1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
"""Base class of epub2/epub3 builders."""

import html
import os
import re
from os import path
from typing import Any, Dict, List, NamedTuple, Set, Tuple
from zipfile import ZIP_DEFLATED, ZIP_STORED, ZipFile

from docutils import nodes
from docutils.nodes import Element, Node
from docutils.utils import smartquotes

from sphinx import addnodes
from sphinx.builders.html import BuildInfo, StandaloneHTMLBuilder
from sphinx.locale import __
from sphinx.util import logging, status_iterator
from sphinx.util.fileutil import copy_asset_file
from sphinx.util.i18n import format_date
from sphinx.util.osutil import copyfile, ensuredir

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


logger = logging.getLogger(__name__)


# (Fragment) templates from which the metainfo files content.opf and
# toc.ncx 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.

COVERPAGE_NAME = 'epub-cover.xhtml'

TOCTREE_TEMPLATE = 'toctree-l%d'

LINK_TARGET_TEMPLATE = ' [%(uri)s]'

FOOTNOTE_LABEL_TEMPLATE = '#%d'

FOOTNOTES_RUBRIC_NAME = 'Footnotes'

CSS_LINK_TARGET_CLASS = 'link-target'

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

MEDIA_TYPES = {
    '.xhtml': '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',
    '.woff': 'application/font-woff',
}

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("([^#:]*#)(.*)")


class ManifestItem(NamedTuple):
    href: str
    id: str
    media_type: str


class Spine(NamedTuple):
    idref: str
    linear: bool


class Guide(NamedTuple):
    type: str
    title: str
    uri: str


class NavPoint(NamedTuple):
    navpoint: str
    playorder: int
    text: str
    refuri: str
    children: List[Any]     # mypy does not support recursive types
                            # https://github.com/python/mypy/issues/7069


def sphinx_smarty_pants(t: str, language: str = 'en') -> str:
    t = t.replace('"', '"')
    t = smartquotes.educateDashesOldSchool(t)
    t = smartquotes.educateQuotes(t, language)
    t = t.replace('"', '"')
    return t


ssp = sphinx_smarty_pants


# 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.
    """

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

    # don't add links
    add_permalinks = False
    # don't use # as current path. ePub check reject it.
    allow_sharp_as_current_path = False
    # don't add sidebar etc.
    embedded = True
    # disable download role
    download_support = False
    # don't create links to original images from images
    html_scaled_image_link = False
    # don't generate search index or include search page
    search = False

    coverpage_name = COVERPAGE_NAME
    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
    template_dir = ""
    doctype = ""

    def init(self) -> None:
        super().init()
        # the output files for epub must be .html only
        self.out_suffix = '.xhtml'
        self.link_suffix = '.xhtml'
        self.playorder = 0
        self.tocid = 0
        self.id_cache: Dict[str, str] = {}
        self.use_index = self.get_builder_config('use_index', 'epub')
        self.refnodes: List[Dict[str, Any]] = []

    def create_build_info(self) -> BuildInfo:
        return BuildInfo(self.config, self.tags, ['html', 'epub'])

    def get_theme_config(self) -> Tuple[str, Dict]:
        return self.config.epub_theme, self.config.epub_theme_options

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

    def get_refnodes(self, doctree: Node, result: List[Dict[str, Any]]) -> List[Dict[str, Any]]:  # NOQA
        """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 doctree.get('refuri'):
            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': html.escape(refuri),
                        'text': ssp(html.escape(doctree.astext()))
                    })
                    break
        elif isinstance(doctree, nodes.Element):
            for elem in doctree:
                result = self.get_refnodes(elem, result)
        return result

    def check_refnodes(self, nodes: List[Dict[str, Any]]) -> None:
        appeared: Set[str] = set()
        for node in nodes:
            if node['refuri'] in appeared:
                logger.warning(
                    __('duplicated ToC entry found: %s'),
                    node['refuri'],
                    type="epub",
                    subtype="duplicated_toc_entry",
                )
            else:
                appeared.add(node['refuri'])

    def get_toc(self) -> None:
        """Get the total table of contents, containing the root_doc
        and pre and post files not managed by sphinx.
        """
        doctree = self.env.get_and_resolve_doctree(self.config.root_doc,
                                                   self, prune_toctrees=False,
                                                   includehidden=True)
        self.refnodes = self.get_refnodes(doctree, [])
        master_dir = path.dirname(self.config.root_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: List[Dict[str, Any]]) -> None:
        """Add the root_doc, pre and post files to a list of refnodes.
        """
        refnodes.insert(0, {
            'level': 1,
            'refuri': html.escape(self.config.root_doc + self.out_suffix),
            'text': ssp(html.escape(
                self.env.titles[self.config.root_doc].astext()))
        })
        for file, text in reversed(self.config.epub_pre_files):
            refnodes.insert(0, {
                'level': 1,
                'refuri': html.escape(file),
                'text': ssp(html.escape(text))
            })
        for file, text in self.config.epub_post_files:
            refnodes.append({
                'level': 1,
                'refuri': html.escape(file),
                'text': ssp(html.escape(text))
            })

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

    def fix_ids(self, tree: nodes.document) -> None:
        """Replace colons with hyphens in href and id attributes.

        Some readers crash because they interpret the part as a
        transport protocol specification.
        """
        def update_node_id(node: Element) -> None:
            """Update IDs of given *node*."""
            new_ids: List[str] = []
            for node_id in node['ids']:
                new_id = self.fix_fragment('', node_id)
                if new_id not in new_ids:
                    new_ids.append(new_id)
            node['ids'] = new_ids

        for reference in tree.findall(nodes.reference):
            if 'refuri' in reference:
                m = self.refuri_re.match(reference['refuri'])
                if m:
                    reference['refuri'] = self.fix_fragment(m.group(1), m.group(2))
            if 'refid' in reference:
                reference['refid'] = self.fix_fragment('', reference['refid'])

        for target in tree.findall(nodes.target):
            update_node_id(target)

            next_node: Node = target.next_node(ascend=True)
            if isinstance(next_node, nodes.Element):
                update_node_id(next_node)

        for desc_signature in tree.findall(addnodes.desc_signature):
            update_node_id(desc_signature)

    def add_visible_links(self, tree: nodes.document, show_urls: str = 'inline') -> None:
        """Add visible link targets for external links"""

        def make_footnote_ref(doc: nodes.document, label: str) -> nodes.footnote_reference:
            """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: nodes.document, label: str, uri: str) -> nodes.footnote:
            """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: nodes.document) -> Tuple[Element, int]:
            """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 = list(tree.findall(nodes.footnote))
            if fns:
                fn = fns[-1]
                return fn.parent, fn.parent.index(fn) + 1
            for node in tree.findall(nodes.rubric):
                if len(node) == 1 and node.astext() == FOOTNOTES_RUBRIC_NAME:
                    return node.parent, node.parent.index(node) + 1
            doc = next(tree.findall(nodes.document))
            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 = next(tree.findall(nodes.document))
            fn_spot, fn_idx = footnote_spot(tree)
            nr = 1
        for node in list(tree.findall(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: str, doctree: nodes.document) -> None:
        """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)
        super().write_doc(docname, doctree)

    def fix_genindex(self, tree: List[Tuple[str, List[Tuple[str, Any]]]]) -> None:
        """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: str) -> bool:
        """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) -> None:
        """Copy images using Pillow, the Python Imaging Library.
        The method tries to read and write the files with Pillow, converting
        the format and resizing the image if necessary/possible.
        """
        ensuredir(path.join(self.outdir, self.imagedir))
        for src in status_iterator(self.images, __('copying images... '), "brown",
                                   len(self.images), self.app.verbosity):
            dest = self.images[src]
            try:
                img = Image.open(path.join(self.srcdir, src))
            except OSError:
                if not self.is_vector_graphics(src):
                    logger.warning(__('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 OSError as err:
                    logger.warning(__('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 the Pillow documentation for Image.convert()
                    # https://pillow.readthedocs.io/en/stable/reference/Image.html#PIL.Image.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 OSError as err:
                logger.warning(__('cannot write image file %r: %s'),
                               path.join(self.srcdir, src), err)

    def copy_image_files(self) -> None:
        """Copy image files to destination directory.
        This overwritten method can use Pillow to convert image files.
        """
        if self.images:
            if self.config.epub_fix_images or self.config.epub_max_image_width:
                if not Image:
                    logger.warning(__('Pillow not found - copying image files'))
                    super().copy_image_files()
                else:
                    self.copy_image_files_pil()
            else:
                super().copy_image_files()

    def copy_download_files(self) -> None:
        pass

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

        This method is overwritten for genindex pages in order to fix href link
        attributes.
        """
        if pagename.startswith('genindex') and 'genindexentries' in addctx:
            if not self.use_index:
                return
            self.fix_genindex(addctx['genindexentries'])
        addctx['doctype'] = self.doctype
        super().handle_page(pagename, addctx, templatename, outfilename, event_arg)

    def build_mimetype(self) -> None:
        """Write the metainfo file mimetype."""
        logger.info(__('writing mimetype file...'))
        copy_asset_file(path.join(self.template_dir, 'mimetype'), self.outdir)

    def build_container(self, outname: str = 'META-INF/container.xml') -> None:  # NOQA
        """Write the metainfo file META-INF/container.xml."""
        logger.info(__('writing META-INF/container.xml file...'))
        outdir = path.join(self.outdir, 'META-INF')
        ensuredir(outdir)
        copy_asset_file(path.join(self.template_dir, 'container.xml'), outdir)

    def content_metadata(self) -> Dict[str, Any]:
        """Create a dictionary with all metadata for the content.opf
        file properly escaped.
        """
        metadata: Dict[str, Any] = {}
        metadata['title'] = html.escape(self.config.epub_title)
        metadata['author'] = html.escape(self.config.epub_author)
        metadata['uid'] = html.escape(self.config.epub_uid)
        metadata['lang'] = html.escape(self.config.epub_language)
        metadata['publisher'] = html.escape(self.config.epub_publisher)
        metadata['copyright'] = html.escape(self.config.epub_copyright)
        metadata['scheme'] = html.escape(self.config.epub_scheme)
        metadata['id'] = html.escape(self.config.epub_identifier)
        metadata['date'] = html.escape(format_date("%Y-%m-%d"))
        metadata['manifest_items'] = []
        metadata['spines'] = []
        metadata['guides'] = []
        return metadata

    def build_content(self) -> None:
        """Write the metainfo file content.opf It contains bibliographic data,
        a file list and the spine (the reading order).
        """
        logger.info(__('writing content.opf file...'))
        metadata = self.content_metadata()

        # files
        if not self.outdir.endswith(os.sep):
            self.outdir += os.sep
        olen = len(self.outdir)
        self.files: List[str] = []
        self.ignored_files = ['.buildinfo', 'mimetype', 'content.opf',
                              'toc.ncx', 'META-INF/container.xml',
                              'Thumbs.db', 'ehthumbs.db', '.DS_Store',
                              'nav.xhtml', self.config.epub_basename + '.epub'] + \
            self.config.epub_exclude_files
        if not self.use_index:
            self.ignored_files.append('genindex' + self.out_suffix)
        for root, dirs, files in os.walk(self.outdir):
            dirs.sort()
            for fn in sorted(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'):
                        logger.warning(__('unknown mimetype for %s, ignoring'), filename,
                                       type='epub', subtype='unknown_project_files')
                    continue
                filename = filename.replace(os.sep, '/')
                item = ManifestItem(html.escape(filename),
                                    html.escape(self.make_id(filename)),
                                    html.escape(self.media_types[ext]))
                metadata['manifest_items'].append(item)
                self.files.append(filename)

        # spine
        spinefiles = set()
        for refnode in self.refnodes:
            if '#' in refnode['refuri']:
                continue
            if refnode['refuri'] in self.ignored_files:
                continue
            spine = Spine(html.escape(self.make_id(refnode['refuri'])), True)
            metadata['spines'].append(spine)
            spinefiles.add(refnode['refuri'])
        for info in self.domain_indices:
            spine = Spine(html.escape(self.make_id(info[0] + self.out_suffix)), True)
            metadata['spines'].append(spine)
            spinefiles.add(info[0] + self.out_suffix)
        if self.use_index:
            spine = Spine(html.escape(self.make_id('genindex' + self.out_suffix)), True)
            metadata['spines'].append(spine)
            spinefiles.add('genindex' + self.out_suffix)
        # add auto generated files
        for name in self.files:
            if name not in spinefiles and name.endswith(self.out_suffix):
                spine = Spine(html.escape(self.make_id(name)), False)
                metadata['spines'].append(spine)

        # add the optional cover
        html_tmpl = None
        if self.config.epub_cover:
            image, html_tmpl = self.config.epub_cover
            image = image.replace(os.sep, '/')
            metadata['cover'] = html.escape(self.make_id(image))
            if html_tmpl:
                spine = Spine(html.escape(self.make_id(self.coverpage_name)), True)
                metadata['spines'].insert(0, spine)
                if self.coverpage_name not in self.files:
                    ext = path.splitext(self.coverpage_name)[-1]
                    self.files.append(self.coverpage_name)
                    item = ManifestItem(html.escape(self.coverpage_name),
                                        html.escape(self.make_id(self.coverpage_name)),
                                        html.escape(self.media_types[ext]))
                    metadata['manifest_items'].append(item)
                ctx = {'image': html.escape(image), 'title': self.config.project}
                self.handle_page(
                    path.splitext(self.coverpage_name)[0], ctx, html_tmpl)
                spinefiles.add(self.coverpage_name)

        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
                metadata['guides'].append(Guide(html.escape(type),
                                                html.escape(title),
                                                html.escape(uri)))
        if auto_add_cover and html_tmpl:
            metadata['guides'].append(Guide('cover',
                                            self.guide_titles['cover'],
                                            html.escape(self.coverpage_name)))
        if auto_add_toc and self.refnodes:
            metadata['guides'].append(Guide('toc',
                                            self.guide_titles['toc'],
                                            html.escape(self.refnodes[0]['refuri'])))

        # write the project file
        copy_asset_file(path.join(self.template_dir, 'content.opf_t'), self.outdir, metadata)

    def new_navpoint(self, node: Dict[str, Any], level: int, incr: bool = True) -> NavPoint:
        """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
        return NavPoint('navPoint%d' % self.tocid, self.playorder,
                        node['text'], node['refuri'], [])

    def build_navpoints(self, nodes: List[Dict[str, Any]]) -> List[NavPoint]:
        """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: List[NavPoint] = []
        navstack.append(NavPoint('dummy', 0, '', '', []))
        level = 0
        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:
                navpoint = self.new_navpoint(node, level)
                navstack.pop()
                navstack[-1].children.append(navpoint)
                navstack.append(navpoint)
            elif node['level'] == level + 1:
                level += 1
                if lastnode and self.config.epub_tocdup:
                    # Insert starting point in subtoc with same playOrder
                    navstack[-1].children.append(self.new_navpoint(lastnode, level, False))
                navpoint = self.new_navpoint(node, level)
                navstack[-1].children.append(navpoint)
                navstack.append(navpoint)
            elif node['level'] < level:
                while node['level'] < len(navstack):
                    navstack.pop()
                level = node['level']
                navpoint = self.new_navpoint(node, level)
                navstack[-1].children.append(navpoint)
                navstack.append(navpoint)
            else:
                raise
            lastnode = node

        return navstack[0].children

    def toc_metadata(self, level: int, navpoints: List[NavPoint]) -> Dict[str, Any]:
        """Create a dictionary with all metadata for the toc.ncx file
        properly escaped.
        """
        metadata: Dict[str, Any] = {}
        metadata['uid'] = self.config.epub_uid
        metadata['title'] = html.escape(self.config.epub_title)
        metadata['level'] = level
        metadata['navpoints'] = navpoints
        return metadata

    def build_toc(self) -> None:
        """Write the metainfo file toc.ncx."""
        logger.info(__('writing toc.ncx file...'))

        if self.config.epub_tocscope == 'default':
            doctree = self.env.get_and_resolve_doctree(self.config.root_doc,
                                                       self, prune_toctrees=False,
                                                       includehidden=False)
            refnodes = self.get_refnodes(doctree, [])
            self.toc_add_files(refnodes)
        else:
            # 'includehidden'
            refnodes = self.refnodes
        self.check_refnodes(refnodes)
        navpoints = self.build_navpoints(refnodes)
        level = max(item['level'] for item in self.refnodes)
        level = min(level, self.config.epub_tocdepth)
        copy_asset_file(path.join(self.template_dir, 'toc.ncx_t'), self.outdir,
                        self.toc_metadata(level, navpoints))

    def build_epub(self) -> None:
        """Write the epub file.

        It is a zip file with the mimetype file stored uncompressed as the first
        entry.
        """
        outname = self.config.epub_basename + '.epub'
        logger.info(__('writing %s file...'), outname)
        epub_filename = path.join(self.outdir, outname)
        with ZipFile(epub_filename, 'w', ZIP_DEFLATED) as epub:
            epub.write(path.join(self.outdir, 'mimetype'), 'mimetype', ZIP_STORED)
            for filename in ('META-INF/container.xml', 'content.opf', 'toc.ncx'):
                epub.write(path.join(self.outdir, filename), filename, ZIP_DEFLATED)
            for filename in self.files:
                epub.write(path.join(self.outdir, filename), filename, ZIP_DEFLATED)