# Source code for searx.engines.startpage

    # SPDX-License-Identifier: AGPL-3.0-or-later
    """Startpage's language & region selectors are a mess ..

    .. _startpage regions:

    Startpage regions
    =================

    In the list of regions there are tags we need to map to common region tags::

      pt-BR_BR --> pt_BR
      zh-CN_CN --> zh_Hans_CN
      zh-TW_TW --> zh_Hant_TW
      zh-TW_HK --> zh_Hant_HK
      en-GB_GB --> en_GB

    and there is at least one tag with a three letter language tag (ISO 639-2)::

      fil_PH --> fil_PH

    The locale code ``no_NO`` from Startpage does not exists and is mapped to
    ``nb-NO``::

        babel.core.UnknownLocaleError: unknown locale 'no_NO'

    For reference see languages-subtag at iana; ``no`` is the macrolanguage [1]_ and
    W3C recommends subtag over macrolanguage [2]_.

    .. [1] `iana: language-subtag-registry
       <https://www.iana.org/assignments/language-subtag-registry/language-subtag-registry>`_ ::

          type: language
          Subtag: nb
          Description: Norwegian Bokmål
          Added: 2005-10-16
          Suppress-Script: Latn
          Macrolanguage: no

    .. [2]
       Use macrolanguages with care.  Some language subtags have a Scope field set to
       macrolanguage, i.e. this primary language subtag encompasses a number of more
       specific primary language subtags in the registry.  ...  As we recommended for
       the collection subtags mentioned above, in most cases you should try to use
       the more specific subtags ... `W3: The primary language subtag
       <https://www.w3.org/International/questions/qa-choosing-language-tags#langsubtag>`_

    .. _startpage languages:

    Startpage languages
    ===================

    :py:obj:`send_accept_language_header`:
      The displayed name in Startpage's settings page depend on the location of the
      IP when ``Accept-Language`` HTTP header is unset.  In :py:obj:`fetch_traits`
      we use::

        'Accept-Language': "en-US,en;q=0.5",
        ..

      to get uniform names independent from the IP).

    .. _startpage categories:

    Startpage categories
    ====================

    Startpage's category (for Web-search, News, Videos, ..) is set by
    :py:obj:`startpage_categ` in  settings.yml::

      - name: startpage
        engine: startpage
        startpage_categ: web
        ...

    .. hint::

       The default category is ``web`` .. and other categories than ``web`` are not
       yet implemented.

    """
    # pylint: disable=too-many-statements

    from typing import TYPE_CHECKING
    from collections import OrderedDict
    import re
    from unicodedata import normalize, combining
    from time import time
    from datetime import datetime, timedelta

    import dateutil.parser
    import lxml.html
    import babel.localedata

    from searx.utils import extract_text, eval_xpath, gen_useragent
    from searx.network import get  # see https://github.com/searxng/searxng/issues/762
    from searx.exceptions import SearxEngineCaptchaException
    from searx.locales import region_tag
    from searx.enginelib.traits import EngineTraits

    if TYPE_CHECKING:
        import logging

        logger: logging.Logger

    traits: EngineTraits

    # about
    about = {
        "website": 'https://startpage.com',
        "wikidata_id": 'Q2333295',
        "official_api_documentation": None,
        "use_official_api": False,
        "require_api_key": False,
        "results": 'HTML',
    }

    startpage_categ = 'web'
    """Startpage's category, visit :ref:`startpage categories`.
    """

    send_accept_language_header = True
    """Startpage tries to guess user's language and territory from the HTTP
    ``Accept-Language``.  Optional the user can select a search-language (can be
    different to the UI language) and a region filter.
    """

    # engine dependent config
    categories = ['general', 'web']
    paging = True
    max_page = 18
    """Tested 18 pages maximum (argument ``page``), to be save max is set to 20."""

    time_range_support = True
    safesearch = True

    time_range_dict = {'day': 'd', 'week': 'w', 'month': 'm', 'year': 'y'}
    safesearch_dict = {0: '0', 1: '1', 2: '1'}

    # search-url
    base_url = 'https://www.startpage.com'
    search_url = base_url + '/sp/search'

    # specific xpath variables
    # ads xpath //div[@id="results"]/div[@id="sponsored"]//div[@class="result"]
    # not ads: div[@class="result"] are the direct children of div[@id="results"]
    search_form_xpath = '//form[@id="search"]'
    """XPath of Startpage's origin search form

    .. code: html

        <form action="/sp/search" method="post">
          <input type="text" name="query"  value="" ..>
          <input type="hidden" name="t" value="device">
          <input type="hidden" name="lui" value="english">
          <input type="hidden" name="sc" value="Q7Mt5TRqowKB00">
          <input type="hidden" name="cat" value="web">
          <input type="hidden" class="abp" id="abp-input" name="abp" value="1">
        </form>
    """

    # timestamp of the last fetch of 'sc' code
    sc_code_ts = 0
    sc_code = ''
    sc_code_cache_sec = 30
    """Time in seconds the sc-code is cached in memory :py:obj:`get_sc_code`."""

    def get_sc_code(searxng_locale, params):
        """Get an actual ``sc`` argument from Startpage's search form (HTML page).

        Startpage puts a ``sc`` argument on every HTML :py:obj:`search form
        <search_form_xpath>`.  Without this argument Startpage considers the request
        is from a bot.  We do not know what is encoded in the value of the ``sc``
        argument, but it seems to be a kind of a *time-stamp*.

        Startpage's search form generates a new sc-code on each request.  This
        function scrap a new sc-code from Startpage's home page every
        :py:obj:`sc_code_cache_sec` seconds.

        """

        global sc_code_ts, sc_code  # pylint: disable=global-statement

        if sc_code and (time() < (sc_code_ts + sc_code_cache_sec)):
            logger.debug("get_sc_code: reuse '%s'", sc_code)
            return sc_code

        headers = {**params['headers']}
        headers['Origin'] = base_url
        headers['Referer'] = base_url + '/'
        # headers['Connection'] = 'keep-alive'
        # headers['Accept-Encoding'] = 'gzip, deflate, br'
        # headers['Accept'] = 'text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8'
        # headers['User-Agent'] = 'Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:105.0) Gecko/20100101 Firefox/105.0'

        # add Accept-Language header
        if searxng_locale == 'all':
            searxng_locale = 'en-US'
        locale = babel.Locale.parse(searxng_locale, sep='-')

        if send_accept_language_header:
            ac_lang = locale.language
            if locale.territory:
                ac_lang = "%s-%s,%s;q=0.9,*;q=0.5" % (
                    locale.language,
                    locale.territory,
                    locale.language,
                )
            headers['Accept-Language'] = ac_lang

        get_sc_url = base_url + '/?sc=%s' % (sc_code)
        logger.debug("query new sc time-stamp ... %s", get_sc_url)
        logger.debug("headers: %s", headers)
        resp = get(get_sc_url, headers=headers)

        # ?? x = network.get('https://www.startpage.com/sp/cdn/images/filter-chevron.svg', headers=headers)
        # ?? https://www.startpage.com/sp/cdn/images/filter-chevron.svg
        # ?? ping-back URL: https://www.startpage.com/sp/pb?sc=TLsB0oITjZ8F21

        if str(resp.url).startswith('https://www.startpage.com/sp/captcha'):  # type: ignore
            raise SearxEngineCaptchaException(
                message="get_sc_code: got redirected to https://www.startpage.com/sp/captcha",
            )

        dom = lxml.html.fromstring(resp.text)  # type: ignore

        try:
            sc_code = eval_xpath(dom, search_form_xpath + '//input[@name="sc"]/@value')[0]
        except IndexError as exc:
            logger.debug("suspend startpage API --> https://github.com/searxng/searxng/pull/695")
            raise SearxEngineCaptchaException(
                message="get_sc_code: [PR-695] query new sc time-stamp failed! (%s)" % resp.url,  # type: ignore
            ) from exc

        sc_code_ts = time()
        logger.debug("get_sc_code: new value is: %s", sc_code)
        return sc_code

    def request(query, params):
        """Assemble a Startpage request.

        To avoid CAPTCHA we need to send a well formed HTTP POST request with a
        cookie.  We need to form a request that is identical to the request build by
        Startpage's search form:

        - in the cookie the **region** is selected
        - in the HTTP POST data the **language** is selected

        Additionally the arguments form Startpage's search form needs to be set in
        HTML POST data / compare ``<input>`` elements: :py:obj:`search_form_xpath`.
        """
        if startpage_categ == 'web':
            return _request_cat_web(query, params)

        logger.error("Startpages's category '%' is not yet implemented.", startpage_categ)
        return params

    def _request_cat_web(query, params):

        engine_region = traits.get_region(params['searxng_locale'], 'en-US')
        engine_language = traits.get_language(params['searxng_locale'], 'en')

        # build arguments
        args = {
            'query': query,
            'cat': 'web',
            't': 'device',
            'sc': get_sc_code(params['searxng_locale'], params),  # hint: this func needs HTTP headers,
            'with_date': time_range_dict.get(params['time_range'], ''),
        }

        if engine_language:
            args['language'] = engine_language
            args['lui'] = engine_language

        args['abp'] = '1'
        if params['pageno'] > 1:
            args['page'] = params['pageno']

        # build cookie
        lang_homepage = 'en'
        cookie = OrderedDict()
        cookie['date_time'] = 'world'
        cookie['disable_family_filter'] = safesearch_dict[params['safesearch']]
        cookie['disable_open_in_new_window'] = '0'
        cookie['enable_post_method'] = '1'  # hint: POST
        cookie['enable_proxy_safety_suggest'] = '1'
        cookie['enable_stay_control'] = '1'
        cookie['instant_answers'] = '1'
        cookie['lang_homepage'] = 's/device/%s/' % lang_homepage
        cookie['num_of_results'] = '10'
        cookie['suggestions'] = '1'
        cookie['wt_unit'] = 'celsius'

        if engine_language:
            cookie['language'] = engine_language
            cookie['language_ui'] = engine_language

        if engine_region:
            cookie['search_results_region'] = engine_region

        params['cookies']['preferences'] = 'N1N'.join(["%sEEE%s" % x for x in cookie.items()])
        logger.debug('cookie preferences: %s', params['cookies']['preferences'])

        # POST request
        logger.debug("data: %s", args)
        params['data'] = args
        params['method'] = 'POST'
        params['url'] = search_url
        params['headers']['Origin'] = base_url
        params['headers']['Referer'] = base_url + '/'
        # is the Accept header needed?
        # params['headers']['Accept'] = 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8'

        return params

    # get response from search-request
    def response(resp):
        dom = lxml.html.fromstring(resp.text)

        if startpage_categ == 'web':
            return _response_cat_web(dom)

        logger.error("Startpages's category '%' is not yet implemented.", startpage_categ)
        return []

    def _response_cat_web(dom):
        results = []

        # parse results
        for result in eval_xpath(dom, '//div[@class="w-gl"]/div[contains(@class, "result")]'):
            links = eval_xpath(result, './/a[contains(@class, "result-title result-link")]')
            if not links:
                continue
            link = links[0]
            url = link.attrib.get('href')

            # block google-ad url's
            if re.match(r"^http(s|)://(www\.)?google\.[a-z]+/aclk.*$", url):
                continue

            # block startpage search url's
            if re.match(r"^http(s|)://(www\.)?startpage\.com/do/search\?.*$", url):
                continue

            title = extract_text(eval_xpath(link, 'h2'))
            content = eval_xpath(result, './/p[contains(@class, "description")]')
            content = extract_text(content, allow_none=True) or ''

            published_date = None

            # check if search result starts with something like: "2 Sep 2014 ... "
            if re.match(r"^([1-9]|[1-2][0-9]|3[0-1]) [A-Z][a-z]{2} [0-9]{4} \.\.\. ", content):
                date_pos = content.find('...') + 4
                date_string = content[0 : date_pos - 5]
                # fix content string
                content = content[date_pos:]

                try:
                    published_date = dateutil.parser.parse(date_string, dayfirst=True)
                except ValueError:
                    pass

            # check if search result starts with something like: "5 days ago ... "
            elif re.match(r"^[0-9]+ days? ago \.\.\. ", content):
                date_pos = content.find('...') + 4
                date_string = content[0 : date_pos - 5]

                # calculate datetime
                published_date = datetime.now() - timedelta(days=int(re.match(r'\d+', date_string).group()))  # type: ignore

                # fix content string
                content = content[date_pos:]

            if published_date:
                # append result
                results.append({'url': url, 'title': title, 'content': content, 'publishedDate': published_date})
            else:
                # append result
                results.append({'url': url, 'title': title, 'content': content})

        # return results
        return results

    def fetch_traits(engine_traits: EngineTraits):
        """Fetch :ref:`languages <startpage languages>` and :ref:`regions <startpage
        regions>` from Startpage."""
        # pylint: disable=too-many-branches

        headers = {
            'User-Agent': gen_useragent(),
            'Accept-Language': "en-US,en;q=0.5",  # bing needs to set the English language
        }
        resp = get('https://www.startpage.com/do/settings', headers=headers)

        if not resp.ok:  # type: ignore
            print("ERROR: response from Startpage is not OK.")

        dom = lxml.html.fromstring(resp.text)  # type: ignore

        # regions

        sp_region_names = []
        for option in dom.xpath('//form[@name="settings"]//select[@name="search_results_region"]/option'):
            sp_region_names.append(option.get('value'))

        for eng_tag in sp_region_names:
            if eng_tag == 'all':
                continue
            babel_region_tag = {'no_NO': 'nb_NO'}.get(eng_tag, eng_tag)  # norway

            if '-' in babel_region_tag:
                l, r = babel_region_tag.split('-')
                r = r.split('_')[-1]
                sxng_tag = region_tag(babel.Locale.parse(l + '_' + r, sep='_'))

            else:
                try:
                    sxng_tag = region_tag(babel.Locale.parse(babel_region_tag, sep='_'))

                except babel.UnknownLocaleError:
                    print("ERROR: can't determine babel locale of startpage's locale %s" % eng_tag)
                    continue

            conflict = engine_traits.regions.get(sxng_tag)
            if conflict:
                if conflict != eng_tag:
                    print("CONFLICT: babel %s --> %s, %s" % (sxng_tag, conflict, eng_tag))
                continue
            engine_traits.regions[sxng_tag] = eng_tag

        # languages

        catalog_engine2code = {name.lower(): lang_code for lang_code, name in babel.Locale('en').languages.items()}

        # get the native name of every language known by babel

        for lang_code in filter(lambda lang_code: lang_code.find('_') == -1, babel.localedata.locale_identifiers()):
            native_name = babel.Locale(lang_code).get_language_name()
            if not native_name:
                print(f"ERROR: language name of startpage's language {lang_code} is unknown by babel")
                continue
            native_name = native_name.lower()
            # add native name exactly as it is
            catalog_engine2code[native_name] = lang_code

            # add "normalized" language name (i.e. français becomes francais and español becomes espanol)
            unaccented_name = ''.join(filter(lambda c: not combining(c), normalize('NFKD', native_name)))
            if len(unaccented_name) == len(unaccented_name.encode()):
                # add only if result is ascii (otherwise "normalization" didn't work)
                catalog_engine2code[unaccented_name] = lang_code

        # values that can't be determined by babel's languages names

        catalog_engine2code.update(
            {
                # traditional chinese used in ..
                'fantizhengwen': 'zh_Hant',
                # Korean alphabet
                'hangul': 'ko',
                # Malayalam is one of 22 scheduled languages of India.
                'malayam': 'ml',
                'norsk': 'nb',
                'sinhalese': 'si',
            }
        )

        skip_eng_tags = {
            'english_uk',  # SearXNG lang 'en' already maps to 'english'
        }

        for option in dom.xpath('//form[@name="settings"]//select[@name="language"]/option'):

            eng_tag = option.get('value')
            if eng_tag in skip_eng_tags:
                continue
            name = extract_text(option).lower()  # type: ignore

            sxng_tag = catalog_engine2code.get(eng_tag)
            if sxng_tag is None:
                sxng_tag = catalog_engine2code[name]

            conflict = engine_traits.languages.get(sxng_tag)
            if conflict:
                if conflict != eng_tag:
                    print("CONFLICT: babel %s --> %s, %s" % (sxng_tag, conflict, eng_tag))
                continue
            engine_traits.languages[sxng_tag] = eng_tag