# Source code for ebooklib.plugins.tidyhtml

    # This file is part of EbookLib.
    # Copyright (c) 2013 Aleksandar Erkalovic <aerkalov@gmail.com>
    #
    # EbookLib is free software: you can redistribute it and/or modify
    # it under the terms of the GNU Affero General Public License as published by
    # the Free Software Foundation, either version 3 of the License, or
    # (at your option) any later version.
    #
    # EbookLib 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 Affero General Public License for more details.
    #
    # You should have received a copy of the GNU Affero General Public License
    # along with EbookLib.  If not, see <http://www.gnu.org/licenses/>.

    import six
    import subprocess

    from ebooklib.plugins.base import BasePlugin
    from ebooklib.utils import parse_html_string

    # Recommend usage of
    # - https://github.com/w3c/tidy-html5

    def tidy_cleanup(content, **extra):
        cmd = []

        for k, v in six.iteritems(extra):

            if v:
                cmd.append('--%s' % k)
                cmd.append(v)
            else:
                cmd.append('-%s' % k)

        # must parse all other extra arguments
        try:
            p = subprocess.Popen(['tidy']+cmd, shell=False,
                                 stdin=subprocess.PIPE, stdout=subprocess.PIPE,
                                 stderr=subprocess.PIPE, close_fds=True)
        except OSError:
            return (3, None)

        p.stdin.write(content)

        (cont, p_err) = p.communicate()

        # 0 - all ok
        # 1 - there were warnings
        # 2 - there were errors
        # 3 - exception

        return (p.returncode, cont)

    class TidyPlugin(BasePlugin):
        NAME = 'Tidy HTML'
        OPTIONS = {'char-encoding': 'utf8',
                   'tidy-mark': 'no'
                  }

        def __init__(self, extra = {}):
            self.options = dict(self.OPTIONS)
            self.options.update(extra)

        def html_before_write(self, book, chapter):
            if not chapter.content:
                return None

            (_, chapter.content) = tidy_cleanup(chapter.content, **self.options)

            return chapter.content

        def html_after_read(self, book, chapter):
            if not chapter.content:
                return None

            (_, chapter.content) = tidy_cleanup(chapter.content, **self.options)

            return chapter.content