# -*- coding:utf-8 -*-
## src/common/rst_xhtml_generator.py
##
## Copyright (C) 2006 Santiago Gala
##                    Nikos Kouremenos <kourem AT gmail.com>
## Copyright (C) 2006-2007 Yann Leboulanger <asterix AT lagaule.org>
## Copyright (C) 2007 Jean-Marie Traissard <jim AT lapin.org>
##
## This file is part of Gajim.
##
## Gajim is free software; you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published
## by the Free Software Foundation; version 3 only.
##
## Gajim is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with Gajim. If not, see <http://www.gnu.org/licenses/>.
##

try:
    from docutils import io
    from docutils.core import Publisher
    from docutils.parsers.rst import roles
    from docutils import nodes, utils
    from docutils.parsers.rst.roles import set_classes
except ImportError:
    print "Requires docutils 0.4 for set_classes to be available"
    def create_xhtml(text):
        return None
else:
    def pos_int_validator(text):
        """
        Validates that text can be evaluated as a positive integer
        """
        result = int(text)
        if result < 0:
            raise ValueError("Error: value '%(text)s' "
                                            "must be a positive integer")
        return result

    def generate_uri_role( role_name, aliases, anchor_text, base_url,
                    interpret_url, validator):
        """
        Create and register a uri based "interpreted role"

        Those are similar to the RFC, and PEP ones, and take
        role_name:
                name that will be registered
        aliases:
                list of alternate names
        anchor_text:
                text that will be used, together with the role
        base_url:
                base url for the link
        interpret_url:
                this, modulo the validated text, will be added to it
        validator:
                should return the validated text, or raise ValueError
        """
        def uri_reference_role(role, rawtext, text, lineno, inliner,
                options={}, content=[]):
            try:
                valid_text = validator(text)
            except ValueError, e:
                msg = inliner.reporter.error( e.message % dict(text=text), line=lineno)
                prb = inliner.problematic(rawtext, rawtext, msg)
                return [prb], [msg]
            ref = base_url + interpret_url % valid_text
            set_classes(options)
            node = nodes.reference(rawtext, anchor_text + utils.unescape(text), refuri=ref,
                            **options)
            return [node], []

        uri_reference_role.__doc__ = """Role to make handy references to URIs.

                Use as :%(role_name)s:`71` (or any of %(aliases)s).
                It will use %(base_url)s+%(interpret_url)s
                validator should throw a ValueError, containing optionally
                a %%(text)s format, if the interpreted text is not valid.
                """ % locals()
        roles.register_canonical_role(role_name, uri_reference_role)
        from docutils.parsers.rst.languages import en
        en.roles[role_name] = role_name
        for alias in aliases:
            en.roles[alias] = role_name

    generate_uri_role('xep-reference', ('jep', 'xep'),
                            'XEP #', 'http://www.xmpp.org/extensions/', 'xep-%04d.html',
                            pos_int_validator)
    generate_uri_role('gajim-ticket-reference', ('ticket', 'gtrack'),
                            'Gajim Ticket #', 'http://trac.gajim.org/ticket/', '%d',
                            pos_int_validator)

    class HTMLGenerator:
        """
        Really simple HTMLGenerator starting from publish_parts

        It reuses the docutils.core.Publisher class, which means it is *not*
        threadsafe.
        """
        def __init__(self, settings_spec=None,
                        settings_overrides=dict(report_level=5, halt_level=5),
                        config_section='general'):
            self.pub = Publisher(reader=None, parser=None, writer=None,
                    settings=None,
                    source_class=io.StringInput,
                    destination_class=io.StringOutput)
            self.pub.set_components(reader_name='standalone',
                    parser_name='restructuredtext',
                    writer_name='html')
            # hack: JEP-0071 does not allow HTML char entities, so we hack our way
            # out of it.
            # &mdash; == u"\u2014"
            # a setting to only emit charater entities in the writer would be nice
            # FIXME: several &nbsp; are emitted, and they are explicitly forbidden
            # in the JEP
            # &nbsp; ==  u"\u00a0"
            self.pub.writer.translator_class.attribution_formats['dash'] = (
                    u'\u2014', '')
            self.pub.process_programmatic_settings(settings_spec,
                    settings_overrides,
                    config_section)


        def create_xhtml(self, text, destination=None, destination_path=None,
                        enable_exit_status=None):
            """
            Create xhtml for a fragment of IM dialog. We can use the source_name
            to store info about the message
            """
            self.pub.set_source(text, None)
            self.pub.set_destination(destination, destination_path)
            output = self.pub.publish(enable_exit_status=enable_exit_status)
            # kludge until we can get docutils to stop generating (rare) &nbsp;
            # entities
            return u'\u00a0'.join(self.pub.writer.parts['fragment'].strip().split(
                    '&nbsp;'))

    Generator = HTMLGenerator()

    def create_xhtml(text):
        return Generator.create_xhtml(text)


if __name__ == '__main__':
    print "test 1\n", Generator.create_xhtml("""
test::

>>> print 1
1

*I* like it. It is for :JEP:`71`

this `` should    trigger`` should trigger the &nbsp; problem.

""")
    print "test 2\n", Generator.create_xhtml("""
*test1

test2_
""")
    print "test 3\n", Generator.create_xhtml(""":ticket:`316` implements :xep:`71`""")