
    line = re.sub(r'{{{(.*?)}}}', r'`\1`', line)

    # link
    line = re.sub(r'\[(https?://[^\s\[\]]+)\s([^\[\]]+)\]', r'[\2](\1)', line)

    # section link
    line = re.sub(r'\[(#[^\s\[\]]+)\s([^\[\]]+)\]', r'[\2](\1)', line)
    # section anchor
    line = re.sub(r'\s#([^\s\[\]]+)', r' <a id="\1"></a>', line)

    # table
    if not table:
        line, count = re.subn(r'\|\|', r'|', line)
        if count > 0:
            header = re.sub(r'[^\|\s]', r'-', line)
            line = '\n' + line + '\n' + header
            table = True
    else:
        line, count = re.subn(r'\|\|', r'|', line)
        if count == 0:
            table = False

    # macro
    line = re.sub(r'(?i)\[\[BR\]\]', r'<br />', line)
    #  TOC is not supported - use other tools
    line = re.sub(r'\[\[PageOutline.*\]\]', r'<!--- TOC --->\n<!--- /TOC --->', line)

    # raw
    line, count = re.subn(r'^{{{$', r'```', line)
    if count > 0:
        raw = True
        line = raw_indent + line

    return line

###

def get_from_url(url):
    # redirect prompts to stderr to allow to redirect the converted output
    old_stdout = sys.stdout
    sys.stdout = sys.stderr
    user = input('Trac username: ') # raw_input() in Python 2
    password = getpass.getpass('Trac Password: ')
    sys.stdout = old_stdout

    headers = {}
    headers['Authorization'] = 'Basic ' + base64.b64encode((user + ':' + password).encode('utf-8')).decode('utf-8') # Python3 compatible
#    headers['Authorization'] = 'Basic ' + (user + ':' + password).encode('base64')[:-1] # Python 2 only

    # WARN: it's to disable SSL Certificate Verification
    ctx = ssl.SSLContext(ssl.PROTOCOL_SSLv23)

    req = Request(url=url + '?format=txt', headers=headers)
    response = urlopen(req, context=ctx)
    return io.BytesIO(response.read())
#    return io.StringIO(response.read())


######################

if len(sys.argv) > 1:
    if sys.argv[1].startswith(('http://', 'https://')):
        trac_input = get_from_url(sys.argv[1])
    else:
        trac_input = open(sys.argv[1])
else:
    trac_input = sys.stdin


for line in trac_input:
    line = line.rstrip()
    if raw:
        line = do_raw(line)
    else:
        line = do_tracwiki(line)

    print(line)