# Source code for searx.infopage

    # SPDX-License-Identifier: AGPL-3.0-or-later
    """Render SearXNG instance documentation.

    Usage in a Flask app route:

    .. code:: python

      from searx import infopage

      _INFO_PAGES = infopage.InfoPageSet(infopage.MistletoePage)

      @app.route('/info/<pagename>', methods=['GET'])
      def info(pagename):

          locale = request.preferences.get_value('locale')
          page = _INFO_PAGES.get_page(pagename, locale)

    """

    from __future__ import annotations

    __all__ = ['InfoPage', 'InfoPageSet']

    import os
    import os.path
    import logging
    import typing

    import urllib.parse
    from functools import cached_property
    import jinja2
    from flask.helpers import url_for
    from markdown_it import MarkdownIt

    from .. import get_setting
    from ..version import GIT_URL
    from ..locales import LOCALE_NAMES

    logger = logging.getLogger('searx.infopage')
    _INFO_FOLDER = os.path.abspath(os.path.dirname(__file__))
    INFO_PAGES: 'InfoPageSet'

    def __getattr__(name):
        if name == 'INFO_PAGES':
            global INFO_PAGES  # pylint: disable=global-statement
            INFO_PAGES = InfoPageSet()
            return INFO_PAGES

        raise AttributeError(f"module {__name__!r} has no attribute {name!r}")

    class InfoPage:
        """A page of the :py:obj:`online documentation <InfoPageSet>`."""

        def __init__(self, fname):
            self.fname = fname

        @cached_property
        def raw_content(self):
            """Raw content of the page (without any jinja rendering)"""
            with open(self.fname, 'r', encoding='utf-8') as f:
                return f.read()

        @cached_property
        def content(self):
            """Content of the page (rendered in a Jinja context)"""
            ctx = self.get_ctx()
            template = jinja2.Environment().from_string(self.raw_content)
            return template.render(**ctx)

        @cached_property
        def title(self):
            """Title of the content (without any markup)"""
            t = ""
            for l in self.raw_content.split('\n'):
                if l.startswith('# '):
                    t = l.strip('# ')
            return t

        @cached_property
        def html(self):
            """Render Markdown (CommonMark_) to HTML by using markdown-it-py_.

            .. _CommonMark: https://commonmark.org/
            .. _markdown-it-py: https://github.com/executablebooks/markdown-it-py

            """
            return (
                MarkdownIt("commonmark", {"typographer": True}).enable(["replacements", "smartquotes"]).render(self.content)
            )

        def get_ctx(self):
            """Jinja context to render :py:obj:`InfoPage.content`"""

            def _md_link(name, url):
                url = url_for(url, _external=True)
                return "[%s](%s)" % (name, url)

            def _md_search(query):
                url = '%s?q=%s' % (url_for('search', _external=True), urllib.parse.quote(query))
                return '[%s](%s)' % (query, url)

            ctx = {}
            ctx['GIT_URL'] = GIT_URL
            ctx['get_setting'] = get_setting
            ctx['link'] = _md_link
            ctx['search'] = _md_search

            return ctx

        def __repr__(self):
            return f'<{self.__class__.__name__} fname={self.fname!r}>'

    class InfoPageSet:  # pylint: disable=too-few-public-methods
        """Cached rendering of the online documentation a SearXNG instance has.

        :param page_class: render online documentation by :py:obj:`InfoPage` parser.
        :type page_class: :py:obj:`InfoPage`

        :param info_folder: information directory
        :type info_folder: str
        """

        def __init__(
            self, page_class: typing.Optional[typing.Type[InfoPage]] = None, info_folder: typing.Optional[str] = None
        ):
            self.page_class = page_class or InfoPage
            self.folder: str = info_folder or _INFO_FOLDER
            """location of the Markdown files"""

            self.CACHE: typing.Dict[tuple, typing.Optional[InfoPage]] = {}

            self.locale_default: str = 'en'
            """default language"""

            self.locales: typing.List[str] = [
                locale.replace('_', '-') for locale in os.listdir(_INFO_FOLDER) if locale.replace('_', '-') in LOCALE_NAMES
            ]
            """list of supported languages (aka locales)"""

            self.toc: typing.List[str] = [
                'search-syntax',
                'about',
                'donate',
            ]
            """list of articles in the online documentation"""

        def get_page(self, pagename: str, locale: typing.Optional[str] = None):
            """Return ``pagename`` instance of :py:obj:`InfoPage`

            :param pagename: name of the page, a value from :py:obj:`InfoPageSet.toc`
            :type pagename: str

            :param locale: language of the page, e.g. ``en``, ``zh_Hans_CN``
                           (default: :py:obj:`InfoPageSet.i18n_origin`)
            :type locale: str

            """
            locale = locale or self.locale_default

            if pagename not in self.toc:
                return None
            if locale not in self.locales:
                return None

            cache_key = (pagename, locale)

            if cache_key in self.CACHE:
                return self.CACHE[cache_key]

            # not yet instantiated

            fname = os.path.join(self.folder, locale.replace('-', '_'), pagename) + '.md'
            if not os.path.exists(fname):
                logger.info('file %s does not exists', fname)
                self.CACHE[cache_key] = None
                return None

            page = self.page_class(fname)
            self.CACHE[cache_key] = page
            return page

        def iter_pages(self, locale: typing.Optional[str] = None, fallback_to_default=False):
            """Iterate over all pages of the TOC"""
            locale = locale or self.locale_default
            for page_name in self.toc:
                page_locale = locale
                page = self.get_page(page_name, locale)
                if fallback_to_default and page is None:
                    page_locale = self.locale_default
                    page = self.get_page(page_name, self.locale_default)
                if page is not None:
                    # page is None if the page was deleted by the administrator
                    yield page_name, page_locale, page