"""
Sphinx plugins for Django documentation.
"""
import os
import re

from docutils import nodes, transforms


try:
    import json
except ImportError:
    try:
        import simplejson as json
    except ImportError:
        try:
            from django.utils import simplejson as json
        except ImportError:
            json = None

from sphinx import addnodes, roles
from sphinx.builders.html import StandaloneHTMLBuilder
from sphinx.writers.html import SmartyPantsHTMLTranslator
from sphinx.util.console import bold
from sphinx.util.compat import Directive

# RE for option descriptions without a '--' prefix
simple_option_desc_re = re.compile(
    r'([-_a-zA-Z0-9]+)(\s*.*?)(?=,\s+(?:/|-|--)|$)')


def setup(app):
    app.add_crossref_type(
        directivename="setting",
        rolename="setting",
        indextemplate="pair: %s; setting",
    )
    app.add_crossref_type(
        directivename="templatetag",
        rolename="ttag",
        indextemplate="pair: %s; template tag"
    )
    app.add_crossref_type(
        directivename="templatefilter",
        rolename="tfilter",
        indextemplate="pair: %s; template filter"
    )
    app.add_crossref_type(
        directivename="fieldlookup",
        rolename="lookup",
        indextemplate="pair: %s; field lookup type",
    )
    app.add_description_unit(
        directivename="django-admin",
        rolename="djadmin",
        indextemplate="pair: %s; django-admin command",
        parse_node=parse_django_admin_node,
    )
    app.add_description_unit(
        directivename="django-admin-option",
        rolename="djadminopt",
        indextemplate="pair: %s; django-admin command-line option",
        parse_node=parse_django_adminopt_node,
    )
    app.add_config_value('django_next_version', '0.0', True)
    app.add_directive('versionadded', VersionDirective)
    app.add_directive('versionchanged', VersionDirective)
    app.add_transform(SuppressBlockquotes)
    app.add_builder(DjangoStandaloneHTMLBuilder)


class VersionDirective(Directive):
    has_content = True
    required_arguments = 1
    optional_arguments = 1
    final_argument_whitespace = True
    option_spec = {}

    def run(self):
        env = self.state.document.settings.env
        arg0 = self.arguments[0]
        is_nextversion = env.config.django_next_version == arg0
        ret = []
        node = addnodes.versionmodified()
        ret.append(node)
        if not is_nextversion:
            if len(self.arguments) == 1:
                linktext = 'Please, see the release notes </releases/%s>' % (arg0)
                xrefs = roles.XRefRole()('doc', linktext, linktext, self.lineno, self.state)
                node.extend(xrefs[0])
            node['version'] = arg0
        else:
            node['version'] = "Development version"
        node['type'] = self.name
        if len(self.arguments) == 2:
            inodes, messages = self.state.inline_text(self.arguments[1], self.lineno + 1)
            node.extend(inodes)
            if self.content:
                self.state.nested_parse(self.content, self.content_offset, node)
            ret = ret + messages
        env.note_versionchange(node['type'], node['version'], node, self.lineno)
        return ret


class SuppressBlockquotes(transforms.Transform):
    """
    Remove the default blockquotes that encase indented list, tables, etc.
    """
    default_priority = 300

    suppress_blockquote_child_nodes = (
        nodes.bullet_list,
        nodes.enumerated_list,
        nodes.definition_list,
        nodes.literal_block,
        nodes.doctest_block,
        nodes.line_block,
        nodes.table
    )

    def apply(self):
        for node in self.document.traverse(nodes.block_quote):
            if len(node.children) == 1 and isinstance(node.children[0], self.suppress_blockquote_child_nodes):
                node.replace_self(node.children[0])


class DjangoHTMLTranslator(SmartyPantsHTMLTranslator):
    """
    Django-specific reST to HTML tweaks.
    """

    # Don't use border=1, which docutils does by default.
    def visit_table(self, node):
        self.body.append(self.starttag(node, 'table', CLASS='docutils'))

    # <big>? Really?
    def visit_desc_parameterlist(self, node):
        self.body.append('(')
        self.first_param = 1

    def depart_desc_parameterlist(self, node):
        self.body.append(')')

    #
    # Don't apply smartypants to literal blocks
    #
    def visit_literal_block(self, node):
        self.no_smarty += 1
        SmartyPantsHTMLTranslator.visit_literal_block(self, node)

    def depart_literal_block(self, node):
        SmartyPantsHTMLTranslator.depart_literal_block(self, node)
        self.no_smarty -= 1

    #
    # Turn the "new in version" stuff (versionadded/versionchanged) into a
    # better callout -- the Sphinx default is just a little span,
    # which is a bit less obvious that I'd like.
    #
    # FIXME: these messages are all hardcoded in English. We need to change
    # that to accomodate other language docs, but I can't work out how to make
    # that work.
    #
    version_text = {
        'deprecated': 'Deprecated in Django %s',
        'versionchanged': 'Changed in Django %s',
        'versionadded': 'New in Django %s',
    }

    def visit_versionmodified(self, node):
        self.body.append(
            self.starttag(node, 'div', CLASS=node['type'])
        )
        title = "%s%s" % (
            self.version_text[node['type']] % node['version'],
            len(node) and ":" or "."
        )
        self.body.append('<span class="title">%s</span> ' % title)

    def depart_versionmodified(self, node):
        self.body.append("</div>\n")

    # Give each section a unique ID -- nice for custom CSS hooks
    def visit_section(self, node):
        old_ids = node.get('ids', [])
        node['ids'] = ['s-' + i for i in old_ids]
        node['ids'].extend(old_ids)
        SmartyPantsHTMLTranslator.visit_section(self, node)
        node['ids'] = old_ids


def parse_django_admin_node(env, sig, signode):
    command = sig.split(' ')[0]
    env._django_curr_admin_command = command
    title = "django-admin.py %s" % sig
    signode += addnodes.desc_name(title, title)
    return sig


def parse_django_adminopt_node(env, sig, signode):
    """A copy of sphinx.directives.CmdoptionDesc.parse_signature()"""
    from sphinx.domains.std import option_desc_re

    count = 0
    firstname = ''
    for m in option_desc_re.finditer(sig):
        optname, args = m.groups()
        if count:
            signode += addnodes.desc_addname(', ', ', ')
        signode += addnodes.desc_name(optname, optname)
        signode += addnodes.desc_addname(args, args)
        if not count:
            firstname = optname
        count += 1
    if not count:
        for m in simple_option_desc_re.finditer(sig):
            optname, args = m.groups()
            if count:
                signode += addnodes.desc_addname(', ', ', ')
            signode += addnodes.desc_name(optname, optname)
            signode += addnodes.desc_addname(args, args)
            if not count:
                firstname = optname
            count += 1
    if not firstname:
        raise ValueError
    return firstname


class DjangoStandaloneHTMLBuilder(StandaloneHTMLBuilder):
    """
    Subclass to add some extra things we need.
    """

    name = 'djangohtml'

    def finish(self):
        super(DjangoStandaloneHTMLBuilder, self).finish()
        if json is None:
            self.warn("cannot create templatebuiltins.js due to missing simplejson dependency")
            return
        self.info(bold("writing templatebuiltins.js..."))
        xrefs = self.env.domaindata["std"]["objects"]
        templatebuiltins = {
            "ttags": [n for ((t, n), (l, a)) in xrefs.items()
                      if t == "templatetag" and l == "ref/templates/builtins"],
            "tfilters": [n for ((t, n), (l, a)) in xrefs.items()
                         if t == "templatefilter" and l == "ref/templates/builtins"],
        }
        outfilename = os.path.join(self.outdir, "templatebuiltins.js")
        f = open(outfilename, 'wb')
        f.write('var django_template_builtins = ')
        json.dump(templatebuiltins, f)
        f.write(';\n')
        f.close()
