"""
Escape the `body` part of .chm source file to 7-bit ASCII, to fix visual
effect on some MBCS Windows systems.

https://bugs.python.org/issue32174
"""

import re
from html.entities import codepoint2name

from sphinx.util.logging import getLogger

# escape the characters which codepoint > 0x7F
def _process(string):
 def escape(matchobj):
 codepoint = ord(matchobj.group(0))

 name = codepoint2name.get(codepoint)
 if name is None:
 return '&#%d;' % codepoint
 else:
 return '&%s;' % name

 return re.sub(r'[^\x00-\x7F]', escape, string)

def escape_for_chm(app, pagename, templatename, context, doctree):
 # only works for .chm output
 if getattr(app.builder, 'name', '') != 'htmlhelp':
 return

 # escape the `body` part to 7-bit ASCII
 body = context.get('body')
 if body is not None:
 context['body'] = _process(body)

def fixup_keywords(app, exception):
 # only works for .chm output
 if getattr(app.builder, 'name', '') != 'htmlhelp' or exception:
 return

 getLogger(__name__).info('fixing HTML escapes in keywords file...')
 outdir = app.builder.outdir
 outname = app.builder.config.htmlhelp_basename
 with app.builder.open_file(outdir, outname + '.hhk', 'r') as f:
 index = f.read()
 with app.builder.open_file(outdir, outname + '.hhk', 'w') as f:
 f.write(index.replace(''', '''))

def setup(app):
 # `html-page-context` event emitted when the HTML builder has
 # created a context dictionary to render a template with.
 app.connect('html-page-context', escape_for_chm)
 # `build-finished` event emitted when all the files have been
 # output.
 app.connect('build-finished', fixup_keywords)

 return {'version': '1.0', 'parallel_read_safe': True}