import re

from markdown.extensions import Extension
from markdown.inlinepatterns import Pattern
from markdown.inlinepatterns import SimpleTagPattern
from markdown.inlinepatterns import SimpleTextPattern
from markdown.util import etree

from markdone_python.common import tag_pattern


class TagPattern(Pattern):
    """
    Returns a !tag rendered as <em>[tag]</em>

    """
    tag = 'em'
    def __init__(self):
        super().__init__(r'\!([\w_-]+\b)')

    def handleMatch(self, m):
        el = etree.Element(self.tag)
        text = m.group(2)
        # text = text.replace('!', '')
        # el.text = '[{}]'.format(re.sub(r'[, ]+', ', ', text))
        el.text = text
        return el


class MarkdoneExtension(Extension):
    def extendMarkdown(self, md, md_globals):
        md.inlinePatterns.add(
            'markdone_tag',
            TagPattern(),
            '_begin',
        )