# .. coding: utf-8
# $Id: __init__.py 8181 2017-09-22 10:29:55Z milde $
# :Author: Günter Milde <milde@users.sf.net>
#          Based on the html4css1 writer by David Goodger.
# :Maintainer: docutils-develop@lists.sourceforge.net
# :Copyright: © 2005, 2009, 2015 Günter Milde,
#             portions from html4css1 © David Goodger.
# :License: Released under the terms of the `2-Clause BSD license`_, in short:
#
#    Copying and distribution of this file, with or without modification,
#    are permitted in any medium without royalty provided the copyright
#    notice and this notice are preserved.
#    This file is offered as-is, without any warranty.
#
# .. _2-Clause BSD license: http://www.spdx.org/licenses/BSD-2-Clause

# Use "best practice" as recommended by the W3C:
# http://www.w3.org/2009/cheatsheet/

"""
Plain HyperText Markup Language document tree Writer.

The output conforms to the `HTML5` specification.

The cascading style sheet "minimal.css" is required for proper viewing,
the style sheet "plain.css" improves reading experience.
"""
__docformat__ = 'reStructuredText'

import os.path
import docutils
from docutils import frontend, nodes, writers, io
from docutils.transforms import writer_aux
from docutils.writers import _html_base

class Writer(writers._html_base.Writer):

    supported = ('html', 'html5', 'html4', 'xhtml', 'xhtml10')
    """Formats this writer supports."""

    default_stylesheets = ['minimal.css','plain.css']
    default_stylesheet_dirs = ['.', os.path.abspath(os.path.dirname(__file__))]

    default_template = 'template.txt'
    default_template_path = os.path.join(
        os.path.dirname(os.path.abspath(__file__)), default_template)

    settings_spec = (
        'HTML-Specific Options',
        None,
        (('Specify the template file (UTF-8 encoded).  Default is "%s".'
          % default_template_path,
          ['--template'],
          {'default': default_template_path, 'metavar': '<file>'}),
         ('Comma separated list of stylesheet URLs. '
          'Overrides previous --stylesheet and --stylesheet-path settings.',
          ['--stylesheet'],
          {'metavar': '<URL[,URL,...]>', 'overrides': 'stylesheet_path',
           'validator': frontend.validate_comma_separated_list}),
         ('Comma separated list of stylesheet paths. '
          'Relative paths are expanded if a matching file is found in '
          'the --stylesheet-dirs. With --link-stylesheet, '
          'the path is rewritten relative to the output HTML file. '
          'Default: "%s"' % ','.join(default_stylesheets),
          ['--stylesheet-path'],
          {'metavar': '<file[,file,...]>', 'overrides': 'stylesheet',
           'validator': frontend.validate_comma_separated_list,
           'default': default_stylesheets}),
         ('Embed the stylesheet(s) in the output HTML file.  The stylesheet '
          'files must be accessible during processing. This is the default.',
          ['--embed-stylesheet'],
          {'default': 1, 'action': 'store_true',
           'validator': frontend.validate_boolean}),
         ('Link to the stylesheet(s) in the output HTML file. '
          'Default: embed stylesheets.',
          ['--link-stylesheet'],
          {'dest': 'embed_stylesheet', 'action': 'store_false'}),
         ('Comma-separated list of directories where stylesheets are found. '
          'Used by --stylesheet-path when expanding relative path arguments. '
          'Default: "%s"' % default_stylesheet_dirs,
          ['--stylesheet-dirs'],
          {'metavar': '<dir[,dir,...]>',
           'validator': frontend.validate_comma_separated_list,
           'default': default_stylesheet_dirs}),
         ('Specify the initial header level.  Default is 1 for "<h1>".  '
          'Does not affect document title & subtitle (see --no-doc-title).',
          ['--initial-header-level'],
          {'choices': '1 2 3 4 5 6'.split(), 'default': '1',
           'metavar': '<level>'}),
         ('Format for footnote references: one of "superscript" or '
          '"brackets".  Default is "brackets".',
          ['--footnote-references'],
          {'choices': ['superscript', 'brackets'], 'default': 'brackets',
           'metavar': '<format>',
           'overrides': 'trim_footnote_reference_space'}),
         ('Format for block quote attributions: one of "dash" (em-dash '
          'prefix), "parentheses"/"parens", or "none".  Default is "dash".',
          ['--attribution'],
          {'choices': ['dash', 'parentheses', 'parens', 'none'],
           'default': 'dash', 'metavar': '<format>'}),
         ('Remove extra vertical whitespace between items of "simple" bullet '
          'lists and enumerated lists.  Default: enabled.',
          ['--compact-lists'],
          {'default': True, 'action': 'store_true',
           'validator': frontend.validate_boolean}),
         ('Disable compact simple bullet and enumerated lists.',
          ['--no-compact-lists'],
          {'dest': 'compact_lists', 'action': 'store_false'}),
         ('Remove extra vertical whitespace between items of simple field '
          'lists.  Default: enabled.',
          ['--compact-field-lists'],
          {'default': True, 'action': 'store_true',
           'validator': frontend.validate_boolean}),
         ('Disable compact simple field lists.',
          ['--no-compact-field-lists'],
          {'dest': 'compact_field_lists', 'action': 'store_false'}),
         ('Added to standard table classes. '
          'Defined styles: borderless, booktabs, '
          'align-left, align-center, align-right, colwidths-auto. '
          'Default: ""',
          ['--table-style'],
          {'default': ''}),
         ('Math output format (one of "MathML", "HTML", "MathJax", '
          'or "LaTeX") and option(s). '
          'Default: "HTML math.css"',
          ['--math-output'],
          {'default': 'HTML math.css'}),
         ('Prepend an XML declaration. (Thwarts HTML5 conformance.) '
          'Default: False',
          ['--xml-declaration'],
          {'default': False, 'action': 'store_true',
           'validator': frontend.validate_boolean}),
         ('Omit the XML declaration.',
          ['--no-xml-declaration'],
          {'dest': 'xml_declaration', 'action': 'store_false'}),
         ('Obfuscate email addresses to confuse harvesters while still '
          'keeping email links usable with standards-compliant browsers.',
          ['--cloak-email-addresses'],
          {'action': 'store_true', 'validator': frontend.validate_boolean}),))

    config_section = 'html5 writer'

    def __init__(self):
        self.parts = {}
        self.translator_class = HTMLTranslator


class HTMLTranslator(writers._html_base.HTMLTranslator):
    """
    This writer generates `polyglot markup`: HTML5 that is also valid XML.

    Safe subclassing: when overriding, treat ``visit_*`` and ``depart_*``
    methods as a unit to prevent breaks due to internal changes. See the
    docstring of docutils.writers._html_base.HTMLTranslator for details
    and examples.
    """

    # <acronym> tag not supported in HTML5. Use the <abbr> tag instead.
    def visit_acronym(self, node):
        # @@@ implementation incomplete ("title" attribute)
        self.body.append(self.starttag(node, 'abbr', ''))
    def depart_acronym(self, node):
        self.body.append('</abbr>')

    # no standard meta tag name in HTML5, use separate "author" meta tags
    # https://www.w3.org/TR/html5/document-metadata.html#standard-metadata-names
    def visit_authors(self, node):
        self.visit_docinfo_item(node, 'authors', meta=False)
        for subnode in node:
            self.add_meta('<meta name="author" content="%s" />\n' % 
                          self.attval(subnode.astext()))
    def depart_authors(self, node):
        self.depart_docinfo_item()

    # no standard meta tag name in HTML5, use dcterms.rights
    # see https://wiki.whatwg.org/wiki/MetaExtensions
    def visit_copyright(self, node):
        self.visit_docinfo_item(node, 'copyright', meta=False)
        self.add_meta('<meta name="dcterms.rights" content="%s" />\n'
                      % self.attval(node.astext()))
    def depart_copyright(self, node):
        self.depart_docinfo_item()

    # no standard meta tag name in HTML5, use dcterms.date
    def visit_date(self, node):
        self.visit_docinfo_item(node, 'date', meta=False)
        self.add_meta('<meta name="dcterms.date" content="%s" />\n'
                      % self.attval(node.astext()))
    def depart_date(self, node):
        self.depart_docinfo_item()

    # TODO: use HTML5 <footer> element?
    # def visit_footer(self, node):
    # def depart_footer(self, node):

    # TODO: use the new HTML5 element <aside>? (Also for footnote text)
    # def visit_footnote(self, node):
    # def depart_footnote(self, node):

    # Meta tags: 'lang' attribute replaced by 'xml:lang' in XHTML 1.1
    # HTML5/polyglot recommends using both
    def visit_meta(self, node):
        if node.hasattr('lang'):
            node['xml:lang'] = node['lang']
            # del(node['lang'])
        meta = self.emptytag(node, 'meta', **node.non_default_attributes())
        self.add_meta(meta)
    def depart_meta(self, node):
        pass

    # no standard meta tag name in HTML5
    def visit_organization(self, node):
        self.visit_docinfo_item(node, 'organization', meta=False)
    def depart_organization(self, node):
        self.depart_docinfo_item()

    # TODO: use the new HTML5 element <section>?
    # def visit_section(self, node):
    # def depart_section(self, node):

    # TODO: use the new HTML5 element <aside>?
    # def visit_topic(self, node):
    # def depart_topic(self, node):