# -*- coding: utf-8 -*-
from __future__ import unicode_literals, print_function

from docutils import nodes, utils
from docutils.parsers.rst import directives, roles, Directive
from pygments.formatters import HtmlFormatter
from pygments import highlight
from pygments.lexers import get_lexer_by_name, TextLexer
import re

INLINESTYLES = False
DEFAULT = HtmlFormatter(noclasses=INLINESTYLES)
VARIANTS = {
    'linenos': HtmlFormatter(noclasses=INLINESTYLES, linenos=True),
}


class Pygments(Directive):
    """ Source code syntax hightlighting.
    """
    required_arguments = 1
    optional_arguments = 0
    final_argument_whitespace = True
    option_spec = dict([(key, directives.flag) for key in VARIANTS])
    has_content = True

    def run(self):
        self.assert_has_content()
        try:
            lexer = get_lexer_by_name(self.arguments[0])
        except ValueError:
            # no lexer found - use the text one instead of an exception
            lexer = TextLexer()
        # take an arbitrary option if more than one is given
        formatter = self.options and VARIANTS[self.options.keys()[0]] \
                    or DEFAULT
        parsed = highlight('\n'.join(self.content), lexer, formatter)
        return [nodes.raw('', parsed, format='html')]

directives.register_directive('code-block', Pygments)
directives.register_directive('sourcecode', Pygments)


_abbr_re = re.compile('\((.*)\)$')


class abbreviation(nodes.Inline, nodes.TextElement):
    pass


def abbr_role(typ, rawtext, text, lineno, inliner, options={}, content=[]):
    text = utils.unescape(text)
    m = _abbr_re.search(text)
    if m is None:
        return [abbreviation(text, text)], []
    abbr = text[:m.start()].strip()
    expl = m.group(1)
    return [abbreviation(abbr, abbr, explanation=expl)], []

roles.register_local_role('abbr', abbr_role)