chunking¶

def select_chunks(self) -> list[etree._Element]:
    """Find chunk elements.

    If ``config.selector`` is set to a dotted Python path it is imported
    and called as ``selector(root, config)``.  Otherwise the ``xpath``
    expression from the chunking config is evaluated.

    Selectors that rebuild a region as a detached tree record copy → source
    in `opm.runtime.source_map` while they build, which is what lets
    ``$get()`` in an ODD step back to the stored document. The map holds
    both trees alive, so it is reset here — once per document, before the
    selector runs.
    """
    source_map.clear()
    source_map.set_base_uri(self.xpath_env.base_uri)
    if self.config.selector:
        chunks = load_selector(self.config.selector)(self.xml_root, self.config)
    else:
        # Use xpath_select (XPath 3.1) so unprefixed names resolve against the
        # document's default namespace — TEI's div/body live in the TEI
        # namespace, which raw lxml xpath() with a prefix-only nsmap silently
        # misses. Matches how process_fragment() selects nodes.
        chunks = xpath_select(
            self.xml_root,
            self.config.xpath or '//text/body/div',
            xpath_env=self.xpath_env,
        )

    if not isinstance(chunks, list):
        chunks = [chunks] if chunks else []

    # Filter to only elements
    self.chunks = [
        chunk for chunk in chunks
        if isinstance(chunk, etree._Element)
    ]
    return self.chunks

def shared_root(self) -> Path:
    """Return the directory holding output shared across documents.

    Each document gets its own subdirectory, so stylesheets and assets
    belong one level up, beside the collection index — one copy for the
    whole edition. Without ``link_doc`` the output directory is itself the
    root.
    """
    return self.output_dir.parent if self.config.link_doc else self.output_dir

def url_prefix(self) -> str:
    """Return the relative path from a chunk page back to [`shared_root`][opm.chunking.ChunkProcessor.shared_root]."""
    return '../' if self.config.link_doc else ''

def write_shared_files(
    self, *, html: bool = True, templates_dir: Path | None = None,
) -> dict[str, str]:
    """Write stylesheets and copy assets into [`shared_root`][opm.chunking.ChunkProcessor.shared_root].

    Chunking always produces several pages sharing one stylesheet, so the
    stylesheets are always written as files — the same thing
    ``--format pb-view`` has always done. Templates receive
    ``odd_css_url`` pointing at it, alongside the ``odd_css`` string, which
    stays available so a template that inlines it keeps working. Stylesheets
    among ``config.assets`` are listed in ``asset_styles``, in declared
    order. ``index_url`` points back at the collection index written at
    [`shared_root`][opm.chunking.ChunkProcessor.shared_root] (see ``build_index``) — empty when the caller sets
    no ``link_doc``, as there is then no such page to link to.

    With *html*, the stylesheet of the packaged page layout is written to
    ``css/opm-layout.css`` too, and ``layout_css_url`` points at it —
    whether or not the page template extends ``opm/layout.html.j2``. A
    project copy at ``opm/opm-layout.css`` under *templates_dir* (the page
    template's directory) replaces the packaged one.

    Safe to call once per document — the writes are idempotent.
    """
    root = self.shared_root()
    prefix = self.url_prefix()
    urls: dict[str, Any] = {
        'odd_css_url': '', 'assets': '', 'asset_styles': [],
        'index_url': f'{prefix}index.html' if self.config.link_doc else '',
    }

    # For pages extending opm/layout.html.j2; written for every HTML run
    # rather than working out which templates do.
    if html:
        css_dir = root / 'css'
        css_dir.mkdir(parents=True, exist_ok=True)
        (css_dir / LAYOUT_CSS_NAME).write_text(layout_css(templates_dir), encoding='utf-8')
        urls['layout_css_url'] = f'{prefix}css/{LAYOUT_CSS_NAME}'

    if self.odd_css:
        css_dir = root / 'css'
        css_dir.mkdir(parents=True, exist_ok=True)
        (css_dir / f'{self.odd_name}.css').write_text(self.odd_css, encoding='utf-8')
        urls['odd_css_url'] = f'{prefix}css/{self.odd_name}.css'

    if self.config.assets:
        sources = copy_assets(self.project_root, self.config.assets, root)
        urls['assets'] = f'{prefix}{ASSETS_DIR}'
        urls['asset_styles'] = asset_styles(sources, prefix)

    return urls

def copy_referenced_images(self, html: str) -> None:
    """Copy the local images *html* references into `output_dir`.

    An ``img/@src`` is written relative to the source document, and the
    chunk pages sit flat in the output directory, so each image goes to the
    same relative path there.  Files are looked up the way EPUB output does:
    next to the source document, then in a sibling ``images/`` directory.
    Remote and root-relative URLs are left alone, as are paths that would
    land outside the output directory and images that cannot be found.
    """
    if self.source_dir is None or not html or '<img' not in html:
        return
    try:
        root = lxml_html.fromstring(f'<div>{html}</div>')
    except (etree.ParserError, ValueError):
        return
    out_root = self.output_dir.resolve()
    for img in root.iter('img'):
        src = img.get('src') or ''
        parts = urlsplit(src)
        if not parts.path or parts.scheme or parts.netloc or src.startswith('/'):
            continue
        href = unquote(parts.path)
        if href in self._copied_images:
            continue
        self._copied_images.add(href)
        source = _resolve_image_sources([href], self.source_dir).get(href)
        if source is None:
            continue
        target = (self.output_dir / href).resolve()
        if not target.is_relative_to(out_root) or target == source.resolve():
            continue
        target.parent.mkdir(parents=True, exist_ok=True)
        shutil.copy2(source, target)

def entry_file(self) -> str:
    """Return the filename of this document's first chunk (its entry point).

    That is the name ``file_pattern`` gives the first chunk once chunks are
    selected, and ``001.html`` before then.
    """
    if self.chunks:
        return self._chunk_file(self.chunks[0], 0)
    return self._numbered_chunk_file(0)

def entry_href(self) -> str:
    """Return the link to this document's entry point, relative to the output root.

    ``config.link_doc`` names the per-document subdirectory, giving
    ``quickstart.xml/001.html``; without it there is no prefix.
    """
    doc = (self.config.link_doc or '').strip('/')
    entry = self.entry_file()
    return f'{doc}/{entry}' if doc else entry

def generate_chunk_metadata(self, chunk: etree._Element, index: int) -> ChunkMetadata:
    """Generate metadata for a chunk."""
    chunk_id = f"chunk-{index + 1:03d}"
    chunk_file = self._chunk_file(chunk, index)

    # Filename stems so templates can link them as {{ chunk.prev }}.html.
    prev_id = (
        Path(self._chunk_file(self.chunks[index - 1], index - 1)).stem
        if index > 0 else None
    )
    next_id = (
        Path(self._chunk_file(self.chunks[index + 1], index + 1)).stem
        if index < len(self.chunks) - 1 else None
    )

    return ChunkMetadata(
        id=chunk_id,
        file=chunk_file,
        xpath=(self.config.xpath + f"[{index + 1}]") if self.config.xpath else '',
        prev=prev_id,
        next=next_id,
        xml_id=chunk.get(XML_ID) or chunk.get('id'),
    )

def build_anchor_index(self) -> dict[str, str]:
    """Map source ``xml:id`` (or plain ``@id``) values to the chunk file that owns them.

    JATS and other no-namespace vocabularies identify elements with ``@id``,
    so both are indexed; ``xml:id`` wins where an element carries both.
    """
    xml_ns = {'xml': 'http://www.w3.org/XML/1998/namespace'}
    anchor_map: dict[str, str] = {}

    for index, chunk in enumerate(self.chunks):
        chunk_file = self.generate_chunk_metadata(chunk, index).file
        source_nodes = chunk.xpath(
            './/*[@xml:id or @id] | self::*[@xml:id or @id]', namespaces=xml_ns,
        )
        for node in source_nodes:
            if not isinstance(node, etree._Element):
                continue
            xml_id = node.get(XML_ID) or node.get('id')
            if xml_id and xml_id not in anchor_map:
                anchor_map[xml_id] = chunk_file

    for xml_id, chunk_file in self._external_anchors.items():
        anchor_map.setdefault(xml_id, chunk_file)

    self._chunk_anchor_map = anchor_map
    return anchor_map

def process_fragment(
    self,
    fragment: FragmentConfig,
    context_node: etree._Element | None = None,
    _cache: dict[tuple, str] | None = None,
    chunk_index: int | None = None,
) -> str:
    """Process a fragment transform.

    The xpath is evaluated with the chunk as context node, so a
    chunk-relative expression (``../../text[@type='translation']/div``)
    picks that chunk's counterpart. An absolute expression that yields one
    element per chunk (``//body/div[@xml:lang='en']``) is instead aligned by
    position — the parallel-column case — using *chunk_index*. Both formats
    pass the index, so ``--format pb-view`` and the HTML output resolve
    fragments identically.
    """
    if fragment.scope == 'global':
        context = self.xml_root
    else:
        context = context_node if context_node is not None else self.xml_root

    # Project-wide parameters provide defaults; fragment params override them.
    params = {**self.parameters, **(fragment.parameters or {})}
    params = self._expand_document_params(params)
    view_root = (
        self.xml_root if fragment.scope == 'global' else self._source_node(context)
    )
    env = self.xpath_env.with_root(view_root).with_parameters(params)

    fragment_content = xpath_select(context, fragment.xpath, xpath_env=env)

    if not fragment_content:
        return ""

    if isinstance(fragment_content, list) and len(fragment_content) == 1:
        fragment_content = fragment_content[0]
    elif (
        isinstance(fragment_content, list)
        and chunk_index is not None
        and len(fragment_content) == len(self.chunks)
        and chunk_index < len(fragment_content)
    ):
        # Parallel columns: one fragment element per chunk, aligned by position.
        fragment_content = fragment_content[chunk_index]

    if isinstance(fragment_content, etree._Element):
        mod = (
            self._fragment_modules[str(fragment.module)]
            if fragment.module
            else self.module
        )
        params_key = frozenset(
            (k, v) for k, v in params.items() if isinstance(v, str)
        )
        if _cache is not None and mod is self.module:
            cache_key = (id(fragment_content), params_key, id(view_root))
            if cache_key in _cache:
                return _cache[cache_key]
        result = run_transform(
            mod,
            fragment_content,
            parameters=params,
            # Fragments must use the same output mode as the chunk body.
            # Without it an `alternate` model degrades to the non-component
            # form, which inlines the alternate content in a <span> — and
            # register entries are block markup (<h1>, <p>, <ul>), so the
            # HTML parser closes the enclosing <p> and the entry spills into
            # the running text instead of staying a popover.
            webcomponents=self.webcomponents,
            apply_template=False,
            footnote_order=self.footnote_order,
            xpath_env=env,
        )
        if _cache is not None and mod is self.module:
            _cache[(id(fragment_content), params_key, id(view_root))] = result
        return result
    elif isinstance(fragment_content, str):
        return fragment_content
    else:
        return str(fragment_content)

def process_chunk(self, chunk: etree._Element, index: int) -> ChunkResult:
    """Process a single chunk with its fragments."""
    metadata = self.generate_chunk_metadata(chunk, index)

    content_html, head_html = self._render_chunk_html(chunk)

    content_html = self._rewrite_html_fragment(content_html, current_file=metadata.file)
    head_html = self._rewrite_html_fragment(head_html, current_file=metadata.file)

    # Per-chunk fragment transforms share a cache so identical
    # (element, params) combinations are not re-transformed.
    _cache: dict[tuple, str] = {(id(chunk), frozenset()): content_html}

    fragments: dict[str, str] = {}
    if self.config.fragments:
        for fragment in self.config.fragments:
            if fragment.scope == 'per-chunk':
                fragments[fragment.name] = self._rewrite_html_fragment(
                    self.process_fragment(fragment, chunk, _cache, index),
                    current_file=metadata.file,
                )

    return ChunkResult(
        metadata=metadata,
        content_html=content_html,
        head_html=head_html,
        fragments=fragments,
    )

def process_global_fragments(self) -> dict[str, str]:
    """Process global fragments once."""
    fragments: dict[str, str] = {}
    if self.config.fragments:
        for fragment in self.config.fragments:
            if fragment.scope == 'global':
                fragments[fragment.name] = self.process_fragment(fragment)
    return fragments

def render_chunk_template(
    self, 
    chunk_result: ChunkResult, 
    global_fragments: dict[str, str],
    template_path: Path | None = None
) -> str:
    """Render a chunk with its template context."""
    tpl = self._load_chunk_template(template_path)
    if tpl is not None:
        # content_html and head_html are pre-extracted in process_chunk() —
        # no HTMLParser round-trip needed here.
        content_html = chunk_result.content_html
        head_html = chunk_result.head_html

        all_fragments = {**global_fragments, **chunk_result.fragments}

        # Ensure all strings are properly encoded UTF-8
        if isinstance(content_html, bytes):
            content_html = content_html.decode('utf-8')
        if isinstance(head_html, bytes):
            head_html = head_html.decode('utf-8')

        # Ensure fragment content is properly encoded
        for key, value in all_fragments.items():
            if isinstance(value, bytes):
                all_fragments[key] = value.decode('utf-8')

        rendered = tpl.render(
            head_html=head_html,
            content_html=content_html,
            odd_css=self.odd_css,
            # Expanded the same way the transform sees them, so a template
            # and XPath never disagree about a parameter's value.
            parameters=self._expand_placeholders(self.parameters),
            lang="",
            context=self._jinja_context,
            # Add chunk-specific context
            fragments=all_fragments,
            chunk=chunk_result.metadata,
            document=self.document,
            documents=self.documents,
            # Stylesheet URLs, plus an assets prefix when configured.
            # The inline strings above stay available either way.
            **self._shared_urls,
        )

        return rendered
    else:
        # Return raw chunk HTML
        return chunk_result.content_html

def generate_manifest(self, global_fragments: dict[str, str]) -> ManifestData:
    """Generate JSON manifest for static site builders."""
    chunks_metadata = [result.metadata for result in self.results]
    return ManifestData(
        chunks=chunks_metadata,
        fragments=global_fragments,
        anchors=self._chunk_anchor_map,
    )

def process_all(
    self,
    template_path: Path | None = None,
    on_progress: Callable[[int, int], None] | None = None,
    output_format: str = 'html',
) -> None:
    """Process all chunks and save files.

    Args:
        template_path: Optional Jinja2 template path (ignored for ``output_format='json'``).
        on_progress: Optional callback ``(current, total)`` called after each chunk is written.
        output_format: ``'html'`` (default) or ``'json'``.  JSON mode writes one
            ``<stem>.json`` per chunk containing all fields as a JSON object, and
            writes global fragments into the manifest rather than separate files.
    """
    use_json = output_format == 'json'

    # Ensure output directory exists
    self.output_dir.mkdir(parents=True, exist_ok=True)

    # Stylesheets and assets live in the shared root, written once for the
    # whole edition; the returned URLs go into every template context.
    page_template = None if use_json else self._chunk_template_path(template_path)
    self._shared_urls = self.write_shared_files(
        html=output_format == 'html',
        templates_dir=page_template.parent if page_template is not None else None,
    )

    # Select chunks
    self.select_chunks()
    self.build_anchor_index()

    # Process global fragments once
    global_fragments = self.process_global_fragments()
    standalone_global_fragments = self._rewrite_fragments(global_fragments)

    if not use_json:
        # Save global fragment files as standalone HTML
        for name, content in standalone_global_fragments.items():
            fragment_file = self.output_dir / f"{name}.html"
            fragment_file.write_text(content, encoding='utf-8')

    total = len(self.chunks)
    # Process each chunk
    for index, chunk in enumerate(self.chunks):
        chunk_result = self.process_chunk(chunk, index)
        self.results.append(chunk_result)

        if use_json:
            stem = self._chunk_file_stem(chunk_result)
            embedded_global_fragments = self._rewrite_fragments(
                global_fragments,
                current_file=chunk_result.metadata.file,
            )
            chunk_data: dict = {
                **asdict(chunk_result.metadata),
                'content': chunk_result.content_html,
                'head': chunk_result.head_html,
                'odd_css': self.odd_css,
                'fragments': {**embedded_global_fragments, **chunk_result.fragments},
                **self._shared_urls,
            }
            chunk_file = self.output_dir / f"{stem}.json"
            chunk_file.write_text(
                json.dumps(chunk_data, indent=2, ensure_ascii=False),
                encoding='utf-8',
            )
        else:
            embedded_global_fragments = self._rewrite_fragments(
                global_fragments,
                current_file=chunk_result.metadata.file,
            )
            rendered_html = self.render_chunk_template(
                chunk_result,
                embedded_global_fragments,
                template_path,
            )
            chunk_file = self.output_dir / chunk_result.metadata.file
            chunk_file.write_text(rendered_html, encoding='utf-8')
            self.copy_referenced_images(chunk_result.content_html)

        if on_progress is not None:
            on_progress(index + 1, total)

    # Generate and save manifest
    manifest = self.generate_manifest(standalone_global_fragments)
    manifest_file = self.output_dir / "manifest.json"
    manifest_file.write_text(
        json.dumps(self._manifest_payload(manifest, manifest_file), indent=2, ensure_ascii=False),
        encoding='utf-8'
    )

def export_pb_view(
    self,
    doc_path: str | None = None,
    on_progress: Callable[[int, int], None] | None = None,
) -> None:
    """Export chunks as data consumable by the ``pb-view`` web component.

    Lays the output out the way ``pb-view`` resolves it in static mode, where
    the data location is derived from the ``static`` root and the document
    ``path`` (``${static}/${path}/...``):

    - ``<output_dir>/<doc_path>/index.json`` — lookup table mapping pb-view's
      computed parameter keys to part files
    - ``<output_dir>/<doc_path>/<xml:id>.json`` — one part per chunk, mirroring
      the response of TEI Publisher's ``/api/parts/<doc>/json`` endpoint
    - ``<output_dir>/<doc_path>/<name>.json`` — one part per global fragment
      (e.g. ``toc.json``), keyed by the fragment xpath and ``user.*`` params;
      a sibling ``<name>.html`` carries the same content as well-formed XML,
      for consumers that store it in an XML database (see
      `_wellformed_fragment_xml`)
    - ``<output_dir>/<doc_path>/<name>-<xml:id>.json`` — per-chunk fragments
    - ``<output_dir>/css/<odd>.css`` — stylesheet, shared by every document
      under the same static root

    ``doc_path`` should match the ``path`` of the consuming ``pb-document``.
    When omitted the data is written directly into ``<output_dir>`` (single
    document at the static root).

    Chunks carrying an ``xml:id`` are addressed by it; chunks without one get
    a stable synthetic id. ``pb-view`` navigates via ``nextId``/``previousId``
    (xml:ids) when present; ``next``/``previous`` are kept truthy for
    ``navigate()`` but ``root`` is left null so subscribed dynamic views do
    not call the parts API with ``root=<xml:id>``.

    ``on_progress`` is an optional callback ``(current, total)`` invoked after
    each chunk is written.
    """
    xml_ns = {'xml': 'http://www.w3.org/XML/1998/namespace'}

    # Data lives under the document path; CSS is shared at the static root.
    data_dir = self.output_dir / doc_path if doc_path else self.output_dir
    data_dir.mkdir(parents=True, exist_ok=True)
    self.select_chunks()
    if not self.chunks:
        raise ValueError('pb-view export: no chunks selected.')

    # Resolve each chunk's identifier up front so we can wire prev/next links.
    # Chunks with an xml:id are addressed by it; chunks without one get a
    # stable synthetic id so they can still be paged through by pb-view via
    # nextId/previousId (and index keys for id=/root=).
    existing_ids = {
        e.get(XML_ID)
        for e in self.xml_root.xpath('//*[@xml:id]', namespaces=xml_ns)
        if isinstance(e, etree._Element) and e.get(XML_ID)
    }
    chunk_ids: list[str] = []
    synthetic_counter = 0
    for chunk in self.chunks:
        xml_id = chunk.get(XML_ID)
        if not xml_id:
            synthetic_counter += 1
            xml_id = f'_chunk{synthetic_counter}'
            while xml_id in existing_ids:
                synthetic_counter += 1
                xml_id = f'_chunk{synthetic_counter}'
            existing_ids.add(xml_id)
        chunk_ids.append(xml_id)

    base_params = self._pb_view_base_params()
    index: dict[str, str] = {}
    total = len(self.chunks)

    # Global fragments once: {name}.json (+ sibling {name}.html), keyed by
    # xpath + fragment user params. Also register under every chunk id/root
    # so a subscribed pb-view that re-fetches on navigation still resolves
    # to the same file. Links stay as in-document anchors (same as main
    # chunk content) so pb-view client navigation can resolve them.
    global_frags = [f for f in (self.config.fragments or []) if f.scope == 'global']
    for frag in global_frags:
        frag_html = self.process_fragment(frag)
        if isinstance(frag_html, bytes):
            frag_html = frag_html.decode('utf-8')

        frag_filename = f'{frag.name}.json'
        (data_dir / frag_filename).write_text(
            json.dumps({'content': frag_html}, indent=2, ensure_ascii=False),
            encoding='utf-8',
        )
        # The JSON keeps the HTML verbatim — pb-view injects it as HTML —
        # while the .html sibling is written as well-formed XML, since that
        # is the copy that gets uploaded into an XML database.
        (data_dir / f'{frag.name}.html').write_text(
            _wellformed_fragment_xml(frag_html, frag.name),
            encoding='utf-8',
        )

        frag_params = self._pb_view_fragment_params(frag)
        frag_key_xpath = frag.xpath_dynamic or frag.xpath
        index[_compute_part_key({**frag_params, 'xpath': frag_key_xpath})] = frag_filename
        for xml_id in chunk_ids:
            index[_compute_part_key({**frag_params, 'id': xml_id, 'xpath': frag_key_xpath})] = (
                frag_filename
            )
            index[_compute_part_key({**frag_params, 'root': xml_id, 'xpath': frag_key_xpath})] = (
                frag_filename
            )

    per_chunk_frags = [f for f in (self.config.fragments or []) if f.scope == 'per-chunk']
    # Shared by process_fragment across chunks, as in process_chunk: identical
    # (node, params) pairs are transformed once.
    frag_cache: dict[tuple, str] = {}

    for i, (chunk, xml_id) in enumerate(zip(self.chunks, chunk_ids)):
        content_html, _ = self._render_chunk_html(chunk)
        response: dict[str, Any] = {
            'content': content_html,
            **self._pb_view_part_nav(i, chunk_ids, xml_id),
        }

        filename = f'{xml_id}.json'
        (data_dir / filename).write_text(
            json.dumps(response, indent=2, ensure_ascii=False),
            encoding='utf-8',
        )

        # The first chunk answers the initial load, where pb-view sends
        # neither id nor root; also register the configured xpath as-is.
        if i == 0:
            index[_compute_part_key(base_params)] = filename
            # pb-view looks itself up by its own ``xpath`` attribute, which
            # names the region it displays — not the expression that selected
            # the chunk roots. ``xpath_dynamic`` supplies the former.
            key_xpath = self.config.xpath_dynamic or self.config.xpath
            if key_xpath:
                index[_compute_part_key({**base_params, 'xpath': key_xpath})] = filename

        # Register every xml:id contained in the chunk so navigation by id
        # (gotoId, prev/next) and by root resolves to this file.
        ids = {xml_id}
        for node in chunk.xpath('.//*[@xml:id]', namespaces=xml_ns):
            if isinstance(node, etree._Element):
                node_id = node.get(XML_ID)
                if node_id:
                    ids.add(node_id)
        for node_id in ids:
            index[_compute_part_key({**base_params, 'id': node_id})] = filename
        index[_compute_part_key({**base_params, 'root': xml_id})] = filename

        # Per-chunk fragment files: {name}-{xml_id}.json
        # Rendered through process_fragment, exactly as the HTML format does,
        # so both evaluate the fragment xpath with the chunk as context node
        # and share one set of runtime options (collections, variables,
        # namespaces, web-component mode).
        for frag in per_chunk_frags:
            frag_html = self.process_fragment(frag, chunk, frag_cache, i)
            if not frag_html:
                continue

            frag_response: dict[str, Any] = {
                'content': frag_html,
                **self._pb_view_part_nav(i, chunk_ids, xml_id),
            }

            frag_filename = f'{frag.name}-{xml_id}.json'
            (data_dir / frag_filename).write_text(
                json.dumps(frag_response, indent=2, ensure_ascii=False),
                encoding='utf-8',
            )

            self._register_fragment_index_keys(
                index,
                frag,
                frag_filename,
                ids,
                xml_id,
                first_chunk=(i == 0),
            )

        if on_progress is not None:
            on_progress(i + 1, total)

    (data_dir / 'index.json').write_text(
        json.dumps(index, indent=2, ensure_ascii=False),
        encoding='utf-8',
    )

    # pb-view loads its stylesheet from <static>/css/<odd>.css, i.e. shared
    # at the static root across all documents.
    odd_css = getattr(self.module, 'ODD_GENERATED_CSS', '')
    css_dir = self.output_dir / 'css'
    css_dir.mkdir(parents=True, exist_ok=True)
    (css_dir / f'{self.odd_name}.css').write_text(odd_css, encoding='utf-8')