# -*- coding: utf-8 -*-

"""

    rhodecode.lib.markup_renderer

    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    Renderer for markup languages with ability to parse using rst or markdown

    :created_on: Oct 27, 2011

    :author: marcink

    :copyright: (C) 2009-2011 Marcin Kuzminski <marcin@python-works.com>

    :license: GPLv3, see COPYING for more details.

"""

# This program 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, either version 3 of the License, or

# (at your option) any later version.

#

# This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.

import re

import logging

from rhodecode.lib import safe_unicode

log = logging.getLogger(__name__)

class MarkupRenderer(object):

    RESTRUCTUREDTEXT_DISALLOWED_DIRECTIVES = ['include', 'meta', 'raw']

    MARKDOWN_PAT = re.compile(r'md|mkdn?|mdown|markdown',re.IGNORECASE)

    RST_PAT = re.compile(r're?st',re.IGNORECASE)

    PLAIN_PAT = re.compile(r'readme',re.IGNORECASE)

    def __detect_renderer(self, source, filename=None):

        """

        runs detection of what renderer should be used for generating html

        from a markup language

        filename can be also explicitly a renderer name

        :param source:

        :param filename:

        """

        if MarkupRenderer.MARKDOWN_PAT.findall(filename):

            detected_renderer = 'markdown'

        elif MarkupRenderer.RST_PAT.findall(filename):

            detected_renderer = 'rst'

        elif MarkupRenderer.PLAIN_PAT.findall(filename):

            detected_renderer = 'rst'

        else:

            detected_renderer = 'plain'

        return getattr(MarkupRenderer, detected_renderer)

    def render(self, source, filename=None):

        """

        Renders a given filename using detected renderer

        it detects renderers based on file extension or mimetype.

        At last it will just do a simple html replacing new lines with <br/>

        :param file_name:

        :param source:

        """

        renderer = self.__detect_renderer(source, filename)

        readme_data = renderer(source)

        return readme_data

    @classmethod

    def plain(cls, source):

        source = safe_unicode(source)

        def urlify_text(text):

            url_pat = re.compile(r'(http[s]?://(?:[a-zA-Z]|[0-9]|[$-_@.&+]'

                                 '|[!*\(\),]|(?:%[0-9a-fA-F][0-9a-fA-F]))+)')

            def url_func(match_obj):

                url_full = match_obj.groups()[0]

                return '<a href="%(url)s">%(url)s</a>' % ({'url':url_full})

            return url_pat.sub(url_func, text)

        source = urlify_text(source)

        return '<br />' + source.replace("\n", '<br />')

    @classmethod

    def markdown(cls, source):

        source = safe_unicode(source)

        try:

            import markdown as __markdown

            return __markdown.markdown(source)

        except ImportError:

            log.warning('Install markdown to use this function')

            return cls.plain(source)

    @classmethod

    def rst(cls, source):

        source = safe_unicode(source)

        try:

            from docutils.core import publish_parts

            from docutils.parsers.rst import directives

            docutils_settings = dict([(alias, None) for alias in

                                cls.RESTRUCTUREDTEXT_DISALLOWED_DIRECTIVES])

            docutils_settings.update({'input_encoding': 'unicode',

                                      'report_level':4})

            for k, v in docutils_settings.iteritems():

                directives.register_directive(k, v)

            parts = publish_parts(source=source,

                                  writer_name="html4css1",

                                  settings_overrides=docutils_settings)

            return parts['html_title'] + parts["fragment"]

        except ImportError:

            log.warning('Install docutils to use this function')

            return cls.plain(source)