[fix] searxng_extra/update/update_engine_descriptions.py (part 1)

Follow up of #2269

The script to update the descriptions of the engines does no longer work since
PR #2269 has been merged.

searx/engines/wikipedia.py
==========================

1. There was a misusage of zh-classical.wikipedia.org:

   - `zh-classical` is dedicate to classical Chinese [1] which is not
     traditional Chinese [2].

   - zh.wikipedia.org has LanguageConverter enabled [3] and is going to
     dynamically show simplified or traditional Chinese according to the
     HTTP Accept-Language header.

2. The update_engine_descriptions.py needs a list of all wikipedias.  The
   implementation from #2269 included only a reduced list:

   - https://meta.wikimedia.org/wiki/Wikipedia_article_depth
   - https://meta.wikimedia.org/wiki/List_of_Wikipedias

searxng_extra/update/update_engine_descriptions.py
==================================================

Before PR #2269 there was a match_language() function that did an approximation
using various methods.  With PR #2269 there are only the types in the data model
of the languages, which can be recognized by babel.  The approximation methods,
which are needed (only here) in the determination of the descriptions, must be
replaced by other methods.

[1] https://en.wikipedia.org/wiki/Classical_Chinese
[2] https://en.wikipedia.org/wiki/Traditional_Chinese_characters
[3] https://www.mediawiki.org/wiki/Writing_systems#LanguageConverter

Closes: https://github.com/searxng/searxng/issues/2330
Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

searx/engines/wikidata.py

@@ -18,7 +18,10 @@ from searx.data import WIKIDATA_UNITS
 from searx.network import post, get
 from searx.utils import searx_useragent, get_string_replaces_function
 from searx.external_urls import get_external_url, get_earth_coordinates_url, area_to_osm_zoom
-from searx.engines.wikipedia import fetch_traits as _fetch_traits
+from searx.engines.wikipedia import (
+    fetch_wikimedia_traits,
+    get_wiki_params,
+)
 from searx.enginelib.traits import EngineTraits
 
 if TYPE_CHECKING:
@@ -165,17 +168,15 @@ def request(query, params):
 
     # wikidata does not support zh-classical (zh_Hans) / zh-TW, zh-HK and zh-CN
     # mapped to zh
-    sxng_lang = params['searxng_locale'].split('-')[0]
-    language = traits.get_language(sxng_lang, 'en')
-
-    query, attributes = get_query(query, language)
-    logger.debug("request --> language %s // len(attributes): %s", language, len(attributes))
+    eng_tag, _wiki_netloc = get_wiki_params(params['searxng_locale'], traits)
+    query, attributes = get_query(query, eng_tag)
+    logger.debug("request --> language %s // len(attributes): %s", eng_tag, len(attributes))
 
     params['method'] = 'POST'
     params['url'] = SPARQL_ENDPOINT_URL
     params['data'] = {'query': query}
     params['headers'] = get_headers()
-    params['language'] = language
+    params['language'] = eng_tag
     params['attributes'] = attributes
 
     return params
@@ -769,12 +770,16 @@ def init(engine_settings=None):  # pylint: disable=unused-argument
 
 
 def fetch_traits(engine_traits: EngineTraits):
-    """Use languages evaluated from :py:obj:`wikipedia.fetch_traits
-    <searx.engines.wikipedia.fetch_traits>` except zh-classical (zh_Hans) what
-    is not supported by wikidata."""
+    """Uses languages evaluated from :py:obj:`wikipedia.fetch_wikimedia_traits
+    <searx.engines.wikipedia.fetch_wikimedia_traits>` and removes
 
-    _fetch_traits(engine_traits)
-    # wikidata does not support zh-classical (zh_Hans)
-    engine_traits.languages.pop('zh_Hans')
-    # wikidata does not have net-locations for the languages
+    - ``traits.custom['wiki_netloc']``: wikidata does not have net-locations for
+      the languages and the list of all
+
+    - ``traits.custom['WIKIPEDIA_LANGUAGES']``: not used in the wikipedia engine
+
+    """
+
+    fetch_wikimedia_traits(engine_traits)
     engine_traits.custom['wiki_netloc'] = {}
+    engine_traits.custom['WIKIPEDIA_LANGUAGES'] = []