# Source code for pybtex_docutils

    """
    API
    ~~~

    The backend renders :class:`pybtex.richtext.Text` instances
    into a list of :class:`docutils.nodes.Text`
    and :class:`docutils.nodes.inline` instances (or subclasses of these).
    For typical use cases, all you need to care about are the methods
    :meth:`Backend.paragraph`,
    :meth:`Backend.citation`, and
    :meth:`Backend.citation_reference`
    which are to be called on *formatted* entries,
    as in the :ref:`minimal example <minimal-example>`.

    Note that you should not import the :mod:`pybtex_docutils` module directly.
    Instead, use pybtex's plugin system to get the :class:`Backend` class,
    again,
    as in the :ref:`minimal example <minimal-example>`.

    .. autoclass:: Backend
       :show-inheritance:
       :members: RenderType, paragraph, citation, citation_reference
    """

    import docutils.nodes
    import itertools

    from pybtex.backends import BaseBackend
    import pybtex.richtext
    import six

    class Backend(BaseBackend):
        name = 'docutils'

        symbols = {
            'ndash': [docutils.nodes.Text(u'\u2013', u'\u2013')],
            'newblock': [docutils.nodes.Text(u' ', u' ')],
            'nbsp': [docutils.nodes.Text(u'\u00a0', u'\u00a0')],
        }
        tags = {
            'emph': docutils.nodes.emphasis,  # note: deprecated
            'em': docutils.nodes.emphasis,
            'strong': docutils.nodes.strong,
            'i': docutils.nodes.emphasis,
            'b': docutils.nodes.strong,
            'tt': docutils.nodes.literal,
        }
        RenderType = list

        # for compatibility only
        def format_text(self, text):
            return self.format_str(text)

        def format_str(self, str_):
            assert isinstance(str_, six.string_types)
            return [docutils.nodes.Text(str_, str_)]

        def format_tag(self, tag_name, text):
            assert isinstance(tag_name, six.string_types)
            assert isinstance(text, self.RenderType)
            if tag_name in self.tags:
                tag = self.tags[tag_name]
                return [tag('', '', *text)]
            else:
                return text

        def format_href(self, url, text):
            assert isinstance(url, six.string_types)
            assert isinstance(text, self.RenderType)
            node = docutils.nodes.reference('', '', *text, refuri=url)
            return [node]

        def write_entry(self, key, label, text):
            raise NotImplementedError("use Backend.citation() instead")

        def render_sequence(self, rendered_list):
            return list(itertools.chain(*rendered_list))

        def paragraph(self, entry):
            """Return a docutils.nodes.paragraph
            containing the rendered text for *entry* (without label).

            .. versionadded:: 0.2.0
            """
            return docutils.nodes.paragraph('', '', *entry.text.render(self))

        def citation(self, entry, document, use_key_as_label=True):
            """Return citation node, with key as name, label as first
            child, and paragraph with entry text as second child. The citation is
            expected to be inserted into *document* prior to any docutils
            transforms.
            """
            # see docutils.parsers.rst.states.Body.citation()
            if use_key_as_label:
                label = entry.key
            else:
                label = entry.label
            name = docutils.nodes.fully_normalize_name(entry.key)
            text = entry.text.render(self)
            citation = docutils.nodes.citation()
            citation['names'].append(name)
            citation += docutils.nodes.label('', label)
            citation += self.paragraph(entry)
            document.note_citation(citation)
            document.note_explicit_target(citation, citation)
            return citation

        def citation_reference(self, entry, document, use_key_as_label=True):
            """Return citation_reference node to the given citation. The
            citation_reference is expected to be inserted into *document*
            prior to any docutils transforms.
            """
            # see docutils.parsers.rst.states.Body.footnote_reference()
            if use_key_as_label:
                label = entry.key
            else:
                label = entry.label
            refname = docutils.nodes.fully_normalize_name(entry.key)
            refnode = docutils.nodes.citation_reference(
                '[%s]_' % label, refname=refname)
            refnode += docutils.nodes.Text(label)
            document.note_citation_ref(refnode)
            return refnode