from docutils import core, nodes
from docutils.parsers.rst import roles


def reST_to_html(source):
    settings_overrides = {
        'footnote_references': 'superscript',
        'auto_id_prefix': 'id-',
        'initial_header_level': 3,
        'doctitle_xform': False,
    }
    formatted = core.publish_parts(source,
                                   writer_name='html5_polyglot',
                                   settings_overrides=settings_overrides)
    return formatted['body']


def ruby_role(name, rawtext, text, lineno, inliner, options={}, content=[]):
    base, ruby = text.split('|', 1)
    template = '<ruby><rb>{base}</rb><rp>（</rp><rt>{ruby}</rt><rp>）</rp></ruby>'

    if 'format' not in options:
        options['format'] = 'html'
    elif options['format'] != 'html':
        msg = inliner.reporter.error(
            'The ruby role only works with the HTML format.', line=lineno)
        prb = inliner.problematic(rawtext, rawtext, msg)
        return ([prb], [msg])

    node = nodes.raw(rawtext, template.format(base=base, ruby=ruby), **options)
    node.source, node.line = inliner.reporter.get_source_and_line(lineno)
    return ([node], [])

roles.register_canonical_role('ruby', ruby_role)