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# Source code for sphinx.builders.epub

    # -*- coding: utf-8 -*-
    """
        sphinx.builders.epub
        ~~~~~~~~~~~~~~~~~~~~

        Build epub files.
        Originally derived from qthelp.py.

        :copyright: Copyright 2007-2016 by the Sphinx team, see AUTHORS.
        :license: BSD, see LICENSE for details.
    """

    import os
    import re
    import codecs
    import zipfile
    from os import path

    try:
        from PIL import Image
    except ImportError:
        try:
            import Image
        except ImportError:
            Image = None

    from docutils import nodes

    from sphinx import addnodes
    from sphinx.builders.html import StandaloneHTMLBuilder
    from sphinx.util.i18n import format_date
    from sphinx.util.osutil import ensuredir, copyfile, EEXIST
    from sphinx.util.smartypants import sphinx_smarty_pants as ssp
    from sphinx.util.console import brown

    # (Fragment) templates from which the metainfo files content.opf, toc.ncx,
    # mimetype, and META-INF/container.xml are created.
    # This template section also defines strings that are embedded in the html
    # output but that may be customized by (re-)setting module attributes,
    # e.g. from conf.py.

    MIMETYPE_TEMPLATE = 'application/epub+zip'  # no EOL!

    CONTAINER_TEMPLATE = u'''\
    <?xml version="1.0" encoding="UTF-8"?>
    <container version="1.0"
          xmlns="urn:oasis:names:tc:opendocument:xmlns:container">
      <rootfiles>
        <rootfile full-path="content.opf"
            media-type="application/oebps-package+xml"/>
      </rootfiles>
    </container>
    '''

    TOC_TEMPLATE = u'''\
    <?xml version="1.0"?>
    <ncx version="2005-1" xmlns="http://www.daisy.org/z3986/2005/ncx/">
      <head>
        <meta name="dtb:uid" content="%(uid)s"/>
        <meta name="dtb:depth" content="%(level)d"/>
        <meta name="dtb:totalPageCount" content="0"/>
        <meta name="dtb:maxPageNumber" content="0"/>
      </head>
      <docTitle>
        <text>%(title)s</text>
      </docTitle>
      <navMap>
    %(navpoints)s
      </navMap>
    </ncx>
    '''

    NAVPOINT_TEMPLATE = u'''\
    %(indent)s  <navPoint id="%(navpoint)s" playOrder="%(playorder)d">
    %(indent)s    <navLabel>
    %(indent)s      <text>%(text)s</text>
    %(indent)s    </navLabel>
    %(indent)s    <content src="%(refuri)s" />
    %(indent)s  </navPoint>'''

    NAVPOINT_INDENT = '  '
    NODE_NAVPOINT_TEMPLATE = 'navPoint%d'

    CONTENT_TEMPLATE = u'''\
    <?xml version="1.0" encoding="UTF-8"?>
    <package xmlns="http://www.idpf.org/2007/opf" version="2.0"
          unique-identifier="%(uid)s">
      <metadata xmlns:opf="http://www.idpf.org/2007/opf"
            xmlns:dc="http://purl.org/dc/elements/1.1/">
        <dc:language>%(lang)s</dc:language>
        <dc:title>%(title)s</dc:title>
        <dc:creator opf:role="aut">%(author)s</dc:creator>
        <dc:publisher>%(publisher)s</dc:publisher>
        <dc:rights>%(copyright)s</dc:rights>
        <dc:identifier id="%(uid)s" opf:scheme="%(scheme)s">%(id)s</dc:identifier>
        <dc:date>%(date)s</dc:date>
      </metadata>
      <manifest>
        <item id="ncx" href="toc.ncx" media-type="application/x-dtbncx+xml" />
    %(files)s
      </manifest>
      <spine toc="ncx">
    %(spine)s
      </spine>
      <guide>
    %(guide)s
      </guide>
    </package>
    '''

    COVER_TEMPLATE = u'''\
        <meta name="cover" content="%(cover)s"/>
    '''

    COVERPAGE_NAME = u'epub-cover.html'

    FILE_TEMPLATE = u'''\
        <item id="%(id)s"
              href="%(href)s"
              media-type="%(media_type)s" />'''

    SPINE_TEMPLATE = u'''\
        <itemref idref="%(idref)s" />'''

    GUIDE_TEMPLATE = u'''\
        <reference type="%(type)s" title="%(title)s" href="%(uri)s" />'''

    TOCTREE_TEMPLATE = u'toctree-l%d'

    LINK_TARGET_TEMPLATE = u' [%(uri)s]'

    FOOTNOTE_LABEL_TEMPLATE = u'#%d'

    FOOTNOTES_RUBRIC_NAME = u'Footnotes'

    CSS_LINK_TARGET_CLASS = u'link-target'

    # XXX These strings should be localized according to epub_language
    GUIDE_TITLES = {
        'toc': u'Table of Contents',
        'cover': u'Cover'
    }

    MEDIA_TYPES = {
        '.html': 'application/xhtml+xml',
        '.css': 'text/css',
        '.png': 'image/png',
        '.gif': 'image/gif',
        '.svg': 'image/svg+xml',
        '.jpg': 'image/jpeg',
        '.jpeg': 'image/jpeg',
        '.otf': 'application/x-font-otf',
        '.ttf': 'application/x-font-ttf',
    }

    VECTOR_GRAPHICS_EXTENSIONS = ('.svg',)

    # Regular expression to match colons only in local fragment identifiers.
    # If the URI contains a colon before the #,
    # it is an external link that should not change.
    REFURI_RE = re.compile("([^#:]*#)(.*)")

    # The epub publisher

    class EpubBuilder(StandaloneHTMLBuilder):
        """
        Builder that outputs epub files.

        It creates the metainfo files container.opf, toc.ncx, mimetype, and
        META-INF/container.xml.  Afterwards, all necessary files are zipped to an
        epub file.
        """
        name = 'epub'

        # don't copy the reST source
        copysource = False
        supported_image_types = ['image/svg+xml', 'image/png', 'image/gif',
                                 'image/jpeg']

        # don't add links
        add_permalinks = False
        # don't add sidebar etc.
        embedded = True

        mimetype_template = MIMETYPE_TEMPLATE
        container_template = CONTAINER_TEMPLATE
        toc_template = TOC_TEMPLATE
        navpoint_template = NAVPOINT_TEMPLATE
        navpoint_indent = NAVPOINT_INDENT
        node_navpoint_template = NODE_NAVPOINT_TEMPLATE
        content_template = CONTENT_TEMPLATE
        cover_template = COVER_TEMPLATE
        coverpage_name = COVERPAGE_NAME
        file_template = FILE_TEMPLATE
        spine_template = SPINE_TEMPLATE
        guide_template = GUIDE_TEMPLATE
        toctree_template = TOCTREE_TEMPLATE
        link_target_template = LINK_TARGET_TEMPLATE
        css_link_target_class = CSS_LINK_TARGET_CLASS
        guide_titles = GUIDE_TITLES
        media_types = MEDIA_TYPES
        refuri_re = REFURI_RE

        def init(self):
            StandaloneHTMLBuilder.init(self)
            # the output files for epub must be .html only
            self.out_suffix = '.html'
            self.playorder = 0
            self.tocid = 0

        def get_theme_config(self):
            return self.config.epub_theme, self.config.epub_theme_options

        # generic support functions
        def make_id(self, name, id_cache={}):
            # id_cache is intentionally mutable
            """Return a unique id for name."""
            id = id_cache.get(name)
            if not id:
                id = 'epub-%d' % self.env.new_serialno('epub')
                id_cache[name] = id
            return id

        def esc(self, name):
            """Replace all characters not allowed in text an attribute values."""
            # Like cgi.escape, but also replace apostrophe
            name = name.replace('&', '&amp;')
            name = name.replace('<', '&lt;')
            name = name.replace('>', '&gt;')
            name = name.replace('"', '&quot;')
            name = name.replace('\'', '&#39;')
            return name

        def get_refnodes(self, doctree, result):
            """Collect section titles, their depth in the toc and the refuri."""
            # XXX: is there a better way than checking the attribute
            # toctree-l[1-8] on the parent node?
            if isinstance(doctree, nodes.reference) and 'refuri' in doctree:
                refuri = doctree['refuri']
                if refuri.startswith('http://') or refuri.startswith('https://') \
                   or refuri.startswith('irc:') or refuri.startswith('mailto:'):
                    return result
                classes = doctree.parent.attributes['classes']
                for level in range(8, 0, -1):  # or range(1, 8)?
                    if (self.toctree_template % level) in classes:
                        result.append({
                            'level': level,
                            'refuri': self.esc(refuri),
                            'text': ssp(self.esc(doctree.astext()))
                        })
                        break
            else:
                for elem in doctree.children:
                    result = self.get_refnodes(elem, result)
            return result

        def get_toc(self):
            """Get the total table of contents, containing the master_doc
            and pre and post files not managed by sphinx.
            """
            doctree = self.env.get_and_resolve_doctree(self.config.master_doc,
                                                       self, prune_toctrees=False,
                                                       includehidden=True)
            self.refnodes = self.get_refnodes(doctree, [])
            master_dir = path.dirname(self.config.master_doc)
            if master_dir:
                master_dir += '/'  # XXX or os.sep?
                for item in self.refnodes:
                    item['refuri'] = master_dir + item['refuri']
            self.toc_add_files(self.refnodes)

        def toc_add_files(self, refnodes):
            """Add the master_doc, pre and post files to a list of refnodes.
            """
            refnodes.insert(0, {
                'level': 1,
                'refuri': self.esc(self.config.master_doc + '.html'),
                'text': ssp(self.esc(
                    self.env.titles[self.config.master_doc].astext()))
            })
            for file, text in reversed(self.config.epub_pre_files):
                refnodes.insert(0, {
                    'level': 1,
                    'refuri': self.esc(file),
                    'text': ssp(self.esc(text))
                })
            for file, text in self.config.epub_post_files:
                refnodes.append({
                    'level': 1,
                    'refuri': self.esc(file),
                    'text': ssp(self.esc(text))
                })

        def fix_fragment(self, prefix, fragment):
            """Return a href/id attribute with colons replaced by hyphens."""
            return prefix + fragment.replace(':', '-')

        def fix_ids(self, tree):
            """Replace colons with hyphens in href and id attributes.

            Some readers crash because they interpret the part as a
            transport protocol specification.
            """
            for node in tree.traverse(nodes.reference):
                if 'refuri' in node:
                    m = self.refuri_re.match(node['refuri'])
                    if m:
                        node['refuri'] = self.fix_fragment(m.group(1), m.group(2))
                if 'refid' in node:
                    node['refid'] = self.fix_fragment('', node['refid'])
            for node in tree.traverse(addnodes.desc_signature):
                ids = node.attributes['ids']
                newids = []
                for id in ids:
                    newids.append(self.fix_fragment('', id))
                node.attributes['ids'] = newids

        def add_visible_links(self, tree, show_urls='inline'):
            """Add visible link targets for external links"""

            def make_footnote_ref(doc, label):
                """Create a footnote_reference node with children"""
                footnote_ref = nodes.footnote_reference('[#]_')
                footnote_ref.append(nodes.Text(label))
                doc.note_autofootnote_ref(footnote_ref)
                return footnote_ref

            def make_footnote(doc, label, uri):
                """Create a footnote node with children"""
                footnote = nodes.footnote(uri)
                para = nodes.paragraph()
                para.append(nodes.Text(uri))
                footnote.append(para)
                footnote.insert(0, nodes.label('', label))
                doc.note_autofootnote(footnote)
                return footnote

            def footnote_spot(tree):
                """Find or create a spot to place footnotes.

                The function returns the tuple (parent, index)."""
                # The code uses the following heuristic:
                # a) place them after the last existing footnote
                # b) place them after an (empty) Footnotes rubric
                # c) create an empty Footnotes rubric at the end of the document
                fns = tree.traverse(nodes.footnote)
                if fns:
                    fn = fns[-1]
                    return fn.parent, fn.parent.index(fn) + 1
                for node in tree.traverse(nodes.rubric):
                    if len(node.children) == 1 and \
                            node.children[0].astext() == FOOTNOTES_RUBRIC_NAME:
                        return node.parent, node.parent.index(node) + 1
                doc = tree.traverse(nodes.document)[0]
                rub = nodes.rubric()
                rub.append(nodes.Text(FOOTNOTES_RUBRIC_NAME))
                doc.append(rub)
                return doc, doc.index(rub) + 1

            if show_urls == 'no':
                return
            if show_urls == 'footnote':
                doc = tree.traverse(nodes.document)[0]
                fn_spot, fn_idx = footnote_spot(tree)
                nr = 1
            for node in tree.traverse(nodes.reference):
                uri = node.get('refuri', '')
                if (uri.startswith('http:') or uri.startswith('https:') or
                        uri.startswith('ftp:')) and uri not in node.astext():
                    idx = node.parent.index(node) + 1
                    if show_urls == 'inline':
                        uri = self.link_target_template % {'uri': uri}
                        link = nodes.inline(uri, uri)
                        link['classes'].append(self.css_link_target_class)
                        node.parent.insert(idx, link)
                    elif show_urls == 'footnote':
                        label = FOOTNOTE_LABEL_TEMPLATE % nr
                        nr += 1
                        footnote_ref = make_footnote_ref(doc, label)
                        node.parent.insert(idx, footnote_ref)
                        footnote = make_footnote(doc, label, uri)
                        fn_spot.insert(fn_idx, footnote)
                        footnote_ref['refid'] = footnote['ids'][0]
                        footnote.add_backref(footnote_ref['ids'][0])
                        fn_idx += 1

        def write_doc(self, docname, doctree):
            """Write one document file.

            This method is overwritten in order to fix fragment identifiers
            and to add visible external links.
            """
            self.fix_ids(doctree)
            self.add_visible_links(doctree, self.config.epub_show_urls)
            return StandaloneHTMLBuilder.write_doc(self, docname, doctree)

        def fix_genindex(self, tree):
            """Fix href attributes for genindex pages."""
            # XXX: modifies tree inline
            # Logic modeled from themes/basic/genindex.html
            for key, columns in tree:
                for entryname, (links, subitems, key_) in columns:
                    for (i, (ismain, link)) in enumerate(links):
                        m = self.refuri_re.match(link)
                        if m:
                            links[i] = (ismain,
                                        self.fix_fragment(m.group(1), m.group(2)))
                    for subentryname, subentrylinks in subitems:
                        for (i, (ismain, link)) in enumerate(subentrylinks):
                            m = self.refuri_re.match(link)
                            if m:
                                subentrylinks[i] = (ismain,
                                                    self.fix_fragment(m.group(1), m.group(2)))

        def is_vector_graphics(self, filename):
            """Does the filename extension indicate a vector graphic format?"""
            ext = path.splitext(filename)[-1]
            return ext in VECTOR_GRAPHICS_EXTENSIONS

        def copy_image_files_pil(self):
            """Copy images using the PIL.
            The method tries to read and write the files with the PIL,
            converting the format and resizing the image if necessary/possible.
            """
            ensuredir(path.join(self.outdir, self.imagedir))
            for src in self.app.status_iterator(self.images, 'copying images... ',
                                                brown, len(self.images)):
                dest = self.images[src]
                try:
                    img = Image.open(path.join(self.srcdir, src))
                except IOError:
                    if not self.is_vector_graphics(src):
                        self.warn('cannot read image file %r: copying it instead' %
                                  (path.join(self.srcdir, src), ))
                    try:
                        copyfile(path.join(self.srcdir, src),
                                 path.join(self.outdir, self.imagedir, dest))
                    except (IOError, OSError) as err:
                        self.warn('cannot copy image file %r: %s' %
                                  (path.join(self.srcdir, src), err))
                    continue
                if self.config.epub_fix_images:
                    if img.mode in ('P',):
                        # See PIL documentation for Image.convert()
                        img = img.convert()
                if self.config.epub_max_image_width > 0:
                    (width, height) = img.size
                    nw = self.config.epub_max_image_width
                    if width > nw:
                        nh = (height * nw) / width
                        img = img.resize((nw, nh), Image.BICUBIC)
                try:
                    img.save(path.join(self.outdir, self.imagedir, dest))
                except (IOError, OSError) as err:
                    self.warn('cannot write image file %r: %s' %
                              (path.join(self.srcdir, src), err))

        def copy_image_files(self):
            """Copy image files to destination directory.
            This overwritten method can use the PIL to convert image files.
            """
            if self.images:
                if self.config.epub_fix_images or self.config.epub_max_image_width:
                    if not Image:
                        self.warn('PIL not found - copying image files')
                        super(EpubBuilder, self).copy_image_files()
                    else:
                        self.copy_image_files_pil()
                else:
                    super(EpubBuilder, self).copy_image_files()

        def handle_page(self, pagename, addctx, templatename='page.html',
                        outfilename=None, event_arg=None):
            """Create a rendered page.

            This method is overwritten for genindex pages in order to fix href link
            attributes.
            """
            if pagename.startswith('genindex'):
                self.fix_genindex(addctx['genindexentries'])
            StandaloneHTMLBuilder.handle_page(self, pagename, addctx, templatename,
                                              outfilename, event_arg)

        # Finish by building the epub file
        def handle_finish(self):
            """Create the metainfo files and finally the epub."""
            self.get_toc()
            self.build_mimetype(self.outdir, 'mimetype')
            self.build_container(self.outdir, 'META-INF/container.xml')
            self.build_content(self.outdir, 'content.opf')
            self.build_toc(self.outdir, 'toc.ncx')
            self.build_epub(self.outdir, self.config.epub_basename + '.epub')

        def build_mimetype(self, outdir, outname):
            """Write the metainfo file mimetype."""
            self.info('writing %s file...' % outname)
            f = codecs.open(path.join(outdir, outname), 'w', 'utf-8')
            try:
                f.write(self.mimetype_template)
            finally:
                f.close()

        def build_container(self, outdir, outname):
            """Write the metainfo file META-INF/cointainer.xml."""
            self.info('writing %s file...' % outname)
            fn = path.join(outdir, outname)
            try:
                os.mkdir(path.dirname(fn))
            except OSError as err:
                if err.errno != EEXIST:
                    raise
            f = codecs.open(path.join(outdir, outname), 'w', 'utf-8')
            try:
                f.write(self.container_template)
            finally:
                f.close()

        def content_metadata(self, files, spine, guide):
            """Create a dictionary with all metadata for the content.opf
            file properly escaped.
            """
            metadata = {}
            metadata['title'] = self.esc(self.config.epub_title)
            metadata['author'] = self.esc(self.config.epub_author)
            metadata['uid'] = self.esc(self.config.epub_uid)
            metadata['lang'] = self.esc(self.config.epub_language)
            metadata['publisher'] = self.esc(self.config.epub_publisher)
            metadata['copyright'] = self.esc(self.config.epub_copyright)
            metadata['scheme'] = self.esc(self.config.epub_scheme)
            metadata['id'] = self.esc(self.config.epub_identifier)
            metadata['date'] = self.esc(format_date('YYYY-MM-dd', language=self.config.language))
            metadata['files'] = files
            metadata['spine'] = spine
            metadata['guide'] = guide
            return metadata

        def build_content(self, outdir, outname):
            """Write the metainfo file content.opf It contains bibliographic data,
            a file list and the spine (the reading order).
            """
            self.info('writing %s file...' % outname)

            # files
            if not outdir.endswith(os.sep):
                outdir += os.sep
            olen = len(outdir)
            projectfiles = []
            self.files = []
            self.ignored_files = ['.buildinfo', 'mimetype', 'content.opf',
                                  'toc.ncx', 'META-INF/container.xml',
                                  self.config.epub_basename + '.epub'] + \
                self.config.epub_exclude_files
            for root, dirs, files in os.walk(outdir):
                for fn in files:
                    filename = path.join(root, fn)[olen:]
                    if filename in self.ignored_files:
                        continue
                    ext = path.splitext(filename)[-1]
                    if ext not in self.media_types:
                        # we always have JS and potentially OpenSearch files, don't
                        # always warn about them
                        if ext not in ('.js', '.xml'):
                            self.warn('unknown mimetype for %s, ignoring' % filename)
                        continue
                    filename = filename.replace(os.sep, '/')
                    projectfiles.append(self.file_template % {
                        'href': self.esc(filename),
                        'id': self.esc(self.make_id(filename)),
                        'media_type': self.esc(self.media_types[ext])
                    })
                    self.files.append(filename)

            # spine
            spine = []
            for item in self.refnodes:
                if '#' in item['refuri']:
                    continue
                if item['refuri'] in self.ignored_files:
                    continue
                spine.append(self.spine_template % {
                    'idref': self.esc(self.make_id(item['refuri']))
                })
            for info in self.domain_indices:
                spine.append(self.spine_template % {
                    'idref': self.esc(self.make_id(info[0] + self.out_suffix))
                })
            if self.get_builder_config('use_index', 'epub'):
                spine.append(self.spine_template % {
                    'idref': self.esc(self.make_id('genindex' + self.out_suffix))
                })

            # add the optional cover
            content_tmpl = self.content_template
            html_tmpl = None
            if self.config.epub_cover:
                image, html_tmpl = self.config.epub_cover
                image = image.replace(os.sep, '/')
                mpos = content_tmpl.rfind('</metadata>')
                cpos = content_tmpl.rfind('\n', 0, mpos) + 1
                content_tmpl = content_tmpl[:cpos] + \
                    COVER_TEMPLATE % {'cover': self.esc(self.make_id(image))} + \
                    content_tmpl[cpos:]
                if html_tmpl:
                    spine.insert(0, self.spine_template % {
                        'idref': self.esc(self.make_id(self.coverpage_name))})
                    if self.coverpage_name not in self.files:
                        ext = path.splitext(self.coverpage_name)[-1]
                        self.files.append(self.coverpage_name)
                        projectfiles.append(self.file_template % {
                            'href': self.esc(self.coverpage_name),
                            'id': self.esc(self.make_id(self.coverpage_name)),
                            'media_type': self.esc(self.media_types[ext])
                        })
                    ctx = {'image': self.esc(image), 'title': self.config.project}
                    self.handle_page(
                        path.splitext(self.coverpage_name)[0], ctx, html_tmpl)

            guide = []
            auto_add_cover = True
            auto_add_toc = True
            if self.config.epub_guide:
                for type, uri, title in self.config.epub_guide:
                    file = uri.split('#')[0]
                    if file not in self.files:
                        self.files.append(file)
                    if type == 'cover':
                        auto_add_cover = False
                    if type == 'toc':
                        auto_add_toc = False
                    guide.append(self.guide_template % {
                        'type': self.esc(type),
                        'title': self.esc(title),
                        'uri': self.esc(uri)
                    })
            if auto_add_cover and html_tmpl:
                guide.append(self.guide_template % {
                    'type': 'cover',
                    'title': self.guide_titles['cover'],
                    'uri': self.esc(self.coverpage_name)
                })
            if auto_add_toc and self.refnodes:
                guide.append(self.guide_template % {
                    'type': 'toc',
                    'title': self.guide_titles['toc'],
                    'uri': self.esc(self.refnodes[0]['refuri'])
                })
            projectfiles = '\n'.join(projectfiles)
            spine = '\n'.join(spine)
            guide = '\n'.join(guide)

            # write the project file
            f = codecs.open(path.join(outdir, outname), 'w', 'utf-8')
            try:
                f.write(content_tmpl %
                        self.content_metadata(projectfiles, spine, guide))
            finally:
                f.close()

        def new_navpoint(self, node, level, incr=True):
            """Create a new entry in the toc from the node at given level."""
            # XXX Modifies the node
            if incr:
                self.playorder += 1
            self.tocid += 1
            node['indent'] = self.navpoint_indent * level
            node['navpoint'] = self.esc(self.node_navpoint_template % self.tocid)
            node['playorder'] = self.playorder
            return self.navpoint_template % node

        def insert_subnav(self, node, subnav):
            """Insert nested navpoints for given node.

            The node and subnav are already rendered to text.
            """
            nlist = node.rsplit('\n', 1)
            nlist.insert(-1, subnav)
            return '\n'.join(nlist)

        def build_navpoints(self, nodes):
            """Create the toc navigation structure.

            Subelements of a node are nested inside the navpoint.  For nested nodes
            the parent node is reinserted in the subnav.
            """
            navstack = []
            navlist = []
            level = 1
            lastnode = None
            for node in nodes:
                if not node['text']:
                    continue
                file = node['refuri'].split('#')[0]
                if file in self.ignored_files:
                    continue
                if node['level'] > self.config.epub_tocdepth:
                    continue
                if node['level'] == level:
                    navlist.append(self.new_navpoint(node, level))
                elif node['level'] == level + 1:
                    navstack.append(navlist)
                    navlist = []
                    level += 1
                    if lastnode and self.config.epub_tocdup:
                        # Insert starting point in subtoc with same playOrder
                        navlist.append(self.new_navpoint(lastnode, level, False))
                    navlist.append(self.new_navpoint(node, level))
                else:
                    while node['level'] < level:
                        subnav = '\n'.join(navlist)
                        navlist = navstack.pop()
                        navlist[-1] = self.insert_subnav(navlist[-1], subnav)
                        level -= 1
                    navlist.append(self.new_navpoint(node, level))
                lastnode = node
            while level != 1:
                subnav = '\n'.join(navlist)
                navlist = navstack.pop()
                navlist[-1] = self.insert_subnav(navlist[-1], subnav)
                level -= 1
            return '\n'.join(navlist)

        def toc_metadata(self, level, navpoints):
            """Create a dictionary with all metadata for the toc.ncx file
            properly escaped.
            """
            metadata = {}
            metadata['uid'] = self.config.epub_uid
            metadata['title'] = self.config.epub_title
            metadata['level'] = level
            metadata['navpoints'] = navpoints
            return metadata

        def build_toc(self, outdir, outname):
            """Write the metainfo file toc.ncx."""
            self.info('writing %s file...' % outname)

            if self.config.epub_tocscope == 'default':
                doctree = self.env.get_and_resolve_doctree(self.config.master_doc,
                                                           self, prune_toctrees=False,
                                                           includehidden=False)
                refnodes = self.get_refnodes(doctree, [])
                self.toc_add_files(refnodes)
            else:
                # 'includehidden'
                refnodes = self.refnodes
            navpoints = self.build_navpoints(refnodes)
            level = max(item['level'] for item in self.refnodes)
            level = min(level, self.config.epub_tocdepth)
            f = codecs.open(path.join(outdir, outname), 'w', 'utf-8')
            try:
                f.write(self.toc_template % self.toc_metadata(level, navpoints))
            finally:
                f.close()

        def build_epub(self, outdir, outname):
            """Write the epub file.

            It is a zip file with the mimetype file stored uncompressed as the first
            entry.
            """
            self.info('writing %s file...' % outname)
            projectfiles = ['META-INF/container.xml', 'content.opf', 'toc.ncx'] \
                + self.files
            epub = zipfile.ZipFile(path.join(outdir, outname), 'w',
                                   zipfile.ZIP_DEFLATED)
            epub.write(path.join(outdir, 'mimetype'), 'mimetype',
                       zipfile.ZIP_STORED)
            for file in projectfiles:
                fp = path.join(outdir, file)
                epub.write(fp, file, zipfile.ZIP_DEFLATED)
            epub.close()