__init__.py

"""
Bootstrap-based sphinx theme from the PyData community
"""
import os
from pathlib import Path

import jinja2
from bs4 import BeautifulSoup as bs
from sphinx import addnodes
from sphinx.environment.adapters.toctree import TocTree
from sphinx.errors import ExtensionError
from sphinx.util import logging
from pygments.formatters import HtmlFormatter
from pygments.styles import get_all_styles

from .bootstrap_html_translator import BootstrapHTML5Translator

__version__ = "0.8.1"

logger = logging.getLogger(__name__)


def update_config(app, env):
    theme_options = app.config["html_theme_options"]

    # DEPRECATE after v0.9
    if theme_options.get("search_bar_position") == "navbar":
        logger.warn(
            (
                "Deprecated config `search_bar_position` used."
                "Use `search-field.html` in `navbar_end` template list instead."
            )
        )

    # Validate icon links
    if not isinstance(theme_options.get("icon_links", []), list):
        raise ExtensionError(
            (
                "`icon_links` must be a list of dictionaries, you provided "
                f"type {type(theme_options.get('icon_links'))}."
            )
        )

    # Update the anchor link (it's a tuple, so need to overwrite the whole thing)
    icon_default = app.config.values["html_permalinks_icon"]
    app.config.values["html_permalinks_icon"] = ("#", *icon_default[1:])

    # Raise a warning for a deprecated theme switcher config
    if "url_template" in theme_options.get("switcher", {}):
        logger.warn(
            (
                "html_theme_options['switcher']['url_template'] is no longer supported."
                " Set version URLs in JSON directly."
            )
        )

    # Add an analytics ID to the site if provided
    # Currently only supports the two types of Google Analytics id.
    gid = theme_options.get("google_analytics_id")
    if gid:
        # In this case it is "new-style" google analytics
        if "G-" in gid:
            gid_js_path = f"https://www.googletagmanager.com/gtag/js?id={gid}"
            gid_script = f"""
                window.dataLayer = window.dataLayer || [];
                function gtag(){{ dataLayer.push(arguments); }}
                gtag('js', new Date());
                gtag('config', '{gid}');
            """
        # In this case it is "old-style" google analytics
        else:
            gid_js_path = "https://www.google-analytics.com/analytics.js"
            gid_script = f"""
                window.ga = window.ga || function () {{
                    (ga.q = ga.q || []).push(arguments) }};
                ga.l = +new Date;
                ga('create', '{gid}', 'auto');
                ga('set', 'anonymizeIp', true);
                ga('send', 'pageview');
            """

        # Link the JS files
        app.add_js_file(gid_js_path, loading_method="async")
        app.add_js_file(None, body=gid_script)


def update_templates(app, pagename, templatename, context, doctree):
    """Update template names and assets for page build."""
    # Allow for more flexibility in template names
    template_sections = [
        "theme_navbar_start",
        "theme_navbar_center",
        "theme_navbar_end",
        "theme_footer_items",
        "theme_page_sidebar_items",
        "theme_left_sidebar_end",
        "sidebars",
    ]
    for section in template_sections:
        if context.get(section):
            # Break apart `,` separated strings so we can use , in the defaults
            if isinstance(context.get(section), str):
                context[section] = [
                    ii.strip() for ii in context.get(section).split(",")
                ]

            # Add `.html` to templates with no suffix
            for ii, template in enumerate(context.get(section)):
                if not os.path.splitext(template)[1]:
                    context[section][ii] = template + ".html"

    # Remove a duplicate entry of the theme CSS. This is because it is in both:
    # - theme.conf
    # - manually linked in `webpack-macros.html`
    if "css_files" in context:
        theme_css_name = "_static/styles/pydata-sphinx-theme.css"
        if theme_css_name in context["css_files"]:
            context["css_files"].remove(theme_css_name)

    # Add links for favicons in the topbar
    for favicon in context.get("theme_favicons", []):
        icon_type = Path(favicon["href"]).suffix.strip(".")
        # Sphinx will auto-resolve href if it's a local file
        app.add_css_file(
            favicon["href"],
            rel=favicon["rel"],
            sizes=favicon["sizes"],
            **{"type": f"image/{icon_type}"},
        )


def add_toctree_functions(app, pagename, templatename, context, doctree):
    """Add functions so Jinja templates can add toctree objects."""

    def generate_nav_html(kind, startdepth=None, show_nav_level=1, **kwargs):
        """
        Return the navigation link structure in HTML. Arguments are passed
        to Sphinx "toctree" function (context["toctree"] below).

        We use beautifulsoup to add the right CSS classes / structure for bootstrap.

        See https://www.sphinx-doc.org/en/master/templating.html#toctree.

        Parameters
        ----------
        kind : ["navbar", "sidebar", "raw"]
            The kind of UI element this toctree is generated for.
        startdepth : int
            The level of the toctree at which to start. By default, for
            the navbar uses the normal toctree (`startdepth=0`), and for
            the sidebar starts from the second level (`startdepth=1`).
        show_nav_level : int
            The level of the navigation bar to toggle as visible on page load.
            By default, this level is 1, and only top-level pages are shown,
            with drop-boxes to reveal children. Increasing `show_nav_level`
            will show child levels as well.

        kwargs: passed to the Sphinx `toctree` template function.

        Returns
        -------
        HTML string (if kind in ["navbar", "sidebar"])
        or BeautifulSoup object (if kind == "raw")
        """
        if startdepth is None:
            startdepth = 1 if kind == "sidebar" else 0

        if startdepth == 0:
            toc_sphinx = context["toctree"](**kwargs)
        else:
            # select the "active" subset of the navigation tree for the sidebar
            toc_sphinx = index_toctree(app, pagename, startdepth, **kwargs)

        soup = bs(toc_sphinx, "html.parser")

        # pair "current" with "active" since that's what we use w/ bootstrap
        for li in soup("li", {"class": "current"}):
            li["class"].append("active")

        # Remove navbar/sidebar links to sub-headers on the page
        for li in soup.select("li"):
            # Remove
            if li.find("a"):
                href = li.find("a")["href"]
                if "#" in href and href != "#":
                    li.decompose()

        if kind == "navbar":
            # Add CSS for bootstrap
            for li in soup("li"):
                li["class"].append("nav-item")
                li.find("a")["class"].append("nav-link")
            # only select li items (not eg captions)
            out = "\n".join([ii.prettify() for ii in soup.find_all("li")])

        elif kind == "sidebar":
            # Add bootstrap classes for first `ul` items
            for ul in soup("ul", recursive=False):
                ul.attrs["class"] = ul.attrs.get("class", []) + ["nav", "bd-sidenav"]

            # Add collapse boxes for parts/captions.
            # Wraps the TOC part in an extra <ul> to behave like chapters with toggles
            # show_nav_level: 0 means make parts collapsible.
            if show_nav_level == 0:
                partcaptions = soup.find_all("p", attrs={"class": "caption"})
                if len(partcaptions):
                    new_soup = bs("<ul class='list-caption'></ul>", "html.parser")
                    for caption in partcaptions:
                        # Assume that the next <ul> element is the TOC list
                        # for this part
                        for sibling in caption.next_siblings:
                            if sibling.name == "ul":
                                toclist = sibling
                                break
                        li = soup.new_tag("li", attrs={"class": "toctree-l0"})
                        li.extend([caption, toclist])
                        new_soup.ul.append(li)
                    soup = new_soup

            # Add icons and labels for collapsible nested sections
            _add_collapse_checkboxes(soup)

            # Open the navbar to the proper depth
            for ii in range(int(show_nav_level)):
                for checkbox in soup.select(
                    f"li.toctree-l{ii} > input.toctree-checkbox"
                ):
                    checkbox.attrs["checked"] = None
            out = soup.prettify()

        elif kind == "raw":
            out = soup

        return out

    def generate_toc_html(kind="html"):
        """Return the within-page TOC links in HTML."""

        if "toc" not in context:
            return ""

        soup = bs(context["toc"], "html.parser")

        # Add toc-hN + visible classes
        def add_header_level_recursive(ul, level):
            if ul is None:
                return
            if level <= (context["theme_show_toc_level"] + 1):
                ul["class"] = ul.get("class", []) + ["visible"]
            for li in ul("li", recursive=False):
                li["class"] = li.get("class", []) + [f"toc-h{level}"]
                add_header_level_recursive(li.find("ul", recursive=False), level + 1)

        add_header_level_recursive(soup.find("ul"), 1)

        # Add in CSS classes for bootstrap
        for ul in soup("ul"):
            ul["class"] = ul.get("class", []) + ["nav", "section-nav", "flex-column"]

        for li in soup("li"):
            li["class"] = li.get("class", []) + ["nav-item", "toc-entry"]
            if li.find("a"):
                a = li.find("a")
                a["class"] = a.get("class", []) + ["nav-link"]

        # If we only have one h1 header, assume it's a title
        h1_headers = soup.select(".toc-h1")
        if len(h1_headers) == 1:
            title = h1_headers[0]
            # If we have no sub-headers of a title then we won't have a TOC
            if not title.select(".toc-h2"):
                out = ""
            else:
                out = title.find("ul").prettify()
        # Else treat the h1 headers as sections
        else:
            out = soup.prettify()

        # Return the toctree object
        if kind == "html":
            return out
        else:
            return soup

    def navbar_align_class():
        """Return the class that aligns the navbar based on config."""
        align = context.get("theme_navbar_align", "content")
        align_options = {
            "content": ("col-lg-9", "mr-auto"),
            "left": ("", "mr-auto"),
            "right": ("", "ml-auto"),
        }
        if align not in align_options:
            raise ValueError(
                (
                    "Theme optione navbar_align must be one of"
                    f"{align_options.keys()}, got: {align}"
                )
            )
        return align_options[align]

    context["generate_nav_html"] = generate_nav_html
    context["generate_toc_html"] = generate_toc_html
    context["navbar_align_class"] = navbar_align_class


def _add_collapse_checkboxes(soup):
    # based on https://github.com/pradyunsg/furo

    toctree_checkbox_count = 0

    for element in soup.find_all("li", recursive=True):
        # We check all "li" elements, to add a "current-page" to the correct li.
        classes = element.get("class", [])

        # expanding the parent part explicitly, if present
        if "current" in classes:
            parentli = element.find_parent("li", class_="toctree-l0")
            if parentli:
                parentli.select("p.caption ~ input")[0].attrs["checked"] = ""

        # Nothing more to do, unless this has "children"
        if not element.find("ul"):
            continue

        # Add a class to indicate that this has children.
        element["class"] = classes + ["has-children"]

        # We're gonna add a checkbox.
        toctree_checkbox_count += 1
        checkbox_name = f"toctree-checkbox-{toctree_checkbox_count}"

        # Add the "label" for the checkbox which will get filled.
        if soup.new_tag is None:
            continue

        label = soup.new_tag("label", attrs={"for": checkbox_name})
        label.append(soup.new_tag("i", attrs={"class": "fas fa-chevron-down"}))
        if "toctree-l0" in classes:
            # making label cover the whole caption text with css
            label["class"] = "label-parts"
        element.insert(1, label)

        # Add the checkbox that's used to store expanded/collapsed state.
        checkbox = soup.new_tag(
            "input",
            attrs={
                "type": "checkbox",
                "class": ["toctree-checkbox"],
                "id": checkbox_name,
                "name": checkbox_name,
            },
        )

        # if this has a "current" class, be expanded by default
        # (by checking the checkbox)
        if "current" in classes:
            checkbox.attrs["checked"] = ""

        element.insert(1, checkbox)


def _get_local_toctree_for(
    self: TocTree, indexname: str, docname: str, builder, collapse: bool, **kwargs
):
    """Return the "local" TOC nodetree (relative to `indexname`)."""
    # this is a copy of `TocTree.get_toctree_for`, but where the sphinx version
    # always uses the "root" doctree:
    #     doctree = self.env.get_doctree(self.env.config.root_doc)
    # we here use the `indexname` additional argument to be able to use a subset
    # of the doctree (e.g. starting at a second level for the sidebar):
    #     doctree = app.env.tocs[indexname].deepcopy()

    doctree = self.env.tocs[indexname].deepcopy()

    toctrees = []
    if "includehidden" not in kwargs:
        kwargs["includehidden"] = True
    if "maxdepth" not in kwargs or not kwargs["maxdepth"]:
        kwargs["maxdepth"] = 0
    else:
        kwargs["maxdepth"] = int(kwargs["maxdepth"])
    kwargs["collapse"] = collapse

    for toctreenode in doctree.traverse(addnodes.toctree):
        toctree = self.resolve(docname, builder, toctreenode, prune=True, **kwargs)
        if toctree:
            toctrees.append(toctree)
    if not toctrees:
        return None
    result = toctrees[0]
    for toctree in toctrees[1:]:
        result.extend(toctree.children)
    return result


def index_toctree(app, pagename: str, startdepth: int, collapse: bool = True, **kwargs):
    """
    Returns the "local" (starting at `startdepth`) TOC tree containing the
    current page, rendered as HTML bullet lists.

    This is the equivalent of `context["toctree"](**kwargs)` in sphinx
    templating, but using the startdepth-local instead of global TOC tree.
    """
    # this is a variant of the function stored in `context["toctree"]`, which is
    # defined as `lambda **kwargs: self._get_local_toctree(pagename, **kwargs)`
    # with `self` being the HMTLBuilder and the `_get_local_toctree` basically
    # returning:
    #     return self.render_partial(TocTree(self.env).get_toctree_for(
    #         pagename, self, collapse, **kwargs))['fragment']

    if "includehidden" not in kwargs:
        kwargs["includehidden"] = False
    if kwargs.get("maxdepth") == "":
        kwargs.pop("maxdepth")

    toctree = TocTree(app.env)
    ancestors = toctree.get_toctree_ancestors(pagename)
    try:
        indexname = ancestors[-startdepth]
    except IndexError:
        # eg for index.rst, but also special pages such as genindex, py-modindex, search
        # those pages don't have a "current" element in the toctree, so we can
        # directly return an empty string instead of using the default sphinx
        # toctree.get_toctree_for(pagename, app.builder, collapse, **kwargs)
        return ""

    toctree_element = _get_local_toctree_for(
        toctree, indexname, pagename, app.builder, collapse, **kwargs
    )
    return app.builder.render_partial(toctree_element)["fragment"]


def soup_to_python(soup, only_pages=False):
    """
    Convert the toctree html structure to python objects which can be used in Jinja.

    Parameters
    ----------
    soup : BeautifulSoup object for the toctree
    only_pages : bool
        Only include items for full pages in the output dictionary. Exclude
        anchor links (TOC items with a URL that starts with #)

    Returns
    -------
    nav : list of dicts
        The toctree, converted into a dictionary with key/values that work
        within Jinja.
    """
    # toctree has this structure (caption only for toctree, not toc)
    #   <p class="caption">...</span></p>
    #   <ul>
    #       <li class="toctree-l1"><a href="..">..</a></li>
    #       <li class="toctree-l1"><a href="..">..</a></li>
    #       ...

    def extract_level_recursive(ul, navs_list):

        for li in ul.find_all("li", recursive=False):
            ref = li.a
            url = ref["href"]
            title = "".join(map(str, ref.contents))
            active = "current" in li.get("class", [])

            # If we've got an anchor link, skip it if we wish
            if only_pages and "#" in url and url != "#":
                continue

            # Converting the docutils attributes into jinja-friendly objects
            nav = {}
            nav["title"] = title
            nav["url"] = url
            nav["active"] = active

            navs_list.append(nav)

            # Recursively convert children as well
            nav["children"] = []
            ul = li.find("ul", recursive=False)
            if ul:
                extract_level_recursive(ul, nav["children"])

    navs = []
    for ul in soup.find_all("ul", recursive=False):
        extract_level_recursive(ul, navs)
    return navs


# -----------------------------------------------------------------------------


def setup_edit_url(app, pagename, templatename, context, doctree):
    """Add a function that jinja can access for returning the edit URL of a page."""

    def get_edit_url():
        """Return a URL for an "edit this page" link."""
        file_name = f"{pagename}{context['page_source_suffix']}"

        # Make sure that doc_path has a path separator only if it exists (to avoid //)
        doc_path = context.get("doc_path", "")
        if doc_path and not doc_path.endswith("/"):
            doc_path = f"{doc_path}/"

        default_provider_urls = {
            "bitbucket_url": "https://bitbucket.org",
            "github_url": "https://github.com",
            "gitlab_url": "https://gitlab.com",
        }

        edit_url_attrs = {}

        # ensure custom URL is checked first, if given
        url_template = context.get("edit_page_url_template")

        if url_template is not None:
            if "file_name" not in url_template:
                raise ExtensionError(
                    "Missing required value for `use_edit_page_button`. "
                    "Ensure `file_name` appears in `edit_page_url_template`: "
                    f"{url_template}"
                )

            edit_url_attrs[("edit_page_url_template",)] = url_template

        edit_url_attrs.update(
            {
                ("bitbucket_user", "bitbucket_repo", "bitbucket_version"): (
                    "{{ bitbucket_url }}/{{ bitbucket_user }}/{{ bitbucket_repo }}"
                    "/src/{{ bitbucket_version }}"
                    "/{{ doc_path }}{{ file_name }}?mode=edit"
                ),
                ("github_user", "github_repo", "github_version"): (
                    "{{ github_url }}/{{ github_user }}/{{ github_repo }}"
                    "/edit/{{ github_version }}/{{ doc_path }}{{ file_name }}"
                ),
                ("gitlab_user", "gitlab_repo", "gitlab_version"): (
                    "{{ gitlab_url }}/{{ gitlab_user }}/{{ gitlab_repo }}"
                    "/-/edit/{{ gitlab_version }}/{{ doc_path }}{{ file_name }}"
                ),
            }
        )

        doc_context = dict(default_provider_urls)
        doc_context.update(context)
        doc_context.update(doc_path=doc_path, file_name=file_name)

        for attrs, url_template in edit_url_attrs.items():
            if all(doc_context.get(attr) not in [None, "None"] for attr in attrs):
                return jinja2.Template(url_template).render(**doc_context)

        raise ExtensionError(
            "Missing required value for `use_edit_page_button`. "
            "Ensure one set of the following in your `html_context` "
            f"configuration: {sorted(edit_url_attrs.keys())}"
        )

    context["get_edit_url"] = get_edit_url

    # Ensure that the max TOC level is an integer
    context["theme_show_toc_level"] = int(context.get("theme_show_toc_level", 1))


# ------------------------------------------------------------------------------
# handle pygment css
# ------------------------------------------------------------------------------

# inspired by the Furo theme
# https://github.com/pradyunsg/furo/blob/main/src/furo/__init__.py


def _get_styles(formatter, prefix):
    """
    Get styles out of a formatter, where everything has the correct prefix.
    """

    for line in formatter.get_linenos_style_defs():
        yield f"{prefix} {line}"
    yield from formatter.get_background_style_defs(prefix)
    yield from formatter.get_token_style_defs(prefix)


def get_pygments_stylesheet(light_style, dark_style):
    """
    Generate the theme-specific pygments.css.
    There is no way to tell Sphinx how the theme handles modes
    """
    light_formatter = HtmlFormatter(style=light_style)
    dark_formatter = HtmlFormatter(style=dark_style)

    lines = []

    light_prefix = 'html[data-theme="light"] .highlight'
    lines.extend(_get_styles(light_formatter, prefix=light_prefix))

    dark_prefix = 'html[data-theme="dark"] .highlight'
    lines.extend(_get_styles(dark_formatter, prefix=dark_prefix))

    return "\n".join(lines)


def _overwrite_pygments_css(app, exception=None):
    """
    Sphinx is not build to host multiple sphinx formatter and there is no way
    to tell which one to use and when.
    So yes, at build time we overwrite the pygment.css file so that it embeds
    2 versions:
    - the light theme prefixed with "[data-theme="light"]" using tango
    - the dark theme prefixed with "[data-theme="dark"]" using native

    When the theme is switched, Pygments will be using one of the preset css
    style.
    """
    default_light_theme = "tango"
    default_dark_theme = "native"

    if exception is not None:
        return

    assert app.builder

    # check the theme specified in the theme options
    theme_options = app.config["html_theme_options"]
    pygments_styles = list(get_all_styles())
    light_theme = theme_options.get("pygment_light_style", default_light_theme)
    if light_theme not in pygments_styles:
        logger.warn(
            f"{light_theme}, is not part of the available pygments style,"
            f' defaulting to "{default_light_theme}".'
        )
        light_theme = default_light_theme
    dark_theme = theme_options.get("pygment_dark_style", default_dark_theme)
    if dark_theme not in pygments_styles:
        logger.warn(
            f"{dark_theme}, is not part of the available pygments style,"
            f' defaulting to "{default_dark_theme}".'
        )
        dark_theme = default_dark_theme

    pygment_css = Path(app.builder.outdir) / "_static" / "pygments.css"
    with pygment_css.open("w") as f:
        f.write(get_pygments_stylesheet(light_theme, dark_theme))


# -----------------------------------------------------------------------------


def setup(app):
    here = Path(__file__).parent.resolve()
    theme_path = here / "theme" / "pydata_sphinx_theme"

    app.add_html_theme("pydata_sphinx_theme", str(theme_path))

    app.set_translator("html", BootstrapHTML5Translator)
    # Read the Docs uses ``readthedocs`` as the name of the build, and also
    # uses a special "dirhtml" builder so we need to replace these both with
    # our custom HTML builder
    app.set_translator("readthedocs", BootstrapHTML5Translator, override=True)
    app.set_translator("readthedocsdirhtml", BootstrapHTML5Translator, override=True)

    app.connect("env-updated", update_config)
    app.connect("html-page-context", setup_edit_url)
    app.connect("html-page-context", add_toctree_functions)
    app.connect("html-page-context", update_templates)
    app.connect("build-finished", _overwrite_pygments_css)

    # Include component templates
    app.config.templates_path.append(str(theme_path / "components"))

    return {"parallel_read_safe": True, "parallel_write_safe": True}