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

from docutils import nodes
from docutils.parsers.rst import Directive
from docutils.statemachine import ViewList
from sphinx import addnodes, version_info as sphinx_version
from sphinx.builders.html import StandaloneHTMLBuilder
from sphinx.directives.code import CodeBlock
from sphinx.domains.std import Cmdoption
from sphinx.errors import ExtensionError
from sphinx.util import logging
from sphinx.util.console import bold
from sphinx.writers.html import HTMLTranslator

logger = logging.getLogger(__name__)
# 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_object_type(
        directivename="django-admin",
        rolename="djadmin",
        indextemplate="pair: %s; django-admin command",
        parse_node=parse_django_admin_node,
    )
    app.add_directive('django-admin-option', Cmdoption)
    app.add_config_value('django_next_version', '0.0', True)
    app.add_directive('versionadded', VersionDirective)
    app.add_directive('versionchanged', VersionDirective)
    app.add_builder(DjangoStandaloneHTMLBuilder)
    app.set_translator('djangohtml', DjangoHTMLTranslator)
    app.set_translator('json', DjangoHTMLTranslator)
    app.add_node(
        ConsoleNode,
        html=(visit_console_html, None),
        latex=(visit_console_dummy, depart_console_dummy),
        man=(visit_console_dummy, depart_console_dummy),
        text=(visit_console_dummy, depart_console_dummy),
        texinfo=(visit_console_dummy, depart_console_dummy),
    )
    app.add_directive('console', ConsoleDirective)
    app.connect('html-page-context', html_page_context_hook)
    return {'parallel_read_safe': True}


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

    def run(self):
        if len(self.arguments) > 1:
            msg = """Only one argument accepted for directive '{directive_name}::'.
            Comments should be provided as content,
            not as an extra argument.""".format(directive_name=self.name)
            raise self.error(msg)

        env = self.state.document.settings.env
        ret = []
        node = addnodes.versionmodified()
        ret.append(node)

        if self.arguments[0] == env.config.django_next_version:
            node['version'] = "Development version"
        else:
            node['version'] = self.arguments[0]

        node['type'] = self.name
        if self.content:
            self.state.nested_parse(self.content, self.content_offset, node)
        try:
            env.get_domain('changeset').note_changeset(node)
        except ExtensionError:
            # Sphinx < 1.8: Domain 'changeset' is not registered
            env.note_versionchange(node['type'], node['version'], node, self.lineno)
        return ret


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

    # Don't use border=1, which docutils does by default.
    def visit_table(self, node):
        self.context.append(self.compact_p)
        self.compact_p = True
        # Needed by Sphinx.
        if sphinx_version >= (4, 3):
            self._table_row_indices.append(0)
        else:
            self._table_row_index = 0
        self.body.append(self.starttag(node, 'table', CLASS='docutils'))

    def depart_table(self, node):
        self.compact_p = self.context.pop()
        if sphinx_version >= (4, 3):
            self._table_row_indices.pop()
        self.body.append('</table>\n')

    def visit_desc_parameterlist(self, node):
        self.body.append('(')  # by default sphinx puts <big> around the "("
        self.first_param = 1
        self.optional_param_level = 0
        self.param_separator = node.child_text_separator
        self.required_params_left = sum(isinstance(c, addnodes.desc_parameter) for c in node.children)

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

    #
    # 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 accommodate other language docs, but I can't work out how to make
    # that work.
    #
    version_text = {
        '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'])
        )
        version_text = self.version_text.get(node['type'])
        if version_text:
            title = "%s%s" % (
                version_text % node['version'],
                ":" if len(node) else "."
            )
            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)
        super().visit_section(node)
        node['ids'] = old_ids


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


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

    name = 'djangohtml'

    def finish(self):
        super().finish()
        logger.info(bold("writing templatebuiltins.js..."))
        xrefs = self.env.domaindata["std"]["objects"]
        templatebuiltins = {
            "ttags": [
                n for ((t, n), (k, a)) in xrefs.items()
                if t == "templatetag" and k == "ref/templates/builtins"
            ],
            "tfilters": [
                n for ((t, n), (k, a)) in xrefs.items()
                if t == "templatefilter" and k == "ref/templates/builtins"
            ],
        }
        outfilename = os.path.join(self.outdir, "templatebuiltins.js")
        with open(outfilename, 'w') as fp:
            fp.write('var django_template_builtins = ')
            json.dump(templatebuiltins, fp)
            fp.write(';\n')


class ConsoleNode(nodes.literal_block):
    """
    Custom node to override the visit/depart event handlers at registration
    time. Wrap a literal_block object and defer to it.
    """
    tagname = 'ConsoleNode'

    def __init__(self, litblk_obj):
        self.wrapped = litblk_obj

    def __getattr__(self, attr):
        if attr == 'wrapped':
            return self.__dict__.wrapped
        return getattr(self.wrapped, attr)


def visit_console_dummy(self, node):
    """Defer to the corresponding parent's handler."""
    self.visit_literal_block(node)


def depart_console_dummy(self, node):
    """Defer to the corresponding parent's handler."""
    self.depart_literal_block(node)


def visit_console_html(self, node):
    """Generate HTML for the console directive."""
    if self.builder.name in ('djangohtml', 'json') and node['win_console_text']:
        # Put a mark on the document object signaling the fact the directive
        # has been used on it.
        self.document._console_directive_used_flag = True
        uid = node['uid']
        self.body.append('''\
<div class="console-block" id="console-block-%(id)s">
<input class="c-tab-unix" id="c-tab-%(id)s-unix" type="radio" name="console-%(id)s" checked>
<label for="c-tab-%(id)s-unix" title="Linux/macOS">&#xf17c/&#xf179</label>
<input class="c-tab-win" id="c-tab-%(id)s-win" type="radio" name="console-%(id)s">
<label for="c-tab-%(id)s-win" title="Windows">&#xf17a</label>
<section class="c-content-unix" id="c-content-%(id)s-unix">\n''' % {'id': uid})
        try:
            self.visit_literal_block(node)
        except nodes.SkipNode:
            pass
        self.body.append('</section>\n')

        self.body.append('<section class="c-content-win" id="c-content-%(id)s-win">\n' % {'id': uid})
        win_text = node['win_console_text']
        highlight_args = {'force': True}
        linenos = node.get('linenos', False)

        def warner(msg):
            self.builder.warn(msg, (self.builder.current_docname, node.line))

        highlighted = self.highlighter.highlight_block(
            win_text, 'doscon', warn=warner, linenos=linenos, **highlight_args
        )
        self.body.append(highlighted)
        self.body.append('</section>\n')
        self.body.append('</div>\n')
        raise nodes.SkipNode
    else:
        self.visit_literal_block(node)


class ConsoleDirective(CodeBlock):
    """
    A reStructuredText directive which renders a two-tab code block in which
    the second tab shows a Windows command line equivalent of the usual
    Unix-oriented examples.
    """
    required_arguments = 0
    # The 'doscon' Pygments formatter needs a prompt like this. '>' alone
    # won't do it because then it simply paints the whole command line as a
    # grey comment with no highlighting at all.
    WIN_PROMPT = r'...\> '

    def run(self):

        def args_to_win(cmdline):
            changed = False
            out = []
            for token in cmdline.split():
                if token[:2] == './':
                    token = token[2:]
                    changed = True
                elif token[:2] == '~/':
                    token = '%HOMEPATH%\\' + token[2:]
                    changed = True
                elif token == 'make':
                    token = 'make.bat'
                    changed = True
                if '://' not in token and 'git' not in cmdline:
                    out.append(token.replace('/', '\\'))
                    changed = True
                else:
                    out.append(token)
            if changed:
                return ' '.join(out)
            return cmdline

        def cmdline_to_win(line):
            if line.startswith('# '):
                return 'REM ' + args_to_win(line[2:])
            if line.startswith('$ # '):
                return 'REM ' + args_to_win(line[4:])
            if line.startswith('$ ./manage.py'):
                return 'manage.py ' + args_to_win(line[13:])
            if line.startswith('$ manage.py'):
                return 'manage.py ' + args_to_win(line[11:])
            if line.startswith('$ ./runtests.py'):
                return 'runtests.py ' + args_to_win(line[15:])
            if line.startswith('$ ./'):
                return args_to_win(line[4:])
            if line.startswith('$ python3'):
                return 'py ' + args_to_win(line[9:])
            if line.startswith('$ python'):
                return 'py ' + args_to_win(line[8:])
            if line.startswith('$ '):
                return args_to_win(line[2:])
            return None

        def code_block_to_win(content):
            bchanged = False
            lines = []
            for line in content:
                modline = cmdline_to_win(line)
                if modline is None:
                    lines.append(line)
                else:
                    lines.append(self.WIN_PROMPT + modline)
                    bchanged = True
            if bchanged:
                return ViewList(lines)
            return None

        env = self.state.document.settings.env
        self.arguments = ['console']
        lit_blk_obj = super().run()[0]

        # Only do work when the djangohtml HTML Sphinx builder is being used,
        # invoke the default behavior for the rest.
        if env.app.builder.name not in ('djangohtml', 'json'):
            return [lit_blk_obj]

        lit_blk_obj['uid'] = '%s' % env.new_serialno('console')
        # Only add the tabbed UI if there is actually a Windows-specific
        # version of the CLI example.
        win_content = code_block_to_win(self.content)
        if win_content is None:
            lit_blk_obj['win_console_text'] = None
        else:
            self.content = win_content
            lit_blk_obj['win_console_text'] = super().run()[0].rawsource

        # Replace the literal_node object returned by Sphinx's CodeBlock with
        # the ConsoleNode wrapper.
        return [ConsoleNode(lit_blk_obj)]


def html_page_context_hook(app, pagename, templatename, context, doctree):
    # Put a bool on the context used to render the template. It's used to
    # control inclusion of console-tabs.css and activation of the JavaScript.
    # This way it's include only from HTML files rendered from reST files where
    # the ConsoleDirective is used.
    context['include_console_assets'] = getattr(doctree, '_console_directive_used_flag', False)