#! /usr/bin/env python

# Copyright 2024 Tomas Brabec
# 
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
# 
#     http://www.apache.org/licenses/LICENSE-2.0
# 
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

try:
    import locale
    locale.setlocale(locale.LC_ALL, '')
except:
    pass

import docutils.frontend
import docutils.utils
import docutils.parsers
import docutils.parsers.rst
import docutils.parsers.rst.directives

# this is merely to specifically identify elements derived
# from the `my_extension` directive
class mydirective(docutils.nodes.Element): pass

class MyExtensionDirective(docutils.parsers.rst.Directive):
    required_arguments = 1;
    optional_arguments = 0;
    final_argument_whitespace = True;
    has_content = True;
    option_spec = {'my_attr': docutils.parsers.rst.directives.unchanged,
                   }

    def run(self):
        self.assert_has_content()
        text = '\n'.join(self.content)
        n = mydirective(text, **self.options)
        self.add_name(n)
        
        # this will turn the directive argument into a title node
        # (as we generally allow the title to contain inline markup,
        # we use the inline parser to get (`textnodes`) list of inline
        # elements/nodes)
        title_text = self.arguments[0]
        textnodes, messages = self.state.inline_text(title_text,
                                                     self.lineno)
        # the following would end up calling TextElement(rawsource,text,*children) constructor
        title = docutils.nodes.title(title_text, '', *textnodes)
        title.source, title.line = (
                self.state_machine.get_source_and_line(self.lineno))
        
        # add a new sub-node and any system messages from the inline parsing
        n += title
        n += messages
        
        # This will parse the directive content
        self.state.nested_parse(self.content, self.content_offset,
                                n)
        return [n]

# This overrides what directive class will be used to process the `my_extension` directive
docutils.parsers.rst.directives._directives['my_extension'] = MyExtensionDirective;

settings = docutils.frontend.OptionParser().get_default_values()

parser_class = docutils.parsers.get_parser_class('restructuredtext')
parser = parser_class()

option_parser = docutils.frontend.OptionParser(
    components=(parser,),
    read_config_files=True,
    description='')

settings = option_parser.parse_args()


document = docutils.utils.new_document('', settings)

text = '''
My title
========

1st paragraph

Subtitle
--------

2nd paragraph

.. my_extension:: This is my extension
   :my_attr: 1 2 3
     4 5 6

   1st extension paragraph
   
   #. 1st numbered item
   #. 2nd numbered item
   
3rd paragraph

- a
- b
'''

parser.parse(text, document)

print(document.pformat())