# Copyright (C) 2011-2013 Stefan Merten

# This file 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 2 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, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
# 02111-1307, USA.

"""
Python based conversion.
"""

###############################################################################
###############################################################################
# Import

import re
import docutils
import docutils.parsers.rst.states as states

__docformat__ = 'reStructuredText'

###############################################################################
###############################################################################
# Classes

class Inliner(states.Inliner):
    """
    Recognizer for inline markup. Derive this from the original inline
    markup parser for best results.
    """

    # Copy static attributes from super class
    vars().update(vars(states.Inliner))

    def quoteInline(self, text):
        """
        `text`: ``str``
          Return `text` with inline markup quoted.
        """
        # Method inspired by `states.Inliner.parse`
        self.document = docutils.utils.new_document("<string>")
        self.document.settings.trim_footnote_reference_space = False
        self.document.settings.character_level_inline_markup = False
        self.document.settings.pep_references = False
        self.document.settings.rfc_references = False

        self.init_customizations(self.document.settings)

        self.reporter = self.document.reporter
        self.reporter.stream = None
        self.language = None
        self.parent = self.document
        remaining = docutils.utils.escape2null(text)
        checked = ""
        processed = []
        unprocessed = []
        messages = []
        while remaining:
            original = remaining
            match = self.patterns.initial.search(remaining)
            if match:
                groups = match.groupdict()
                method = self.dispatch[groups['start'] or groups['backquote']
                                       or groups['refend'] or groups['fnend']]
                ( before, inlines, remaining, sysmessages,
                  ) = method(self, match, 0)
                checked += before
                if inlines:
                    assert len(inlines) == 1, "More than one inline found"
                    inline = original[len(before)
                                      :len(original) - len(remaining)]
                    rolePfx = re.search("^:" + self.simplename + ":(?=`)",
                                        inline)
                    refSfx = re.search("_+$", inline)
                    if rolePfx:
                        # Prefixed roles need to be quoted in the middle
                        checked += (inline[:rolePfx.end()] + "\\"
                                    + inline[rolePfx.end():])
                    elif refSfx and not re.search("^`", inline):
                        # Pure reference markup needs to be quoted at the end
                        checked += (inline[:refSfx.start()] + "\\"
                                    + inline[refSfx.start():])
                    else:
                        # Quote other inlines by prefixing
                        checked += "\\" + inline
            else:
                checked += remaining
                break
        # Quote all original backslashes
        checked = re.sub('\x00', "\\\x00", checked)
        return docutils.utils.unescape(checked, 1)

###############################################################################

class Text():
    """
    Functions for computing valid reStructuredText plain text.
    """

    inliner = Inliner()

    @staticmethod
    def plain(text, indent, literal):
        """
        Return a plain text preventing further interpretation by
        reStructuredText. Text may contain linefeeds.

        :Parameters:

          text : str
            The string to turn into output text.

          indent : str
            The string to use for indent in case of internal linefeeds.

          literal : bool
            Output literally instead of quoting.
        """
        sep = "\n" + indent
        if literal:
            quoted = text
        else:
            quoted = Text.inliner.quoteInline(text)
        return sep.join(quoted.split("\n"))

#print(Text.plain("Some \\ back\slashes", ""))

# indent
# directive
# field_names
# substitution
# inline markup
# token
# label
# start_delimiter
# end_delimiter
# target_definition